Hypotheses: Use of spinal anesthesia is safe and effective in an outpatient population of preterm infants undergoing inguinal hernia repair (IHR) and eliminates routine postoperative hospital admission for apnea monitoring.
Methods: From October 1982 through October 1997, all preterm (gestational age [GA], < or =37 weeks), high-risk (preterm infants whose postconceptual age at surgery [PCAS] is <60 weeks) infants undergoing IHR with spinal anesthesia were studied prospectively. No exclusions were made for preexisting conditions. Elective IHRs and incarcerated hernias were both considered. A postoperative apnea rate was calculated and compared with published postoperative apnea rates in preterm infants after receiving general anesthesia.
Results: For 269 IHRs performed, 262 spinal anesthetic placements (97.3%) were successful in 259 infants; 246 placements were achieved on the first attempt and 16 on the second. The mean GA was 32 weeks (GA range, 24-37 weeks); mean PCAS, 43.7 weeks (PCAS range, 33.4-59.3 weeks); and mean birth weight, 1688 g (weight range, 540-3950 g). Two hundred six patients (78.6 %) did not require supplemental anesthesia; 56 (21.4%) did: 34 received intravenous anesthesia; 6, general; 12, local; and 4, other regional. One hundred fifty-three infants had a history of apnea. Thirteen episodes of apnea were noted in 13 infants (4.9%) following the 262 procedures; all 13 were inpatients undergoing concomitant therapy for apnea (mean GA, 28 weeks; PCAS, 42.9 weeks). Four of these infants received supplemental anesthesia. This apnea rate is significantly lower than the published rate (10%-30%) (P = .01). One hundred three infants underwent IHR on an outpatient basis, 39 of whom had a history of apnea. None of these developed apnea postoperatively. The mean birth weight of this group was 2091 g (weight range, 710-3693 g); mean GA, 33 weeks (GA range, 25-37 weeks); and mean PCAS, 44.3 weeks (PCAS range, 35.4-59.2 weeks). All 103 patients were discharged home the day of surgery. Average time from room entry to incision was 26.3 minutes, which is similar to anesthesia induction time for patients receiving general anesthesia. Average time from bandaging to leaving room was 1 minute, less than usual time for patients receiving general anesthesia.
Conclusions: Spinal anesthesia is safe, effective, and eliminates the need for postoperative hospital admission in an outpatient population of preterm infants undergoing IHR. This results in considerable cost savings without compromising quality of care.