Clinical diagnosis of pneumothorax is late: Use of trend data and decisionsupport might allow preclinical detection

Pneumothorax in the newborn has a significant mortality and morbidity. Earl y diagnosis would be likely to improve the outlook. Forty-two consecutive c ases of pneumothorax that developed after admission to a tertiary referral neonatal medical intensive care unit over 4 y from 1993 to 1996 were review ed. The time of onset of the pneumothorax was determined by retrospective e valuation of the computerized trend of transcutaneous carbon dioxide (tcpCO (2)) and oxygen tensions. The timing of the occurrence in the notes and x-r ays determined the time of clinical diagnosis noted at the time. The differ ence was the time the condition was undiagnosed. The overall mortality befo re discharge was 45% (19cases), four patients succumbing within 2 h. The me dian time (range) between onset of pneumothorax and clinical diagnosis was 127 min (45-660 min). most cases, the endotracheal tube was aspirated and t he transcutaneous blood gas sensor was repositioned, and in at least 40% of the cases, the baby was reintubated before the diagnosis was made. Referen ce centiles were constructed for level of tcpCO(2) and slope of the trended tcpCO(2) over various time intervals tin minutes) from 729 infants from 23 to 42 wk gestation who needed intensive care during the first 7 d of life from the same time period. The 5-min tcpCO(2) trend slopes were compared in index and matched control infants. The presence of five consecutive and ov erlapping 5-min slopes greater than the 90th centile showed good discrimina tion for a pneumothorax (area under the receiver operating characteristic c urve, 89%). We concluded that I) the clinical diagnosis of pneumothorax was late, occurring when infants decompensate; 2) trend monitoring of tcpCO(2) might allow the diagnosis to be made earlier if used properly; and 3) use of reference centiles of the trended slopes of tcpCO(2) might be used for a utomatic decision support in the future.