The Impact of Smoking on the Prognosis of Elderly Surgical Patients

After obtaining approval from the ethics committee, patients are recruited, informed of the trial process and potential risks, and their informed consent is obtained and signed. According to the WHO definition, patients are classified into smokers (defined as those who smoke more than one cigarette per day continuously or cumulatively for six months; more than four times a week but averaging less than one cigarette per day) and non-smokers (never smoked). Fecal and blood samples are collected from both groups of patients preoperatively, and perioperative data is gathered. Postoperatively, an uninformed observer assesses the patients for delirium and recovery quality.