This prospective study aims to evaluate the hemodynamic effects of different surgical positions-supine, lithotomy, and prone-in patients undergoing percutaneous nephrolithotomy (PCNL). Hemodynamic parameters are assessed using the Pressure Recording Analytical Method (PRAM) both while patients are awake and under general anesthesia. The study investigates how positioning-independently and in combination with anesthesia-influences cardiovascular function, including mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), stroke volume index (SVI), pulse pressure variation (PPV), stroke volume variation (SVV), cardiac contractility parameters (dP/dtmax), arterial elastance (Ea), cardiac power index (CPI), and cardiac cycle efficiency (CCE). The findings are expected to contribute to optimizing perioperative management and enhancing patient safety during PCNL procedures.
This prospective clinical trial investigates the hemodynamic effects of different surgical positions-supine, lithotomy, and prone-in patients undergoing percutaneous nephrolithotomy (PCNL). The study evaluates hemodynamic variables both in the awake state and under general anesthesia to distinguish the individual and combined impacts of anesthesia and patient positioning on cardiovascular function. Hemodynamic measurements are performed using the Pressure Recording Analytical Method (PRAM), a minimally invasive technique that allows continuous assessment of parameters such as mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), pulse pressure variation (PPV), stroke volume variation (SVV), stroke volume index (SVI), cardiac contractility parameters (dP/dtmax), arterial elastance (Ea), cardiac power index (CPI), and cardiac cycle efficiency (CCE). Each patient is sequentially positioned in the three surgical positions while awake, and the same measurements are repeated after the induction of general anesthesia in the corresponding positions. The primary aim is to determine how surgical positioning under general anesthesia alters key cardiovascular parameters. Secondary objectives include comparing hemodynamic changes across positions in both conscious and anesthetized states, identifying potential risks associated with specific positions, and guiding intraoperative patient management to improve safety and outcomes in PCNL procedures. The study is conducted at a single center and includes adult patients with ASA physical status I-II scheduled for elective PCNL surgery. The findings are expected to provide valuable data for anesthesiologists and surgeons to optimize perioperative cardiovascular stability, particularly during position changes in urological surgeries.
Study Type
OBSERVATIONAL
Enrollment
40
In addition, prior to the operation and throughout the PCNL procedure, hemodynamic measurements were obtained while patients were positioned in the supine, lithotomy, and prone positions, as necessitated by the surgical protocol.
Atatürk University Faculty of Medicine
Erzurum, Turkey (Türkiye)
Evaluate the effects of supine, lithotomy, and prone position on cardiac cycle efficiency (CCE) during the anesthetic period.
The primary objective was to evaluate the effects of different surgical positions on cardiac cycle efficiency (CCE), a parameter derived from pulse contour analysis during the anesthetic period. First measurement was recorded five minutes after anesthesia induction, while the patient was in the baseline supine position. Second measurement was recorded five minutes after transitioning to the lithotomy position, prior to ureteral catheter insertion. The third measurement was recorded five minutes after repositioning to the prone position
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
Mean Arterial Pressure assessment
Mean Arterial Pressure (MAP), derived via the PRAM method, was assessed in awake patients at three predefined surgical positions.
Time frame: Pre-anesthetic period at three predefined time points: 1) Before anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position (while still awake) 3) 5 minutes after transitioning to prone position (before induction)
Heart Rate (HR) Assessment
Heart Rate (HR) was recorded using the PRAM method in awake patients at three predefined surgical positions.
Time frame: Pre-anesthetic period at three predefined time points: 1) Before anesthesia induction in the supine position, 2) 5 minutes after transitioning to lithotomy position (while still awake) 3) 5 minutes after transitioning to prone position (before induction)
Cardiac Index (CI) Assessment
Cardiac Index (CI) was measured using the PRAM method in awake patients at three predefined surgical positions.
