Neonate and Neonatal Diseases

(Introduction)

Neonate and Neonatal Diseases

(Introduction)Rongxiu Zheng, MDPediatric Dpt. General Hospital of Tianjin Medical University

• Classification and definition of neonateClassification and definition of neonate

• Characteristic and nursing care of neonateCharacteristic and nursing care of neonate

• Neonatology: The branch of pediatrics that deals with the diseases and care of newborns.

• Neonatal period: From birth to the 28th day of life (4 weeks after birth).

• Perinatal period: From the 28th completed week of gestation to the 7th day after birth..

The two periods are highly vulnerable for life with the highest morbidity and mortality.

Classification of the neonates

By both GA and BW

By birth

weightBy gestational

age

• Gestation is the period of time between conception and birth, during which the fetus grows and develops inside its mother's uterus.

• Gestational age is measured in weeks from the first day of the mother's last normal menstrual period to the day of delivery

• Full term infant: An infant born at a gestational age between 37 and 42 completed weeks

• Preterm infant: An infant that is born prior to 37 weeks of gestation

• Post-term infant: An infant that is born after the 42nd week of gestation.

早产儿早产儿 足月儿足月儿 过期产儿过期产儿

Birth weight, BW

the first weight of an infant, obtained within the first hour after birth.

•Normal birth weight(NBW): This refers to all infants whose weight at birth is between 2500g and 4000g.

•Low birth weight(LBW): BW<2500g

•Very low birth weight(VLBW): BW<1500g

•Extremely low birth weight(ELBW): BW<1000g)

•Macrosomia: BW>4000g

Low birth weight•An extremely important factor in newborn mortality•Complications increases as BW decreases•Resuscitation rate of those less than 1500g is 80%

macrosomiamacrosomia NBWNBW

VLBWVLBW ELBWELBW

1.AGA ( appropriate for gestational age) Infants with birth weight for their gestational age that falls between the 10th and 90th centiles.

2.SGA ( small for gestational age) Infants with birth weight for their gestational age that falls below the 10th centiles.

3.LGA ( large for gestational age) Infants with birth weight for their gestational age that falls above the 90th centiles.

Point A represents a

premature infant. Point B indicates an infant of similar birth weight who is mature but small for gestational age.

Weight for gestational age chart

Characteristic and Characteristic and

nursing care of neonatenursing care of neonate

An infant’s intrauterine to extrauterine transition requires many biochemical and physiologic changes.

Many of a newborn’s special problems are related to poor adaptation due to asphyxia, premature birth, life-threatening congenital anomalies, or adverse effects of delivery.

Features in appearance of normal term neonate and preterm neonate

pink ， well-nurished ，Less fine-hair

term

Dark-red,edema ，transparent ， more fine-hair

preterm

SkinSkin

soft ear stick to the skull,

poor figuration

preterm

Good ear figuration, well-developed cartilage

term

earear

早产儿

乳腺无结节或结节＜＜ 4mm4mm

足月儿

乳腺结节＞＞ 4mm4mm ，平均，平均 7m7mmm

Galactophore noGalactophore nodede

term

Well-developed, testes decend

preterm

Under-developed, no testes in the sac

genitaliagenitalia （（ malemale ））

preterm

the labia majora don’t cover the labia minus

term

the labia majora cover the labium minus;

genitaliagenitalia （（ femalefemale ））

preterm

Shallow and less

term

Obvious, over all the sole

Sole markingsSole markings

Respiratory system

Fetal lung development•Filled with fluid•Surfactant synthesis : begins at 24-28w, peak at 35w

Establishment of breathing after birth•opening of the alveoli by mechanical,chemical,thermal, sensory stimuli

Characteristics of Newborn respirationsNormal1. 30-60 rate2. shallow and irregular3. 5-15 second periods of apnea

Abnormal findings: retractions, grunting, nasal flaring, 20 sec or more apnea; abnormal rate

Circulatory system

Transitional Physiology

•Increased aortic pressure and decreased venous pressure•Increased systemic pressure and decreased pulmonary artery pressure.•Closure of the foramen ovale: occurs due to increased pressure in the left atrium.•Closure of the ductus arteriosus.•Closure of the ductus venosus

Circulatory system

Characteristics of cardiac function in newborn

Heart rate: ranges from 120 to 160 per minute.

