A Comparative Study of Transcutaneous Electrical Nerve Stimulation and Pethidine - Promethazine For Pain Relief in Active Phase of Labor

Several agents have been used for labor pain relief. Clinical trials have shown pethidine – promethazine combination as an effective mean. Transcutaneous electrical nerve stimulation (TENS) is a new method for pain relief which uses mild electrical stimulation for inhibition of pain signals in nerves. This method has been used successfully for chronic pains such as low back pain, rheumatic pains, acute surgical and traumatic pains. In this study we compared these two methods for reducing labor pain.The aim of this study was to compare the effectiveness of transcutaneous electrical nerve stimulation (TENS) and pethidine-promethazine in reducing labor pain in the active phase of labor.Patients and In this clinical trial study, 100 pregnant women admitted in Shaheed Akbarabadi hospital for labor were included in the study and alternatively were allocated into one of two the groups: TENS group (A) or combined pethidine (50mg, IM) and promethazine (25mg, IM) group (B). Pain intensity during maximum uterus contractions was evaluated with Visual Analogue Scale (VAS) in all of the cases. Four hours after delivery, pain relief and efficacy of the method was asked from the mothers. Demographic data were recorded in all cases. Data analysis was accomplished with SPSS V. 15 software. For statistical analysis t-test, regression and Chi2 were used. P value under 0.05 was assumed as significant. Mean pain intensity in 3-4cm dilatation in group A was 7.65±1.05 and in group B was 8.16±1.14 and difference was significant (P=0.003). Mean pain intensity in 6-7cm dilatation was 8.55±0.76 and 8.38±0.87, respectively which was not statistically significant (P>0.05). In full dilatation this measure was 8.73±0.84 and 8.54±0.69, respectively which was not statistically significant (P>0.05). Mean number of contractions in full dilatation in group A was significantly higher than group B (6.18±7.22 vs 3.87±66 P=0.02). Mean duration of labor in group A was 3.49±2.64 hrs and in group B was 3.31±1.5hrs which was not statistically significant (P>0.05). With respect to the results of this research and the previous studies, TENS is a side-effect free, cheap and suitable method for controlling labor pain and can be used solely and as adjuvant therapy for this purpose.