A Comparative Study between the Performing Spinal Anesthesia in Sitting versus Lateral Position on Patient Hemodynamics

Abstract

pinal anesthesia is frequently accompanied by hypotension, which may be defined in absolute terms as a systolic blood pressure of 90 or 100 mmHg or in relative terms as a percentage (20% fall from baseline). The severity of hypotension depends on the height of the block, the position of the patient and the volume status. Spinal anesthesia induced hypotension is caused by an increase in venous capacitance because of sympathectomy causing venodilation in the lower part of the body. Hypotension caused by a reduction in systemic vascular resistance is physiologically compensated by an increase in cardiac output. However, a high level of spinal block can inhibit the cardioaccelerator fibers leading to a fall in the heart rate and hence, instead of a compensatory increase, cardiac output usually decreases. The combined effect of reduced cardiac output and decreased systemic vascular resistance accounts for the high incidence of hypotension after spinal anesthesia. The aim of this study was to compare the effect of performing spinal anesthesia in sitting versus lateral position on patient hemodynamics (BP & HR). The design of the study included two groups, each constitutes of 40 patients (n=40).