This prospective observational study aims to evaluate renal perfusion in adult patients undergoing elective minimally invasive abdominal surgery. Renal perfusion will be assessed using two non-invasive monitoring techniques: Doppler ultrasonography-derived Renal Resistive Index (RRI) and Near-Infrared Spectroscopy (NIRS)-derived renal regional oxygen saturation (rSO₂).
Measurements will be obtained at predefined perioperative time points, including after induction of anesthesia, during pneumoperitoneum, before extubation, and during the early postoperative period. Perioperative changes in renal perfusion parameters will be analyzed and correlated with clinical variables such as intra-abdominal pressure, pneumoperitoneum duration, hemodynamic parameters, fluid administration, urine output, and postoperative renal function.
The study also aims to investigate the relationship between intraoperative renal perfusion changes and the development of postoperative acute kidney injury. The findings may contribute to improved perioperative monitoring and optimization of renal perfusion during minimally invasive abdominal surgery.
Patients aged 18 to 80 years
Patients with ASA physical status I, II, or III
Patients undergoing elective minimally invasive abdominal surgery for any reason
Patients whose expected surgical duration is longer than 1 hour
Body mass index greater than 35 kg/m²
Severe respiratory system disease
Severe heart failure, NYHA class III-IV
Presence of a cardiac pacemaker or cardiac defibrillator implant