Cigarette smoking is bad, but is everything in cigarette smoke harmful? Specifically, what can be said about nicotine? Nicotine is an anti-inflammatory alkaloid. It can be protective against ulcerative colitis. It improves glucose homeostasis. Nicotine may also have therapeutic value for Parkinson’s disease management. In addition, it has antinociceptive effects. So, how does nicotine affect postoperative pain and PONV? Given the information we already know about nicotine’s positive properties, this is a logical next line of inquiry.
Drs. Basem M. Mishriky and Ashraf S. Habib, Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, searched the literature to find randomized controlled trials that examined the effect of nicotine on postoperative pain and/or PONV for patients undergoing general anesthesia. Their results are summarized in the manuscript “Nicotine for Postoperative Analgesia: A Systematic Review and Meta-Analysis,” which appears in the August 2014 issue of Anesthesia & Analgesia.
Nine studies that included 662 patients met their inclusion criteria. Nicotine was administered as a transdermal patch in six studies (5 mg/16 hours to 21 mg/24 hours administered before anesthesia induction) or as a nasal spray in three studies (3 mg at the end of surgery). The patients in the studies postoperatively received either patient-controlled analgesia with only morphine (three studies) or a combination of nonsteroidal anti-inflammatory drugs and opioids (six studies). One study had a much larger treatment effect of pain at rest at 24 hours. Given all of the studies, pain relief was no different between patients who received nicotine compared to control. Opioid sparing, however, was more consistent (about 5 mg morphine at 24 hours). In two studies, patients who received nicotine stayed longer in the PACU. Postoperative nausea and the need for rescue antiemetics, both during the first postoperative hour, were higher in patients who received nicotine. Nausea incidence was also higher at 24 hours with nicotine administration. Based on one study, insomnia at 24 hours was higher (27% vs 7%) for patients who received nicotine. Patient satisfaction was no different between patients who received nicotine and those who did not based on the results of two studies. Among only nonsmokers, opioid sparing was 6 mg morphine at 24 hours.
A study in this journal, “The antinociceptive response to nicotinic agonists in a mouse model of postoperative pain,” published in 2008, showed that in a mouse model, nicotine is antinociceptive. Like many animal studies, the effect is not always the same in humans. In this review, though opioid sparing was most prominent in nonsmokers, PONV limits nicotine’s usefulness. Whether use of a propofol infusion for anesthesia and otherwise aggressive treatment of PONV in combination with nicotine might maximize analgesia and limit PONV remains to be determined.