neonates dr.i.lakshminarayana. structure normal new born adaptation to extra uterine life nutrition...
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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?