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Webster, Joan, Osborne, Sonya, Gill, Richard, Chow, Carina Faran Kalan,Wallin, Siobhan, Jones, Lee, & Tang, Annie(2014)Does preoperative oral carbohydrate reduce hospital stay? A randomizedtrial.AORN Journal, 99(2), pp. 233-242.
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https://doi.org/10.1016/j.aorn.2013.12.003
Preoperative oral carbohydrate
1
Manuscript No: AORN-D-13-00018R2
Title: Does preoperative oral carbohydrate reduce hospital stay? A randomized trial.
Investigators
Prof. Joan Webster, RN, BA. Nursing Director, Research, RBWH, Herston, QLD,
School of Nursing & Midwifery, Griffith University, School of Nursing & Midwifery,
University of Queensland.
Dr Sonya Ranee Osborne, RN, PhD. Senior Lecturer, School of nursing. Block N,
Queensland University of Technology, Kelvin Grove, 4059, QLD. Australia. E-mail
Mr Richard Gill, RN BN. Nurse Unit Manager, Department of Colorectal Surgery,
9AN, Ned Hanlon Bld, RBWH, Butterfield St, Herston, 4029, QLD, Australia. E-mail
Dr Carina Faran Kalan Chow, MBBS, FRACS. Colorectal Surgeon, Royal Brisbane
and Womens Hospital & Mater Hospital. Senior Lecturer, University of Queensland
Address: Surgery & Perioperative Services, Level 8, Ned Hanlon Building, RBWH,
Herston Q 4029 Email: [email protected]. Phone: +61 7 36465353
Preoperative oral carbohydrate
2
Siobhan Wallin, BHlthSci, NutrDiet, PhD candidate. Senior Clinical Dietitian
Department of Nutrition and Dietetics, Level 2 The James Maybe Building
RBWH, Herston,4029 QLD. E-mail [email protected]
Phone: +61 7 36467997
Lee Jones, B Sci, PhD Candidate, Statistician, School of Population Health,
University of Queensland. Public Health Building, Level 0, Herston Rd., Herston,
QLD., 4006, Australia , E-mail [email protected].
Annie Tang, RN, BN. Registered Nurse, Department of Colorectal Surgery, 9AN,
Ned Hanlon Bld, RBWH, Butterfield St, Herston, 4029, QLD, Australia. E-mail
Correspondence address: Prof. Joan Webster, level 2, building 34, Royal Brisbane
and Women’s Hospital Herston, 4029 QLD, Australia
Email: [email protected]
Telephone: +61 7 3646 8590
Fax: +61 3646 5832
Funding: The study was funded through a competitive grant from the Royal Brisbane
and Women’s Hospital Research Foundation
Preoperative oral carbohydrate
3
Abstract
Background: Carbohydrate-rich fluids are used to improve postoperative
recovery but the effectiveness of the product for reducing length of hospital
stay is uncertain.
Objective: To assess the effectiveness of preoperative loading with
carbohydrates on postoperative outcomes.
Participants: Forty six patients booked for elective colorectal surgery.
Methods: Participants were allocated to a Carbohydrate-rich fluid group or
Usual Care group during their pre-admission clinic visit. The primary outcome
was ‘Time to readiness for discharge’.
Results: Patients in the control group spent on average 4.3 days (95%
confidence interval 3.2 to 5.7) and the Carbohydrate-rich fluid group spent 4.1
days (95% confidence interval 3.2 to 5.4) until the primary outcome was met
(p=0.824).
Conclusion: The safety of preoperative high carbohydrate fluids is supported
but we were unable to confirm or refute the benefit of CHO for shorter
hospital stay following elective colorectal surgery.
Preoperative oral carbohydrate
4
Introduction
Surgical fast track pathways, based on work by Kehlet et al (2002), employ a number
of perioperative strategies, which aim to improve postoperative outcomes1. One of the
components of these pathways is the use of preoperative, oral, carbohydrate-rich
nutritional supplement (CHO). These supplements have been shown to counteract
postoperative insulin resistance and stress reactions associated with surgical trauma2
and to improve postoperative recovery3. Preoperative oral CHO appears to be
effective in reducing thirst, hunger and fatigue in the postoperative period4 and in
reducing anxiety preoperatively5. The effect of CHO on postoperative nausea and
vomiting is less clear. One study showed that drinking 800ml of a carbohydrate fluid
on the night before surgery and 400mls 2 hrs prior to surgery reduced nausea and
vomiting in the carbohydrate group following laparoscopic cholecystectomy6.
