This study aims to investigate the relationship between preoperative Cardiac Power Output (CPO), which reflects the pumping capacity of the heart, and the P-POSSUM score, a widely used surgical risk assessment tool, in patients aged 65 years and older undergoing abdominal surgery. Simple and non-invasive measurements performed in the preoperative period will be used to obtain CPO values and to evaluate whether these measurements are helpful in predicting postoperative morbidity and mortality. No additional procedures beyond routine clinical care will be performed as part of this observational study. The findings of this study may contribute to a more accurate assessment of surgical risk and help improve patient safety in the perioperative period.

This is a prospective, observational study designed to evaluate the relationship between preoperative Cardiac Power Output (CPO) and the P-POSSUM risk score in patients aged 65 years and older undergoing abdominal surgery, including both elective and emergency procedures. CPO is a hemodynamic parameter reflecting overall cardiac pumping power and may provide additional physiologic information beyond traditional risk models. P-POSSUM is widely used to estimate postoperative morbidity and mortality based on physiological and operative variables.

Eligible patients will be assessed in the preoperative period. Preoperative CPO will be obtained using non-invasive hemodynamic measurements as part of routine perioperative practice. The P-POSSUM score will be calculated for each patient using standard definitions. Patients will be followed during the postoperative period to document clinical outcomes, including postoperative complications and mortality within the predefined follow-up window, as well as length of hospital stay when available.

The primary objective is to assess the association between preoperative CPO and the P-POSSUM score. Secondary objectives include exploring whether preoperative CPO is associated with postoperative outcomes and whether it may help refine perioperative risk stratification. This study does not involve any investigational treatment; no additional interventions beyond standard clinical care will be performed. All data will be handled in accordance with applicable privacy and confidentiality regulations, and patient identifiers will not be included in the analysis dataset.

Inclusion Criteria: Being 65 years of age or older,

• Undergoing abdominal surgery in general surgery practice (including elective and emergency procedures),
• ASA (American Society of Anesthesiologists) class I-III,
• Adequate recording with transthoracic echocardiography,
• Having given informed consent.

Exclusion Criteria:Advanced heart failure with ejection fraction (EF) <30%,

• Severe valvular disease (severe stenosis or insufficiency),
• Unstable coronary artery disease or recent myocardial infarction (within the last 3 months),
• Pulmonary hypertension,
• Severe arrhythmia (uncontrolled atrial fibrillation, ventricular tachycardia, etc.)

This study will include patients aged 65 and over who are scheduled for abdominal surgery at Necmettin Erbakan University Faculty of Medicine Hospital.