Heart murmur: •Murmurs are usually produced by turbulent blood flow.•90% of all murmurs are transient and not associated with anomalies.•Usually involve incomplete closure of the ductus arteriosis or foramen ovale.

Heart size: The heart of the newborn infant often seems large with respect to the size of the chest when measured by adult standards.

Blood pressure: from 46 to 80 mmHg(systolic)

Urinary system

Renal function: does not meet the standards of later lifeGFR(glomerular filtration rate):

is lower, about one fourth to one half of that in an adult.

Urine often contains protein in small amounts..

Urine may contain an abundance of urates which may give the diaper a pink stain during the first week of life.

The ability to dilute urine is good. but the time taken to reach the maximal ability is relatively long, so newborns are apt to become water overloaded.Urine pH ranges from 5 to 7, specific gravity ranges from 1.006 to 1.020.

The first urination occurs within 24 hrs. It ranges from 4 to 6 times/day in the first day and 20 times or so /day in later days of the neonatal period.

Hemotological system

Blood volume: ranges from 80 to 100 ml/kg.

Hemoglobin: ranges around 15~22g/dL.

RBC: RBCs range from 5000 to 7000 thousand/mm3.

WBC: Leukocyte number may be about 18000/ mm3 or so at birth, and generally increase in number for the first 24 hrs with relative neutrophilia. Counts as high as 25000 to 35000/ mm3 may be encountered. After the first few days (5 days or so ) the white cell count is likely to be below 14000/ mm3 with characteristically relative lymphocytosis of infancy and early childhood.

Alimentary system

The first stool will generally be passed within 12 hr of life and consists of meconium.

Meconium stools begin to be replaced by transitional stools on the third or fourth day with the establishment of milk feeding. Typical milk stool follows after an interval of 3 or 4 days.

The frequency of stools in newborn infants averages 3 to 5 times a day by the end of the first week. It is unusual for an infant to have as many as 6 or 7 stools after the 2nd day.

The first feeding should be at 6 hrs of postnatal age for a full term baby, 12 hrs for a premature body.

Nervous system Nervous system

Head: is relatively large, i.e. from 10 to 12% of body weight.

Spinal cord: relatively long. The end of it reaches the level

of the third or forth lumbar vertebra.

Physiological reflex:

There are some physiological reflexes which appear at birth, then disappear at 4 months of life.

REFLEX TESTING METHOD NORMAL RESPONSES

Moro Suddenly but gently drop the neonates head backward (relative to the trunk)

Neonate extends and abducts all extremities bilaterally and symmetrically

Grasp place a finger in the neonates palm neonate grasps the finger

Rooting touch a finger to the neonate’s cheek or the corner of mouth.

neonate turns the head toward the stimulus, opens the mouth and searches for the stimulus

Sucking place a finger in the neonate’s mouth neonate sucks on the finger

stepping hold the neonate in an upright position and touch one foot lightly to a flat surface (such as the bed)

neonate makes walking motions with both feet

Moro Suddenly but gently drop the neonates head backward (relative to the trunk)

Neonate extends and abducts all extremities bilaterally and symmetrically

Grasp place a finger in the neonates palm

neonate grasps the finger

Rooting

touch a finger to the neonate’s cheek or the corner of mouth.

neonate turns the head toward the stimulus, opens the mouth and searches for the stimulus

Sucking

place a finger in the neonate’s mouth neonate sucks on the finger

stepping

hold the neonate in an upright position and touch one foot lightly to a flat surface (such as the bed)

neonate makes walking motions with both feet

Immune system

Normal or slightly higher level of IgG is due to active transfer from the mother to fetus via the placenta, but IgM and IgA are low (they cannot pass through the placenta); therefore the newborns are at high risk for gram negative bacterial infection. T lymphocyte functions are somewhat reduced in newborn infants. White blood cells display low function in killing microorganisms.

Immunization

• BCG vaccinations in all population at high risk of tuberculosis infection

• HBV vaccination as soon as possible where perinatal infections are common

Thermoregulation

Newborn physiology •Normal temperature: 36.5–37.5°C•Hypothermia: < 36.5°C --Significant contribution to deaths in low birth weight infants and preterm newborns•Stabilization period: 1st 6–12 hours after birth

The body temperature is likely to be influenced by the environmental temperature.