However, a study in a similar population and using the same pre-operative regimen,
found no differences between groups on any of the measured outcomes, including
nausea and vomiting7. Nor did the product reduce nausea and vomiting in patients
who received the drink before coronary artery surgery8 or thyroidectomy
9.
Although some advantages of using a carbohydrate-rich preoperative beverage have
been demonstrated, there is less information about whether these advantages translate
into improved post-operative clinical outcomes, such as shorter recovery times. For
example, clinicians and hospital administrators are interested in whether pre-loading
with a carbohydrate drink reduces hospital length of stay. Following abdominal
surgery, patients usually remain in hospital until their gastrointestinal function has
been restored, so any treatment which facilitates this function may be useful.
Preoperative oral carbohydrate
5
However, in their original paper, Kehlet and colleagues (2002) suggested that the
evidence base for the use of carbohydrate enriched pre-operative drinks to improve
outcomes required further investigation before the intervention could be
recommended1. Since that time, there have been three trials of CHO that have
included gastroenterology patients but their findings are contradictory10-12
. None of
these trials compared ‘usual care’ with the administration of a pre-operative
carbohydrate drink, and one included a heterogeneous population11
, which may have
masked any effects the product may have in a more homogeneous group.
At the Royal Brisbane and Women’s Hospital, a standard protocol exists for fasting
pre-operative patients, which could be easily adapted to include a clear carbohydrate
drink for some patients. This provided an opportunity for an independent, pragmatic
trial to add to the evidence around the use of preoperative CHO. Consequently, the
primary aim of this study was to test if a pre-operative carbohydrate drink would
improve clinical outcomes among gastroenterology patients undergoing elective
bowel surgery.
Methods:
Design:
We used a single-site, parallel-group, randomized controlled trial. The Consolidated
Standards of Reporting Trials (CONSORT 2010) Statement, a method for ensuring
transparent reporting of trials (Figure 1), was used to guide trial design and
reporting13
.
Participants and setting:
The trial was conducted at the Royal Brisbane and Women's Hospital, Brisbane,
Australia (RBWH). All colorectal patients undergoing elective bowel surgery and
Preoperative oral carbohydrate
6
who were > 18 years of age were eligible for inclusion. Exclusion criteria included
those who were non-English speaking and who did not have an interpreter; pregnant
women; those unable to consume clear fluids; those with gastrointestinal obstruction,
liver cirrhosis, diabetes mellitus or cognitive impairment; and those who were
receiving corticosteroid treatment exceeding 5 mg/day. We also excluded, participants
enrolled in other trials.
The trial was approved by the Hospital’s Human Research Ethics Committee and was
pre-registered (ACTRN12611000868987). All participants provided written consent.
Intervention
Patients randomized to the intervention arm of the study were asked to drink 800ml of
the CHO between 1900 and 2400 hours on the night before surgery and to have no
solid food from midnight. The beverage is a clear fluid with 50 kcal per 100 ml, 290
mOsm/kg, and a pH of 5.0). In accordance with the RBWH protocol, other clear
fluids were allowed during the night. At 0500 hours on the morning of surgery,
patients were asked to drink a further 200mls of the solution and to record any side-
effects caused by the drink.
Control
Patients randomized to the control arm of the study followed the RBWH protocol, that
is, they were not permitted to take solid food from midnight but could drink clear
fluids up to 0500 hours. Patients in both groups were asked to keep a record of their
fluid intake pre-operatively. Details were recorded on a pre-prepared form, which
sought information about both the quantity and type of fluids consumed.
