Robotic-assisted laparoscopic prostatectomy (RALP) is a surgical method with good short-term results and accepted as the gold standard because of its minimal invasiveness. The pneumoperitoneum and deep Trendelenburg position (at least 25°-45° upside down) required for RALP surgeries can cause significant pathophysiological changes in both the pulmonary and cardiac systems, as well as complicate hemodynamic management.

In this study, investigators aimed to determine the changes in the cardiovascular system during deep Trendelenburg position with the hemodynamic parameters monitored by the pressure record analytical method (PRAM) and the Longitudinal Strain measured with simultaneous transesophageal echocardiography.

RALP is the gold standard surgical technique in prostate surgery. Many Robotic-laparoscopic surgical techniques also require the intraoperative deep Trendelenburg position. However, the possible side effects of the deep Trendelenburg position on the cardiovascular system during surgery are unknown. Although the Trendelenburg position is a life-saving maneuver in hypovolemic patients, it also carries undesirable risks. Although the increase in venous return is expected to protect the cardiac output (CO) in the deep Trendelenburg position, the increase in intrathoracic pressure due to the intraperitoneal pressure may cause deterioration in venous return and a decrease in CO . In addition, the changing heart configuration in the deep Trendelenburg position may also cause an increase in the workload of the heart. Therefore, the need to evaluate hemodynamic management with advanced monitoring techniques, including fluid therapy in the perioperative period, has arisen in patients undergoing RALP.

The pressure Recording Analytical Method (PRAM), is one of the most up-to-date monitoring methods designed for continuous CO measurement derived from the arterial pressure wave analysis, with a high signal sampling rate (1000 Hz). Many studies have shown that PRAM is a reliable monitoring method in major surgery. Cardiac Cycle Efficiency (CCE), which the PRAM method adds to our daily practice, is an index that defines hemodynamic performance in terms of energy consumption and efficiency. It can be expressed as the ratio of systolic energy performance to the total energy expenditure of the cardiac cycle and indicates the ability of the cardiovascular system to maintain homeostasis at different energy levels. However, data on how cardiac functions change in the deep Trendelenburg position are still limited.

In this study, investigators aimed to demonstrate the reliability of the CCE value through its correlation with the Longitudinal Strain (LS) by observing the effect of the deep Trendelenburg position in RALP surgeries on cardiac functions using PRAM and Transesophageal Echocardiography (TEE).

Inclusion Criteria:

• Patients with American Society Of Anesthesiology physical status 1-3

• Underwent Robotic-assisted laparoscopic prostatectomy

• Patients with intra-arterial blood pressure monitoring before anesthesia induction.

  .Exclusion Criteria:

• Under 18 years of age

• Arrhythmia (atrial fibrillation, frequent premature beat)

• History of myocardial infarction in the last 3 months

• Heart failure

• Severe pre-existing lung disease

• Severe valvular heart disease

• Chronic renal disease on dialysis,

The patients with ASA (American Society Of Anesthesiology) physical status 1-3 who underwent RALP with intra-arterial blood pressure monitoring before anesthesia induction