Comparison of continuous and intermittent transcutaneous electrical nerve stimulation in postoperative pain management after coronary artery bypass grafting: a randomized, placebo-controlled prospective study.

OBJECTIVE

We compared the effectiveness of continuous transcutaneous electrical nerve stimulation (TENS) and intermittent TENS in the management of pain after coronary artery bypass grafting (CABG).

METHODS

We randomized 100 patients who had undergone median sternotomy for CABG into 4 groups with 25 patients each: (1) continuous TENS (CTENS) and pharmacologic analgesia, (2) intermittent TENS (ITENS) and pharmacologic analgesia, (3) placebo TENS (PTENS) and pharmacologic analgesia, and (4) pharmacologic analgesia alone (control). We studied these groups with regard to the relief of postoperative pain during the first 24 hours. For each patient we recorded the following: demographic characteristics; vital signs; intensity of pain with a visual analogue scale (VAS) before treatment (VAS(0)), at the 12th hour (VAS(12)), and at the 24th hour (VAS(24)); and analgesic intake.

RESULTS

The groups were comparable with respect to age, sex, and body mass index at baseline. Mean VAS scores decreased within each group; however, the mean VAS(12) and VAS(24) scores decreased significantly in the CTENS and ITENS groups, compared with PTENS and control groups (P < .05). We found no significant difference between the CTENS and ITENS groups with respect to decreasing VAS(12) and VAS(24) scores (P > .05). Narcotic intake was significantly less in the CTENS and ITENS groups than in the control and PTENS groups (P < .01). Furthermore, narcotic requirements were significantly lower in the CTENS group than in the ITENS group (P < .01).

CONCLUSIONS

CTENS and ITENS after median sternotomy for CABG decreased pain and reduced narcotic requirements more than in the PTENS and control treatments during first postoperative 24 hours. Neither CTENS nor ITENS is superior to the other in decreasing pain; however, CTENS leads to a greater reduction in the narcotic requirement than ITENS.