Time frame: Pre-anesthetic period at three predefined time points: 1) Before anesthesia induction in the supine position, 2) 5 minutes after transitioning to lithotomy position (while still awake) 3) 5 minutes after transitioning to prone position (before induction)
Stroke Volume Index (SVI) Assessment
Stroke Volume Index (SVI) was assessed via the PRAM method in awake patients at three predefined surgical positions.
Time frame: Pre-anesthetic period at three predefined time points: 1) Before anesthesia induction in the supine position, 2) 5 minutes after transitioning to lithotomy position (while still awake) 3) 5 minutes after transitioning to prone position (before induction)
dP/dt max Assessment
dP/dt max, an index of cardiac contractility, was assessed using the PRAM method in awake patients at three predefined surgical positions.
Time frame: Pre-anesthetic period at three predefined time points: 1) Before anesthesia induction in the supine position, 2) 5 minutes after transitioning to lithotomy position (while still awake) 3) 5 minutes after transitioning to prone position (before induction)
Arterial Elastance (Ea) Assessment
Arterial Elastance (Ea) was measured using the PRAM method in awake patients at three predefined surgical positions.
Time frame: Pre-anesthetic period at three predefined time points: 1) Before anesthesia induction in the supine position, 2) 5 minutes after transitioning to lithotomy position (while still awake) 3) 5 minutes after transitioning to prone position (before induction)
Cardiac Cycle Efficiency (CCE) Assessment
Cardiac Cycle Efficiency (CCE) was derived using the PRAM method in awake patients at three predefined surgical positions.
Time frame: Pre-anesthetic period at three predefined time points: 1) Before anesthesia induction in the supine position, 2) 5 minutes after transitioning to lithotomy position (while still awake) 3) 5 minutes after transitioning to prone position (before induction)
Cardiac Power Index (CPI) Assessment
Cardiac Power Index (CPI) was assessed using the PRAM method in awake patients at three predefined surgical positions.
Time frame: Pre-anesthetic period at three predefined time points: 1) before anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position (while still awake) 3) 5 minutes after transitioning to prone position (before induction)
Mean Arterial Pressure (MAP) Assessment under General Anesthesia
Mean Arterial Pressure (MAP) was measured using the PRAM method in patients under general anesthesia at three surgical positions in the operating room
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
Heart Rate (HR) Assessment under General Anesthesia
Heart Rate (HR) was recorded using the PRAM method in patients under general anesthesia at three surgical positions in the operating room.
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
Cardiac Index (CI) Assessment under General Anesthesia
Cardiac Index (CI) was assessed using the PRAM method in patients under general anesthesia at three surgical positions in the operating room.
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
Stroke Volume Index (SVI) Assessment under General Anesthesia
Stroke Volume Index (SVI) was measured using the PRAM method in patients under general anesthesia at three surgical positions in the operating room.
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
Pulse Pressure Variation (PPV) Assessment under General Anesthesia
Pulse Pressure Variation (PPV) was measured using the PRAM method in patients under general anesthesia at three surgical positions in the operating room.
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
Stroke Volume Variation (SVV) Assessment under General Anesthesia
Stroke Volume Variation (SVV) was assessed using the PRAM method in patients under general anesthesia at three surgical positions in the operating room.
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
dP/dt max Assessment under General Anesthesia
dP/dt max, an index of cardiac contractility, was assessed using the PRAM method in patients under general anesthesia at three surgical positions in the operating room.
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
Arterial Elastance (Ea) Assessment under General Anesthesia
Arterial Elastance (Ea) was measured using the PRAM method in patients under general anesthesia at three surgical positions in the operating room.
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
Cardiac Power Index (CPI) Assessment under General Anesthesia
Cardiac Power Index (CPI) was assessed using the PRAM method in patients under general anesthesia at three surgical positions in the operating room.
Time frame: Intraoperative period (under general anesthesia) at three predefined time points: 1) 5 minutes after anesthesia induction in the supine position 2) 5 minutes after transitioning to lithotomy position 3) 5 minutes after repositioning to prone position
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