Contralateral pneumothoraces in the newborn: incidence and predisposing factors

A prospective study was performed to ascertain the incidence of, and risk factors for, the development of a contralateral pneumothorax in 32 neonates with respiratory distress, without evidence of pulmonary hypoplasia, who had an initial unilateral air leak requiring pleural drainage. The mean postnatal age of occurrence of the first pneumothorax was 31.04 hours (range 0.1 to 92 hours); a subsequent contralateral pneumothorax developed in 14 infants (44%) at a mean postnatal age of 61.5 hours (range 8 to 106 hours). Thirteen of the 14 infants with a subsequent contralateral pneumothorax had pulmonary interstitial emphysema visible on the chest radiograph taken immediately after drainage of the first pneumothorax, compared with eight of the 18 infants without a contralateral pneumothorax (P less than .005). Other factors significantly associated with a contralateral pneumothorax were alveolar-arterial oxygen gradient (P less than .01) and FiO2 (P less than .005), both measured one hour after the pneumothorax, and gestational age (P less than .05). Multivariate discriminant function analysis did not usefully add to the predictive power of pulmonary interstitial emphysema alone. Infants with pulmonary interstitial emphysema at the time of an initial unilateral pneumothorax are at significant risk for the development of a contralateral pneumothorax.