A Comparison of Tramadol and Pethidine Analgesia on the Duration of Labour

The ideal obstetric analgesia should provide good analgesic efficacy without reducing intensity of uterine contractions. The aim of this study was to compare the efficacy of pethidine and tramadol as labour analgesia on duration of labour.

A total of 170 multigravida women in active labour were randomly assigned to two equal groups. Then, 85 pregnant women received pethidine (50mg) and 85 pregnant women received tramadol (100mg) intramuscularly. Primary outcome measures were: the duration of labour, the analgesic efficacy, maternal side-effects, mode of delivery. The secondary outcomes were also assessed.

The duration of labour was shorter in tramadol group in stage one (64.7%) delivered between 120 +/- 30 minutes, while it was longer in pethidine group (67.1%) delivered between 180 +/- 30 minutes. In stage two, 44.7% of tramadol group delivered within 15 +/- 5 minutes while 51.8% in pethidine group delivered between 25 +/- 5 minutes. Visual analog score (VAS) for pain was used just before administration of drugs,1 hour and 3 hours after drug administration. The women in pethidine group had lower VAS pain score than those in tramadol group after 1 hour (4 vs 6; P =<0.001). There was a significantly higher incidence of vomiting and dizziness in pethidine group (29.4% vs 1.2%; P =<0.001).

Tramadol seems to result in a shorter duration of labour and lower incidence of maternal side effects. However, its analgesic efficacy was not as effective as pethidine.