Embed Size (px)
Citation preview
UCHENNA IFEANYI NWAGHA PG/M.S.c /03/37434
PREGNANCY- INDUCED CHANGES IN SOME VENTILATORY INDICES IN ENUGU, SOUTH EAST NIGERIA
Human Physiology
A DISSERTATION SUBMITTED TO UNIVERSITY OF NIGERIA, IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF MASTER
OF SCIENCE (M.Sc.) DEGREE IN MEDICAL PHYSIOLOGY
Webmaster
Digitally Signed by Webmaster’s Name DN : CN = Webmaster’s name O= University of Nigeria, Nsukka OU = Innovation Centre
2011
UNIVERSITY OF NIGERIA
ii
PREGNANCY- INDUCED CHANGES IN SOME VENTILATORY INDICES
IN ENUGU, SOUTH EAST NIGERIA.
A DISSERTATION SUBMITTED TO UNIVERSITY OF NIGERIA, IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD
OF MASTER OF SCIENCE (M.Sc.) DEGREE IN MEDICAL PHYSIOLOGY
UCHENNA IFEANYI NWAGHA
PG/M.S.c /03/37434
DEPARTMENT OF HUMAN PHYSIOLOGY, FACULTY OF MEDICAL
SCIENCES, COLLEGE OF MEDICINE, UNIVERSITY OF NIGERIA,
ENUGU CAMPUS.
MARCH 2011
iii
CERTIFICATION
We hereby declare that the contents of this project were conceptualized
and developed after a problem identification and discussion with the
supervisor. We are certain that the candidate conducted the study
conscientiously. He has also satisfactorily completed the requirements of the
course work. The work is original, has not been presented to any other
examining body and has not been published in any form. It was carried out
under the supervision of the following:
Prof J.C. Igweh (Chief Supervisor)............................................................
Dr E.E. Iyare (Co-Supervisor) ….................................................................
Dr U.S.B Anyaehie (Head of Department)....................................................
iv
DECLARATION
I hereby declare that the work reported in this book was done by me
under the supervision of Prof. J. C. Igweh. It has not been presented to any
other examining body and has not been published in any form
……………………………………… Uchenna Ifeanyi Nwagha
v
DEDICATION
This work is dedicated to my lovely wife, Dr Tessy Nwagha, my
children Kenechukwu, Lotachukwu and Kaosisochukwu. I also dedicate
this work to the memory of my late elder brother (Eng. Chigozie
Nwagha: Ochiagha).
������������������������������������������������������������������������������������
vi
����������������������������������������������������������������ACKNOWLEDGEMENTS
I want to thank my Project supervisor Professor J.C. Igweh
and Dr E.E. Iyare for their scientific input. He was very
inspirational and always encouraged me whenever I develop
inertia. To my Head of department, DR U.S.B. Anyaehie, I cannot
thank you enough especially for the effort you put in making this
dream a reality. I am also grateful to the academic staff who will
always urge me to finish this work. This acknowledgement will be
incomplete if I fail to recognize the role played by the staff,
students, and pregnant women at the University of Nigeria
Teaching Hospital, Kenechukwu Specialist hospital and
Chukwuasokam maternity hospital for their understanding. They
were simply great and I say thank you all for your support
throughout the duration of the study.
vii
ABSTRACT
Pregnancy is essentially a physiological process, which
involves a great number of physiological changes, affecting
virtually all the organ systems in the body. Literature is sparse on
the changes in ventilatory function during pregnancy in our
locality. The objective of this study is to establish the value of
Forced Vital Capacity (FVC), Forced Expiratory Volume in one
second (FEV1), FEV1/FVC ratio and Peak Expiratory Flow Rate
(PEFR) during pregnancy.
The study is a descriptive cross sectional study carried out at
the antenatal and booking clinics of the University of Nigeria
Teaching Hospital (UNTH), Ituku-Ozalla, Kenechukwu specialist
hospital Enugu and Chukwuasokam maternity hospital in Emene.
Two hundred (200) normal pregnant women and 100 non-pregnant
women were recruited. A standard Spirometer (Micro lab ML3500
MK8, Cardinal Health Germany 234 GMBH) was used to
determine the ventilatory function. The mean FVC was 2.93 ± .73
litres in the non-pregnant state but decreased significantly as
pregnancy progressed to 2.55± .51 litres in the 3rd trimester. The
percentage predicted also decreased significantly from 100.70±
31.11% in the non-pregnant state to 82.30± 19.01 % in the 3ird
trimester (P=0.000). The mean FEV1 was 2.55±0.62 litres per
viii
second in the non-pregnant state but decreased significantly, as
pregnancy progressed to 2.24±0.45 litres/second in the 3rd
trimester. Furthermore, the percentage predicted decreased
significantly from 102.02± 30.70 31.11% in the non-pregnant state
to 82.89±18.32 % in the 3rd trimester (P=0.000). The mean PEFR
was 5.38±1.44 litres in the non pregnant state but decreased non
significantly as pregnancy progressed to 5.18± 1.42 litres in the
3rd trimester (P=0.883). However, the percentage predicted
decreased significantly from 93.4 ± 32.16 % in the non pregnant
state to 79.39 ± 20.90 % in the 3rd trimester (P=0.014). The mean
FEV1/FVC was 87.56± 2.87 % in the non-pregnant state but
increased significantly, as pregnancy progressed to 91.30± 1.91 %
in the 3rd trimester. The percentage predicted was 107.37 ± 3.88
% in the non pregnant state, 102.97 ± 1.24 % in the 1st trimester,
109.56 ± 5.33 % in the second trimester and 105.77 ± 5.82% the
3rd trimester ( P=0.000). The FVC and the percentage predicted
and the FEV1 and the percentage predicted were within normal
range in the non-pregnant and during pregnancy. However, the
values decreased significantly, as pregnancy progressed. The
decrease in FEV1 during pregnancy is not of same magnitude as the
decrease in FVC. Consequently, the FEV1/FVC ratio increased, It
ix
can therefore be said that physiological restriction occurs during
pregnancy.
x
TABLE OF CONTENTS
Title Page i
Certification ii
Declaration iii
Dedication iv
Acknowledgements v
Abstract vi
Table of contents ix
List of Tables xii
List of Figures xiii
Chapter One:
1.0 INTRODUCTION 1
1.1 Background 1
1.2 Aims and Objectives 4
1.3 Justification for the Study 5
1.4 Hypothesis 6
1.5 Main Outcome Measures 6
Chapter Two:
2.0 LITERATURE REVIEW 7
2.1 Ventilatory Functions in Health 7
2.2 Ventilatory Functions in Disease 15
xi
2.3. Respiratory Functions in Pregnancy 19
Chapter Three:
3.0 SUBJECTS AND METHODS 30
3.1 Study Area 30
3.2 Ethical Clearance 31
3.3 Sampling Size and Sampling Technique 31
3.4 Inclusion Criteria 33
3.5 Exclusion Criteria 33
3.6 Control Population 35
3.7 Recruitment of Subjects 35
3.8 Methods 35
3.9 Equipment and Procedure 38
3.10 Statistical Analysis 41
Chapter Four:
4.0 RESULTS 42
4.1 Socio-Demographic Characteristics 42
4.2 Educational Status 44
4.3 Occupation 44
4.4 Forced Vital Capacity 46
4.5 Forced Expiratory Volume in one Second 48
4.6 Peak Expiratory Flow Rate 51
xii
4.7 Ratio of FEV1/FVC (Percentage) and the Percentage Predicted...53
Chapter Five:
5.0 DISCUSSION 55
5.1 Conclusion and Recommendations 60
References 62
Appendix 1: Ethical Committee Approval
Appendix 2: Map of Enugu state
Appendix 3: Sample Questionnaire
xiii
LIST OF TABLES
Table 1: Some Demographic Characteristics of the Subjects.
Table 2: Educational Status of the Participants.
Table 3: Occupation of the Subjects
Table 4: Mean and Standard Deviation (SD) Forced Vital Capacity
FVC (litres) and Percentage Predicted (%).
Table 5: Mean and Standard Deviation (SD) of Forced Expiratory
Volume in One Second (FEV1, litres /s) and Percentage
Predicted.
Table 6: Mean and Standard Deviation (SD) Peak Expiratory Flow
Rate (PEFR) Litres and Percentage Predicted.
Table 7: Mean and Standard Deviation (SD) of FEV1/FVC (%) and
Percentage Predicted
xiv
LIST OF FIGURES
Figure 1: Mean FVC in pregnant and non-pregnant control.
Figure 2: Mean percentage predicted FVC among pregnant and none
pregnant control.
Figure 3: Exploratory scatter diagram showing the mean forced
expiratory volume in one second.
Figure 4: Mean FEV in one second Percentage predicted.
Figure 5: Mean PEFR among pregnant and non-pregnant women.
Figure 6: Mean PEFR percentage predicted in pregnant and non-
pregnant control.
Figure 7: Mean FEV in one second/FVC during pregnancy.
xv
1
CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Pregnancy is essentially a physiological process, which
involves a great number of physiological changes, affecting
virtually all the organ systems in the body. By the end of the first
12 to 14 weeks, most of these changes would have reached an
appreciable magnitude. Indeed, it is believed that most of these
changes are initiated in the luteal phase of every ovulatory
menstrual cycle; the formation of corpus luteum of pregnancy only
accentuates the situation (Chapman et al, .1997). Thus, the
menstrual cycle functions, not just to produce fresh eggs each
month, but also acts proactively to prepare the body for pregnancy.
The cardiovascular system, which has physio-anatomical
relationship with the respiratory system, is markedly involved in
these changes. Obvious haemodynamic changes in the maternal
circulation during pregnancy include; increased cardiac output,
blood volume and decrease in peripheral vascular resistance. Some
studies have also shown differences in some cardiovascular
parameters during the different stages of the menstrual cycle and
these include; vasomotor tone (Ramsay et al., 1993), plasma
volume (Sakai et al., 1992), cardiac output (Lees et al., 1967,
2
Clark et al., 1989) and heart rate (Manhem et al., 1994). During the
first trimester of pregnancy, each of these changes becomes
pronounced, reaches a peak in early second trimester. A returns to
pre-pregnancy state occurs six weeks post partum.
The changes in ventilatory function during pregnancy may
be unrelated to the obvious anatomical changes, which occur
because of upward displacement by the gravid uterus. The sub-
costal angle increases progressively from 68 degrees in early
pregnancy to 103 degrees in late pregnancy and returns to normal
within a few weeks of delivery (Thomas et al., 1938).Furthermore,
it has been noted that the transverse diameter of the chest wall
increases by about 2cm while the diaphragm is raised by about
4cm (Thomas et al., 1938, McGinty 1938,). However, the total
lung capacity decreases only slightly because of compensatory
increase in the transverse and antero-posterior diameters of the
chest, as well as flaring of the ribs (Broughton-Pipkin 2007). In
the respiratory tract, hormonal changes stimulate the mucosal
vasculature leading to capillary engorgement and swelling of the
lining of the nose, oropharynx, larynx, and trachea. Airway
resistance is reduced, causing increased ventilation and decreased
partial pressure of CO2.This may probably be due to the
3
progesterone-mediated loosening of ligaments and relaxation of
the bronchial musculature. (Lyons and Anthonio 1959).
Despite the upward displacement, the diaphragm moves
with greater excursions during breathing in the pregnant than in the
non-pregnant state. In fact, breathing is more diaphragmatic than
thoracic during gestation; an advantage during supine positioning
and high regional blockade (Lyons and Anthonio 1959). From the
middle of the second trimester, expiratory reserve volume, residual
volume and functional residual capacity are progressively
decreased, by approximately 20% at term (Berry and McMurray
1989, Sroczynski 2002, McAuliffe et al., 2004). Lung compliance
is relatively unaffected, but chest wall compliance is reduced,
especially in the lithotomy position. A progressive increase in
minute ventilation starts soon after conception and peaks at 50%
above normal levels around the second trimester. This increase is
effected by a 40% rise in tidal volume and a 15% rise in
respiratory rate (Lyons and Anthonio 1959, Liberatore et al.,
1984). Since dead space remains unchanged, alveolar ventilation is
about 70% higher at the end of gestation. The increased ventilation
decreases arterial and alveolar carbon dioxide tensions. An average
paCO2 of 32 mmHg (4.3 kPa) and arterial oxygen tension of
105 mmHg (13.7 kPa) persist during most of gestation (Lyons and
4
Anthonio 1959).These changes have far reaching clinical
implications, as prior knowledge will assist greatly in the
management of pregnant women with respiratory disorders.
