PCEA for labor analgesia based on VAS scores: a prospective randomized controlled trial

Objective To determine whether cervical dilatation during placement of epidural catheter for labor analgesia affects cesarean section rates or duration of labors. A prospective randomized controlled trial was conducted to investigate the efficacy of PCEA for labor analgesia based on VAS scores.Methods One hundred and seventy-six ASA 1～2 parturients were randomly assigned to PCEA group (n=84) and control group (n=92) when their VAS pain scores were ≥4 cm. In PCEA group, the parturients received bupivacaine 0.1% with fentanyl 2 mag/ml. The PCEA setting was 8 ml for loading dose; 4 ml/h for background dose; 4 ml for PCA-demand dose; 15 min lockout interval and maximum dose per hour was 20 ml. In the control group, parturients received continuous midwife care.Results The duration of first labour, third labour and activity duration were similar in either group with cervical dilatation 4 cm (n=43) or ≥4 cm (n=133) when epidural labor analgesia started. The duration of second labour was similar in both groups when cervical dilatation was less than 4 cm (P0.05), but when the cervical dilatation was more than or equal to 4 cm during beginning of PCEA, the duration of second labour was longer in the PCEA group compared with that of the control group (98.1±15.8 vs 69.3±17.9, P0.01). There was no significant difference in the cesarean section rates based on cervical dilatation 4 cm or ≥4 cm when epidural labor analgesia started (P05), but the overall cesarean section rates was significantly higher when cervical dilatation was 4 cm as compared with ≥4 cm during starting of PCEA (P0.01).Conclusion It is reasonable to start PCEA labor analgesia according to VAS scores, neither prolonged labor duration nor increased caesarean section rates are found even if the cervical dilatation is less than 4 cm when epidural labor analgesia starts.