Ondansetron Administration Prior to Subarachnoid Block in Cesarean Section: An Evidence Based Practice Analysis

Abstract

<p>Subarachnoid block (SAB) is a preferred regional technique utilized by many institutions for caesarean section. A sensory block height of T5 is necessary for a successful caesarean under SAB. Unfortunately, side effects often emerge related to the physiological changes as a result of sympathetic nervous system inhibition. Current research suggests up to 55%-90% of parturients experience extended block height resulting in hypotension and bradycardia.There is a reduction in cardiac output due to a decrease in systemic vascular resistance and venous pooling. Similarly, the shift of cardiac autonomic balance toward parasympathetic stimulation causes bradycardia and activation of left ventricular mechanoreceptors due to a decreased ventricular volume. The mechanism is known as the Bezold-Jarisch reflex (BJR).</span></p>