Hemodynamic Changes Due to Prone Position

Perioperative prone position may be associated with hemodynamic instability. The causes of instability have not yet been precisely elucidated. The aim of this study is to demonstrate physiological changes during prone positioning in healthy volunteers .

The prone position could decrease the cardiac index (CI), mainly due to reduction in stroke volume, with little changes in heart rate. Mean arterial pressure (MAP) could be maintained by increased systemic vascular resistance (SVR) in the majority of patients. The aim of this study is to describe hemodynamic changes in two different surgical prone positions in 10 healthy non-anesthetized volunteers (flat position and using a support system allowing a free abdomen) by non-invasive measurement of hemodynamics (ClearSight, Edwards) and indirectly evaluated intra-abdominal pressure using ultrasound. The ClearSight system provides advanced hemodynamic parameters (cardiac index CI, stroke volume SV, stroke volume variation SVV, systemic vascular resistance SVR, mean arterial pressure MAP) from a finger cuff.