PPHN Epidemiology:

Selective Pulmonary Vasodilators:

• oxygen (during hypoxemia)
• hyperventilation to pH > 7.5 (may have detrimental CNS and pulmonary effects)
• Now - inhaled Nitric Oxide

Pressors:

• Dopamine primarily for increasing cardiac contractility and systemic blood pressure.
• Dobutamine combines inotrophic effects with peripheral vasodilation. May be especially useful in babies with LV dysfunction.

Vasodilators:

• Nitroprusside is a non-specific vasodilator (pulmonary and systemic). It is helpful in some newborns with PPNH. It also may serve as a NO donor in the lung.
• Tolazoline is a structural analog of histamine that was introduced as an effective pulmonary vasodilator in 1961. Selective pulmonary vasodilatory effects may be enhanced by infusing through SVC (or scalp vein), or by endotracheal administration. Its use for PPHN has been mostly abandoned due to problems with profound systemic vasodilation after an initial positive response.

ECMO:

• Better than conventional treatment alone (ref. Bartelett’s "play the winner" study)
• Following ECMO, survival 80%, major disability 27%, IQ average in those without major disability.

Magnesium sulfate:

• One uncontrolled trial for severe PPHN unresponsive to conventional treatment.
• Improved oxygenation by 1 hr
• 78% survival (7 of 9 patients)

Adenosine:

• Stimulates pulmonary endothelial receptors to release nitric oxide.
• Completely metabolized by vascular endothelium.
• 1 published trial; 18 pts with PPHN randomized to get adenosine (25-50 mcg/kg/min) or saline infusion; 4/9 improved with adenosine vs 0/9 with saline.

L-Argenine:

• Precursor for Nitric oxide formation
• Anecdotal use for PPHN shows improved oxygenation without systemic hypotension.

Prostaglandins: