Persistent Pulmonary Hypertension (PPHN)

Presentation

• Cyanosis disproportionate to degree of respiratory distress
• Pre-ductal vs post-ductal SpO2 saturation gradient > 5%
• Prominent apical impulse or tricuspid regurgitation murmur
• Labile oxygenation

Initial Workup

• Pre and post-ductal pulse oximetry
• Arterial blood gases
• Chest X-ray to assess underlying parenchymal lung disease
• Echocardiogram (essential to rule out structural congenital heart disease)

Diagnostic Criteria

• Echocardiographic evidence of right-to-left or bidirectional shunting
• Elevated pulmonary artery pressure estimates (TR jet velocity)
• Structurally normal heart (excluding PFO/PDA)

Extended Pharmacology & Critical Care

• Alprostadil (PGE1) continuous infusion: Start at 0.05 to 0.1 mcg/kg/min; monitor strictly for apnea, hyperthermia, and extreme vasodilation.
• Milrinone loading dose 50 mcg/kg over 15 mins (only if stable blood pressure), followed by 0.33 to 0.75 mcg/kg/min infusion.
• Strict I&O monitoring; maintain urine output > 1-2 mL/kg/hr using indwelling catheter if necessary.
• Maintain hematocrit > 35-40% via PRBC administration to optimize oxygen delivery in cyanotic lesions.
• Nursing: Q1 hour blood pressure monitoring (arterial line preferred), monitor for feeding intolerance indicating gut hypoperfusion.

Standardized Discharge & Follow-Up Criteria

• Adequate weight gain explicitly > 15-30g/day over a continuous 3-5 day period.
• Maintenance of temperature in an open crib with standard clothing for 48 hours.
• Successful completion of the 90-120 minute Infant Car Seat Challenge.
• Caregiver successfully completed CPR training, rooming-in, and independent medication administration.
• Referrals placed for High-Risk Infant Follow-Up Clinic, Early Intervention (PT/OT), and appropriate sub-specialists.

Diagnostic & Management Algorithm

• PPHN Targeted Reversal: [START] Severe Hypoxemia + Echo R->L shunt -> [ACTION] Optimize lung recruitment / reverse acidosis -> [PHARMACOLOGY] Inhaled Nitric Oxide (iNO) 20ppm -> [EVALUATE] Oxygenation index (OI) > 40? -> [YES] ECMO

References

1. Nair J, Lakshminrusimha S. Update on PPHN: Mechanisms and treatment. Semin Perinatol.
2. Konduri GG. New approaches for persistent pulmonary hypertension of newborn. Clin Perinatol.