Neonatal illness and infections Flashcards
Legally ‘viable’ neonate
From 24 weeks
Neonatal period
1-28 days after birth
Perinatal period
24 weeks gestation to 7 days post birth
Classification of babies
Preterm - <37 weeks (6-8% of babies)
Term 37 -42 weeks
Post dates Over 42 weeks
Classification of baby weight
Low birth weight is <10 centile
Infant mortality
Stillbirth is intrauterine death after 24 weeks
Abortion is fetal loss before 24 weeks
Infant mortality is 7/1000, neonatal mortality is 5/1000 and perinatal mortality is 8/1000
Intra-uterine infections
Rubella - vaccinate before conception. Toxoplasmosis/syphilis/listeria - treat both in- and ex-utero. Hep B - vaccinate at birth. CMV/Herpes - treat after birth. HIV - treat mother before birth, C/S, treat baby after birth and avoid breast feeding
Neonatal diabetes
Congenital abnormalities are increased
Increased birth weight w/ organomegaly and polycthaemia
Hypoglycaemia after birth
Respiratory distress syndrome (RDS)
Transition from Intra-uterine to extra-uterine life
Cardiopulmonary switch - forming a double circulation and closing shunts (foramen ovale and DA). Establishment of enteral feeding with gut flora and Vit K (should be given a perinatal dose)
Temperature maintenance and infection prevention
Apgar score
2 1 0
Appearance pink blue white
Pulse >100 <100 none
Grimace cough Grimace none
Activity Normal Some None
Respiration strong weak none
Normal 7-10 Mildly depressed 4-6 Severely depressed 0-3
CNS disorders in the term neonate
Hypoxic ischaemic encephalopathy (HIE) Physical birth trauma Meningitis Fits/epilepsy Inherited Neuromuscular disorders
Hypoxic ischaemic encephalopathy - cause
Develops 2ary to perinatal fetal hypoxia due to placenta problems +- birth –> occurs in 6/1000 live births
Causes fetal distress –> decreased fetal movements, meconium staining, fetal acidosis leading to CNS depression +- permenant damage
Neurological injuries from Physical birth trauma
Facial nerve palsy - pressure from maternal pelvis or forceps
Erb’s (C5/6) or Klumpke’s (C8T1) brachial plexus palsies
Fractures of clavicle, femur or humerus
Caput, cephalhaematoma or subaponeurotic haemorrhage
Intracranial haemorrhage - subdural, subarachnoid or parenchymal
Fits/epilepsy in neonates
Subtle seizures can be common – hard to identify and poorly localized - grand mal –> treat with clonazepam if persistent
Any number of causes
Hypoxic ischaemic encephalopathy - severity
Mild - irritable for 1-2days but not further problems
Moderate - abnormalities last for days to wks with risk of fits and 1/4 chance of neurodevelopmental problems
Severe - unconscious, poor resp effort, severe fits – always have some long term deficits - can also have liver/renal failure, DIC, NEC and pulmonary HTN
Inherited neuromuscular disorders (MMMHI)
Myasthenia Myopathies Myotonic dystrophy Hypotonias IEM (inborn errors of metabolism)
Neonatal hypoglycaemia
BM lower than 2.6mmol/L – if severe, persistent and symptomatic it will lead to CNS damage
Symptoms: lethargy, poor feeding, jittery, fits and comas, bradycardia, hypotension
Causes of neonatal hypoglycaemia
Poor stores or increased demand - IUGR, postmature, sepsis, HIE, Polycythaemia, IEM
Hyperinsulinaemia - Diabetic mother, rare syndromes, abnormalities of insulin stimulation and release
Management of Neonatal diabetes
Glucose stick measurement – with lab to confirm
Early feeds – if glucose <2mmol/L give 10% glucose IV bolus
If persistent exclude rarer causes
Bilirubin metabolism
80% from Hb breakdown which is conjugated by the liver and secreted as bile – some of which is then reabsorbed
In blood 90% unconjugated bound to albumin & 10% conjugated
Why is bilirubin high in neonates?
