Neonatology Flashcards
Suggest possible risk factors for a pre-term birth.
- previous preterm delivery
- multiple pregnancy
- smoking or elicit drug use during pregnancy
- maternal illness (e.g. DM, HTN, pre-eclampsia, chorioamnionitis) or under/overweight
- early pregnancy within 6 months of previous
- physical injury/trauma
Describe the antenatal management of a woman at risk of preterm delivery.
- Plan for delivery in appropriate centre, consider tocolysis to delay birth and allow transfer
- Give mother 2 doses IM dexamethasone (12-24 hrs apart) if <34 weeks gestation
- Give mother magnesium sulphate (neuroprotective)
Describe how you would stabilise a preterm baby after birth.
- warm up baby: place in food-grade plastic bag and under radiant heater
- respiratory support as required:
- CPAP or positive end-expiratory pressure (PEEP)
- consider elective intubation + ETT surfactant if <27/40
What is respiratory distress syndrome of the newborn? How would it present?
Surfactant deficiency (production starts about 35/40) resulting in increased surface tension, widespread alveolar collapse and inadequate oxygenation… hypoxia.
Presents at delivery or within 4 hrs of birth:
- tachypnoea (>60 bpm)
- increased WOB: recessions, nasal flaring
- expiratory grunting (try to create +ve airway pressure during expiration)
- cyanosis if severe
How would neonatal RDS appear on a CXR?
Bilateral ‘ground-glass’ appearance of lungs (general atelectasis) with low lung volumes (collapse)
How would you manage a premature neonate with RDS?
- surfactant therapy via catheter or ETT
- resp. support with: high-flow nasal cannulae, CPAP or intubation
- IV 10% glucose until stable (then NG tube feeds)
Name 2 complications of treatment for RDS.
- Bronchopulmonary dysplasia: high supplemental O2 conc. (free radical production) and pulmonary barotrauma from mechanical ventilation cause airway inflammation and smooth muscle hypertrophy… chronic lung disease with airway hyperresponsiveness
- Retinopathy of prematurity
What is retinopathy of prematurity?
- High O2 conc./hyperoxia (suppresses O2-regulated angiogenic growth factors) + loss of maternal-foetal interaction (maternally provided FAs) causes arrest of retinal vascularisation.
- Increased metabolic activity of poorly vascularised retina causes it to become hypoxic, promoting vasoproliferation. New vessels poorly perfuse retina and are leaky… fibrous scar formation… can cause retinal detachment in severe cases (although in most infants, ROP regresses spontaneously).
What is the pathophysiology of NEC? Name some risk factors.
Damage to intestinal mucosa… bacterial translocation to mucosal wall… bowel wall inflammation + oedema… ischaemia… bowel wall necrosis + perforation.
Risk factors: - prematurity esp. if on formula feeds - low birth weight and IUGR - Abx (co-amox) for >10 days in full term infants: congenital anomalies, perinatal asphyxia...
Describe the typical presentation of NEC.
Early features:
- abdo. distension + erythema
- altered stool pattern
- feeding difficulties
- bilious vomiting
Late features:
- bloody mucoid stool
- peritonism
- shock, DIC + multi-organ failure
what Ix would support the Dx of NEC?
Serial AXR which can show:
- bowel wall thickening/oedema
- persistent dilated bowel loops
- pneumatosis intestinalis (intramural gas)
- pneumoperitoneum (if perf.)
- Rigler’s sign (air both sides of bowel wall)
- football sign (air outlining falciform lig.)
How would you manage a neonate with NEC?
- NBM for bowel rest
- NG tube to decompress bowel
- IV fluids, TPN + IV Abx for 10-14 days
- systemic support e.g. intubation + ventilation, treat shock, DIC, etc.
If perforated/necrotic bowel is suspected:
- surgery: bowel resection +/- stoma formation
Name 2 CNS complications of prematurity.
- Intraventricular haemorrhage - Dx via cranial USS
2. Periventricular leucomalacia - ischaemia of periventricular white matter.
A 4 hr old baby presents in respiratory distress. What is your DDx?
- meconium aspiration syndrome
- congenital pneumonia
- persistent pulmonary HTN
- congenital diaphragmatic hernia
- congenital lung malformations
- HF secondary to CHD
- transient tachypnoea of the newborn
What is the pathophysiology of meconium aspiration syndrome?
Foetal hypoxia… meconium passage in utero (increased peristalsis and relaxation of anal sphincters) + reflex gasping… aspiration.
Causes:
- surfactant inhibition
- respiratory tract obstruction
- chemical pneumonitis
- predisposes to infection
