The correlation between the Trendelenburg position and the stroke volume variation

Background: The stroke volume variation (SVV), based on lung-heart interaction during mechanical ventilation, is a useful dynamic parameter for fluid responsiveness. However, it is affected by many factors. The aim of this study was to evaluate the effects of SVV on Trendelenburg (T) and reverse Trendelenburg (RT) position and to further elaborate on the patterns of the SVV with position. Methods: Forty-two patients undergoing elective surgery were enrolled in this study. Fifteen minutes after standardized induction of anesthesia with propofol, fentanyl, and rocuronium with volume controlled ventilation (tidal volume of 8 ml/kg of ideal body weight, inspiration : expiration ratio of 1 : 2, and respiratory rate of 10-13 breaths/min), the patients underwent posture changes as follows: supine, T position at slopes of operating table of -5 o , -10 o , and -15 o , and RT position at slopes of operating table of 5 o , 10 o , and 15 o . At each point, SVV, cardiac output (CO), peak airway pressure