Assessments of Dynamic Variables of Fluid Responsiveness to Predict Desufflation-induced Hypotension in Urologic Patients Undergoing Laparoscopic Surgery

Laparoscopic surgery can induce hemodynamic pertubations. Pneumoperitoneum, inevitable in laparoscopic surgery, induces increase in intra-abdominal pressure, which can decrease cardiac output. Simultaneously, pneumoperitoneum can stimulate sympathetic system and increase vascular resistance/arterial blood pressure. Patients undergoing laparoscopic surgery may show a normal range of blood pressure during pneumoperitoneum even when the patients are in hypovolemia, and desufflation at the end of main surgical procedure can cause an abrupt hypotension revealing hypovolemia. Therefore, appropriate fluid management is essential for preventing desufflation-induced hypotension in laparoscopic surgery. Recently, dynamic variables are used to predict and guide fluid therapy during controlled ventilation. these variables arise from heart-lung interactions during positive ventilation, which influence left ventricular stroke volume. Several dynamic variables are derived from variations in left ventricular stroke volume (stroke volume variation, SVV), for example pulse pressure variation (PPV), and variations in pulse oximetry plethysmography waveform amplitude (PWV), which have all been shown to predict fluid responsiveness in different clinical and experimental settings. However, there are few evidences regarding which type of dynamic variables can predict desufflation-induced hypotension in laparoscopic surgery. Therefore, this study was designed to assess the predictive abilities of three different type of dynamic variables including PPV, SVV, and PWV for desufflation-induced hypotension in patients undergoing laparoscopic surgery.