Hemodynamic Changes During Spinal Surgery in the Prone Position

Abstract

Decreases in SV and CI are the main causes of a decrease in BP in the prone position during lumbar spinal surgery.

Cerebral Oxygenation in Preterm Infants

“…This suggests that baroreflex-mediated HR responses may be impaired during this period, resulting in a reduced ability to maintain MAP in the prone position, potentially reflecting reduced cardiac output. This is consistent with findings of reduced cardiac index, a measure of cardiac output relative to body surface area, in adults 47,48 and children 49 in the prone compared with the supine position. Reduced cardiac output may explain the large deficit in cerebral oxygenation seen in the prone position at 2 to 3 months CA.…”

The Prone Position During Surgery and its Complications: A Systematic Review and Evidence-Based Guidelines

“…7À11 Reduced stroke volume and cardiac index results in a drop in blood pressure often seen when a patient is turned from supine to prone. 10 Respiratory changes include a 30% to 35% decrease in respiratory compliance and increase in peak airway pressure. 7 This in turn decreases venous return and cardiac output.…”

Changes in the hemodynamic parameters between the prone and supine positions measured by an arterial pulse contour cardiac output monitoring system

“…Regarding the frames, some suggested that the SV decreases when patients are placed on a convex saddle frame [6,8,12]. In the current study, a longitudinal bolster device that partially supports the chest and pelvis, partially compresses the abdomen, and positions the legs above the heart was used.…”

“…Most of the previous relevant studies showed that the SV, CI [6], and blood pressure [7,8] decrease when patients are made to assume a prone position. When a patient assumes a prone position, the arterial pressure can remain stable, but the CO usually decreases due to the reduced venous return.…”

“…In the current study, a longitudinal bolster frame was used, and the patient's legs were positioned above the heart. When a patient's arms and legs are positioned lower than the heart, pooling of the intravascular volume occurs in the extremities, and the preload and SV can decrease [6].…”