Incidence and risk factors of pneumothorax in premature low birth weight infants under mechanical ventilation

Objective: pulmonary air-leakage especially pneumothorax (ptx), is a severe complication in neonates. The aim of this study was to assess the predisposing factors and frequency of ptx among the low birth weight (LBW) premature infants, under mechanical ventilation. Methods: This cross sectional study was performed in 121 LBW intubated premature infants at neonatal intensive care unit of a children hospital in Rasht, Iran during 18 months. Birth weight, gestational age(GA), sex, mode of delivery, initial diagnosis, respirator settings, history of surfactant therapy or ptx, 5th minute apgar score were recorded in neonates with or without ptx. Univariate and multivariate regression analysis were done. Finding: A total of 42 (34.7%) of infants developed ptx. Mean GA of neonates with ptx (case group) was 30±2.42 W and in neonates without ptx (control group) was 30.17±2.95 W. Mean birth weight in case and control groups were 1330 ± 386gr and 1482 ± 507gr respectively. In case group 69% and in control group 50% were delivered by cesarean section. 54.8% of cases and 53.2% of control group were male. No mentioned items reached statistical significance. Respiratory distress syndrome was the most common lung pathology in both groups. The rate of ptx was higher in cases with low apgar score at 5th minute (P=0.006). Surfactant therapy decreased the incidence of ptx (P=0.023). After multivariate logistic regression analysis only low apgar score at 5th minute significantly increased the risk of ptx. Conclusion:  The incidence of ptx in this study was slightly higher than other reports and this may be due to assessment of only LBW premature intubated neonates. After multivariate logistic regression analysis only low apgar score at 5th minute increased the risk of ptx significantly.