Randomisation
We used a computer generated randomized list to determine allocation sequence and a
telephone service was used to allocate patients to their group. Randomisation was in a
Preoperative oral carbohydrate
7
1:1 ratio between the two study groups. Block randomisation was used with random
variation in block sizes. In trials with relatively small numbers, this process ensures
that an equal number of participants are allocated to each group and that the allocation
to the group is not predictable. The process reduces the potential for allocation bias, or
the opportunity to select particular patients for a one group or the other.
Procedure
Patients were screened, consented and enrolled at the pre admission clinic and then
randomized to either the routine care group (Control) or the CHO group
(Intervention). Baseline demographic and risk factor data were also collected at this
stage. Surgery-related data was retrieved from the operating theatre database and
outcome data recorded prospectively on a pre-prepared outcome data sheet. Patients
were followed until hospital discharge or death and any reason for a delay in
discharge noted.
Post operatively, care was individualised according to the type of surgery but most
patients followed the standard protocol. That is, clear fluids from day one followed by
free fluids, such as milk based drinks, pureed soups etc. on day 2-4 and to a general
diet when tolerated. Some patients, with uneventful surgery, were placed on a rapid
rehabilitation diet, which involved clear fluids and, if tolerated free fluids at the next
meal, followed by a general diet if free fluids were tolerated. No record was kept of
which patients received which approach. All patients go through bed exercises,
supervised by a physiotherapist, on the day after surgery and are mobilised on day
two if their pain is well managed.
Preoperative oral carbohydrate
8
Surgeons were unaware of group allocation but the trial was not blinded to patients or
clinical staff. None of the investigators had any conflicts of interest and were not
involved with sponsorship from the product manufacturers. The high carbohydrate
beverage was not donated. The primary outcome was readiness for discharge. This
was assigned by ward staff (not research staff or investigators) and there was no
indication in the medical record to indicate to which arm of the study the patient was
assigned. Consequently, the outcome was blinded to investigators.
Outcome Measures
Primary Outcome
1. Time to readiness for discharge: Time in days (or hours) until all of the
following criteria were met: passing flatus, stool and urine; eating
satisfactorily (75% diet according to the patients ‘Food and Fluid
Consumption Chart’); managing on oral analgesics; afebrile; mobilising
independently to shower and toilet; requiring wound dressing changes less that
twice daily; without drains requiring inpatient management.
Secondary Outcomes
1. Time to first flatus
2. Time to first bowel movement
3. Mortality: death from any cause whilst on the trial
4. Adverse outcomes (such as re-admission, aspiration, any reaction or side
effects caused by the drink).
Sample Size and study power
Preoperative oral carbohydrate
9
The primary endpoint in this study was time to readiness for discharge. We based our
sample size calculation on the results of a small study10
that showed a mean reduction
of 2.5 days in patients having colorectal surgery. To show such a difference with 80%
power at p=0.05 we required 27 participants in each arm. We intended to inflate this
by an additional three patients per arm (60 patients in all) to allow for any drop outs
or missing data. We did not have any useful data on which to base a sample size
calculation for secondary outcomes.
Statistical methods
All patients for whom outcome data were available were analysed in their allocated
treatment groups (i.e. intention to treat). To reduce the effect of outliers and skewness
within the data, continuous outcome variables were logarithmically transformed and
analysed using t-tests. Geometric means and 95% confidence intervals were reported.
Categorical outcome measures were analysed with chi-squared; Fisher’s exact test
was used when expected cell counts became small. All study outcomes were analysed
using a two-sided P-value of less than .05 to indicate statistical significance. Data was
analysed using IBM SPSS Statistics 19. (IBM Corporation, 2010)
Results
Between August 2011 and April 2012, 74 potentially eligible patients were screened
for inclusion. Forty six of these patients consented and were enrolled in the trial; 22 in
the CHO group and 24 in the Control group. One patient from the Control group did
not have surgery before the trial enrolment period finished, so was excluded. One
additional patient, also in the Control group, remained in hospital for an extended
period, almost eight weeks. He failed to reach our primary outcome of ‘readiness for
discharge’ before he was transferred, so was not included in the outcome analysis.
