Neonates

Dr.I.Lakshminarayana

Structure

Normal new born Adaptation to extra uterine life Nutrition Maintaining temperature Common neonatal problems Neonatal examination Case discussion

Anthropometry

Term 37-42 weeks Pre term < 37 weeks Post term >42 weeks Normal birth weight 2.5- 4 kg (average 3.5

kg/7.5 pounds) Low birth weight <10th centile ELBW <0.4th centile Head circumference average 35 cm Length 50 cm

Normal to lose weight 5-7% in first ten days From then on babies gain 15 g/day

The transition-Respiratory

In utero fetal lung is filled with fluid 25ml/kg Compression of chest wall during delivery Chemoreceptor stimulation causes a gasp

(<6sec)

Sensory stimulation

Clamping cord will increase the systemic pressure and reduce pulmonary pressure.

Transition-cardiovascular

UV through ductus venosus to IVC

IVC

RA RV,PA,Aor

Thro FO

To LA

Changes in circulation at birth Cord is clamped, collapse of veins and

ductus venosus, increase in sytemic pressure Ist breath lungs expand, vasodilation,

pulmonary vascular resistance falls by 80%,increase in LA pressure, closure of FO

Ductus arteriosus closes owing to rise in Pao2 by 12 hours

Nutrition

Breast is best Advantages of breast feeding- Protects

against respiratory/gastrointestinal infections Increases response to immunisation Reduces risk of NEC Reduces incidence of allergy and atopy Increases cognitive development

Nutritional requirement

Term babies require 100kcal/kg/day Breast milk provides 70kcal/100ml 1.3 gm protein,4.1 gm fat,7.2 gm

carbohydrates

Breast milk composition

Fat –supply energy, build cell membranes, LCPUFA, EFA help in cognitive development and improved retinal function

Carbohydrates – Lactose converted to lactic acid by lacto bacillis protects gut

Protein – Whey based easily absorbed, antibodies, lactoferrin, enzymes

Maintaining temperature

Cold can kill Ideal temperature close to 37 Heat loss can occur due to large surface area

for a small body mass Heat loss occurs by conduction, convection,

evaporation and radiation Heat production- hydrolysis of triglycerides in

brown fat using oxygen

Clinical effects of hypothermia Reduced surfactant synthesis Reduced surfactant efficiency Hypoglycemia Increased oxygen requirement Increased utilisation of calorie reserves Increased postnatal weight loss

Common neonatal problems

Benign

Birth Marks

Rash

Other problems

Feeding Hypoglycemia Jaundice

Jaundice

Know basic physiology of bilirubin metabolism

Day 1 jaundice always pathalogical commonest cause being blood group incompatability

Prolonged jaundice>14 days think could this be obstructive

High bilirubin levels cause kernicterus

Problems that need immediate attentionRespiratory

TTN, RDS, Meconium aspiration, congenital pneumonia, CDH

Infection

GBS, Staphylococci ,E.Coli, Listeria

Cardiac causes

Duct dependant systemic /pulmonary circulation

Congenital anomalies of gut – duodenal atresia, anal atresia,NEC in preterm infants.

New born examination

History –mother’s medical ,antenatal history, FH of heart disease, DDH

Explore parental concerns , feeding Check weight, HC, length and plot on chart Detailed head to toe examination with infant

undressed with particular emphasis in picking up birth trauma and congenital abnormalities

Examine eyes , hips

Case discussion

32 hour old baby referred by midwife for jaundice

What questions would you ask the mother? How will you manage this baby? How will you monitor treatment?

3 week old baby referred for prolonged jaundice

What are the likely causes What condition you would like to rule out? What investigations would you perform?

You are the FY1 in neonates. You are called by the midwife to review a baby who is 15 minutes old. She is concerned that the baby is grunting.

What are the initial questions you will ask the midwife?

What are the causes of respiratory distress in babies?

What are the investigations you will request? How will you manage this baby?