The frequency of apneas in premature infants after inguinal hernia repair: do they need overnight monitoring in the intensive care unit?

BACKGROUND: Postoperative apneas are reported in up to 49% of premature infants undergoing anesthesia for inguinal hernia repair. Our current practice is to monitor all of these babies in the intensive care unit (ICU) overnight after surgery. In addition to the considerable expense to the health care system, these cases are cancelled if no ICU bed is available.
METHODS: A retrospective chart review of all premature infants undergoing inguinal hernia repairs over the past 5 years was undertaken. All postoperative apneas were identified. Potential risk factors were evaluated.
RESULTS: Five (4.7%) of 126 premature infants had apneas after inguinal hernia repair. All of these babies had a previous history of apneas. They also had lower weights both at birth (1.08 vs 1.73 kg) and at the time of surgery (3.37 vs 4.4 kg) as well as lower gestational ages (29 vs 32.3 weeks). They were much more likely to have a complicated past medical history. Markers for this included intraventricular hemorrhage, patent ductus arteriosus, bronchopulmonary dysplasia, and requirement for mechanical ventilation and supplemental oxygen after birth. The use of sevoflurane was the only anesthetic factor which had significance.
CONCLUSION: Postoperative apnea in premature infants after inguinal hernia repair using current anesthetic techniques is much less common than previously reported. Infants with prior history of apneas are at highest risk. Other risk factors appear to include gestational age, birth weight, weight at time of surgery, and a complicated neonatal course. Selective use of postoperative ICU monitoring for high-risk patients could result in significant resource and cost savings to the health care system.