Cotinine Test in Evaluating Smoking Cessation at the Day of Bariatric Surgery.

BACKGROUND AND AIMS: Smoking increases the risk of postoperative complications after bariatric surgery. Therefore, preoperative smoking cessation is mandatory according to Danish guidelines before elective bariatric surgery. The aim of this study was to investigate if patients scheduled for bariatric surgery continue to smoke on the day of their operation despite recommendations. MATERIALS AND METHODS: A prospective single-center study including all patients scheduled for bariatric surgery from June to December 2017 at Zealand University Hospital in Denmark. Urine samples were collected on the day of surgery to test for cotinine. During the minimum preoperative period of 3 months, patients were repeatedly informed of the increased risk of complications, that smoking cessation was mandatory, that rescheduling of the surgery was possible if more time to achieve smoking cessation was necessary, and if tested positive on the day of surgery, the operation would be canceled. RESULTS: Of the 71 patients included, 9 patients (13%) were tested positive. After confrontation with the test result, all but 1 patient confessed to smoking. Overall, 6 out of 12 patients (50%) who were actively smoking at the time of referral tested positive, and 2 out of 25 patients (8%) who claimed to have smoked previously tested positive. No patients claiming no smoking history tested positive. CONCLUSION: Despite information that smoking cessation was mandatory, and the scheduled bariatric operation would be canceled in case of smoking, up to 50% of patients with a history of smoking still smoked on the day of surgery.

Time course of postoperative hypoxaemia.

OBJECTIVE: To study the time course of nocturnal episodic and constant hypoxaemia during the first five nights after a major abdominal operation in patients not given supplementary oxygen. DESIGN: Open study. SUBJECTS: 17 patients undergoing major elective operations and with no recognised risk factors. MAIN OUTCOME MEASURES: Arterial oxygen saturation measured by pulse oximetry. RESULTS: The level of constant hypoxaemia was lowest during night 2 (p < 0.01) as was the time spent below 90% saturation (p < 0.01) compared with the other four postoperative nights. Episodic hypoxaemia was most common during night 3 (p < 0.05). It was not possible to predict the postoperative occurrence of hypoxaemia from the preoperative spirometric measurements. Preoperative awake arterial oxygen saturation correlated significantly with mean constant hypoxaemia on postoperative nights 1, 3, 4, and 5, but not with episodes of sudden desaturation after operation. Preoperative overnight oximetry correlated significantly with constant hypoxaemia on all five postoperative nights and with episodic hypoxaemia on nights 3 and 4. CONCLUSION: In the light of these results which show the natural history of postoperative hypoxaemia without supplementary oxygen, and because postoperative hypoxaemia may be associated with dysfunction of organ systems after major operations, controlled studies of supplementary oxygen in the late postoperative period are warranted.