Furthermore, normal pregnant women also undergo significant
changes in ventilatory function during spinal anaesthesia (Lyons
and Anthonio 1959, Kelly et al., 1996). Thus, this study aims at
generally and specifically evaluating some ventilatory function
changes as they affect normal pregnant women in our environment
1.2 AIM AND OBJECTIVES
Aim: To determine the effect of pregnancy on some ventilatory
function parameters in healthy women in Enugu, South East
Nigeria.
Objectives
• To establish the value of Forced Vital Capacity (FVC) in
pregnancy.
• To establish the value of Forced Expiratory Volume in one
second (FEV1) in pregnancy.
• To verify the changes in FEV1/FVC during pregnancy.
• To evaluate the changes in Peak Expiratory Flow Rate
(PEFR) during pregnancy.
5
• To assess the effect of gestational age (1st 2nd and 3rd
trimester) on these parameters.
1.3. JUSTIFICATION FOR THE STUDY
There is no doubt that in pregnancy, many physiological
changes do take place. The existence of data for ventilatory
function in non-pregnant women in Nigeria is unquestionable, but
this cannot be said about data in pregnancy. This study will assist
in getting baseline values in all the trimesters of pregnancy, to
enable accurate interpretation of spirometric values in the
management of obstructive or restrictive lung diseases during
pregnancy.
Respiratory changes in pregnancy are of clinical importance
to the anaesthetist, during administration of anaesthesia to pregnant
women especially during childbirth and specifically during
caesarean section. Increased oxygen consumption and the
decreased expiratory reserve volume due to the reduced functional
residual capacity may result in rapid fall in arterial oxygen tension
despite careful maternal positioning and pre- oxygenation. Even
with short periods of apnea, either from obstruction of the airway
or inhalation of a hypoxic mixture of gases, the gravida has little
defense against the development of hypoxia. The increased minute
6
ventilation, combined with decreased functional residual capacity
hastens inhalatory induction or changes in the depth of anaesthesia
when breathing spontaneously. Marked changes in lung function
also occur during epidural or spinal anaesthesia. Thus, baseline
values are critical and invaluable while performing these
procedures in normal women, but more especially in women with
compromised cardiopulmonary functions. These will go a long
way in reducing maternal mortality and morbidity.
1.4 HYPOTHESIS
• There are no differences in (FEV1, FVC, FVC/FEV1, and
PEFR) between pregnant and non-pregnant women.
• Alternatively, there are differences in (FEV1, FVC, FVC/FEV1
and, PEFR,) between pregnant and non-pregnant women.
1.5 MAIN OUTCOME MEASURE
The main outcome measure is the comparative changes in
these ventilatory parameters between the pregnant and non-
pregnant women.
7
CHAPTER TWO
2.0 LITERATURE REVIEW
2.1. VENTILATORY FUNCTIONS IN HEALTH
Pulmonary ventilation, which involves the inflow and
outflow of air in the lungs, is affected by variable independent
factors. Many parameters can be measured but some of the
common ones include the following:
• Vital Capacity (VC): This is the volume change between
maximal inspiration and maximal expiration. It can be measured
during normal inspiration and expiration or during forced
ventilatory effort (FVC). FVC measures about 4.8 liters in
males and 3.7 liters in females.
• Forced Expiratory Volume in one second (FEV1): FEV1 is
the volume of air exhaled during the first one second of
expiratory maneuver starting from total lung capacity (TLC).It
is the most frequently used index to assess airway obstruction,
bronchodilation and constriction. The FEV1 should normally be
more than 80% of the predicted value for age, race and height.
When expressed as percentage of VC (FEV1 percentage VC), it
is an index of assessing and quantifying airflow limitation. In
patients with obstructive lung disease, the IVC is more than the
EVC, which is more than FVC. Thus when using the FEV1/VC
8
ratio as an index, the actual VC should be specified; hence
FEV1percentageFVC or FEV1percentageIVC. The normal ratio
of FEV1/ FVC is 0.8 to 1.
• Expiratory Peak Flow Rate (PEFR): This is the maximum
flow generated during expiration performed with maximal force
and started after a full inspiration. PEFR is appreciably larger if
the maneuver is performed without pause, immediately after the
inspiration than if it is performed after a pause. The normal
value is between 250 and 450litres /minute.
• Functional Residual Capacity (FRC): FRC is the volume of
air contained in the lungs after a normal expiration. It is
determined by the interaction between elastic recoil of the chest
and lungs. It is increases in obstructive airway disease and
reduces in restrictive airway or situations where intra abdominal
contents push the diaphragm upwards. It measures 2.4 liters in
males and 1.9 liters in females.
• Residual Volume: This is the volume of air in the lungs after
maximum exhalation starting from the functional residual
capacity. It increases with age and in small airway pathology. It
measures about 1.2 liters in male and 0.93 liters in females.
9
• Expiratory Reserve Volume (ERV): This is the amount of
additional air that can be expired after normal expiration. The
normal value in health is about 1.2 liters in males and 0.93 liters
in females.
• Total Lung Capacity (TLC): TLC is the volume of air
contained in the lungs after a full inhalation. The normal value
is about 4.7litres in females and to 6 liters in males.
• Tidal Volume (TV): Tidal volume is the amount of air taken in
or out when extra effort is not applied. The value is usually
500ml or 7ml/kg body weight.
Several factors determine the value of ventilatory
parameters. These variations occur from one geographical location
to the other, and even within the same population. Furthermore,
other socio-demographic and anthropometric factors influence
results. The relationship between some ventilatory parameters with
age has been established. In a study, using 3046 healthy persons,
blacks and whites, aged 7 and above; a representative population of
lifetime nonsmokers except for some black adult males, who were
healthy smokers or ex-smokers showed that FVC increases with
age up to 24 years, remains stable until 35years and then
declines(Schoenberg et al., 1978) .Furthermore another study from
10
a randomly selected population representative of the white
population of Tucson, Arizona and involving 3,115 persons
showed that after eight years, FEV1 and FVC increase with age up
to twenty years in women and twenty seven in men and then
decline with increasing age (Knudson et al., 1976). In Nigeria, Nku
et al.(2006) measuring lung function values in 600 apparently
healthy Nigerian women aged between 18 and 57 years, Abid et
al.(1990) assessing respiratory function on school children using
three hundred and eighty-eight students, comprising of 257 males
and 131 females, and Onadeko et al.(1979) also working with
children, confirmed these age related variations. However in a
Greek elderly population, spirometry prediction equations for
normal FVC and FEV1 derived from tests on 71 healthy persons
(38 men, 33 women) aged older than 60 years (Baltopoulos et al.,
2000) and in Nigeria, peak expiratory flow rate (PEFR) measured
in 300 healthy adult male and female (Ebomoyi and Iyawe 2005)
showed that older men have some decline in lung function and thus
should have a different prediction equation.
Lung function is also affected by weight. Forced expiratory
volume in one second (FEV1), Forced Vital Capacity (FVC) and
peak expiratory flow rates (PEFR) were determined in 400 healthy
11
Sudanese school children aged between 7 and 12 years (Mabrouk
and Ibrahim 1995) and a similar work by Onadeko et al.(1984) in
Nigeria showed that PEFR correlated positively with weight up to
40 kg, and then declines. Akgun and Ozgonul (1969), performing
spirometric studies in normal Turkish subjects aged 8-20 years and
Mojiminiyi et al. (2006) working in Northern Nigeria with 376
male and 240 female aged between 6 and 18 years, have gone
further to elucidate this point. It is important to note that the
correlation of PEFR with weight is more in children than in adults
(Femi-Pearse and Elebute 1971) and may probably be due to
increasing weight associated with age. A longitudinal birth cohort
study was performed in 5390 men and women born full term and
prospectively followed from the foetal period to adulthood. Weight
at birth and infancy were recorded, and FEV1 and FVC were
assessed by standard spirometry at the age 31 years. It was noted
that birth weight was continuously and independently associated
with adult respiratory function (Canoy et al., 2007).
A significant association between height and lung function
also occur (Onadeko et al., 1979, Abid et al., 1990, Nku et al.,
2006). Forced vital capacity (FVC), forced expiratory volume in
one second (FEV1), forced expiratory ratio (FEV1/FVC x 100),
forced mid expiratory flow (FMF), and peak expiratory flow (PEF)
12
measured in 2000 non-smoking black African schoolchildren aged
6-19 years agreed with these findings. Indeed, Mabrouk and
Ibrahim (1995) working with Sudanese children and Al-Riyami et
al. (2004) working with 837 healthy Omani schoolchildren aged 6–
19 years discovered that among all the anthropometric variables
studied, height correlates better with lung function than age and
weight. This is more profound with PEFR and FVC in children and
adults (Akgun and Ozgonul 1969, Femi-Pearse and Elebute 1971).
Furthermore, it has been shown that the best correlate is with the
trunk length or sitting height (Albert Miller 1987). In cripples and
patients with spinal deformities whose height cannot be measured,
arm span may be used as Tan et et al., (2009) using sixty-six white
subjects recruited from patients referred by general practitioners to
the department of echocardiography at Sunderland Royal Hospital,
Sunderland, UK, demonstrated a positive correlation of ventilatory
function with arm span.
Values of pulmonary function are generally lower in females
than in males even when other factors like age, height and weight
are accounted for. In some of these studies, Jaja (1991) working in
Lagos, Nigeria studied the static and dynamic long volumes of 181
(123 males and 58 females) apparently healthy Nigerian adults
aged between 17 and 34 years, Olanrewaju (1991) working in
13
Ogun state Nigeria used 131 school children and adolescents aged
between 5 and 20 years, while Orie (1999) worked with eighty
eight apparently healthy young Kenyan university students (64
males, 20-25 years and 24 females, 19-23 years)..The higher values
for males could be accounted for by the size and shape of the rib
cage muscles (Femi-Pearse and Elebute 1971).Furthermore; it has
been shown that height influences the prediction equation in boys
to a greater extent, whereas age and weight had greater influence
on girls (Vijayan et al., 2000)2.
The relationship between race and ethnicity with lung
function has been established, with clear differences noted between
whites and African American children and adults. While Schwartz
et al.(1988) analysed spirometric data on 1,963 healthy,
nonsmoking blacks and whites to examine sex and race
differences, Hankinson et al.(1999) measured spirometric
reference values for Caucasians, African-Americans, and Mexican-
Americans of 8 to 80 years of age developed from 7,429
asymptomatic, lifelong nonsmoking participants in the third
National Health and Nutrition Examination Survey (NHANES III).
In children, several reasons have been given for these
variations and these include low socioeconomic status( Demissie et
al.,1996; Vedal et al., 1984), obesity (Chen et al., 1993, Wise et
14
al., 1998) , low intake of antioxidant vitamins (Schwartz and
Weiss 1994, Cook et al., 1997, Schunemann et al., 2001, Hu and
Cassano 2000 ), low birth weight (Barker et al., 1991,Boezen et al.,
2002), in-utero exposure to tobacco (Cunningham et al., 1995,Li et
al., 2000, Mannino et al.,2001), and smaller trunk/leg ratio of
African Americans (Hsi et al., 1983 ). Among these variables, it
has been shown that differences in body proportions, chest wall
anatomy, mechanical properties of the thorax, can be used to
explain racial differences (Hsi et al., 1983, Donnelly et al., 1991,
Ip et al., 2000, Korotzer et al., 2000, Milivojevic-Poleksic et al.,
2001, Harik-Khan et al., 2004). These peculiar body proportions
may be related to genetic influences. There are also significant
racial differences that exists among Caucasian and African Blacks
(Shamssain1991, Al-Riyami et al., 2004,, Olanrewaju 1991, Orie
1999) .It is important to note that even within the same ethnic
group, differences still occur. Okafor (1995) found that Ibos had a
higher peak flow rate than their Yoruba counterparts and suggested
that this may be due to differences in altitude.
