Spinal anesthesia (SA) is considered a safe procedure, but it may have some side effects including hypotension and bradycardia. Sympathetic fiber blockade and vasodilation are the main causes of hypotension. SA is performed more frequent in elderly patients despite the higher risk of hypotension and its consequences. The percentage of hypotension in elderly patients is estimated to be over 70%[1]. For prevention of hypotensive side effect may have risk of hypervolemia or myocardial ischemia in elderly population. Hypotension and bradycardia both may arise from Bezold-Jarish reflex (BJR), spinal anesthesia causes decrease in preload that stimulates BJR which may be mediated by peripheral serotonin receptors (5HT-3)[2]. These receptors are located peripherally as cardiac chemoreceptors on the cardiac vagal afferent and centrally as chemoreceptor trigger zone[3]. Shivering is a common association with spinal anesthesia during intra and postoperative periods. The causes of shivering are not clearly understood it may be due to union of some mechanisms including modulation of thermoregulatory thresholds, decreasing body core temperature, body heat distribution changes and the cooling effect of the injected fluids into neuraxis[4]. While patients feel very uncomfortable due to shivering, it causes monitors artifacts and increases the postoperative pain, heart rate,oxygen consumption and metabolic rate.These effects may lead to myocardial ischemia, hypoxemia, hypercarbia and lactic acidosis [5].