Postoperative apnea after inguinal hernia repair in formerly premature infants: impacts of gestational age, postconceptional age and comorbidities

PURPOSE: It is common practice for premature infants undergoing elective inguinal hernia (IH) repair to be hospitalized for postoperative apnea monitoring. This study evaluated the risk of apnea after IH repair with regard to gestational age (GA) and postconceptional age (PCA) in formerly premature infants. METHODS: Formerly premature infants who had undergone elective IH repair between 01/2000 and 12/2012 were reviewed retrospectively in terms of GA, PCA, body weight, and comorbidities. All postoperative apneas were evaluated. RESULTS: A total of 428 formerly premature infant charts were reviewed. Eleven babies had postoperative apnea. Infants younger than 45 weeks PCA were found more prone to develop postoperative apnea after IH repair. In older infants (PCA between 46 and 60 weeks), comorbidities create predisposition to apnea postoperatively. These comorbidities are bronchopulmonary dysplasia, necrotizing enterocolitis and former apnea episodes. Anemia and lower birth weight are also risk factors. CONCLUSION: This study suggests that low GA and PCA, low birth weight, anemia, and complicated past medical history affect respiratory complication rates, particularly apnea in formerly premature infants undergoing elective IH repair. Severe apneas occurred earlier than mild ones. Overnight monitoring is mandatory in small infants with low GA and PCA. Otherwise healthy, older infants may be operated on outpatient basis.