A comparison of tramadol and pethidine analgesia on the duration of labour: A randomised clinical trial.

Background: The ideal obstetric analgesia should provide analgesic efficacy without attenuation of uterine contractions. Aims: To compare the outcome of intramuscular administration of pethidine and tramadol in labour analgesia. Methods: One hundred and sixty full-term parturients were randomly assigned to two equal groups in active labour. Group P received 50 mg pethidine; and group T, 100 mg tramadol intramuscularly. Primary outcome measure was the duration of the labour. The analgesic efficacy, maternal side-effects, mode of delivery, maternal satisfaction and Apgar score as the secondary outcome were assessed. Results: The duration of labour was shorter in group T, for first stage (190 vs 140 min; P < 0.0001) and for second stage (33 vs 25 min; P = 0.001). There were no differences in Groups P and T with respect to median (7 vs 8) and maximum (7.5 vs 8) visual analog scores (VAS) for pain at 10 min and one hour after drug administration. Women in group P had lower VAS pain scores than those in group T in the second stage of labour (8 vs 9; P = 0/009). There was a significantly higher incidence of nausea and vomiting (35% vs 15%; P = 0.003) and drowsiness (80% vs 29%; P < 0.0001) in group P. Conclusion: Both 100 mg tramadol and 50 mg pethidine provide moderate analgesia in first stage of labour. Tramadol seems to cause a shorter duration of labour and lower incidence of maternal side-effects. However, its analgesic efficacy was not found to be as effective as pethidine, especially in the second stage of labour. [ABSTRACT FROM AUTHOR]