Other reasons for exclusion are shown in Figure 1. Over half (26; 59.0%) of the
Preoperative oral carbohydrate
10
enrolled participants were oncology patients, 18 (40.9%) were male; 37 (84.1%) had
laparoscopic surgery and 4 (9.1%) had surgery under epidural anaesthesia. Other
baseline data, by group, is shown in Table 1.
None of the patients reported side-effects from consuming the CHO beverage but four
did not drink the product before surgery, reasons for this are shown in Figure 1.
Patients in the CHO group drank larger quantities of fluid overall than those in the
control group (CHO 2393ml, SD 1165; Control group 1320ml, SD 982; p = 0.002).
Outcomes
There was no difference in the mean time to readiness for discharge with patients in
the control group on average spending 4.3 days and the CHO group spending 4.1
days until this outcome was met (t=0.224, p=0.824). Nor were differences
demonstrated until passage of first flatus; the control group average was 49.8 hours
compared to 34.7 hours in the CHO group (t=1.551, p=0.129). Although the time to
first bowel movement, on average was shorter in the CHO group (46.5 hours)
compared with the control group (68.4 hours), the result was not statistically different
(t=1.784, p=0.082). Table 2 shows the unadjusted results and Table 3 shows results
adjusted for length of surgery and time from last fluid intake.
Adverse outcomes
Overall, 4 (18%) patients in the control group had an adverse event compared with 2
(9%) in the CHO group, the difference was not statistically significant (Fisher’s exact,
p=0.376). None of these events were related to the intervention and occurred at
various times in the post surgical period. In the control group there was one wound
Preoperative oral carbohydrate
11
dehiscence in a patient admitted for repair of an enterocutaneous fistula; one episode
was reported of an airway obstruction, which occurred in the Post Anaesthetic Care
Unit (PACU) following an open anterior resection in a patient with sleep apnoea; one
patient was retuned to theatre for division of adhesions and formation of an ileostomy
eight days after an ileo-anal anastomosis; and one patient with multiple comorbidities,
who had a hemi-colectomy, died two days after the surgery. In the intervention group,
a patient who had an anterior resection and ileostomy was retuned to theatre for
insertion of a urinary stent; and one morbidly obese patient with an anterior resection
was admitted post operatively to the Intensive Care Unit, following an upper airway
obstruction in the PACU.
Discussion
This is the fourth study to investigate the effect of preoperative loading with an oral,
carbohydrate-rich nutritional supplement on length of stay in elective colorectal
patients. The intervention had no effect on our primary outcome, time to readiness
for discharge. Time to first flatus and to first bowel movement were shorter, though
not statistically so, in the intervention group. Theoretically, such a reduction could be
due to a shorter time between ingestion of carbohydrates and surgery. It is well
understood that starvation changes the body’s metabolism, including increased insulin
resistance and reduced muscle function2. However, although those in the intervention
group ingested a higher volume of fluid than those in the control group, they did not
have a longer starvation period.
This raises important issues about our preoperative policy, which allows patients to
eat until midnight and to have no fluid after 05.00hrs. Delays to surgery frequently
occur and, in our case, the average time between the last fluid intake and surgery was
Preoperative oral carbohydrate
12
approximately eight hours. This delay is well outside recommendations from decades
of research and recent guidelines, which state that drinking clear fluids up to 2-hours
before elective surgery is safe and beneficial14, 15
.
Strengths and weaknesses of the study
The robust design, use of a ‘usual care’ group that allowed a realistic comparison
between the intervention and control and the ability to follow-up all but two
participants, were important features of the study. Although over one-third of
potentially eligible patients were excluded before randomisation, for only two of these
was the reason because the potential participant refused consent, making future, larger
trials feasible.
Recruiting participants some weeks before the date of surgery introduces the potential
for post-randomisation loss, due to surgical cancellations or patients receiving
treatment elsewhere. Nevertheless, only one patient was lost in this way, even though
in some cases there was up to two months between recruitment and surgery. In
addition, having ‘readiness to discharge’ as the primary end point may also be a
limiting factor if patients are very ill. In our case however, only one patient failed to
meet one or more components of the end point before being discharged, almost eight
weeks after surgery.
