Lidocaine, Nicotine Patches Can Reduce Postoperative Pain

SAN FRANCISCO — Placing a nicotine patch behind a patient's ear before radical retropubic prostatectomy or placing lidocaine patches on each side of the surgical wound could reduce postoperative pain or narcotic use, results of two studies suggest.

The lidocaine patch significantly reduced pain after surgery, and the nicotine patch significantly reduced cumulative morphine consumption 24 hours after surgery, Dr. Ashraf S. Habib and associates reported in two separate poster presentations at the annual meeting of the American Society of Anesthesiologists (ASA).

Both prospective, randomized, double-blind, placebo-controlled studies of patients undergoing radical retropubic prostatectomy used standardized postoperative analgesia via patient-controlled morphine administration and six hourly 15-mg IV doses of ketorolac.

In what may be the first reported study of the treatment of acute postoperative pain with 5% lidocaine patches, surgeons placed a patch on either side of the wound at the end of surgery on 36 patients and a placebo patch on 34 patients. The two groups were similar in age, height, weight, ASA class, length of surgery, and amount of intraoperative opiates received.

Postoperative pain scores on coughing were significantly lower in the lidocaine group than in the placebo group in the postanesthesia care unit (PACU) and at 6, 12, and 24 hours post surgery, after investigators accounted for a significant effect of morphine. Pain scores at rest were significantly lower in the lidocaine group than in the placebo group up to 6 hours after surgery, and were not significantly different at 12 and 24 hours, said Dr. Habib, director of quality improvement at Duke University Medical Center, Durham, N.C.

There were no significant differences between groups in cumulative morphine consumption or in duration of stay in the PACU or in the hospital.

In the other study, a 7-mg nicotine patch was applied behind the ear of 44 patients 30–60 minutes before anesthesia induction, and a placebo patch behind the ear of 46 patients. By 24 hours after surgery, patients in the nicotine group had used a mean of 33 mg of morphine, significantly less than the mean 45 mg used by the placebo group, Dr. Habib said.

There were no significant differences between groups at any time points in pain scores on coughing or at rest, or in incidence of nausea and vomiting.

There were significant negative correlations between serum nicotine levels at 4 hours and cumulative morphine consumption at 24 hours, and between serum nicotine levels at 24 hours and morphine consumption at all time points (in the PACU and at 6, 12, and 24 hours after surgery).

Dr. Habib has no association with the companies that make the lidocaine or nicotine patches.

The nicotine group used 33 mg of morphine, significantly less than the 45 mg used by the placebo group. DR. HABIB