Objective Positive airway pressure (PAWP) is considered an important risk factor in the development of a pneumothorax in very low birthweight (VLBW) infants. The aim of this study was to determine the differences in PAWP levels between infants who developed a pneumothorax compared with controls.
Methods From April 2004 to 2007 we identified 25 VLBW infants with pneumothorax. A chart review was performed on 23 infants in whom the onset occurred during the first 7 days of life and randomly paired and matched them with a control group for a similar birthweight, gestational age, and type of ventilatory support up to the day the pneumothorax occurred. The PAWP were averaged on a time-weighted basis every 6 h during the first 120 h of life and more frequently before the onset of pneumothorax.
Results Baseline characteristics were similar between the groups. The median age of onset was 14.5 h (range 1.25–273). There was a difference between the groups in the decline of PAWP during the first 14 h of life (p<0.0001) and overall by 120 h age (p = 0.0005). The mean PAWP at the time of occurrence and 6 h before the onset was higher than at 12 h before the onset. Incidences of adverse outcomes were similar between the groups.
Conclusion Pneumothoraces were associated with higher PAWP and there was a statistically significant difference in the PAWP decline between the groups over time. The PAWP trend was notably higher before pneumothorax onset.