Postoperative respiratory complications in ex-premature infants after inguinal herniorrhaphy

Abstract

Background/Purpose: The duration of postoperative cardiorespiratory monitoring of premature infants after inguinal herniorrhaphy is uncertain. Prolonged observation requiring hospital admission may be unnecessary and increases costs. Methods: This study was a retrospective review of 191 inguinal herniorrhaphies performed between 1993 and 1996 at the Hermann Children's Hospital. The authors reviewed their experience to identify factors associated with postoperative apnea and bradycardia and determine a safe period of observation. Results: Among 191 elective inguinal herniorrhaphies performed, 57 (29.8%) were in expremature infants (≤60 weeks postconception). Five (8.8%) infants either failed extubation or were unable to extubate (group 1). The average age for this group was 41.0 ± 1.2 weeks compared with 47.2 ± 1.0 ( P = .06) for those who were successfully extubated (group II). Preoperative apnea-bradycardia was found in four (80%) infants in group I compared with 32 (61.5%) in group II ( P = 0.67). All group I and 21 (40.4%, P = .09) group II infants with a history of preoperative apnea required intubation for an average of 24.4 ± 7.8 days and 8.2 ± 2.4 days, respectively ( P = .04). American Society of Anesthesia (ASA) scores were 2.6 ± 0.4 for group I compared with 1.8 ± 0.1 for group II ( P = .01). The use of both intraoperative narcotics (three [60%] in group I v six [12%] in group II, P = .01]) and vecuronium (four [80%] in group I v 16 [31%] in group II, P = .03) were significantly more common in group I infants. Operating room time was 46.4 ± 4.1 minutes for group I compared with 60.6 ± 3.9 minutes for group II ( P = .27). Postoperative apnea-bradycardia occurred in all five group I infants and two (3.8%, P = .001) group II infants. Group II infants were treated successfully with supplemental oxygen. Conclusions: All instances of postoperative apnea-bradycardia and laryngospasm occurred within 4 hours after operation without significant differences between groups. The risk of postoperative cardiorespiratory distress requiring reintubation in premature infants who undergo inguinal herniorrhaphy is not insignificant (8.8%). The judicious use of narcotics and vecuronium, and limiting patient selection to those with ASA score of less than 3 may lessen the need for reintubation. When present cardiorespiratory distress occurs early; therefore we recommend outpatient inguinal herniorrhaphy as a safe and cost-effective choice.