One important limitation to the study was the sample size. We based our sample size
on a mean reduction of 2.5 days in time to readiness for discharge. At the time of
planning, this reduction was drawn from results of the only available study10
. The
actual difference in time to readiness for discharge in our study was less than one day;
Preoperative oral carbohydrate
13
consequently our study was seriously underpowered to show a difference in the
primary outcome. As a result we are unable to draw conclusions about the
effectiveness or not of the intervention. In addition, because we were constrained by
hospital policy, the intervention was unable to be administered as recommended. than
recommended. So, essentially, the study compared clear fluids with high carbohydrate
fluids. The delay between last ingestion of fluid and surgery may also have impacted
on the study outcomes.
Despite these limitations, there are now four trials assessing the effectiveness of CHO
on hospital length of stay. These trials provide an opportunity for a systematic review
and meta-analysis to enable a clearer picture to be formed about whether CHO
confers any benefit to patient undergoing colorectal surgery. Effect estimates from
any such review would also allow investigators to calculate a more realistic sample
size for any future trial.
Differences between this and other studies
In this study the effect of preoperative carbohydrate loading on readiness to discharge
is inconclusive. Our results are at variance with results from a small trial where 35
participants undergoing colectomy or resection were divided into three groups (pre-
operative water drink, pre-operative fasting and preoperative carbohydrate drink)10
.
Time to readiness for discharge in this study was statistically shorter in the
carbohydrate group when compared with the water group but not when compared
with the fasting group. However, our results concur with the two other trials to have
used hospital length of stay as an outcome11,12
. In the first of these trials, 162 patients
undergoing colorectal surgery or liver resections were randomly allocated to either an
oral carbohydrate drink or a placebo taken the evening before and two hours prior to
surgery. Outcomes of the 142 patients whose results were analysed included
Preoperative oral carbohydrate
14
postoperative fatigue, total length of hospital stay and time to ‘fit for discharge’. No
differences between groups were found for any of these outcomes11
. In the second
trial, one of the three interventions was oral intake of 400mls of CHO on the evening
before and on the morning of surgery. Length of hospital stay was assessed but no
between group differences were demonstrated12
. Our population was very similar to
both of these trials and our control and intervention groups well matched for all risk
factors, as was the Mathur (2010) 11
and the Kaska (2010) trials12
. It was unclear if
this was the case in the Noblett (2005) trial, which found a benefit for preoperative
carbohydrate loading10
.
The effectiveness of enhanced preoperative nutrition has also been recently evaluated
in a Cochrane Review. Although the review demonstrated shorter length of stay
among those receiving enhanced nutrition, the authors included studies evaluating any
nutritional intervention, delivered by any route (parenteral, enteral or oral) for
extended periods prior to surgery. Consequently, results from the review are not
comparable with those from the current study16
. Similarly, trials were available where
high carbohydrate drinks were administered as a component of a fast-track protocol17
.
However, because the individual effect of CHO could not be estimated, comparisons
with our results were not possible.
As with other studies in similar populations, no adverse events related to the trial
product were observed 10-12
and there were no anaesthetic complications.
Implications for practice
Until larger, independent trials provide evidence of benefit, use of high carbohydrate
fluids to improve patient outcomes cannot be recommended.
Implications for research
Preoperative oral carbohydrate
15
Independent, well designed, pragmatic trials are required to establish if pre-operative,
high carbohydrate fluids provide any meaningful postoperative benefit. Any such trial
should include an economic analysis, be suitably powered to detect clinically
important differences and provide an assessment of patient preferences.
Conclusion
The safety of preoperative high carbohydrate fluids is confirmed but we are unable to
confirm or refute the benefit of CHO for shorter hospital stay.
Preoperative oral carbohydrate
16
References
1. Kehlet H, Wilmore DW. Multimodal strategies to improve surgical outcome. Am
J Surg . 2002;183:360-41
2. Ljungqvist O. Modulating postoperative insulin resistance by preoperative
carbohydrate loading. Best Pract Res Clin Anaesthesiol. 2009;23:401-9.
