Effect of Delayed Remote Ischemic Preconditioning on Postoperative Pulmonary Complications in Elderly Patients Having Non-Cardiac Thoracic Surgery

Study Summary: The Effect of a Simple Arm Cuff Procedure on Lung Complications After Surgery in Older Adults 1. What is the purpose of this study? This clinical study aims to find out if a simple, non-invasive procedure called Delayed Remote Ischemic Preconditioning (RIPC) can help reduce lung complications (like pneumonia or breathing difficulties) in older patients (aged 65 and above) after non-cardiac and non-chest surgery. 2. What is the RIPC procedure? RIPC involves briefly and repeatedly applying and releasing pressure on one upper arm using a standard blood pressure cuff. This is done 24 hours before surgery. The goal is to gently stimulate the arm's circulation, which may activate the body's natural protective mechanisms and help protect the lungs during and after surgery. RIPC Group: The cuff will inflate to a higher pressure (200 mmHg) for 5 minutes, then release for 5 minutes. This cycle repeats 4 times. Control Group: The cuff will inflate to a very low pressure (20 mmHg) with the same timing, serving as a comparison to see if the higher pressure has a specific effect. 3. Who can participate? Patients may be eligible if they: Are 65 years of age or older. Are scheduled for elective non-cardiac, non-chest surgery under general anesthesia, expected to last 1-3 hours. Are in relatively stable health (ASA physical status I-II). Patients cannot participate if they have certain pre-existing conditions, such as significant heart or lung disease, severe infections, or bleeding disorders. 4. What will happen during the study? Before Surgery: Eligible patients will receive a full explanation and sign a consent form. They will be randomly assigned (like flipping a coin) to either the RIPC group or the Control group. The procedure will be performed 24 hours before surgery. Some blood tests and an ultrasound scan will be done. During Surgery: Standard anesthesia and surgical care will be provided. After Surgery: We will monitor patients for a