Decreased pain tolerance before surgery and increased postoperative narcotic requirements in abstinent tobacco smokers.

<bold>Introduction: </bold>The clinical influence of smoking cessation on pain tolerance before surgery and postoperative pain perception is not fully understood. This clinical study investigated the effect of smoking cessation on pain threshold during the perioperative period in patients undergoing hepatic resection.<bold>Methods: </bold>We enrolled 148 male patients (68 non-smokers and 80 abstinent smokers) who underwent hepatic resection and received postoperative patient-controlled intravenous analgesia. Patients were tested for preoperative pain thresholds in response to electrical stimuli. We recorded the cumulative amount of extra morphine equivalent required during the first 48h after surgery. Pain intensity was evaluated at 1h, 6h, 24h and 48h after surgery using the visual analogue scale (VAS). Additionally, button-pressing consumption was recorded by a patient-controlled analgesia (PCA) pump.<bold>Results: </bold>The groups did not differ with respect to baseline clinical characteristics. Compared with non-smokers, abstinent smokers exhibited lower pain thresholds before surgery and demanded a larger quantity of extra morphine equivalent during the first 48h after surgery. Abstinent smokers also exhibited more severe postoperative pain than non-smokers. Postoperative complications, such as nausea, vomiting, dizziness, sedation, and respiratory depression, did not significantly differ between the two groups.<bold>Conclusions: </bold>In this study, smokers deprived of cigarettes exhibited decreased pain tolerance before surgery and required a larger quantity of postoperative extra morphine equivalent than non-smokers. Health care providers must be aware of the potential for increased narcotic requirements in smokers. [ABSTRACT FROM AUTHOR]