Other variables known to affect ventilatory function include
physical activity. Onadeko et al.(1970) using sportsmen
comprising 259 males and 151 females, made up of secondary
school students, University undergraduates, young clerical and
15
technical workers and soldiers, discovered that FEV1 and FVC
were higher in sportsmen than the predicted value for normal
Nigerians of similar age, sex, height and weight. Physical activity
increases muscle mass while improving pulmonary perfusion,
thereby increasing pulmonary function values.
Dwellers in higher altitude have higher lung functions than
dwellers in lower altitude as noted in New Guinea and Jos
(Woolcock et al., 1972; Abuja and Ahuja 1983).
Lung function can also be regulated by circadian rhythm and
may be associated with short-term variations. Results showed that
patients' overall airway resistance was at its most prominent level
around 12:00 pm but reached its minimum between 4:00 to 5:00
pm, showing that lung function was at its best in the late afternoon
(Timonen et al., 1997).
2.2 VENTILATORY FUNCTIONS IN DISEASE
Two main types of functional pulmonary disorders
can be diagnosed by spirometry: They are obstructive and
restrictive lung diseases.
16
Obstructive Fung Diseases
In this case, the airways are narrowed, usually causing
an increase in the time it takes to empty the lungs.
Obstructive lung disease can be caused by conditions such as
emphysema, bronchitis, infection (which produces
inflammation), and asthma. Spirometric changes include the
following; as predicted for age, height, sex, weight or race
(Pellegrino et al., 2005).
• Normal or lower than predicted value for FVC.
• Lower FEV1 with higher FEV2 and FEV3.
• Lower FEV1 divided by FVC.
• Lower FEF 25%-75%.
• Lower PEFR.
• Lower maximum voluntary ventilation (MVV).
• Normal or lower slow vital capacity (SVC).
• Normal or higher TLC.
• Higher RV
• Higher FRC.
• Higher RV divided by TLC ratio.
17
• Normal or lower ERV.
Restrictive Lung Disease
In restrictive lung conditions, there is a loss of lung tissue, a
decrease in the lung's ability to expand, or a decrease in the lung's
ability to transfer oxygen to the blood (or carbon dioxide out of the
blood). Restrictive lung disease may be due to conditions such as
pneumonia, lung cancer, scleroderma, pulmonary fibrosis,
sarcoidosis, and multiple sclerosis. Other restrictive conditions
include some chest injuries, being very overweight (obesity),
pregnancy, and loss of lung tissue due to surgery. Lung function
test parameters in restrictive conditions as predicted for age, height,
sex, weight or race are as follows; (Pellegrino et al.,2005).
• Lower than predicted value for FVC
• Normal or lower FEV1 with higher FEV2 and FEV3.
• Normal or higher FEV1/FVC.
• Normal or lower FEF 25%-75%.
• Normal or higher PEFR
• Normal or lower MVV
• Lower SVC
18
• Lower TLC
• Normal or higher FRC
• Normal or higher RV
• Normal or lower ERV
• Normal or higher RV/TLC ratio.
There are other patterns of spirometric changes, which can be
used as valuable alternatives to some of the above parameters. It
has been shown that FEV1/FEV6 ratio can be used as a valid
alternative for FEV1/FVC in the diagnosis of airway obstruction
(Vandevoorde et al.,2005 ).Furthermore forced expiratory volume
in one second/forced expiratory volume in six seconds <73%
predicted and forced expiratory volume in six seconds <82%
predicted, can be used as valid alternatives to forced expiratory
volume in one second/forced vital capacity <70% predicted and
forced vital capacity <80% predicted, as fixed cut-off terms for the
detection of an obstructive or restrictive spirometric pattern in
adults (Vandevoorde et al.,2006 ).
19
2.3. RESPIRATORY FUNCTIONS DURING PREGNANCY
Pregnancy induces some physiological and biochemical
changes that affects usually all the organ systems in the body.
Indeed, the changes in the respiratory system have far-reaching
implications for the pregnant woman, her baby and health care
providers. Nasal obstruction during pregnancy, or rhinitis of
pregnancy, has been accepted as a distinct and very common
pathological and clinical entity for many years. It is believed to
occur in about 22% of pregnant women and can appear any time
during pregnancy (Ellegård et al., 2000).The nasal obstruction is
associated with clear rhinorrhea and physical examination shows
oedematous nasal mucosa. Although some studies have been
unable to demonstrate the reason for this phenomenon, (Bende et
al., 1989; Ellegård 2003). It is known to be caused by a number of
related factors. The generalised increase in interstitial fluid volume
seen during pregnancy also affect the nasal mucosa, and is made
worse by the direct effect of oestrogen on the nasal mucosa, which
causes increased vascularity and mucosal oedema. Electron
micrographic and histochemical studies performed by Toppozada
et al.(1982) on the respiratory epithelium of thirty symptomless
pregnant females, regardless of the duration of pregnancy, have
20
suggested that nasal congestion is due to an over activity of the
parasympathetic system, leading to increased glandular secretion
and vascular congestion. This may be due to an allergic response to
placental proteins, foetal proteins or the women’s own sex
hormones. Furthermore, a study involving twenty-seven
nonsmoking healthy pregnant women aged 22 to 38 years, who had
no history of respiratory allergy or chronic nasal or sinus problems,
showed a rise in the serum level of placental growth hormone in
pregnancy rhinitis and this may be involved in its pathogenicity
(Ellegård et al., 1998) .Symptoms of nasal obstruction can be
exacerbated by fluid overload or oedema associated with
pregnancy induced hypertension (PIH) or pre-eclampsia. In such
cases, manipulation of the airway can result in profuse bleeding
from the nose or oropharynx; endotracheal intubation can be
difficult; and only a smaller than usual endotracheal tube may fit
through the larynx.
There have been a lot of changes and major advances in
respiratory function testing, but little has been applied to pregnant
women especially in our environment and it is hoped that our work
in this area will help to improve the situation.
21
Hyperventilation occurs in pregnancy. The attendant
hypocapnia and alkalosis of results from a complex interaction of
pregnancy, induced changes in wakefulness and central
chemoreflex drives to breathe, acid-base balance, metabolic rate
and cerebral blood flow (Jenson et al., 2008).
There had been a lot of controversy surrounding the effects
of pregnancy on vital capacity with many conflicting results. An
earlier study by Cugel et al. (1953) using 19 healthy women
showed no change in vital capacity either in supine or upright
position. Sims et al. (1976) in a serial study of 27 women with
asthma and 12 controls later confirmed these findings. However,
Gazioglu et al. (1970) who studied eight patients serially and
Knuttgen and Emerson 1974 who studied 13, subjects serially
showed a significantly raised vital capacity in late pregnancy. It
should however be noted the smaller sample size used in the last
two studies may have affected the findings.
Puranik et al, (1994) working in India, evaluated pulmonary
function status in fifty normal pregnant women tested monthly.
The parameters studied were Vital Capacity (VC), Forced Vital
Capacity (FVC) and Forced Expiratory Volume in 1st second
(FEV1) using Vitalograph Spirometer; tidal volume (VT),
22
inspiratory capacity (IC) and expiratory reserve volume (ERV)
using Expirograph and resting minute ventilation (VE) using
Tissot's spirometer. Control values were obtained in the same
subject 8-10 weeks after delivery. The increase seen in VT, VE and
IC was very highly significant. The small increment in frequency
of respiration was significant and the declining trend observed in
ERV was very highly significant. VC and FVC were maintained by
the rise in IC and a concomitant fall in ERV. Rise in VC is
attributed mainly to rise in VT than the rise in frequency.
Interestingly, another study in India using a dry bellows spirometer
and a Wright's peak flow meter showed a significant reduction in
peak expiratory flow rate, forced vital capacity and forced
expiratory volume in one second during the third trimester
compared to controls (Mokkapatti et al., 1991). However, Chhbra
et al. (1988) studying 70 selected women, 50 pregnant and 20 non-
pregnant controls found that out of seven parameters studied five
showed changes. There were changes in respiratory frequency,
tidal volume, vital capacity, inspiratory capacity and expiratory
reserve volume. Maximum voluntary ventilation and timed vital
capacity did not change. RF, VT, VC and IC rose significantly
while ERV had a significant fall. These changes may be affecting
23
antenatal behavior of pregnant women and their pregnancy
outcomes.
Kolarzyk et al.,(2005) working in Poland on 51 pregnant
women aged 26.6±4.9 years and 40 healthy women (control
group), showed statistically significant increase during pregnancy
in cases of tidal volume (VT) and minute ventilation (MV)
(whereas breath frequency was nearly on the same level).There
were also differences in inspiratory drive (VT/TI), occlusion
pressure (P0.1), RRS. In addition, there was a correlation between
BMI at the baseline with P0.1, MV, and VT/TI. Another Polish
study was more elaborate in its findings (Sroczynski 2002). It
examined the function of the respiratory system in pregnant women
in the last month of non-complicated pregnancy. Spirometry with
Lungtest 1000 was performed in 31 pregnant women at a mean
gestational age of 37.72 weeks. In 24 of them, the test was repeated
after delivery .The results were compared with a control group of
31 healthy non-pregnant women. The vital capacity in the last
month of pregnancy did not differ from values after delivery and in
the control group. Component volumes changed: tidal volume was
increased, expiratory reserve volume decreased, and inspiratory
reserve volume remained unchanged. Minute ventilation recorded
24
at rest in pregnancy increased despite decreased breathing rate,
whereas maximum voluntary ventilation was lower than after
delivery and in the control group, evidencing reduced breathing
reserve. The important forced expiratory parameters remained
unchanged in pregnancy. Parameters characterising bronchioles
revealed increased airflow (bronchodilation). Furthermore,
dyspnoeic symptoms found in pregnant women correlated with
changes in vital capacity components. Symptoms depended on the
mechanics of ventilation and not on the status of bronchi
(Sroczynski 2002).
Rees et al. (1990) working in England measured some
ventilatory parameters longitudinally during pregnancy and post
partum in 20 normal subjects with a computer-assisted mass
spectrometer. It showed that resting tidal volume, minute
ventilation, oxygen consumption, and carbon dioxide production
increased during pregnancy. End-tidal carbon dioxide tension fell
progressively during pregnancy. Respiratory exchange ratio was
0.9 at 36 to 39 weeks' gestation and 0.8 at 5-13 weeks post partum.
Respiratory frequency did not change during pregnancy. Wise and
colleagues (1992) in the USA observed that the major physiologic
changes that occur in pregnancy are the increased minute
25
ventilation, which is caused by increased respiratory center
sensitivity and drive; a compensated respiratory alkalosis; and a
low expiratory reserve volume. The vital capacity and measures of
forced expiration are well preserved. Patients who have many lung
diseases tolerate pregnancy well, with the exception of those who
have pulmonary hypertension or chronic respiratory insufficiency
from parenchymal or neuromuscular disease.
Working in China, Lui (1992) measured the lung functions
in different pregnant stages in 41 women with pregnancy and 12
normal women without pregnancy. Forced Vital Capacity (FVC)
significantly, but gradually decreased as pregnancy advanced.
After 28 weeks of gestation, the Vital Capacity (VC), Forced
Expired Volume in 1 second (FEV1) significantly decreased as
compared with the normal values. These results suggested that the
lung function changed gradually during pregnancy, especially after
the 28th week, but more significantly in VC, FVC and FEV1.
Maybe there are slight obstructions in the bronchial tubes, after the
28th week of gestation and it may be the reason for occurrence of
shortness of breath and the lung infection.
