Diastolic function: the influence of pneumoperitoneum and Trendelenburg positioning during laparoscopic hysterectomy

Abstract

Several reports concerning the haemodynamic changes during gynaecologic laparoscopy have been published so far, and the effects of head-down tilt and pneumoperitoneum have not been clearly separated. However, its main effect seems to be an increase in systemic vascular resistance. We investigated how the augmented afterload can affect diastolic function. : Our study involved 20 healthy women, classified as having ASA status I: 10 undergoing laparoscopic hysterectomy and 10 undergoing conventional open hysterectomy. Measurements were made in awake patients and after induction of anaesthesia and then repeated after carbon dioxide insufflation and head-down positioning and at the end of surgery. Diastolic function was primarily studied by transthoracic echocardiography. We observed that pneumoperitoneum caused a significant reduction in stroke volume, cardiac output and left ventricular end-diastolic volume; the diastolic filling times showed a progressive reduction in the E-velocity (the velocity of early mitral inflow, corresponding to the ventricular passive filling phase, measured by pulsed-wave Doppler), a prolonged deceleration time and an augmented isovolumetric relaxation time. After head-down tilting, stroke volume, cardiac output and left ventricular end-diastolic volume increased in both laparoscopic hysterectomy and conventional open hysterectomy groups. We have found that pneumoperitoneum has important effects on left ventricular volumes, causing a drop in left ventricular end-diastolic volume; it also affects diastolic function with a delay in deceleration time and isovolumetric relaxation time without any effects on intracavitary pressures.