Persistent fetal circulation represents a failure to make the transition from the fetal condition of pulmonary artery hypertension to the adult condition of subsystemic pulmonary artery pressure. Blood is shunted through the foramen ovale and ductus arteriosus, causing profound hypoxemia. The syndrome has carried a high neonatal mortality, because the hypoxemia is not relieved by 100% oxygen or positive end-expiratory pressure. Two cases are described in which the "shunt test" was applied, first at a baseline PaCO2, then at reduced carbon dioxide tension. A decrease in alveolar-arterial oxygen pressure gradient implied to us that pulmonary artery pressure was reduced by hyperventilation. Continued oxygenation was successfully maintained by hyperventilation therapy at high respiratory rates.
Get full access to this article
View all access options for this article.
References
1.
LevinDL, HeymannMA, KittermanJA, GregoryGA, PhibbsRH, RudolphAM. Persistent pulmonary hypertension of the newborn infant. J Pediatr1976;89:626–30.
2.
RudolphAM, YuanS.Response of the pulmonary vasculature to hypoxia and H+ ion concentration changes. J Clin Invest1966;45:399–411.
3.
GersonyWM, MorishimaHO, DanielSS, et al. The hemodynamic effects of intrauterine hypoxia: An experimental model in newborn lambs. J Pediatr1976;89:631–35.
4.
FoxWW, GewitzMH, DinwiddieR, DrummondWH, PeckhamGJ. Pulmonary hypertension in the perinatal aspiration syndromes. Pediatrics1977;59:205–11.
5.
DrummondWH, PeckhamGJ, FoxWW. The clinical profile of the newborn with persistent pulmonary hypertension. Clin Pediatr1977;16:335–41.
6.
NelsonRM, EganEA, EitzmanDV. Increased hypoxemia in neonates secondary to the use of continuous positive airway pressure. J Pediatr1977;91:87–91.
7.
GoetzmanBW, SunshineP, JohnsonJD, et al. Neonatal hypoxia and pulmonary vasospasm: Response to tolazoline. J Pediatr1976;89:617–21.
8.
BehrmanRE. Persistence of the fetal circulation. J Pediatr1976;89:636–37.
9.
RoweRD. Abnormal pulmonary vasoconstriction in the newborn. Pediatrics1977;59:318–21.
10.
BostonRW, GellerF, SmithCA. Arterial blood gas tensions and acid-base balance in the management of the respiratory distress syndrome. J Pediatr1966;68:74–89.
11.
PeckhamGJ, FoxWW. Physiologic factors affecting pulmonary artery pressure in infants with persistent pulmonary hypertension. J Pediatr1978;93:1005–10.