Peak expiratory flow rate has exhibited variations in
pregnancy. Peak expiratory flow rates (PEFR) were measured
26
longitudinally in 60 pregnant women aged 20-28 years (average 24
yrs),with height between 130-160 cm (average 154.5 cm), each
month beginning from 3rd month of gestation and also 8-10 weeks
postpartum using Wright's Peak Flow Meter. The PEFR declined
from 329.12 +/- 4.40 lpm in 3rd month to 286.22 +/- 3.81 lpm in
9th month of gestation and increased to 347.86 +/- 2.93 lpm in
postpartum period (Puranik et al., 1995). However Brancazio et al.
(1997) working longitudinally in the USA on 57 women during
each trimester of pregnancy and postpartum demonstrated that
peak expiratory flow rate does not change with pregnancy and
advancing gestation. This finding is in agreement with a recent
study in Northern Nigeria using 250 female (123 pregnant and 127
non-pregnant).Although values obtained were lower than that of
Caucasians, there were no significant changes between pregnant
and non-pregnant subjects (Salisu et al,. 2007).
Pulmonary function does not seem to be affected by fundal
height or number of fetuses. A cross sectional study of respiratory
function was performed in 68 women with twin pregnancies (17
examined in the first trimester, 35 second trimester, 16 third
trimester) and 140 women with singleton pregnancies (28, 80, 40,
respectively) and 22 non-pregnant women in a London teaching
27
hospital. In both the twin and singleton pregnancies, the mean FRC
and expiratory reserve ventilation of women studied in the third
trimester and minute ventilation of women studied in each
trimester differed significantly from that of the non-pregnant
women. There were, however, no significant differences
demonstrated in respiratory function between healthy women with
twin as compared with singleton pregnancies (McAuliffe et al.,
2002). Furthermore, Strauss et al.(2001) working retrospectively,
carried out 69 spirometric pulmonary function tests on19
singleton, seven twin, 38 triplet and five quadruplet pregnancies;
maternal age 19–37 years; pregnancy weeks 22–41.The the vital
capacity, forced expired volume in 1 second, Tiffeneau's index,
blood gases as well as blood pH levels were not significantly
different in singleton, twin, triplet or quadruplet pregnancies before
or after 30 weeks of gestation. Finally, no significant difference in
pulmonary function measurements could be found between higher-
order pregnancies with or without subjective dyspnea. Thus, no
clinically relevant correlation between any spirometrically
measurable pulmonary function values and pregnancy data
referring to uterine size, fundal height or breathlessness were found
(Strauss et al., 2001).
28
Various physiological and pathological conditions may
affect lung function during pregnancy. A study performed by
Schultz et al. (1989) in Denmark showed a significant decrease in
FRC, PEFR and FEV1 because of the postural changes, however,
arterial oxygenation, MVV and DLCO remained largely the same
(Schultz et al., 1989).
In Switzerland, it has been shown that epidural analgesia
improves lung function (Von Ungern-Sternberg et al.,
2004).Spirometry was performed in sixty consenting parturients
receiving epidural analgesia during the antepartum visit and in
labour. After effective epidural analgesia was established; at both
assessments and the women were pain-free the results were as
follows: Values were within normal ranges but increased
significantly after effective epidural analgesia; median inter
quantan range (IQR)) increase for vital capacity 7.4 (3.0-13 [-12-
27])% , forced vital capacity 4.4 (1.7-9.8 [-13-26])% ; forced
expiratory volume in 1 s 5.5 (1.7-8.6 [-14-28])% ; and peak
expiratory flow rate 2.3 (-1.6-5.8 [-18-16])% (Von Ungern-
Sternberg et al., 2004).
Unsal et al. (2003) measured FVC, FEV1 and PEFR in 13
pre-eclamptic and 15 control subjects undergoing caesarean
29
section; and 11 pre-eclamptic and 15 control subjects undergoing
vaginal delivery (VD) on the postpartum third day. It was
demonstrated that certain pulmonary functions might be impaired
in the early postpartum period in pre-eclamptic women undergoing
caesarean section. Pre-eclamptic women had significantly lower
FVC, FEV1 and PEFR measurements than the control. When the
subjects were grouped according to the mode of delivery, FVC and
FEV1 values were observed to be significantly different between
the pre-eclamptic and control groups undergoing caesarean section.
None of these parameters was significantly different between the
pre-eclamptic and control groups who had delivered vaginally.
Lung function is affected by multifactorial variables
including normal pregnancy. These changes are further modified
by some obstetrics complications. Thus, base line values are
extremely invaluable in the management of pregnant women with
obstetric and pulmonary complications.
30
CHAPTER THREE
3.0 SUBJECTS AND METHODS
3.1 STUDY AREA
The study is a descriptive cross sectional study carried out at
the antenatal and booking clinics of the University of Nigeria
Teaching Hospital (UNTH), Ituku-Ozalla and Kenechukwu
specialist hospital Enugu and Chukwuasokam maternity hospital in
Emene between April and July 2010. Enugu State was created in
1991 from the old Anambra state. It has an approximate land mass
of 8727.1km2. It shares borders with Abia state to the south,
Ebonyi state to the East, Benue state to the North East, Kogi state
to the North West and Anambra state to the West. Enugu is located
in the hilly tropical rain forest about 230 m above sea level. The
average annual temperature is between 23.1oc and 31oC with a
rainfall of 1520 to 2030mm .There are two major seasons, rainy
season (April to October) and dry season (November to February).
See appendix 3; map if Enugu state
It has a mixed rural and urban population with majority
being Igbo’s, with a projected population of 3.3 million out of
which 50% are females. Enugu State has a crude birth rate of 45
per 1000 , crude death rate of 18 per 1000 of the population and a
life expectancy of at birth of 51years (Enugu State Health Ministry
31
,2004). The maternal mortality rate ranges between 750 to 850 per
100,000 live births (Onah et al., 2005, Ezeugwu et al.,2009).Major
occupation range from trading and civil service in the urban but
subsistent farming in the rural areas.
3.2 ETHICAL CLEARANCE
Ethical clearance was obtained from the ethical committee
of the UNTH, Enugu.
3.3 SAMPLING SIZE AND SAMPLING TECHNIQUE
To calculate the minimum sample size for comparing the
means of FVC, FEV1, PEFR, and, FVC/FEV1 and their various
percentage predicted values among the groups, the following
formula was used (Campbell and Machin 1996):
n = 2 (Z� + Z )2 � 2
�2
Where n = minimum sample size in each group
Z� = % point of the normal distribution corresponding to
the one – sided significance level (e.g. if significance level is 5%,
then Z� = 1.65)
Z = one sided percentage point of the normal distribution;
corresponding to the power. If the power is 80% then Z = 0.84.
32
� = Population Standard deviation
� = m2 – m1 = expected difference in means
From, previous studies the expected mean differences ranges
from 5% to 10 %. For FVC, FEV1, PEFR, and ERV; the average
population standard deviation is about ± 0.76 and the average mean
difference is about 0.56
Therefore n = 2(1.65 + 0.84)2 x 0.762 (0.56)2
= 12.4002 x 0.58 = 23 0.31
For the percentage predicted values, the average population
standard deviation is about ± 15 while the average mean difference
is about 10.
n = 2(1.65 + 0.84)2 x 152 (10)2
= 12.4002 x 225 = 28 100
Thus, the minimal sample size for this study is about 28 for
each group making 112. However, we recruited 200 pregnant
women and 100 non-pregnant by systematic random sampling.
This was to take care of those who will not complete the
rigorous processes involved in standard spirometry.
33
3.4 INCLUSION CRITERIA
• All confirmed pregnant women who do not have any of the
exclusion criteria.
• Willingness to participate.
• Ability to demonstrate sufficient proficiency in carrying out the
tests needed to assess ventilatory function.
3.5. EXCLUSION CRITERIA
Patients with the following will be excluded:
• Pre existing cardio-respiratory diseases like asthma, Chronic
Obstructive
Airway Disease (COPD), Congestive Cardiac Failure (CCF).
• Presence of spinal deformities (scoliosis, kyphoscoliosis)
• Upper and lower respiratory tract infections.
• Medications that alter lung function (e.g. bronchodilators and
constrictors).
• Acute malaria in pregnancy.
• Pre-eclampsia.
• Diabetes in pregnancy.
• Other pregnancy complications (threatened abortion,
antepartum haemorrhage etc).
34
• HIV positive patients.
• Smokers.
• Subjects who had worked or who work in dusty environments
like coal mining or street sweepers.
• Others include febrile conditions, multiple pregnancy, chronic
renal disease, sickle cell anaemia.
For optimal and repeatable results to be obtained, the
following was avoided;
• Consuming alcohol within four hrs of testing.
• Vigorous exercise within 30 minutes of testing.
• Wearing clothes that substantially restrict chest and abdominal
movement
• Eating large meal within two hours of testing.
• Chest or abdominal pain of any aetiology.
• Pain in the mouth or face that will be worsened by mouthpiece,
dementia or confusional state and stress incontinence (Miller et
al,.2004).
These were clearly explained to these subjects during
counseling in the booking clinic. Those who met the criteria were
tested immediately while the rests were followed up later to their
respective antenatal clinics.
35
3.6 CONTROL POPULATION
They were recruited from normal non-pregnant female staff
of the UNTH Enugu, who met the inclusion criteria for the
pregnant subjects. These subjects were matched for age, and
height. Pregnancy was be ruled out by performing the test on the
7th day of the last normal menstrual period and performing
pregnancy test using early morning urine.
3.7 RECRUITMENT OF STUDY SUBJECTS
Subjects were recruited by systematic random sampling of
all the women at various trimesters that were resident in Enugu
state and attending the antenatal clinic. The method of recruitment
was also same for the non-pregnant control subjects. One out of
every two patients attending the ANC was recruited by simple
random sampling using a lucky dip of yes or no. Verbal informed
consent was also obtained from the patients. After obtaining
ethical clearance and informed consent, about 300 patients who
meet the above criteria were recruited.
3.8 METHODS
A pre-tested questionnaire patterned after the 1976 British
MRC questionnaire on respiratory symptoms, as modified by
36
Pistelli et al. (2001) was used. Some house officers were trained
on the administration of the questionnaire and they obtained obtain
the information directly from the subjects. These include, general
information, familial diseases, general diseases, respiratory
diseases, respiratory symptoms, allergic symptoms, active
smoking, passive smoking, occupational history, environmental
conditions, social and economic conditions, diet, physical activity,
daily activity pattern, use of respiratory medicines, use of health
services, health status and quality .
English language combined with vernacular where
necessary was used by the investigator in administering the
questionnaire. The following history were obtained from the
subjects; personal history, history of present pregnancy, past
obstetric history, past medical history, family and social history
and review of systems. The gestational age was assessed from the
last normal menstrual period. Only those who were sure of their
last menstrual period were included. Trimester was defined as first
trimester (< 14 weeks), second (14 weeks – 27 weeks) and third (>
27weeks). Clinical and obstetric examinations were performed.
Axillary temperature was taken to exclude fever and temperature
of less than 37.5oc was considered as normal.
The following anthropometric measurements were performed;
37
• Weight was measured to the nearest 0.5 kilogram using a
standard weighing scale (STADIOMETER, SECA,
MODEL 220, GERMANY).
• The height was measured in meters, without shoes, with the
feet together, standing as tall as possible with the eyes level
and looking straight ahead. Measurement was done to the
nearest centimeter using a standard measuring stick.
(STADIOMETER, SECA, MODEL 220, GERMANY).
All the subjects and controls were subjected to the same
instrument and method of measurement.
• Body mass index was calculated by dividing the weight in Kg
with the square of the height in meters and expressed as Kg/m2.
The mid-upper arm circumference (MUAC), which is the
circumference of the upper arm at that same midpoint, was
measured in centimetres with a non-stretchable tape measure.
The waist circumference was measured by locating the iliac
crest and thereafter applying a tape above it asking the
participant to wrap it round them. The tape was checked to
make sure it was horizontal across the back and front of the
subjects. The hip circumference was measured by positioning
the measuring tape around the maximum circumference of the
buttocks at the level of the groin (NHANES III).
38
The following laboratory investigations as done in our
antenatal clinic (ANC) were performed; haemoglobin, blood group
and genotype, urinalysis, fasting blood sugar and two hour post
prandial. Other investigations include; screening for HIV, hepatitis
B surface antigen and VDRL screening for syphilis.
3.9 EQUIPMENT AND PROCEDURE
The ambient temperature was measured on each day. The
respiratory rate was also measured. A standard Spirometer (Micro
lab ML3500 MK8, Cardinal Health Germany 234 GMBH) with
disposable mouth piece was used throughout the study to
determine some forced ventilatory functions (FEV1, FVC,
FVC/FEV1, and PEFR ).This involve general and where necessary
individual demonstration of how best to blow the spirometer.
Subjects were relaxed, and dentures removed, tight fitting cloths
loosened. Ambient temperature, barometric pressure and time of
day and position of measurement were recorded. The time of day
was within 2 hr of previous test times.
Although testing may be performed in either the sitting or
standing position (Townsend 1984, ATS 1979), the sitting position
was used for safety reasons in order to avoid falling due to syncope
associated with pregnancy. The chair had arms and without
39
wheels. The age, weight, height and ethnic origin of the subjects
are keyed into the equipment and then customized to measure
either the forced or the relaxed spirometric indices. Subject were
instructed to sit upright in a straight backed chair, with belt
loosened, breath normally for a minute , then take a deep breath as
much as possible and apply the lip around the mouth piece of the
spirometer firmly. She then breathes out as quickly and as forcibly
as possible into the spirometer. Checks were made to ensure there
were no leakages of air from the mouthpiece. Procedure was
repeated if there was any leakage. The equipment automatically
selects the best out of three maneuvers when the American
Thoracic Society/European Respiratory Society (ATS/ERS)
guidelines must have been met (three good blows with values
within 5% or 0.15 litre (150 ml).
• Most common cause of inconsistent readings is poor
patient technique
• Sub-optimal inspiration
• Sub-maximal expiratory effort
• Delay in forced expiration
• Shortened expiratory time
• Air leak around the mouthpiece
40
• Inadequate or incomplete blow
• Lack of blast effort during exhalation
• Slow start to maximal effort
• Lips not sealed around mouthpiece
• Coughing during the blow
• Extra breath during the blow
• Glottic closure or obstruction of mouthpiece by tongue
or teeth
• Poor posture – leaning forwards
The spirometer has an inbuilt mechanism that automatically
rejects results associated with poor technique.
Prevention of infection transmission was achieved through
proper hand washing and use of barrier devices, such as suitable
gloves. Hands were washed immediately after direct handling of
mouthpieces, tubing, breathing valves or interior spirometer
surfaces. Gloves were worn when handling potentially
contaminated equipment if the practitioner has any open cuts or
sores on his/her hands. Hands were always washed between
patients. To avoid cross-contamination, breathing tubes, valves and
manifolds were disinfected or sterilized regularly. Any other
equipment that comes into direct contact with mucosal surfaces
41
were disinfected, sterilized or, if disposable, discarded after each
use.
3.10 STATISTICAL ANALYSIS.
Values were recorded percentages and mean ± standard
deviation where applicable. Analyses of data were done using
Statistical Package for Social Sciences (SPSS) version 11, graph
pad prism version 5.02 and graph pad prism state mate version
2.00. Normality tests were performed and comparison of mean was
done by the one-way analysis of variance (ANOVA) if data
obeyed Gaussian distribution However where data did not obey
Gaussian distribution, the kruskal Wallis test was used. These were
however followed by Tukey,s honestly significant post hoc
multiple comparison. The respiratory function indices in
pregnancy were compared with the values found in the matched
controls.
42
CHAPTER FOUR
4.0 RESULTS
4.1. SOCIO-DEMOGRAPHIC CHARACTERISTICS
Out of the three hundred subjected recruited, 172 (40
control, 30 first trimester, 48 second trimester and 54 third
trimester) met the ERS/ATS quality control. Some socio
demographic characteristics of the subjects are represented in table
1.The mean age of the subjects in years were; control, 30.75
±5.45; 1st trimester, 30.07 ± 4.41, 2nd trimester, 31.50 ± 3.76, and
3rd trimester, 29.44 ±5.08. These were not statistically significant
(P=0.165).The highest parity occurred in the control subjects, 2.95
±1.48 while the least parity was in the 3rd trimester 1.67 ±1.67
(P=0.005).The chest circumference was 88.87 ±4.67 cm in the non
pregnant subjects and increased all through pregnancy to 97.66 ±
9.65cm in the 3rd trimester, (P=0.000). The non pregnant women
weighed 71.07± 9.42 kg .This increased to 78.62 ± 13.63 kg in the
3rd trimester (P=0.010). The differences in height were not
statistically significant, (P=.505). Although, the BMI increased as
pregnancy progressed, these were not statistically significant
(P=0.058). The mid arm circumference, the hip circumference and
the waist circumference were higher in the pregnant compared with
43
the non-pregnant control (P=0.048, P<0.0001 and P<0.0001
respectively).
Table 1: Some Demographic Characteristics of the Subjects
Variables Control 1st
trimester
2nd
trimester
3rd
trimester
Sig.
Age (years) 30.75 ±5.45 30.07 ± 4.41 31.50 ± 3.76 29.44±5.08 0.165ns
Parity 2.95 ±1.48 1.83 ±1.64 2.25 ±2.15 1.67 ±1.67 0.005*
Chest C
(cm)
88.87 ±4.67 90.57±7.05 92.25 ±6.44 97.66 ±9.65 0.000*
Height (M) 1.65 ±0.06 1.65 ±0.05 1.66 ±0.06 1.66 ±0.07 0.505ns
Weight
(Kg)
71.07± 9.42 74.59 ±9.87 75.75 ±9.81 78.61±13.62 0.014*
BMI
(Kg/m2)
27.29 ± 2.82 27.24 ±4.18 28.62 ±3.64 28.83 ±3.22 0.058ns
MAC (cm) 28.55 ±2.54 29.30 ±2.33 29.56 ±3.05 30.50 ±4.52 0.048*
Hip C (cm) 98.85 ±8.17 100.57±8.21 105.50±5.91 107.56±8.57 0.000*
Waist C
(cm)
87.42 ±9.57 94.67 ±12.01 98.56 ±8.34 99.17 ±9.25 0.000*
C = Circumference, M= Meter. Kg = Kilogram, Cm=Centimeter,
BMI = Body Mass Index, MAC= Mid Arm Circumference.
Ns=non-significant (P >0.05), * P < 0.05).
44
4.2 EDUCATIONAL STATUS
All the subjects had formal education. Majority had diploma
and other certificates other than university after their secondary
school (30.2%). 29.7% had university education, while only 8.7%
had primary education. These are presented in table 2.
Table 2: Educational Status of the Participants
Variable Control 1st
trimester
2nd
trimester
3rd
trimester
Total
N % N % N % N % N %
Primary 8 4.65 4 2.33 3 1.74 0 0 15 8.7
Secondary 12 6.98 9 5.23 15 8.72 18 10.47 54 31.4
*Post
secondary
20 11.63 17 9.88 6 3.49 9 5.23 52 30.2
University 0 0 0 0 24 19.95 27 51 29.7
Total 40 23.3 30 17.4 48 27.9 54 31.4 172 100
• ( Participants with diploma and certificates other than university
degree)
4.3 OCCUPATION OF THE SUBJECTS
Housewives and civil servants constituted majority of the
subjects with 25.0% and 25.6 % distribution respectively. Lawyers,
45
bankers and apprentices were the least represented with 1.7% each.
The findings are presented in table 3.
Table 3: Occupation of the Subjects
Variable Control 1st
trimester
2nd
trimester
3rd
trimester
Total
N % N % N % N % N %
Teachers 11 6.4 9 5.2 12 7 9 5.2 41
Apprentices 0 0 0 0 0 0 3 1.7 3 1.7
Bankers 0 0 0 0 3 1.7 0 0 3 1.7
Traders 0 0 0 0 6 3.5 3 1.7 9 5.2
Civil
Servants
17 9.9 11 6.4 9 5.2 6 3.5 43 25.0
Housewives
4 2.3 4 2.3 12 7 24 13.9 44 25.6
Hair
dressers
0 0 0 0 3 1.7 0 0 3 1.7
Lawyers 0 0 0 0 0 0 3 1.7 3 1.7
Nurses 8 6 3.5 0 0 0 0 14 8.1
Students 0 0 0 0 3 1.7 6 3.5 9 5.2
Total 40 23.3 30 17.4 48 27.9 54 31.4 172 100
46
4.4 FORCES VITAL CAPACITY (FVC) AND PERCENTAGE
PREDICTED FVC
The mean values for FVC and the percentage predicted are
shown in table 4, figures 1 and 2. The mean FVC was 2.93 ± .73
liters in the non-pregnant state but decreased significantly as
pregnancy progressed to 2.55± .51 liters in the 3rd trimester.
Furthermore, although the percentage predicted was within normal
range it also decreased significantly from 100.70± 31.11% in the
non pregnant state to 82.30± 19.01 % in the 3ird trimester
(P<0.0001).However the changes in FVC were mainly as a result
of the differences between control versus 2nd trimester (P=0.011)
control versus 3rd trimester (P=0.006), 1st trimester versus 2nd
trimester P=0.026) and 2nd trimester versus 3rd trimester (P=0.017).
For the percentage predicted the changes are mainly due to
differences between control versus 2nd trimester (P=0.006) and
control versus 3rd trimester (P<0.0001).
47
Table 4: Mean and Standard Deviation (SD) Forced Vital Capacity
FVC (liters) and Percentage Predicted (%).
Number FVC (liters)
Percentage Predicted
(%)
P value
Control 40 2.93± 0.73a 100.70±31.11e (P<0.0001).
1st trimester 30 2.93 ±0.33b 92.10± 1.70f
2nd trimester 48 2.56 ±0.41c 85.61± 13.20g
3rd trimester 54 2.55 ± 0.51d 82.30± 19.01h
Post-hoc multiple comparison; a versus c (P=0.11), a versus d (P=0.006),
b versus c (P=0.026), e versus g (P=0.006), and e versus h (P<0.0001).
Figure 1: Mean FVC in pregnant and non pregnant control
FVC(l) C
ontrol
FVC(l) 1s
t trim
estre
FVC(l) 2n
d trim
estre
FVC(l) 3r
d trim
estre
0
1
2
3
4
Litr
es
48
contro
l
1st t
rimes
tre
2nd tr
imes
tre
3rd tr
imes
tre0
50
100
150
200
Duration of pregnancy
Per
cent
age
pred
icte
d
Figure 2: Mean Percentage Predicted FVC among Pregnant and
none Pregnant Control
4.5. FORCED EXPIRATORY VOLUME IN ONE SECOND
(FEV1) AND PERCENTAGE PREDICTED
The mean values for FEV1 and the percentage predicted are
shown in table 5, figures 3 and 4. The mean FEV1 was 2.55±0.62
liters per second in the non-pregnant state but decreased
significantly, as pregnancy progressed to 2.24±0.45 liters/second in
the 3rd trimester. Furthermore, the percentage predicted decreased
significantly from 102.02± 30.70 31.11% in the non-pregnant state
to 82.89±18.32% in the 3rd trimester (P<0.0001). The changes in
FEV1 was only because of the differences between control versus
49
3rd trimester (P=0.013). For the percentage predicted the changes
were mainly due to differences between control versus 2nd trimester
(P=0.033) and control versus 3rd trimester (P<0.0001).
Table 5: Mean and Standard Deviation (SD) of Forced Expiratory
Volume in One Second (FEV1, liters /s) and Percentage
Predicted
Number FEV1(l/s) Percentage Predicted FEV1 (%)
P value
Control 30 2.55±0.62a 102.02±
30.70e
(P<0.0001
).
1st trimester 40 2.47±0.24b 93.40± 7.79f
2nd trimester 48 2.32±0.36c 89.44±
13.58g
3rd trimester 54 2.24±0.45d 82.89±18.32h
Post hoc multiple comparison; a versus d (P = 0.013), e versus g
(P=0.033), e versus h (P<0.0001).
50
Figure 3: Exploratory Scatter Diagram Showing the Mean Forced
Expiratory Volume in one Second
Control
1st t
rimes
tre
2nd tr
imes
tre
3rd tr
imes
tre0
50
100
150
200
250
Duration of pregnancy
Per
cent
age
pred
icte
d
Figure 4: Mean FEV in one Second Percentage Predicted
Control
1st t
rimes
tre
2nd tr
imes
tre
3rd tr
imes
tre0
1
2
3
4
5
Duration of pregnancy
Litr
es
51
4.6 PEAK EXPIRATORY FLOW RATE (PEFR
LITERS/SECOND) AND PERCENTAGE PREDICTED
The mean values for PEFR and the percentage predicted are
shown in table 6, figures 5 and 6. The mean PEFR was 5.38±1.44
liters in the non pregnant state but decreased non significantly as
pregnancy progressed to 5.18± 1.42 liters in the 3rd trimester
(P=0.883). However, the percentage predicted decreased
significantly from 93.4 ± 32.16 % in the non pregnant state to
79.39 ± 20.90 % in the 3rd trimester ( P=0.014). The changes in
the percentage predicted was mainly due to differences between
control versus 3rd trimester (P=0.021).
Table 6: Mean and Standard Deviation (SD) Peak Expiratory Flow Rate (PEFR) Liters and Percentage Predicted Number PEFR (l/s) Percentage
Predicted
PEFR (%)
P value
Control 40 5.38±1.44a 93.4 ±
32.16e
a vs. b vs. c
vs. d
(P=0.883)
e vs. f vs. g
vs. h (
P=0.014)
1st trimester 30 5.24± 0.92b 87.60 ± 5.98f
2nd trimester 48 5.21± 1.08c 83.19 ±
15.46g
3rd trimester 54 5.18± 1.42d 79.39 ±
20.90h
Post hoc multiple comparison e versus h (P= 0.021)
52
Control
1st t
rimes
ter
2nd tr
imes
tre
3rd tr
imes
tre
0
2
4
6
Duration of pregnancy
Litr
es/s
econ
d
Figure 5: Mean PEFR among Pregnant and Non-Pregnant Women
contro
l
1st t
rimes
ter
2nd tr
imes
tre
3rd tr
imes
tre0
50
100
150
200
250
Duration of pregnancy
Per
cent
age
pred
icte
d
Figure 6: Mean PEFR Percentage Predicted in Pregnant and Non
Pregnant Control
53
4.7 RATIO OF FEV1/FVC (%) AND THE PERCENTAGE
PREDICTED
The mean values for FEV1/FVC and the percentage
predicted are shown in table 7 and figure 7. The mean FEV1/FVC
was 87.56± 2.87 % in the non-pregnant state but increased
significantly, as pregnancy progressed to 91.20± 4.21 % in the 3rd
trimester. Furthermore ,the percentage predicted was normal in all
the groups;107.37 ± 3.88 % in the non pregnant state, 102.97 ±
1.24 % in the 1st trimester, 109.56 ± 5.33 % in the second trimester
and 105.77 ± 5.82% the 3rd trimester (P<0.0001). The changes in
FEV1/FVC was only because of the differences between control
versus 3rd trimester (P=0.013). For the percentage predicted the
changes were mainly due to differences between control versus 2nd
trimester (P=0.033) and control versus 3rd trimester (P<0.0001).
54
Table 7: Mean and Standard Deviation (SD) of FEV1/FVC (%) and Percentage Predicted Number FEV1/FVC
(%)
Percentage
Predicted
P value
Control 40 87.56± 2.87a 107.37 ±
3.88e
(P<0.0001).
1st trimester 30 87.57± 1.38b 102.97 ±
1.24f
2nd trimester 48 90.69± 4.37c 109.56 ±
5.33g
3rd trimester 54 91.20± 4.21d 105.77 ±
5.82h
A versus d (P=0.013), e versus g and h (p=0.033)
Control
1st t
rimes
tre
2nd tr
imes
tre
3rd tr
imes
tre70
80
90
100
110
Duration of pregnancy
Per
cent
age
Figure 7: Mean FEV in one second/FVC during pregnancy
55
CHAPTER FIVE
5.0 DISCUSSION
All the subjects were within the reproductive age group and
there were no significant changes between the age groups .The fact
that the highest parity occurred in the control group represents a
selection bias as most of those who met the selection criteria for
the control population had completed their families. Expectedly,
the chest circumference increased as pregnancy progressed. Earlier
studies had demonstrated this phenomenon (Thomas et al., 1938,
Gibson 1966, Broughton-Pipkin 2007).
Although the height did not show any significant changes,
the weight, the BMI and the mid arm circumference increased as
pregnancy progressed. During pregnancy, caloric intake increases
to ensure appropriate development of the foetus. The amount of
weight gained during a single pregnancy varies among women.
The overall pregnancy weight gain for women starting pregnancy
at a normal weight, with a BMI of 18.5-24.9 range from 11.4
to15.9 kg (Broughton-Pipkin 2007). Gestational weight is a unique
and complex biological phenomenon that supports the functions of
growth and development of the foetus. Gestational weight gain is
influenced not only by changes in maternal physiology and
56
metabolism, but also by placental metabolism. The placenta
functions as an endocrine organ, a barrier, and a transporter of
substances between maternal and foetal circulation. Practitioners
may make different recommendations based on specific and
individualized patients needs, based on factors including low
maternal age, nutritional status, foetal development, and morbid
obesity. During pregnancy, insufficient or excessive weight gain
can compromise the health of the mother and foetus and also affect
lung function.
All the subjects had formal education. Indeed the majority
had secondary education as the least qualification. Again, this
represents a selection bias, as the illiterates that were initially
recruited had difficulties understanding the instruction to be
followed during spirometry. Indeed, lack of understanding of the
procedure also led to the inability of the most of the recruited
subjects to meet the ERS criteria on quality control.
Understandably, majority of the subjects were civil servants and
housewives as Enugu has always been known as a city of civil
servants. Majority of core professionals (Doctors, lawyers, Bankers
etc) that were recruited abandoned the procedure due time factor,
57
as each procedure took a minimum of 30 minutes to obtain a
reliable result.
The FVC and the percentage predicted and the FEV1 and the
percentage predicted were within normal range in both the non-
pregnant and pregnant subjects. However, the values decreased
significantly, as pregnancy progressed. Although some earlier
studies did not demonstrate any significant change in these
parameters during pregnancy Puranik et al.,1994, Chhbra et
al.,1988), however, majority and more recent studies agreed with
our findings (Mokkapatti et al.,1991, Lui 1992, Neeraj et al.,2010 )
This study also demonstrated that PEFR was normal in all
the subjects but decreased none significantly during pregnancy.
Conversely, the percentage predicted values showed a significant
decline. The findings in the PEFR from most studies varied wildly
depending on the equipment and the geographic location. While
some studies agreed with our findings (Mokkapatti et al.,1991,
Puranik et al,.1995 , Neeraj et al.,2010 ), others did not illicit any
significant decline (Brancazio et al., 1997,Salisu et al,. 2007).
The FEV1/FVC increased significantly, as pregnancy
progressed. In a study in northern India, this parameter also
increased but none significantly (Neeraj et al.,2010).
58
It was noted that the magnitude of decrease in FEV1 during
pregnancy was not as much as the decrease in FVC. The
consequence of this differential change is the rise in the FEV1/FVC
ratio.
The decrease in FVC in our study may be due to a
comparative decrease in the negativity of the intrapleural pressure
occasioned by an upward displacement of the diaphragm by the
enlarging uterus (Shaikh et al 1983). Decrease in FEV1, and PEFR
may be due to a decline in alveolar PCO2 (caused by
hyperventilation). In the respiratory tract, hormonal changes
stimulate the mucosal vasculature leading to the reduction in
airway resistance. This leads to increased ventilation and decreased
partial pressure of CO2. This may probably be due to the
progesterone-mediated loosening of ligaments and relaxation of the
bronchial muscles (Lyons and Anthonio 1959). Furthermore, the
decrease in PEFR could be due to lesser force of contraction of
main expiratory muscles like the anterior abdominal wall muscles
and internal intercostals muscles (Phatak et al 2003). In addition, it
has been demonstrated that reduced haemoglobin level in
pregnancy causes muscle weakness and this significantly affects
ventilatory muscles.(Puranik et al.,1995, Neerag et al., 2009).
Majority of pregnant women in Nigeria are anaemic and this may
59
negatively affect the strength of contraction of the respiratory
muscles (Ogunbode 1984, Nwagha et al.,2009).
The reduced value for FVC, lower FEV1 with higher
FEV1/FVC is an indication that some degree of ventilatory
restriction occur during pregnancy in our environment (Pellegrino
et al., 2005). This phenomenon is physiological process that results
from the reduction in lung volume occasioned by the growing
uterus. Indeed, a further decrease in lung volume occurs during
the early phase of each uterine contraction, resulting from
redistribution of blood from the uterus to the central venous pool. It
is therefore pertinent that, this should be taken into cognizance
during the diagnosis and treatment of pregnant women with
respiratory disorders.
This study forms a baseline for the determination of changes
in some ventilatory function parameters during pregnancy in
Enugu; South East Nigeria using a state of the art computerized
Spirometer. However, it would have been more appropriate if
patients were recruited in the 1st trimester and longitudinally
followed up to delivery and six weeks post partum to ascertain the
actual time it will take for these changes to come back to normal.
60
Furthermore, the haemoglobin content and percentage oxygen
saturation should be obtained during the time of the study.
5.1 CONCLUSIONS AND RECOMMENDATIONS
The present study highlights observation that the respiratory
parameters are significantly compromised during pregnancy in
Enugu, Southeastern Nigeria. Respiratory changes in pregnancy are
of clinical importance to the anaesthetist during administration of
anesthesia to pregnant women especially during childbirth and
specifically during caesarean section. The decreased FVC, PEFR,
FEV1 and increased FEV1/FVC ratio is a strong indication that
pregnancy causes physiological restriction in the lungs. With the
combination of increased oxygen consumption and the decreased
expiratory reserve volume due to the reduced functional residual
capacity, rapid fall in arterial oxygen tension despite careful
maternal positioning and pre oxygenation may occur during labour
and spinal anaesthesia. Even with short periods of apnea, either
from obstruction of the airway or inhalation of a hypoxic mixture
of gases, the gravida has little defence against the development of
hypoxia. Furthermore, the increased minute ventilation, combined
with decreased functional residual capacity hastens inhalatory
61
induction or changes in the depth of anaesthesia when breathing
spontaneously. The baseline values that we established are
therefore critical and invaluable while performing these procedures
in normal pregnant women, but more especially in women with
compromised cardiopulmonary functions.
Health care providers who attend to pregnant women during
labour and caesarean section should there be extra vigilant. Supine
positioning should be avoided as much as possible .Oxygen should
always be available is all labour rooms and theatre. Pregnant
women with respiratory disorders should undergo lung function
test during labour to ascertain the degree of severity and to institute
appropriate intervention. These will go a long way in reducing
maternal mortality and morbidity and hasten the attainment of
Millennium Developmental goal 5 (Reduction in maternal
mortality by 75 % by the year 2015).
62
REFERENCES
Abid Ali M, Vahalia KV, Murtuza Ali M (1990).A study of
respiratory function in normal school children in
northern Nigeria. Afr J Med Med Sci 19:207-12.
Ahuja GK, Ahuja CI (1983). A comparative Study of Ventilatory
Pulmonary Tests in health and disease in Nigerian
Males. W Afr Med J 2: 61-5.
American Thoracic Society. Standardization of spirometry (1979).
Am Rev Respir Dis 119:831–38.
Akgun N, Ozgonul H (1969). Spirometric Studies in Normal
Turkish Subjects aged 8-20 years. Thorax 24:714-21.
Al-Riyami BM, Al-Rawas OA, Hassan MO (2004). Normal
spirometric reference values for Omani children and
adolescents. Respirology 9(3):387-91.