High Hb (14-19g/dL) with a shorter RBC half life
reduced activity of glucuronyl transferase
Increased gut circulation with decreased motility (stasis)
Physiological neonatal jaudice
Occurs 1-2 days after birth and reaches the peak at 4-5days
Should always be <250umol/L and will resolve by 10days
visible in 60% of term babies
Dangers of neonatal jaudice
Unconjugated bilirubin crosses the BBB causing neuronal damage in the basal ganglia, 8th nerve and cortex
Toxic at 450-500umol/L if health or 350umol/L if sick
At lower levels changes are reversible (sleepiness) but higher levels lead to sensorineural deafness
V. high levels cause Kernicterus
Kernicterus
Bilirubin induced brain dysfunction
lethargy and poor feeding – hypertonicity and fits
50% will die and survivors develop choreoathetotic cerebral palsy, deafness and learning disabilities
Causes of Early neonatal jaudice
Early (48hrs) – as above + bacterial infections, polycythaemia, sequestered blood or IEM
Causes of prolonged (>2wks) neonatal jaudice (4,4)
Unconjugated –> haemolysis as with early, hypothyroidism, breast milk jaudice, or rare causes
Conjugated –> Hepatitis (infective or idiopathic) biliary atresia (intra- or extra- hepatic band, holedochal cyst or tumour), a1-antitripsin deficiency or CF
Treatment of extra-hepatic biliary atresia
operation – kasai portoenterostomy by 6 weeks to perserve function
Treatment of Neonatal jaundice
Good hydration and feeding - bilirubin monitoring
Phototherapy –> blue light isomerises bilirubin so it is excreted in urine
Otherwise can give exchange transfusions of 2 x 80ml x kg
Treatment of rhesus disease
Prevent development by giving mother anti-D in first pregnancy
If it has happened treat with intrauterine transfusions (cord or intraperitoneal)
Why are babies at risk of sepsis?
Low neutrophils and complement - only have maternal IgG
Symptoms of sepsis in neonates?
Lethargy, poor feeding and vomiting – may develop ileus and apnoea
Can become hypoglycaemic, neutrophilic or neutropenic, thrombocytopaenic or DIC
Sources of neonatal sepsis
Intrauterine or congential (present <48hrs) - group B strep is present in 15% of mothers,
E.coli or staph aureus, gonococcus, chlamydia, listeria, candida
If after 48hrs then likely acquired.
Treatment of neonatal sepsis
Always investigate to identify source and causative organism
For broad cover give penicillin and gentamicin - if organism known give specific abx
Signs of respiratory distress in neonates
Tachypnoea = RR>60, grunting, using the alae nasi, intercostal and subcostal recession, cyanosis
Check the O2 stat and PO2/PCO2
Causes of respiratory distress in neonates (8)
Transient tachypnoea of the newborn, RDS due to surfactant deficiency in preterm of IDM babies, Pneumothorax, meconium aspiration, pulmonary HTN, Heart failure, acidosis, congential abnormalities (diaphragmatic hernia)
Transient tachypnoea of the newborn
slow removal of lung liquid after a CS
Cardiac disease in neonates
structural problems will present as cyanosis or heart failure
May have arrhythmias
Murmurs in the neonatal period are common – PDA, VSD or functional (most common)
Gastrointestinal abnormalities in neonates
Obstructions - oesophageal or intestinal atresia, tracheo-oesophageal fistula,
Meconium ilieus or hernias, hirschspung’s disease, imperforate anus
Necrotising enterocolitis - preterm babies or those exposed to hypoxia
Exomphalos or gastroschisis
Symptoms of GI obstruction in neonates
High - early vomiting without abdominal distension. no bile if before ampulla of vater
Low - failure to pass meconium within 24hrs and abdominal distension precedes vomiting.
Genitourinary problems in neonates
Should pass urine by 24hrs –> if not screen for structural abnormalities
Vaginal bleeding/discharge is normal due to withdrawal of maternal hormones
Kidney and bladder problems in neonates
UTI in males should be investigated for congenital abnormalities
Renal pelvic dilation could be physiological but requires follow up
Posterior urethral valves and vesicoureteric reflux should be assessed and managed (operatively or conservatively)
Genital abnormalities in neonates
Hypospadias (misplaced urethral opening)
Ambiguous genitals should be assessed and action taken immediately
Undescended testes should be operated on before 1yr
Milia
pearls of keritin which appear on the skin, particularly on the face and may be itchy – they are almost entirely benign
They can occur in the mucosa (epstein’s pearls) or palate (bohn’s nodules). in the elderly they should be biopsied to exclude Favre-Racouchot syndrome
Miliaria
Sweat rash caused by dysfunction of sweat glands, more common in children - crystalline is most common, rubra is painful and profunda is most severe
Heel prick test
Taken on day five ideally - checks for PKU, congenital hypothyroidism, sickle cell, CF and MCAD deficiency
Breast milk jaundice
Late onset jaundice from the first to sixth weeks of life in a healthy breast fed baby – thought to be caused by hormone metabolites in the breast milk which block conjugation of bilirubin
Breastfeeding jaundice
Early onset jaudice in primigravid mothers where there is inadequate early hydration due to poor milk production leading to jaundice
Group B neonatal sepsis
Biggest cause of sepsis as 15% of mother carry and most babies are colonised but not infected – causes respiratory distress in first 24hrs
Can lead to multi-organ failure –> very sensitive to penicillin and should treat aggressively
Sudden infant death syndrome
Commonest cause of death of children in the first year of life (after this is accidents) Peaks at 3months of age. RFs: prematurity, smoking, phyerthermia, sleeping prone, male, multiple birth, bottle fed, Maternal drug use, winter, low social class
Management of meconium ilieus
Gastrograffin enema is both diagnostic and theraputic. surgical decompression can be used.
