Pulmonary vascular air embolism in the newborn.

Unreported cases (SK Lee and AK Tanswell): case 1, boy of 25 weeks' gestation weighing 850 g; peak inspiratory/peak expiratory ventilator pressure (PIP/PEP) was 36/5 cm H20; he had pulmonary interstitial emphysema and arrhythmia. Case 2, girl of 27 weeks' gestation weighing 880 g; PIP/PEP was 34/4 cm H20; she had pulmonary interstitial emphysema, pneumothorax, and arrhythmia. Case 3, boy of 24 weeks' gestation weighing 640 g; PIP/PEP was 18/4 cm H20; he had pulmonary interstitial emphysema and arrhythmia. birth weight of 1328 g. The average postnatal age at onset was the third day of life. This, with a male:female ratio of 2-1 (33:16) in those cases where sex was documented, reflects the 91% incidence of the respiratory distress syndrome of the newborn in this population. The remaining 9% of cases were term infants with various diagnoses including meconium aspiration, viral pneumonia, amniotic fluid aspiration, and congenital alveolar dysplasia. As would be expected all infants had severe pulmonary insufficiency, as evidenced by average peak inspiratory/expiratory ventilator pressures (PIP/PEP) of 41/7 cm H20 with a peak fractional inspiratory oxygen of 0-9. Among all the cases reported there is no correlation between PIP/PEP and gestational age, or with time of occurrence. The time of occurrence of pulmonary vascular air embolism does, however, correlate with gestational age (n=41; linear regression equation: y=9-6x-228*98; r=0-464; p<001) for the total populations in which this was reported. The most significant correlations were observed when only data for premature infants of <37 weeks' gestation (n=37; r=0-593; p<0001), or <2500 g birth weight (n=45; r=0-552; p<0-001) were included in the regression analyses. The four reported infants with birth weights of >2449 g had a mean (SD) time of occurrence of 113 (92) hours, while the four reported infants with a gestational age of >36 weeks' gestation had a mean time of occurrence of 69 (38) hours.