3. Gustafsson UO, Hausel J, Thorell A, Ljungqvist O, Soop M, Nygren J. Adherence
to the enhanced recovery after surgery protocol and outcomes after colorectal
cancer surgery. Arch Surg. 2011;146:571-7.
4. Yagmurdur H, Gunal S, Yildiz H, Gulec H, Topkaya C. J Res Med Sci. The
effects of carbohydrate-rich drink on perioperative discomfort, insulin response
and arterial pressure in spinal aesthesia.2011;16:1483-9.
5. Hausel J, Nygren J, Lagerkranser M. et al. A carbohydrate-rich drink reduces
preoperative discomfort in elective surgery patients. Anesth Analg. 2001;93:1344-
50.
6. Hausel J, Nygren J, Thorell A, Lagerkranser M, Ljungqvist O. Randomized
clinical trial of the effects of oral preoperative carbohydrates on postoperative
nausea and vomiting after laparoscopic cholecystectomy. Br J Surg. 2005;92:415-
21.
7. Bisgaard T, Kristiansen VB, Hjortsø NC, Jacobsen LS, Rosenberg J, Kehlet H.
Randomized clinical trial comparing an oral carbohydrate beverage with placebo
before laparoscopic cholecystectomy. Br J Surg. 2004;91:151-8.
8. Jarvela K, Maaranen P, Sisto T. Pre-operative oral carbohydrate treatment before
coronary artery bypass surgery. Acta Anaesthesiol Scand. 2008;52:793-7
Preoperative oral carbohydrate
17
9. Lauwick SM, Kaba A, Maweja S, Hamoir EE, Joris JL. Effects of oral
preoperative carbohydrate on early postoperative outcome after thyroidectomy.
Acta Anaesthesiol Belg. 2009;60:67-73.
10. Noblett SE, Watson DS, Huong H, Davison B, Hainsworth PJ, Horgan AF. Pre-
operative oral carbohydrate loading in colorectal surgery: a randomized controlled
trial. Colorectal Dis. 2006;8:563-9.
11. Mathur S, Plank LD, McCall JL. et al. Randomized controlled trial of preoperative
oral carbohydrate treatment in major abdominal surgery. Br J Surg. 2010;97:485-
94.
12. Kaska M, Grosmanová T, Havel E, Hyspler R, Petrová Z, Brtko M. et.al. The
impact and safety of preoperative oral or intravenous carbohydrate administration
versus fasting in colorectal surgery--a randomized controlled trial.Wien Klin
Wochenschr. 2010 Jan;122(1-2):23-30
13. Schulz KF, Altman DG, Moher D. CONSORT Group. CONSORT 2010
statement: updated guidelines for reporting parallel group randomized trials. Int J
Surg. 2011;9:672-7.
14. Smith I, Kranke P, Murat I. et al. Perioperative fasting in adults and children:
guidelines from the European Society of Anaesthesiology. Eur J Anaesthesiol.
2011;28:556-69.
15. ASoA. Practice guidelines for preoperative fasting and the use of pharmacologic
agents to reduce the risk of pulmonary aspiration: application to healthy patients
undergoing elective procedures: an updated report by the American Society of
Anesthesiologists Committee on Standards and Practice Parameters.
Anesthesiology. 2011;114:495-511.
Preoperative oral carbohydrate
18
16. Burden S, Todd C, Hill J, Lal S. Pre-operative Nutrition Support in Patients
Undergoing Gastrointestinal Surgery. Cochrane Database Syst Rev. 2012; Issue
11.
17. Ramírez JM, Blasco JA, Roig JV, Maeso-Martínez S, Casal JE, Esteban F, Lic
DC; Spanish working group on fast track surgery. Enhanced recovery in colorectal
surgery: a multicentre study. BMC Surg. 2011 Apr 14;11:9. doi: 10.1186/1471-
2482-11-9.
