Postanesthesia Apnea in Former Preterm Infants for Inguinal Herniorrhaphy: An Update of Risk Factors from an Individual Participant Data Meta-analysis

Postmenstrual age (PMA) is the major risk factor for postanesthesia apnea. The authors hypothesized that modern anesthesia may reduce the at-risk PMA cutoff threshold. The aim of this individual participant data meta-analysis was to identify the PMA above which postanesthesia apnea risk is less than 1%. Individual participant data from 12 prospective studies undergoing open inguinal herniorrhaphy were analyzed. A total of 132 of 751 (17.6%) former preterm infants experienced postanesthesia apnea. The data indicate that the PMA cutoff at which the risk of postanesthesia apnea was approximately 10%, approximately 5%, and less than 1% was 53 weeks, 57 weeks, and 65 weeks, respectively, after general anesthesia and approximately 38 weeks, 40 weeks, and 45 weeks, respectively, after neuraxial anesthesia. Anemia was a risk factor only for infants more than 48 weeks PMA. Postanesthesia apnea onset was earlier and odds for occurrence were higher for general anesthesia without (odds ratio, 6; P = 0.008) and with caudal block (odds ratio, 2.94; P = 0.012) compared to neuraxial anesthesia. Anesthetic technique has important implications; neuraxial anesthesia appears to reduce the at-risk PMA for postanesthesia apnea compared with general anesthesia.