Albert Miller (1987). Pulmonary function: A guide for Students
and House Officers. Orlando: Grume and Stratton Inc
p.28.
Baltopoulos G,Fildisis G,Karatzas S, Georgiakodis F,Myrianthefs
P (2000). Reference values and prediction equations
for FVC and FEV (1) in the Greek elderly. Lung 178
(4): 201-12.
63
Barker DJP, Godfrey KM, Fall C, Osmond C, Winter P D,
Shaheen S O (1991). Relation of birth weight and
childhood respiratory infection to adult lung function
and death from chronic obstructive airway disease.
BMJ 303:671–5.
Bende M, Hallgårde M, Sjögren U, Uvnäs-Moberg K (1989).Nasal
congestion during pregnancy. Clin Otol Allied Sci 14
(5):385-7.
Berry MJ, McMurray RG and Katz VL (1989). Pulmonary and
ventilatory responses to pregnancy, immersion, and
exercise. Appl Physiol 66: 857-62.
Boezen HM, Vonk JM, van Aalderen WM, Brand PLP, Gerritsen J,
Schouten JP, and Boersma ER (2002). Perinatal
predictors of respiratory symptoms and lung function
at a young adult age. Eur Respir J 20:383–90.
Brancazio LR, Laifer SA, Schwartz T (1997). Peak expiratory flow
rate in normal pregnancy. Obstet Gynecol 89 (3):383-
6.
Broughton-Pipkin F (2007). Maternal Physiology In; Dewhurst
Textbook of Obstetrics and Gynaecology.7th edition,
Edmonds DK(Ed), Blackwell Publishing Oxford. PP
10-18.
64
British MRC Committee on etiology of chronic Bronchitis (1960):
standardized questionnaires on Respiratory
symptoms.Br Med J 2:1665-66.
Cambell MJ and Machin D (1996). Medical Statistics: A
Commonsense Approach. John Wiley and Sons. 2:
156 – 7.
Canoy D,Pekkanen J,Elliot P,Pouta A,Laitinen J,Hartikainen
AL,Zitting P,Patel S,Little MP.Jarvelin MR ( 2007).
Early growth and adult respiratory function in men
and women followed from the fetal period to
adulthood. Thorax 62:396-402.
Chapman AB,Zamudio S,Woodmansee W, Merouani A, Osorio F,
Johnson A et al(1997). Systemic and Renal
Hemodynamic changes in the luteal phase of the
menstrual cycle mimic early pregnancy. Am J Physiol
273 (5 pt 2):777-82.
Chen Y, Horne SL, Dosman JA (1993). Body weight and weight
gain related to pulmonary function decline in adults: a
six-year follow up study. Thorax 48:375–80.
65
Chhbra S, Nangia V, Ingley KN (1988). Changes in respiratory
function tests during pregnancy. Ind J Physiol
Pharmacol 32 (1):56-60.
Clark SL, Cotton DB, Lee W, Bishop C, Hill T, Southwick J,
Pivarnick J (1989). .Central haemodynamic
assessment of normal term pregnancy. Am J Obstet
Gynecol 161:1439-42.
Cook G, Carey I, Whincup P, et al., (1997). Effect of fresh fruit
consumption on lung function and wheeze in children.
Thorax 52:628–33.
Cugell DW, Frank NR, Gaensler EA, Badger TL (1953).
Pulmonary function in Pregnancy; Serial Observations
in normal women. American Review of Tuberculosis
and Pulmonary Diseases 67:568-97.
Cunningham J, Dockery DW, Gold DR, Speizer FE (1995). Racial
differences in the association between maternal
smoking during pregnancy and lung function in
children. Am J Respir Crit Care Med 152:565–9.
Demissie K, Ernst P, Hanley JA, Locher, U, Menzies D, Becklake
MR (1996). Socioeconomic status and lung function
among primary school children in Canada. Am J
Respir Crit Care Med 153:719–23.
66
Donnelly PM, Yang TS, Peat JK, Woolcock AJ (1991). What
factors explain racial differences in lung volumes?
Eur Respir J 4: 829-38.
Ebomoyi MI and Iyawe VI (2005). Variations of peak expiratory
flow rate with anthropometric determinants in a
population of healthy adult Nigerians. Niger J Physiol
Sci 20:85-89.
Ellegård E, Oscarsson J, Bougoussa M, Igout A, Hennen G, Edén
S, Karlsson G (1998). Serum level of placental growth
hormone is raised in pregnancy rhinitis. Arch
Otolaryngol Head Neck Surg. 124(4):439-43.
Ellegård EK (2003). The etiology and management of pregnancy
rhinitis. Am J Respir Med. 2(6):469-75.
Ellegård EK, Hellgren M, Toren K, Karlsson G (2000).The
Incidence of Pregnancy Rhinitis. Gynecol Obstet
Invest 49:98-101.
Ezugwu EC, Onah HE, Ezugwu FO and Okafor II (2009) .Maternal
Mortality in a Transitional Hospital in Enugu, South
East Nigeria. Afr J Reprod Health 13 (4):67-72.
Femi-Pearse D and Elebute EA (1971). Peak flow rate in
Nigerians. Thorax 26:597-601.
67
Femi-Pearse D and Elebute EA (1971). Ventilatory functions in
healthy adult Nigerians. Clin Sci 41:203-211.
Gazioglu K, Kaltreider NL, Rosen M, Yu PN (1970). Pulmonary
function during pregnancy in normal women and in
patients with cardiopulmonary diseases. Thorax
25:445-450
Gibson MJ (1966). Heart Size in Pregnancy. Brit J Radiol 39: 456-
7
Hankinson JL, Odencrantz JR, Fedan KB (1999). Spirometric
reference values from a sample of the general U.S.
population. Am J Respir Crit Care Med 159:179–87.
Harik-Khan RI, Muller DC and Wise RA (2004). Racial Difference
in Lung Function in African-American and White
Children: Effect of Anthropometric, Socioeconomic,
Nutritional, and Environmental Factors. Am J
Epidemiol 160 (9):893-900.
Hu G and Cassano PA (2000). Antioxidant nutrients and
pulmonary function: The Third National Health and
Nutrition Examination Survey (NHANES III). Am J
Epidemiol 151:975–81.
68
Hsi BP, Hsu KH, Jenkins DE (1983). Ventilatory functions of
normal children and young adults: Mexican-
American, white, and black. III. Sitting height as a
predictor. J Pediatr 102: 860–5.
Ip MS, Karlberg EM, Karlberg JP, Luk KD, Leong JC (2000).
Lung function reference values in Chinese children
and adolescents in Hong Kong. I. Spirometric values
and comparison with other populations. Am J Respir
Crit Care Med 162: 424-9.
Jain SK and Gupta CK (1967). Lung function Studies in Healthy
Men and women over forty. India J Med Res 55:612-
19.
Jaja SI (1991). Lung Function in Young Nigerian Adult. W Afr
Med J 10:255-82.
Jenson D,Duffin J,Lam YM, Webb KA,Simpson JA,Davies
GA,Wolfe LA,O,Donnell DE (2008). Physiological
mechanisms of hyperventilation during human
pregnancy. Respir Physiol Neurobiol 161(1):76-86.
Kelly MC, Fitzpatrick KTJ, Hill DA (1996). Respiratory effects of
spinal anaesthesia for caesarean section. Anaesthesia
51:1120-1122.
69
Knuttgen HG and Emerson K (1974) .Physiological response to
pregnancy at rest and during Exercise. J App Phy
36:549-53.
Kolarzyk E, Szot WM, Lyszczarz J (2005). Lung function and
breathing regulation parameters during pregnancy.
Arch Gynecol Obstet 272(1):53-8.
Korotzer B, Ong S, Hansen JE (2000). Ethnic differences in
pulmonary function in healthy nonsmoking Asian-
Americans and European-Americans. Am J Respir
Crit Care Med 161: 1101-8.
Knudson RJ, Slatin RC, Lebowitz MD (1976). The maximal
expiratory flow volume curve: Normal Standards,
variability and Effects of Age. Am Rev Respir Dis
113: 587-600.
Lees MM, Taylor SH, Scott DB Kerr MG (1967). A study of
cardiac output at rest throughout pregnancy. J Obstet
Gynaecol Br Commonwealth 74:319-28.
Liberatore SM, Pistell R, Patalano F, Moneta E, Incalzi RA,
Ciappi G(1984). Respiratory Function during
Pregnancy. Respiration 46:145-50.
70
Liu CT (1992). Lung function changes during pregnancy.
Zhonghua Fu Chan Ke ZA Zhi 27(2):84-5.
Li YF, Gilliland FD, Berhane K, McConnell R, Gauderman WJ,
Rappaport EB, Peters JM (2000). Effects of in utero
and environmental tobacco smoke exposure on lung
function in boys and girls with and without asthma.
Am J Respir Crit Care Med 162:2097–104.
Lyons HA, Anthonio R (1959). The sensitivity of the respiratory
center in pregnancy and after the administration of
progesterone. Trans Assoc Am Physicians 72:173-180.
Mabrouk AA and Ibrahim SA (1995) .Normal values for lung
function test in Sudan Children. East Afr Med J
72:258-62.
Manhem K and Jern S (1994).Influence of daily life activation on
pulse rate and blood pressure changes during the
menstrual cycle. J Hum Hypertens 8:851– 856
Mannino DM, Moorman JE, Kingsley B, Rose D, Repace J (2001).
Health effects related to environmental tobacco smoke
exposure in children in the United States: data from
the Third National Health and Nutrition Examination
Survey. Arch Pediatr Adolesc Med 155:36–41.
71
McAuliffe F, Kametas N, Eepinoza J, Greenough A, Nicolaides K
(2004). Respiratory function in pregnancy at sea level
and at high altitude. Brit J Obstet Gynaecol
111(4):311-5.
McAuliffe F,Kametas N, Costello J, Rafferty GF, Greenough
A, Nicolaides K (2002). Respiratory function in
singleton and twin pregnancy. Brit J Obstet
Gynaecol 109 (7):765-9.
McGinty AP (1938). The comparative effect of pregnancy and
phrenic nerve interruption on the diaphragm and their
relation to pulmonary tuberculosis. Am J Obstet
Gynecol 35:237-48.
Miller MR, Crapo R, Hankinson J, Brusasco V, Burgos F, Casaburi
R, Coates A et al (2005).General considerations for
lung function testing. Eur Respir J 26:153-161.
Milivojevic-Poleksic L, Wells AU, Moody A, Fergusson W,
Tukuitonga C, Kolbe J(2001). Spirometric lung
volumes in the adult Pacific Islander population:
comparison with predicted values in a European
population. Respirology 6: 247-53.
72
Mojiminiyi FBO, Igbokwe UV,Ajagbonna OP,Jaja SI, Ettarh RR,
Okoro RU et al (2006).Peak Expiratory Flow Rate in
Normal Hausa- Fulani Children and Adolescents of
Northern Nigeria. Ann Afri Med 5:10-15.
Mokkapatti R,Prasad EC,Venkatraman S ,Fatima K (1991)
.Ventilatory functions in pregnancy. Indian J Physiol
Pharmacol 35:237-40.
Neeraj, Sodhi C, Pramod J, Singh J, Kaur V (2010). Effect of
advanced uncomplicated pregnancy on pulmonary
function parameters of north Indian subjects.
Indian J Physiol Pharmacol 54(1):69-72.
Nku CO, Peters EJ, Eshiet AI, Bisong SA, Osim EE (2006).
Prediction formulae for lung function parameters in
females of South Eastern Nigeria. Niger J Physiol Sci
21:43-7.
Ogunbode O. (1984).Management of anaemia in pregnancy. Nig
Med Pract. 8(5/6): 105-107V
Okafor VCO (1995). Peak flow rate in normal adult Ibos. FMCP
Diss. National Postgraduate Medical College.
Olanrewaju DM (1991). Spirometric standards for healthy
Nigerians. East Afri Med J 68 (10):812-9.
73
Onadeko BO, Lyun AO, Sofowora EA, Adamu SO (1979).
Ventilatory function in normal Nigerian School
Children. Afr J Med Sci 8:25-9.