Preoperative oral carbohydrate
19
Potentially eligible
Colorectal patients undergoing elective bowel surgery and who were >
18 years of age
(n = 74)
Reasons for exclusion (n = 28)
Unable to drink large quantities (n = 5)
Diabetic (n = 7)
Taking cortisone (n = 6)
Enrolled in another trial (n = 2)
Missed (n = 5)
Refused consent (n = 2)
Other (n = 1)
EN
RO
LM
EN
T
AL
LO
CA
TIO
N
AN
AL
YS
IS
FO
LL
OW
- U
P
Randomized
(n = 46)
Allocated to CHO group
(n = 22)
Allocated to the control
group
(n = 24)
Number included in
outcome analysis
N = 22
Number included in
outcome analysis
N = 22
Number of protocol violations = 4
Nausea = 2
Asleep = 1
Surgery date changed, no high
carbohydrate drink available for
second date = 1
Number of protocol violations = 0
All patients in the Control group
received standard care
Post randomization exclusion (n = 0) Post randomization exclusion (n = 2)
Surgery cancelled (n = 1)
Extended hospital stay (n = 1)
Figure 1. Flow of participants through the trial
Preoperative oral carbohydrate
20
Table 1. Characteristics of study population. Values are numbers (percent) of
patients or mean [standard deviation].
CHO group Control group
age in years 54.5 [36.0, 79.0] 61.0 [27.0, 77.0]
Male 8/22 (36.4) 10/22 (36.4)
weight in kilos 69.3 [47.8, 142.6] 76.1[48.0, 97.7]
ASA Grade > 2 5/22 (22.7) 3/22 (13.6)
Oncology patient 12/22 (54.5) 14/22 (63.6)
Epidural anaesthesia 2/22 (9.1) 2/22 (9.1)
Time between last fluid intake and
surgery (in hours)
5.1 [3.1, 26.9] 6.8 [3.4, 16.7]
Duration of surgery (in hours) 3.1 [0.4, 7.2] 3.2[0.9, 8.0]
Laparoscopic surgery 19/22 (86.4) 18/22 (81.8)
Type of surgery
Anterior resection 11/22 (50.0) 7/22 (31.8)
Hemicolectomy 3/22 (13.6) 2/22 (9.1)
Restoration of continuity 5/22 (22.7) 8/22 (36.4)
Sigmoid colectomy 1/22 (4.5) 0/22 (0.0)
Total colectomy 1/22 (4.5) 1/22 (4.5)
Proctectomy and pouch 1/22 (4.5) 3/22 (13.6)
Other surgery 6/22 (27.2) 9/22 (40.9)
N.B. Total sum of types of surgery is greater than 22 in each group; some patients had
more than one type of surgery.
Preoperative oral carbohydrate
21
Table 2: Unadjusted outcome variables*
Group mean 95% CI t p-
value lower upper
Time to readiness
for discharge (days)
Control
group
(n = 21) a
4.3 3.2 5.7 0.224 0.824
CHO group
(n = 22)
4.1 3.2 5.4
Time to fist
flatus (hours)
Control
group
(n = 22)
49.8 33.4 74.2 1.551 0.129
CHO group
(n = 22)
34.7 26.0 46.1
Time to first
bowel movement
(hours)
Control
group
(n = 22)
68.4 50.6 92.5 1.784 0.082
CHO group
(n = 21) b
46.5 33.2 65.2
* Outcome variables were logarithmically transformed and geometric means and
confidence intervals are shown
a One patient died before discharge
b Time of bowel movement not recorded for one patient
Preoperative oral carbohydrate
22
Table 3: Outcome variables adjusted by duration of surgery and time to last
fluid *
* Outcome variables were logarithmically transformed and geometric means and
confidence intervals are shown
a One patient died before discharge
b Time of bowel movement not recorded for one patient
Group mean 95% CI F p-value
lower upper
Time to readiness
for discharge (days)
Control group
(n = 21)a
4.4 3.3 5.7 0.106 0.746
CHO group
(n = 22)
4.1 3.2 5.3
Time to fist
flatus (hours)
Control group
(n = 22)
50.1 35.5 70.5 2.468 0.124
CHO group
(n = 22)
34.5 24.7 48.2
Time to first
bowel movement (hours)
Control group
(n = 22)
68.8 50.6 93.6 3.349 0.075
CHO group
(n = 21) b
46.2 33.7 63.4