Persistent Pulmonary Hypertension in the Newborn
24/12/10
CK Notes
CAUSES
- persistent foetal circulation (PFC): failure of conversion, non-closure of ductus arteriosis or
foramen ovale
- respiratory event + hypoxia: meconium aspiration, pneumonia, congenital lung hypoplasia,
diaphragmatic hernia
- sepsis -> acidosis -> prevents closure of the ductus arteriosus: group B Strep, endotoxin
- haematological: hypervisocity syndrome
DIAGNOSIS
- shock
- septic screen
- CXR: often normal
- ECHO: no LV or congenital lesion, RV or RA dilation, TR, shunt from PDA or PFO
- hyperoxia test: sampling of right radial artery and umbilical artery catheter in high O2
(cardiac lesion = no differential between samples, PPHN = > 20% difference in SaO2, right
radial > UAC from right to left shunt)
MANAGEMENT
- transfer to PICU
- airway control – intubation is mandatory
- ventilation to normalise pCO2 and adequate oxygenation
- circulatory management: IVF boluses 10-20mL/kg up to 60mL/kg, achieve adequate cardiac
filling volumes and pressure, prostaglandin infusion until echocardiographic evidence of a
duct-independent lesion, dobutamine infusion for fluid-refractory shock
- normoglycaemia
- remove treat and control cause of sepsis: panculture, empiric antibiotic therapy
(ampicillin/gentamicin/acyclovir)
- correct acidosis
- if evidence of fluid and vasopressor refractory shock with RV dysfunction and PPHN on echo
with ScvO2 <70% commence salvage therapy
SALVAGE THERAPY
- pulmonary vasodilation: iNO, inhaled or infused prostaglandin
- ECMO: refractory PPHN to iNO
Jeremy Fernando (2010)
PROGNOSIS
- recovers over 3-5 days
- normal tone and musculature of pulmonary artery occurs
- good long term cardiovascular and survival if isolated
Jeremy Fernando (2010)