Smokers experience more pain and are more likely to suffer from severe pain following ambulatory surgery, according to a study presented here at the American Society of Anesthesiologists 2010 Annual Meeting.
Severe postoperative pain is a common problem that leads to low patient satisfaction and additional healthcare expenses. Previous research has suggested that smokers have more postoperative pain than nonsmokers. The researchers set out to confirm the relationship with a large well-powered prospective multicenter cohort study.
The team collected data from 2157 adults who underwent elective ambulatory surgery under general anesthesia. The procedures took place in 12 American hospitals, and the researchers collected pre-, intra-, and postoperative data. The study’s primary end point was severe acute postoperative pain (7 or greater on a verbal rating scale from 0 to 10), which could be reported any time after the cessation of anesthesia until 48 hours after hospital discharge.
The average age of the participants was 49.5 ± 15.4 years, 64.6% were female, and 15.2% were smokers. Average body mass index (BMI) was 28.3 ± 6.9 mg/kg2. Overall, 24.5% of patients reported severe postoperative pain while in the postanesthesia care unit (PACU), and 33.6% reported severe postoperative pain by 48 hours after hospital discharge. In the PACU, 22.0% of nonsmokers and 38.5% of smokers reported severe pain; by 48 hours postdischarge, the rate was 54.1% among smokers and 29.9% among nonsmokers.
To identify and quantify the impact of risk factors, the researchers used logistic regression analysis, with P < .05 as the significance level. In the PACU, smokers reported a higher average pain score (4.94; 95% confidence interval [CI], 4.59 - 5.28) than nonsmokers (3.74; 95% CI, 3.60 - 3.88; P < .001). A similar result was reported at 48 hour postdischarge (6.35; 95% CI, 6.02 - 6.68 for smokers and 4.60; 95% CI, 4.47 - 4.74 for nonsmokers). Current smoking status was an independent predictor (P = .001) of a heightened risk for severe postoperative pain in the PACU (odds ratio [OR], 1.74; 95% CI, 1.26 - 2.41) and at 48 hours postdischarge (OR, 2.25; 95% CI, 1.64 - 3.09; P > .001).
The researchers identified other independent predictors of severe postoperative pain in the PACU, including being younger than 40 years of age (OR, 1.53; 95% CI, 1.19 - 1.97), having a BMI above 30 mg/kg2 (OR, 1.36; 95% CI, 1.07 - 1.74), having a preoperative anticipation of postoperative pain of 4 or higher (OR, 1.45; 95% CI, 1.12 - 1.88), and undergoing surgery that takes longer than 1 hour (OR, 1.36; 95% CI, 1.05 - 1.76).
“It is critical for physicians to acknowledge smoking status during preoperative evaluation, particularly when strategizing about how to best apply prophylaxis and analgesic therapies for postoperative and posthospital-discharge pain management,” the researchers write in the abstract.
“We think if a patient is a smoker, [he or she] will have more pain after surgery, and that [can] develop into chronic pain. The surgeon may need to do extra things, like [implement a] regional block or give more pain medication,” Alparslan Turan, MD, associate professor of anesthesia at The Cleveland Clinic, in Ohio, who participated in the research, told Medscape Medical News.
“Clearly, not all patients are managed very well in terms of postoperative pain. We have some understanding of what [the contributing] factors are, but it’s incomplete,” Judy Kersten, MD, professor of anesthesiology at the Medical College of Wisconsin in Milwaukee, who attended the presentation, told Medscape Medical News. “The fact that someone might have a modifiable risk factor, in terms of approaching their postoperative pain, is very encouraging. This is something that could be addressed preoperatively in a visit with the anesthesiologist to institute some smoking cessation, not only for a long-term benefit, but for a short-term benefit in terms of pain control.”
The study did not receive commercial support. Dr. Turan and Dr. Kersten have disclosed no relevant financial relationships.
American Society of Anesthesiologists (ASA) 2010 Annual Meeting: Abstract 788. Presented October 18, 2010.