Neonatology Flashcards
What is hypoglycaemia defined as in neonates?
BM <2.6
What puts a newborn at risk for hypoglycaemia and hypothermia?
preterm; SGA; LBW; infants of diabetic mothers; intraprtum asphyxia or needed resus at birth; maternal beta-blocker use
What is the main cause of neonatal jaundice?
physiological
What does dark urine indicate?
increased conjugated bilirubin
What do pale stools indicate?
cholestasis- need to rule out obstruction
What effect does TPN have on jaudnice?
can cause direct hyperbilirubinaemia after >2weeks
What are the causes of neonatal aundice?
physiological; blood group incompatibility; other haemolytic disorders; sepsis; liver disease; metabolic disorders
Why does physiological jaundice happen?
increased production; decreased uptake and binding by hepatocytes; decreased conjugation; decreased excretion; increased enteroheptic circulation of bilirubin
Under what time from birth is jaundice always pathological?
<24 hours
What is jaundice <24 hours from birth usually caused by?
haemolysis with excessive production of bilirubin
What are the causes of haemolysis <24 hours of age?
ABO incompatibility; Rh immunisation; sepsis; other blood group incompatibilities; red cell defects
What should be considered as a cause of jaundice in a baby <24 hours old if there is >15% conjugated bilirubin?
hepatits
What investigations should be done for early pathological jaundice?
total and conjugated serum bilirubin conc.; maternal blood group and antibody titres; babys blood group ; direct antigolbulin test; FBC and blood film; CRP; TFTs: LFTs
What is the function of the direct antiglobulin test?
detects antibodies on the baby’s red cells
What are the causes of too high serum bilirubin jaundice?
mild dehydration/insufficient milk supply; haemolysis; breakdown of extravasated blood; polycythaemia; infection; increased enterohepatic circulation
When is physiological jaundice too long?
> 10 days; esp. >2 weeks (>21 days for preterm)
What is the cause of persistent unconjugated hyperbilirubinaemia?
breast milk jaundice; continued poor milk intake; haemolysis; infection; hypothyroidism
What is the usual cause if jaundice suddenly reappears after the infant has gone home?
haemolyssi
What type of hypobilirubinaemia is always abnormal?
conjugated hyperbilirubinaemia
What causes persistnet conjugated hyperbilirubinaemia?
hepatitis; biliary atresia
What can cause hepatitis ina neonate?
infection or metabolic disorder
What is the cause of kernicterus?
unconjugated bilirubin crosses the BBB which is toxic to the brain
What is kernicterus characterised by?
death of brain cells and yellow staining esp. in the grey matter of the brain
What are the signs of acute bilirubin encephalopathy?
lethargy; poor feeding; temperature instabilit;y hypotonia; opisthotonos; spasticity and seziures
What is opisthotonos?
arching of the head, neck and back
What level of unconjugated bilirubin is at risk of leading to kernicterus?
> 340micromol/L
What increases the risk of developing kernicterus?
preterm; asphyxia; acidosis; hypoxia; hypothermia; meningitis; sepsis; decreased albumin binding
What is the treatment for jaundice
adequate hydration; phototherpay; exchange transfusion
How often should a baby with jaundice be breastfed for the first few days?
8-12 times per day
When does physiological jaundice tend to set in?
day 2
When does physiological jaundice tend to resolve?
day 10-14
What is the function of phototherapy in jaundice?
converts trans-bilirubin to the more water soluble cis-form which is excreted in bile without conjugation
What are the SEs of phototherapy?
dehydration; skin rash; eye damage
What can cause conugated jaundice?
biliary atresia; TPN; hypothyroidism; a1 antitrypsin; galactosaemia; CF; Down;s syndrome
What should be suspected in an asymptomatic infant in which jaundice occurs after 8 days of age?
UTI
How does the appearance of jaundice differe between conjugated and unconjugated hyperbilirubinaemia?
unconjugated- more yellow compared with conjugated- more green
How is gestational age related to hyperbilirubinaemia?
risk of unconjugated hyperbilirubinaemia is inversely proportional to GA
What 3 factors contribute to the development of TTN?
delayed resoprtion of fetal lung fluid; pulmonary immaturity and milk surfactant deficiency
What are the risk factors for developing TTN?
elective C/S; male sex; macrosomia; excessive maternal sedation; prolonged labour; birth asphyxia; fluid overload to mother; maternal asthma; delayed clamping of umbilical cord; breech; polycythaemia; diabetes; prematurity; maternal substance abuse; LBW
What is tachypnoea defined as in infants?
> 60 breaths/min
What is the differential diagnosis of TTN?
pneumonia/sepsis; heart disease; RDS; cerebral hyperventialtion; metabolic disorders; polycythaemia
What can cause cerebral hyperventilation?
meningitis or hypoxis-ischeamic insult (CNS lesion cause over stimulation of th resp centre)
What metabolic disorders can cause tachypneoa?
hypothermia; hyperthermia; hypoglycaemia
Why may materal dibaetes cause polycythaemia?
poor control during pregnnacy leads to chornic fetal hypoxia which may result in increased neonatal erythroepoeisis
What are the risk factors for developing polycythaemia?
high altitude; delayed cord clamping; high-risk delivery; enhanced fetal erythropoeisis- fetal hypoxia–placental inusfficiency and endocrine disorders; genetic trisomies
What can cause placental insufficiency?
materanl hypertensive disease; abruptio placentae; postmatiruty; cyanotic congenital heart disease; IUGR; maternal smoking
Why do endocrine disorders cause fetal hypoxia and increased erythropoiesis?
increased metabolism–increased oxygen consumption
Which endocrine disorders are implicated in polycythaemia?
maternal diabetes; congential thyrotoxicosis; congenital adrenal hyperplasia; secondary hyperinsulinism
What are the perinatal RF for neonatal sepsis?
Group B strep colonisation; PROM (>18hours); signif GBS bacteuria; maternal temp >38 degrees during labour; chorioamnionitis; sustainined intraprtum fetal tachy; prior delivery of infant with GBS disease
What investigations should be doen for neonatal sepsis?
blood cultures; LP; urine culture; BM; FBC; CRP
What are the most common causes of neonatal sepsis?
GBS; e.coli; s. aureus; enterococcus; staph. epi; klebsiella
What is the treatment for new delivered baby with sepsis?
benzylpenicillin and gent
What is given to babies with central catheters for sepsis in the NICU?
vanc and fluclox
