Ozsaker E et al, 2014: The effect of transcutaneous electrical nerve stimulation for pain relief during extracorporeal shock-wave lithotripsy procedure.
Ozsaker E, Diramali A
Department of Surgical Nursing, Nursing Faculties, Ege University, Izmir, Turkey.
The purpose of this study was to investigate the effect of transcutaneous electrical nerve stimulation (TENS) for pain relief during extracorporeal shock-wave lithotripsy (ESWL) procedure. An experimental study with repeated measures design was used in this study. Fifty patients aged 20-65 years receiving ESWL treatment were used for this convenience sample. Two applications were used for each patient: one involving administration of TENS instrument for ESWL treatment and the other without TENS. For effective stimulation, 2 stimulator electrodes were placed paravertebrally at L1 and 2 near the lithotripter shock tube before ESWL. Blood pressure, heart rate, pain intensity, analgesic use, and side effects were measured every 10 minutes during the procedure and after the end of ESWL. Results showed that TENS application decreased patients' intensity of pain and amount of analgesic requests and, related to that, decreased the incidence of side effects and increased patients' satisfaction during ESWL. TENS application is recommended as a pain-relieving technique during ESWL.
Pain Manag Nurs. 2014 Mar;15(1):59-68. doi: 10.1016/j.pmn.2012.06.003. Epub 2012 Aug 18.
This is a nice study with clear cut results. Although I have some doubts concerning the design of the study: Patients were informed about the planned treatment in two sessions and gave consent to the first without TENS and the second with TENS. With all what we know about placebo and nocebo effects it is difficult to imagine that the patients did not expect and actually feel more pain without TENS.