Effect of transcutaneous electrical acupoint stimulation on postoperative analgesia after ureteroscopic lithotripsy: a randomized controlled trial

Transcutaneous electrical acupoint stimulation (TEAS) is an effective analgesic measure. We studied the analgesic effect of TEAS by applying it alone after ureteroscopic lithotripsy, rather than applying it as a supplementary analgesic measure. Participants (n=120) scheduled to undergo ureteroscopic holmium laser lithotripsy, were enrolled and randomly assigned into Group T (TEAS n=60) and Group C (Control, n=60). The participants in Group T were treated with TEAS for postoperative analgesia. TEAS were implemented on bilateral Shenyu (BL23) and Yinlingquan (SP9) at the time backward and the time at 4, 8, 12 h postoperatively. TEAS was re-implemented three times on the target acupoints for the next 2days. When TEAS failed to meet the analgesic effect, the participants were given tramadol hydrochloride tablets of 100 mg. Participants of Group C were given tramadol hydrochloride tablets for postoperative analgesia. The primary outcome of VAS scores at the time backward (T-0), 4 h (T-1), 12 h (T-2), 24 h (T-3), 48 h (T-4) postoperatively and the amount of remedy for analgesic consumption within 48 h postoperatively were compared. The secondary outcome of adverse reactions and plasma concentrations of serotonin (5-HT) and substance P (SP) at T-0, T-1, T-2, T-3, T-4 were detected, respectively. The VAS scores at T-1, T-2, T-3, T-4 postoperatively in two groups were lower than T-0. Compared to group C, the VAS scores at T-1 (3.68 +/- 0.68 vs. 4.79 +/- 0.82, P=0.01), T-2 (2.64 +/- 0.72 vs. 3.92 +/- 0.88, P=0.03), T-3 (2.21 +/- 0.88 vs. 3.38 +/- 0.74, P < 0.01) in Group T were lower, and total remedy of analgesic consumption was significantly lower (127.14 +/- 28.46 vs. 415.27 +/- 86.37, P < 0.01) within 48 h postoperatively. The plasma concentrations of 5-HT in Group T was lower than Group C at T-1 (348.54 +/- 138.49 vs. 418.69 +/- 124.68, P=0.03), T-2 (324.28 +/- 112.73 vs. 398.52 +/- 114.53, P < 0.01), T-4 (309.64 +/- 129.09 vs. 388.46 +/- 115.36, P=0.04) postoperatively and concentrations of SP at T-1 (59.38 +/- 24.68 vs. 78.93 +/- 26.32, P < 0.01), T-2 (49.36 +/- 25.55 vs. 66.49 +/- 23.57, P=0.02), T-3 (42.19 +/- 24.36 vs. 64.15 +/- 28.16, P=0.04), T-4 (39.26 +/- 19.88 vs. 54.64 +/- 20.62, P=0.02) postoperatively were also lower than Group C. Meanwhile, the occurrences of vertigo (6.7 vs. 18.3%, P < 0.01), nausea and vomiting (11.7 vs. 21.7%, P < 0.01), constipation (10.0 vs. 20.0%, P=0.03) in Group T were also lower. Application of TEAS alone was associated with effective alleviation of postoperative pain, reduction of postoperative analgesics consumption, decrease of plasma concentration of algogenic substance and the incidence of adverse reactions after ureteroscopic lithotripsy.