THE IMPACT OF BUPIVACAINE DOSE ON POST SPINAL SHIVERING IN CESAREAN SECTION: A RANDOMIZED TRIAL

Abstract

Objective: The aim of this study was to investigate the relationship between the intrathecal dose of hyperbaric bupivacaine and the incidence and severity of post spinal shivering in parturients undergoing cesarean section Material and methods: A hundred full term pregnant ladies undergoing elective cesarian section were randomized into two equal groups according to bupivacaine dose given for spinal anesthesia. low dose bupivacaine group (LB group) and high dose bupivacaine group (HB group) received 8 mg and 10mg bupivacaine respectively. The incidence and severity of shivering were recorded as primary outcomes. Other measurements were heart rate, mean arterial blood pressure, tympanic membrane temperature, sensory block level. Results: The level of spinal block was higher in HB group compared with LB group (p = 0.02). The incidence of intra-operative shivering was 15 (30 %) in HB group and 10 (20 %) in LB group (p = 0.032) while the shivering scores were not significant. The incidence of postoperative shivering was 16 (32 %) in HB group and 11 (22 %) in LB group (p = 0.043). Intra-operative tympanic membrane temperatures showed a highly significant reduction from the baseline (p < 0.0001) while postoperative values showed no significant difference from the baseline. Conclusions: The level of the spinal block rather than the dose of intrathecal bupivacaine affects the incidence of shivering. At low levels of the spinal block the incidence of shivering is decreased with no effect on the degree of shivering.