Onadeko BO, Lyun AO, Sofowora EO, Adamu SO (1984). Peak
expiratory flow rate in normal Nigerian Children. Afr
J Med Sci 13:25-32.
Onadeko BO, Falase A, Ayeni O (1970). Pulmonary function
studies in Nigerian Sportsmen. Afr J Med Sci
5(4):291-95.
Onah HE, Okaro JM, Umeh U, Chigbu CO (2005). Maternal
mortality in health institutions with emergency
obstetric care facilities in Enugu State, Nigeria. J
Obstet Gynaecol 25 (6): 569-74.
Orie NN (1999). Comparison of normal respiratory function values
in young Kenyans with those of other African and
Caucasians. East Afr Med J 76 (1):31-34.
Pellegrino R, Viegi G, Brusasco V, Crapo RO, Burgos F, Casaburi
R, Coates A, Van der Grinten CP, Gustafsson P,
Hankinson J, Jensen R, Johnson DC, MacIntyre N,
McKay R, Miller MR, Navajas D, Pedersen OF,
Wanger J (2005). Interpretative strategies for lung
function tests. Eur Respir J 26(5):948-68.
74
Pistelli F, Viegi G, Carrozzi L, Rönmark E, Lundbäck B, Giuntini
G (2001). Appendix 3: Compendium of respiratory
standard questionnaires for adults (CORSQ). Eur
Respir Rev 11:80, 118–43.
Puranik BM, Kurhade GA, Kaore SB, Patwardhan SA, Kher JR
(1995). PEFR in pregnancy: a longitudinal study.
Indian J Physiol Pharmacol 39(2):135-9.
Puranik BM, Kaore SB, Kurhade GA, Agrawal SD, Patwardhan
SA, Kher JR (1994). A longitudinal study of
pulmonary function tests during pregnancy. Indian J
Physiol and Pharmacol 38:129-132.
Ramsay MM, Broughton Pipkin F and Rubin PC (1993). Pressor,
heart rate and plasma catecholamine responses to
noradrenaline in pregnant and non-pregnant women
Brit J Obstet Gynaecol 100:170-6.
Rees GB, Roughton PF, Symonds EM, Patrick JM (1990). A
longitudinal study of respiratory changes in normal
human pregnancy with cross-sectional data on
subjects with pregnancy-induced hypertension. Am J
Obstet Gynecol 162 (3):826-30.
75
Sakai K, Maeda H, Tsukimori K, Nagata H (1992). How blood
viscosity influences changes in circulation during
pregnancy. Fukuoka Igaku Zasshi 83:328-32.
Salisu AI,Adelaiye AB,Babashani M (2007); A formula for
predicting Peak Expiratory Flow Rate in non Pregnant
and Pregnant women in second and third trimesters of
pregnancy in Kura Local Government Area ,Kano
state Nigeria. Research Journal of Medical Sciences
5:279-83.
Schoenberg JB, Beck GJ, Bouhuys (1978). Growth and Decay of
pulmonary Function in Healthy Blacks and Whites.
Resp Physiol 33:367-93.
Schultz P, Ostergaard A, Dahl R, Norregaard O (1989).Lung
function and postural changes during pregnancy.
Respir Med 83 (6):467-70.
Schunemann HJ, Grant BJ, Freudenheim JL, Muti P, Browne
RW, Drake JA, Klocke RA, Trevisan M (2001). The
relation of serum levels of antioxidant vitamins C and
E, retinol and carotenoids with pulmonary function in
the general population. Am J Respir Crit Care Med
163:1246–55.
76
Schwartz J, Katz SA, Fegley RW, Tockman MS (1988). Sex and
race differences in the development of lung function.
Am Rev Respir Dis 138:1415–21.
Schwartz J, Weiss ST (1994). Relationship between dietary
vitamin C intake and pulmonary function in the First
National Health and Nutrition Examination Survey
(NHANES I). Am J Clin Nutr 59:110–14.
Shaikh RM, Deshpande DR, Ganeriwal SK, Reddy BV. Effect of
pregnancy on vital capacity and FEVpercentage. J
Obst Gynecol 1983; 33: 495-499.
Shamssain MH (1991). Forced expiratory indices in normal black
southern African children aged 6-19. Thorax 46
(6):452-3.
Sims CD, Chamberlain GVP, de Swiet M (1976). Lung functions
test in bronchial asthma during and after pregnancy.
Brit J Obstet Gynaecol 84:434-37.
Sroczynski T (2002). Evaluation of respiratory tract function in
healthy women in the last month of uncomplicated
pregnancy. Ann Acad Med Stetin 48:331-50.
State Ministry of Health, Enugu (2004).Health Sector Reform:
Implementing the District Health System.
77
Strauss A, Müller-Egloff S, Schwaiblmair M, Knitza R, Hepp H
(2001). Maternal pulmonary function and dyspnea in
multifetal pregnancies. Prenat Neonat Med 6(4): 234-
41.
Tan MP, Wynn NN, Umeroy M, Henderson A, Gillham A Junejo S
et al (2009). Arm Span to Height Ratio Is Related to
Severity of Dyspnea, Reduced Spirometry Volumes,
and Right Heart Strain. Chest 135:448-454.
Thomas KJ and Cohen ME (1938). Studies on the circulation in
Pregnancy.II.Vital capacity observations in normal
pregnant women. Surg Gynecol Obstet 66:591–603.
Timonen KL, Randell JT, Salonen RO, and Pekkanen J (1997).
Short-term variations in oscillatory and spirometric
lung function indices among schoolchildren. Eur
Respir J 10: 82-87.
Toppozada H, Michaels L, Toppozada M, El-Ghazzawi I, Talaat
M, Elwany S (1982). The human respiratory nasal
mucosa in pregnancy. An electron microscopic and
histochemical study. J Laryngol Otol 96:613-26.
78
Townsend MC (1984). Spirometric forced expiratory volumes
measured in the standing versus the sitting posture.
Am Rev Respir Dis 130:123–4.
Unsal M, Yanik FF, Gurkan N, Katar D (2003). Pulmonary
functions in pre-eclamptic Women. Eur J Obstet
Gynecol Reprod Biol 111(1):33-7.
Vandevoorde J, Verbanck S, Schuermans D, Kartounian J.Vincken
W (2005). FEV1/FEV6 and FEV6 as an Alternative
for FEV1/FVC and FVC in the Spirometric Detection
of Airway Obstruction and Restriction. Chest
127:1560-4.
Vandevoorde J, Verbanck S, Schuermans D, Kartounian J.Vincken
W (2006). Obstructive and restrictive spirometric
patterns: fixed cut-offs for FEV1/FEV6 and FEV6.
Eur Respir J 27:378-383.
Vedal S, Schenker MB, Samet JM, Speizer FE (1984). Risk factors
for childhood respiratory disease. Analysis of
pulmonary function. Am Rev Respir Dis 130:187–92.
Vijayan VK, Reetha AM, Kuppurao KV, Venkatesan P,
Thilakavathy S (2000). Pulmonary function in normal
south Indian children aged 7-19 years. Indian J Chest
Dis Allied Sci 42(3):147-56.
79
Von Ungern-Sternberg BS,Regli A,Bucher E,Reber A, Schneider
MC (2004;). The effect of epidural analgesia in labor
on maternal respiratory function. Anesthesia 59
(4):350-3.
Wise RA, Enright PL, Connett JE, Anthonisen NR, Kanner RE,
Lindgren P et al (1998). Effect of weight gain on
pulmonary function after smoking cessation in the
Lung Health Study. Am J Respir Crit Care Med
157:866–72.
Wise RA, Polito AJ, Krishnana V (2006). Respiratory physiologic
changes in pregnancy. Immunol Allergy Clin North
Am 26 (1):1-12.
Woolcock AJ, Colman MK, Blackburn CRB (1972). Factors
affecting normal values for Ventilatory Lung
functions. Am Rev Respir Dis 106:692-709.
80
SAMPLE OF FORM /QUESTIONNAIRE
1. Serial no………………………………………………...................
2. Age in years……………………………………………………….
3. Marital status: Married Single Widowed Divorced
4. Educational qualification:
(a) Nil………………………………………………...……...…..
(b) Primary school……………………………………………….
(c). Secondary school…………………………………………….
(d). Post secondary levy……………………………………..…....
(f). University……………………………………………….……
5. Religion;
(a) Christian…….…………Denomination………...…..………..
(b) Moslem………………………………………...…………….
(c) Traditional……………...…………………………………….
(d) Others (specify)…………………...………………………….
6. Occupation:…………………………………………………………
7. Last menstrual period………………………………….……………
8. Gestational age………………………………………………...……
9. Parity…………………………………………………..…………...
10. Number of spontaneous abortions……………….…………………
11. Number of induced abortion………………………………………..
12. Number of living children…………………..…..…………………..
81
13. Complications of previous delivery………………….…..…………
14. QUESTIONNAIRE ON RESPIRATORY SYMPTOMS
SYMPTOMS
I am going to ask you some questions now please answer yes or no.
Insert 1 if YES and 2 If NO.
COUGH
15. Do you have cough now?...................................................................
16. Do you cough on most days for as much as three months a year?.....
17. For how long have you been coughing?............................................
18. Do you have seasonal cough? ………………………………….......
PHLEGM
19. Do you bring up phlegm when you cough at this time? ……………
20. Do you bring up phlegm on most days for as much as three months
each year?...........................................................................................
21. Do you bring up phlegm seasonally?.................................................
22. What is the colour of the phlegm?.....................................................
23. Is there blood in it?.............................................................................
BREATHLESSNESS
24. Are you troubled by shortness of breath when hurrying on level
ground or walking up a slight hill?.....................................................
If yes
82
25. Do you get short of breath walking with other people of your own
age on level ground? …………………………….…………………
26. Do you have to stop for breath when walking at your own pace on
level ground? ………………………………….……………………
WHEEZING
27. Do you ever perceive a whistling sound in your chest while
breathing? …………………………………………………………..
If Yes, how long ago………………………………………………..
28. Do you have recurrent attacks of shortness of breath with
wheezing? ………..............................................................................
OTHERS
29. Do you have nasal stuffiness? ……………………….......................
Do you sneeze often? …………………………………………........
30. Have you had attacks of chest pain in the past months?
If Yes, How long ago……………………………………………….
31. Have you had chest pains that were aggravated by breathing or
coughing? …... ……………………………………………………..
32. Do you have chest pains aggravated by exertion? …………………
33. Do you smoke now? ……………………………………………......
If No
83
34. Did you ever smoke as much as one stick of cigarette daily for up
to 1year?.............................................................................................
If Yes
35. For how long have you smoked?........................................................
36. Do you have close contacts or members of your household that
smoke in your presence? ………………………………………..….
37. Did you work indoors with firewood and stoves?..............................
38. Have you ever been told you have the following diseases in the
past before?........................................................................................
i) Heart Disease
ii) Pneumonia
iii) Pulmonary Tuberculosis
iv) Asthma�
FINDINGS ON PHYSICAL EXAMINATION
39. Blood Pressure measurement (mmHg)…………41.Pulse Rate……
40. Weight………kg; Height…….…m; BMI………Kg/m2.
41. Midarm circumference……. cm ;waist circumference……cm;. Hip
Circumference………….……………………………………….......
42. Respiratory Rate…………………………………………………….
43. Chest examination findings in details………………………………
44. Cardiovascular System…………………………………...................
84
45. Gastrointistinal tract………………..……………………………….
46. Obstetric Examination; Symphysiofundal height
…………………..
i.e.………………………..…Presentation………………… …….
D. LABORATORY INVESTIGATIONS
E. VENTILATORY FUNCTION TESTS.
47. FVC (litres) ……….……..……%predicted….………………..……
48. FEV1 (litres/second)…………..…...% predicted…………...………
49. FVC/FEV1(%)..................................%predicted...............................
50. PEFR (liters)…………………….…%predicted………..………….
……………………………………………………………….. Name and Signature of Supervisor
………………………………………………………………….. Name and Signature of Head of Department
