Pulmonary dysfunction after primary closure of an abdominal wall defect and its improvement with bronchodilators.

To determine the extent of pulmonary dysfunction following primary closure of an abdominal wall defect, we obtained pulmonary function tests (PFT) in 11 newborn infants with gastroschisis and 6 with large omphaloceles admitted to a newborn ICU in a children's hospital. Patients were 1 to 30 days of age at the time of the PFT; all required endotracheal intubation and mechanical ventilation for operative procedures or for postoperative ventilatory support. Full-term infants (n = 21) undergoing minor surgical procedures provided comparative measurements. Flow-volume curves were obtained with manual inflation of the lungs followed by forced deflation using negative pressure, or by passive expiration, under sedation and pharmacologic paralysis. Deflation flow-volume curves gave measurements of forced vital capacity (FVC) and maximal expiratory flow at 25% of vital capacity from residual volume (MEF25). Modified passive mechanics technique gave passive expiratory curves that provided measurements of respiratory system compliance (Crs) and resistance (Rrs). Tests were done: within 48 h (period A), 3-7 days (period B), and 8-30 days after surgical repair (period C). Pulmonary function testing after nebulized 0.1% isoetharine (a bronchodilator), to test for bronchial reactivity, began midway during the study period in 15 patients. Preoperative and postoperative tests were obtained in 5 patients. Closure of an abdominal wall defect decreased FVC, Crs, and MEF25 by up to 50% of normal, reference values after surgery (P less than 0.05). FVC and MEF25 approached values of normal infants by 4 weeks, whereas Crs remained 50% lower.(ABSTRACT TRUNCATED AT 250 WORDS)