Neutral environmental temperature: the environmental temperature at which the core temperature of the infant atrest is between 36.7 and 37.3°C and oxygen consumption and caloric utilization are lowest

Temperature control for newborn infants is important to avoid the excess stress which hypo- or hyperthermia imposes on a newborn. To provide a neutral thermal environment, the incubator temperature should be kept at the temperatures shown in the followingtables.

Skin

At birth the infant is generally covered with vernix caseosa, a cheesy- white substance adherent to the skin. It is helpful for protecting the baby against infections, and should not be taken off.

Keeping the skin of the baby clean is very important because it is apt to be infected.

Umbilical cord

After the ligation of the umbilical cord, it comes off from 1 to 7 days of postnatal age.

It has to be prevented against contamination and be kept it from bleeding.

Water metabolism

Water may contribute up to 75% of body weight (40% extracellular).

During the first few days there are a loss of fluid leading to about 6% loss of body weight (physiologic) and usually do not exceed 10%. Insensible water loss is about 40ml/100cal.

Requirments for calories and fluid of neonate

• Associated with GA, BW and health condition

day 1 day 2 day 3 calorie fluid calorie fluid calorie fluid Full term 60 － 80 60 － 80 100 － 120 80 － 100 120 － 150 110 －

150Preterm 80 － 100 70 － 100 110 － 130 90 － 120 130 － 150 130 －

180

unit ： calorie(kcal/kg.d) fluid(ml/kg.d)

High risk neonates

The term designates infants who should be under close observation by experienced physicians and nurses.

Neonatal Intensive Care Unit, (NICU)

The special medical unit which take special care for those high risk babies with modern medical equipments and techniques such as purified air ward, resuscitation technique, mechanical ventilator, color Doppler mapping, radiated heater and so on.

Problems Preemies May face

• Temperature Instability

• Respiratory problems

• Heart problems

• Gastrointestinal problems

• Neurological Problems

• Infections

Respiratory Problem

• Air sacs in the lungs not able to stay open due to lack of surfactant in the lungs

• Lung damage due to long term respiratory problems

• Incomplete lung development• Apnea (stop breathing) 50% of babies born at or

before 30 weeks will have this problem

Heart Problems

• Patent ductus arteriosus

• Congenital heart defects

Gastrointestinal Problems

• Difficulty feeding

• Poor digestion

• Infection of the intestinal tract

Neurological Problems

• Bleeding in the brain

• Poor muscle tone

• Seizures

• Vision problems

Infections

• Respiratory

• Urinary tract

• Blood infections

• Intestinal infections

Characteristics of Pre Term Infant

• Small body

• Little body fat

• Little scalp hair

• Body hair

• Weak cry

• Weak body tone

Treatment of the Pre term Infant

• Need special care in Neonatal Intensive Care Unit

• Temperature Control

• Oxygen by mask or ventilator

• Intravenous Fluids

• Medications

• Feedings by NG tube

Several physiological states of the newborn

Physiologic jaundice

Mild jaundice may occur in most newborns, this is due to the immaturity of the baby's liver, which leads to a slow processing of bilirubin. It generally appears at 2 to 4 days of age and disappears by 1 to 2 weeks of age. The appearance of visible jaundice before 48 hrs, or a serum concentration of bilirubin exceeding 12 mg/dL at any time of neonatal period are considered to be abnormal. For premature infants, the serum bilirubin concentration exceeding 15 mg/dL is abnormal.

Pseudomenstration

Vaginal bleeding may occur at the age of 5 to 7 days in some newborn girls and lasts for 1 to 2 days. Placentally transmitted and withdrawn maternal hormones are responsible for temporary vaginal bleeding.

Enlargement of the breasts

Enlargement of the breasts, and production of milk may occur at the age of 3 to 5 days in some newborn boys or girls. This stops at the postnatal age of 2 to 3 weeks. This is also caused by transmission and withdraw of maternal hormones. This no requires management.

Essential Newborn Care Interventions

• Clean childbirth and cord care– Prevent newborn infection

• Thermal protection– Prevent and manage newborn hypo/hyperthermia

• Early and exclusive breastfeeding– Started within 1 hour after childbirth

• Initiation of breathing and resuscitation– Early asphyxia identification and management