Effects of biological rhythm on labor pain, epidural analgesia and delivery mode in parturients / 中华围产医学杂志

ABSTRACT

Objective To investigate the influence of biological rhythm on labor pain,epidural analgesia and delivery mode in parturients.Methods In this retrospective cohort study,3 571 Chinese nulliparas with term singleton cephalic pregnancy who were preparing to deliver vaginally and receive epidural analgesia,were included.Parturients were divided into four groups according to the beginning time of analgesia,i.e.,morning group (701 to 1300,n=955),afternoon group (1301 to 1900,n=1 159),evening group (1901 to 100,n=763),and night group (100 to 700,n=694).Pain scores were assessed using a numeric rating scale (NRS) before and after epidural analgesia.Delivery mode,incidence of adverse events and neonatal outcomes were also compared among the four groups with monovariance analysis,LSD,Chi-square test or Fisher's exact test,Bonferroni,General Linear Model (GLM) and Logistic regression analysis.Results (1) The NRS pain scores of morning,afternoon,evening and night groups before analgesia were 8.6± 1.0,8.8± 1.0,8.9± 1.0 and 8.7± 1.0,respectively.After adjusted by GLM,the NRS pain scores of the four groups were 8.6±0.0,8.8 ± 0.0,8.9±0.0 and 8.7±0.0,respectively.Univariate and multivariable analyses showed that pain scores before analgesia were higher in afternoon group than in morning group (P＜0.01),and they were significantly higher in evening group than in morning and night groups (all P＜0.05).(2) At 10 and 30 minutes after epidural analgesia,the NRS pain scores of the four groups were 4.3± 1.0 and 1.8±0.9,4.8± 1.0 and 2.1 ±0.9,4.9± 1.1 and 2.2± 1.0,and 4.4± l.l and 1.8± 1.0,respectively,which were also significantly higher in afternoon and evening groups than in morning and night groups (all P ＜ 0.01 or 0.05) ; and the proportions of analgesia satisfaction (NRS pain score ≤ 3) were 19.7％ (188/955) vs 97.4％ (930/955),11.6％ (134/1 159) vs96.0％ (1 113/1 159),11.3％ (84/743) vs95.2％ (707/743),18.7％ (130/694) vs 95.6％ (670/694),respectively,which were significantly lower in afternoon and evening groups than in morning and night groups (all P＜0.01 or 0.05).(3) Delivery mode,incidence of adverse events and neonatal outcomes were similar among the four groups.Conclusions More severe labor pain before analgesia occur in parturients who receive epidural analgesia in the afternoon and at night,and less efficient analgesia and a lower rate of satisfaction are observed at 10 and 30 minutes after analgesia.However,delivery mode,neonatal outcomes and incidence of adverse events are not influenced by biological rhythm.