A randomized controlled trial of the efficacy of transcutaneous electrical nerve stimulation (TENS) versus lidocaine in the relief of episiotomy pain.

The aim was to compare the efficacy of transcutaneous electrical nerve stimulation (TENS) and local infiltration of 2% lidocaine in the relief of episiotomy pain measured using a pain visual analog scale (VAS). A randomized, double blind, controlled clinical trial was conducted from January 1 to May 15, 1998, in the Labor-Delivery Complex of Chong Hua Hospital, Cebu City. Skin electrodes were attached to two acupoints. "Shenmen" on the wrist and "hegu" on the hand are acupoints for general pain relief and relaxation. These acupoints were stimulated using a nerve stimulator. Stimulation was started during advance labor and discontinued right after episiorrhaphy. VAS scores were taken during certain periods and compared with VAS scores for those using the conventional method of 2% lidocaine infiltration into the episiotomy site. There were 68 patients who met the inclusion criteria. 38 in the TENS group and 30 in the Control group. The patients profile of the two groups did not differ significantly in terms of age, age of gestation, parity, and length of episiotomy. Among those with VAS score of 5 (bearable), 37% was failed TENS, requiring rescue anesthesia. The proportion of patients with pain during episiotomy and 12 hours after episiorrhaphy showed no significant difference between the two groups. But during episiorrhaphy and 1 hour after episiorrhaphy, the TENS group was superior to the lidocaine group, with p-values of 0.05 (0.0392 and 0.0063, respectively) based on the Mann Whitney U-Test. Ambulation time was shorter in the TENS group. Episiotomy tenderness was nil in the TENS group. There was no swelling and edema in the perineum of patients in the TENS. The need for oral analgesics was likewise much lower in the TENS group. TENS as a form of anesthesia-analgesia cannot totally alleviate episiotomy pain as measured by VAS scoring system, with 37% as failed TENS. The study showed there was a difference only in pain relief during repair, and 1 hour after repair. With TENS being superior to lidocaine, ambulation time was shorter and episiotomy tenderness was nil in the TENS group. Likewise, lesser number of patients requested for oral analgesics in the TENS group.