This is a prospective observational study designed to evaluate the effect of smoking on early postoperative respiratory symptoms such as cough, airway secretions, and wheezing in adult patients undergoing elective abdominal surgery. Participants will be divided into two groups based on smoking history. The study aims to assess the incidence of minor pulmonary complications-such as increased secretions requiring suctioning, oxygen need, and early respiratory discomfort-within the first 24 hours after surgery. Data will be collected on parameters including secretion volume, oxygen saturation, aspiration frequency, and presence of cough or wheezing. The results will help determine whether active smoking is associated with a higher frequency of early postoperative pulmonary events.

Cigarette smoking is a well-established risk factor for adverse postoperative outcomes, including respiratory complications. However, many studies have primarily focused on major complications such as pneumonia, reintubation, or prolonged mechanical ventilation, often underestimating early and subtle pulmonary effects of smoking. This study aims to fill that gap by evaluating early minor postoperative pulmonary events-specifically cough, airway secretions, and wheezing-within the first 24 hours after extubation in adult patients undergoing elective abdominal surgery.

The study is designed as a prospective observational cohort conducted in a single tertiary-care hospital. Adult patients (aged 18-65) undergoing elective abdominal surgery under general anesthesia will be included. Participants will be classified into two groups based on smoking history: current smokers and non-smokers. The primary outcome is the occurrence of early minor pulmonary complications, including secretion burden requiring aspiration, Peripheral Oxygen Saturation(SpO₂ ) desaturation (SpO₂ <90%), presence of audible wheezing, and persistent postoperative cough. These events will be documented by trained clinical staff using standardized clinical criteria and data collection forms.

The hypothesis of this study is that active smokers are more likely to develop early minor pulmonary complications within the first 24 hours after surgery compared to non-smokers. The findings will contribute to a better understanding of early perioperative respiratory risk among smoking patients and may support the refinement of risk assessment and preoperative counseling.

Inclusion Criteria:

• Age between 18 and 65 years
• Undergoing elective abdominal surgery under general anesthesia
• ASA physical status I-II-III
• Able to provide informed consent
• Classified as either active smoker (≥10 pack-years) or nonsmoker (never smoked or quit >1 year ago)

Exclusion Criteria:

• Diagnosed chronic pulmonary disease (e.g., Obstructive Sleep Apnea, asthma, Chronic Obstructive Pulmonary Disease)
• Acute respiratory tract infection within the past 30 days
• Morbid obesity (Body Mass Index >35 kg/m²)
• Emergency surgery
• Pregnancy or breastfeeding
• Refusal to participate

Adult patients between 18 and 60 years old scheduled for elective abdominal surgery at a tertiary care hospital. Participants include both current smokers and nonsmokers. All patients are American Society of Anesthesiologists (ASA) class I-II-III and free of known chronic respiratory diseases.

Individual participant data (IPD) will not be shared because this is a single-center, observational study and no explicit consent for data sharing was obtained from participants. Only aggregate results will be published.