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.