Neonatal and Newborn Flashcards
What % of infants are visibly jaundiced during the first week of life?
50%
What is the most common mechanism of neonatal jaundice?
Physiological - slow conjugation of bilirubin
What are the ‘golden rules’ of physiological jaundice? (4)
- Jaundice is not apparent in first 24 hours of life
- The infant remains well
- The serum bilirubin does not reach treatment level
- The jaundice has faded by 14 days
If jaundice is apparent within the first 24 hours of life, what is it strongly suggestive of?
Either excessive haemolysis or sepsis, it is never physiological
What is kernicterus?
Unconjugated bilirubin (never conjugated) can enter the brain and cause neuronal damage.
What can increase the risk of developing kernicterus? (4)
- High serum bilirubin
- Pre-term birth
- Acidosis
- Hypoxia
What is the first-line treatment if serum bilirubin is high?
Phototherapy treatment - light of a wavelength that converts unconjugated bilirubin to non-toxic isomers allows bilirubin excretion without conjugation
What are the haemolytic causes of neonatal jaundice, often presenting within 24 hours of birth?
- ABO incompatibility
- Rhesus or other isoimmunization
- Red cell defects (e.g. G6PD deficiency)
What is hypoxic ischaemic encephalopathy?
It is a form of brain damage caused by a lack of oxygen to the brain.
What are the causes of hypoxic ischaemic encephalopathy (HIE)? (5)
- Reduced umbilical blood flow e.g. cord prolapse
- Reduced placental gas exchange e.g. placental abruption
- Reduced maternal placental perfusion
- Maternal hypoxia from whatever cause
- Inadequate postnatal cardiopulmonary circulation
What grading system is used to determine the severity of HIE?
Sarnat grade - mild, moderate or severe
How can HIE present? (9 features to assess)
Many different clinical features and depends on the severity, but the following are signs to assess:
- Level of consciousness
- Muscle tone
- Posture
- Tendon reflexes
- Suck
- Moro
- Autonomic dysfunction
- Heart rate
- Seizures
How is HIE managed?
- Resuscitate at birth; insert IV +/- arterial line
- Assess history and examine for features of dysmorphism and birth trauma e.g. fractures
- Exclude other causes of encephalopathy e.g. meningitis, metabolic disturbances, maternal drugs, CNS malformation
- Monitor and maintain homeostasis
- Cranial USS
- Mild fluid resuscitation
What are the disabilities likely caused by HIE/what is the prognosis? (6)
- Spastic quadriplegia
- Cerebral palsy
- Severely reduced IQ
- Cortical blindness
- Hearing loss
- Epilepsy
What % of babies born <32 weeks have a cerebral haemorrhage and ischaemia?
10-15%
Where is the origin of most cerebral haemorrhages in newborns, and where does the bleeding extend to?
The vascular germinal matrix (subependymal), with bleeding extending into the lateral ventricles
What are the causes of cerebral haemorrhage in newborns? (5)
- Severe RDS
- Pneumothorax
- Hypotension
- Hypoxia
- Fluctuations in pCO2
(anything that rapidly alters the cerebral blood flow)
When do most cerebral haemorrhages occur in newborns?
Within 72 hours of birth
How do cerebral haemorrhages in newborns present? (5)
50% are asymptomatic, larger bleeds:
- Systemic collapse
- Bulging fontanelle
- Neurological dysfunction e.g. seizures or abnormal movements
- Anaemia
- Jaundice
How is a suspected cerebral haemorrhage investigated?
Cranial USS
How can a cerebral haemorrhage in newborn be prevented? (5)
- Antenatal steroids
- Maintenance of BP, blood gases, coagulation
- Gentle handling
- Ventilation and suction
- Postnatal surfactant
What is the most common neonatal surgical emergency?
Necrotising enterocolitis (NEC)
What is NEC?
It is a condition characterised by a triad of abdominal distension, GI bleeding and pneumatosis intestinalis (air in bowel wall on abdominal X-ray)
What causes NEC?
Impaired blood flow through the bowel (intestinal ischaemia), which predisposes the mucosa to invasion by enteric organisms
How do babies present with NEC, and when is the most common time after birth? (7)
- Apnoea
- Temperature instability
- Bradycardia
- Lethargy
- Abdominal distension
- Bloody diarrhoea
- Emesis
- most common time is in the second week after birth
In what % of cases of NEC does bowel perforation occur?
20%
What are the predisposing features to developing NEC? (6)
- Prematurity
- IUGR
- Hypoxia
- Polycythaemia
- Exchange transfusion
- Rapid increase in milk feeding
In addition to perforation of the bowel, what are the other complications if NEC is missed early on? (5)
- Shock
- DIC; multiorgan failure
- Oedema
- Pneumatosis intestinalis (‘soap bubble’ or ‘halo’ signs)
- Signs of intestinal perforation
What is the prophylactic management of NEC?
Antenatal corticosteroids and breast milk feeds, if baby is high risk then antibiotics
What are the investigations that can be performed in suspected NEC?
- FBC, U&Es, creatinine, coagulation screen, albumin, blood culture
- Blood gas
- AXR
- Stool culture
What is the management of confirmed/suspected NEC? (5)
- Stop milk feeds for 7-10 days
- Insert NG tube
- IV antibiotics for 7-10 days
- Systemic support
- Surgery if perforation, deterioration despite above steps taken, GI obstruction due to stricture formation
What is the % mortality of NEC?
22%