In this recurring feature, Physical Medicine & Rehab Coding Alert provides you with summaries of a cross section of recent clinical studies. Here's what's new this month. HI TENS Vs. LI TENS Effect on Postpartum Pain "A comparison of high- versus low-intensity, highfrequency transcutaneous electric nerve stimulation for painful postpartum uterine contractions." Olsen MF, Elden H, Janson ED, Lilja H, Stener-Victorin E. Acta Obstet Gynecol Scand. 2007; 86(3):310-4. Researchers noted that breast-feeding in the postpartum period can induce intense uterine contractions with pain in the lower abdomen. Thus, their primary aim in this study was to compare the effects of high- and low-intensity, high-frequency transcutaneous electric nerve stimulation (TENS) on pain and discomfort of postpartum uterine contractions. Their secondary aim was to evaluate discomfort patients experienced from the stimulation itself. Twenty-one newly delivered women participated in a single-blind trial: 12 women received high-intensity, high-frequency TENS (HI TENS), and nine women received low-intensity, high-frequency TENS (LI TENS). Researchers placed the electrodes abdominally on each side of the uterus and delivered one minute of stimulation. Researchers used a visual analogue scale and a verbal scale to evaluate the pain intensity. Findings: The median decrease in pain ratings before and after treatment was larger in the HI TENS group than in the LI TENS group. The reduction of pain was most pronounced in the HI TENS group. Further, the HI TENS group experienced significantly less discomfort of the uterine contractions after stimulation. On the other hand, subjects also experienced more discomfort of the stimulation than women in the LI TENS group.