Persistent Pulmonary Hypertension in the Newborn
CAUSES
- persistent foetal circulation (PFC): failure of conversion, non-closure of ductus arteriosus 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: hyperviscosity 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
PROGNOSIS
- recovers over 3-5 days
- normal tone and musculature of pulmonary artery occurs
- good long term cardiovascular and survival if isolated
Further reading
- Wiesbauer F. Hypertension. Medmastery
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC