This study aims to identify the risk factors associated with postoperative pulmonary complications (PPCs) in patients aged 65 years and older who undergo major abdominal surgery.

The study is designed as a retrospective observational analysis using data from patient records.

Understanding these risk factors may help clinicians improve perioperative care and reduce the risk of respiratory problems after surgery in elderly patients.

This is a retrospective observational study. No follow-up was performed; all data were collected from existing patient records.

Inclusion Criteria:

• Patients aged 65 years or older.
• Patients who underwent major abdominal surgery at [Institution Name].
• Availability of complete perioperative and postoperative clinical records.
• Postoperative hospital stay of at least 24 hours.

Exclusion Criteria:

• Patients younger than 65 years.
• Patients undergoing minor or non-abdominal surgery.
• Incomplete or missing perioperative or postoperative medical records.
• Patients who underwent emergency surgery

The study population consists of patients aged 65 years and older who underwent major abdominal surgery. Only patients with complete perioperative and postoperative medical records were included. Patients were retrospectively classified into two groups based on the occurrence of postoperative pulmonary complications (PPCs) within the first 24 hours after surgery.

This is a retrospective observational study using existing patient medical records. Individual participant data (IPD) will not be publicly shared to protect patient confidentiality and comply with institutional and ethical regulations. Aggregate data may be shared upon reasonable request.