Use of transcutaneous electrical nerve stimulation for postoperative pain.
ABSTRACT This study examined the effects of transcutaneous electrical nerve stimulation (TENS) on incisional pain caused by the procedure of cleaning and packing an abdominal surgical wound. Seventy-five subjects (mean age 56.9 years) were randomly assigned to one of three intervention groups: TENS, placebo-TENS, or no-treatment control. The appropriate experimental treatment was administered during the routine dressing change which took place two mornings after surgery. Using an 11-point, visual analogue pain scale, subjects described pain experienced during the dressing change. Subjects who received TENS reported a significantly lower level of pain after dressing change than did those subjects who received either placebo-TENS or no-treatment. Drug administration variables did not contribute significantly to level of reported pain.
Article: Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment.[show abstract] [hide abstract]
ABSTRACT: Placebo treatments have been reported to help patients with many diseases, but the quality of the evidence supporting this finding has not been rigorously evaluated. We conducted a systematic review of clinical trials in which patients were randomly assigned to either placebo or no treatment. A placebo could be pharmacologic (e.g., a tablet), physical (e.g., a manipulation), or psychological (e.g., a conversation). We identified 130 trials that met our inclusion criteria. After the exclusion of 16 trials without relevant data on outcomes, there were 32 with binary outcomes (involving 3795 patients, with a median of 51 patients per trial) and 82 with continuous outcomes (involving 4730 patients, with a median of 27 patients per trial). As compared with no treatment, placebo had no significant effect on binary outcomes (pooled relative risk of an unwanted outcome with placebo, 0.95; 95 percent confidence interval, 0.88 to 1.02), regardless of whether these outcomes were subjective or objective. For the trials with continuous outcomes, placebo had a beneficial effect (pooled standardized mean difference in the value for an unwanted outcome between the placebo and untreated groups, -0.28; 95 percent confidence interval, -0.38 to -0.19), but the effect decreased with increasing sample size, indicating a possible bias related to the effects of small trials. The pooled standardized mean difference was significant for the trials with subjective outcomes (-0.36; 95 percent confidence interval, -0.47 to -0.25) but not for those with objective outcomes. In 27 trials involving the treatment of pain, placebo had a beneficial effect (-0.27; 95 percent confidence interval, -0.40 to -0.15). This corresponded to a reduction in the intensity of pain of 6.5 mm on a 100-mm visual-analogue scale. We found little evidence in general that placebos had powerful clinical effects. Although placebos had no significant effects on objective or binary outcomes, they had possible small benefits in studies with continuous subjective outcomes and for the treatment of pain. Outside the setting of clinical trials, there is no justification for the use of placebos.New England Journal of Medicine 06/2001; 344(21):1594-602. · 53.30 Impact Factor