4. Discussion
bradycardia, hypothermia, anxiety, intraoperative shivering, Shivering, shivering
The findings from our study suggest that phenylephrine infusion significantly reduced the incidence of intraoperative shivering. The incidence of intraoperative shivering in the phenylephrine group was 29.1% compared to 47.5% in the control group. This translated to an 18.4% reduction in intraoperative shivering among the patients who received phenylephrine. A similar finding was reported by Palanisamy et alThe mechanism by which phenylephrine reduces shivering remains unknown. Shivering is commonly associated with hypothermia. Central neuraxial anesthesia reduces the vasoconstriction and shivering thresholds by approximately 0.6℃ when measured above the level of block.Our study did not find any significant difference in core temperature between phenylephrine and control group. Even though the decrease in mean core temperature from baseline at the end of surgery was lower in the phenylephrine group (0.26℃) than in the control group (0.57℃), this data was not statistically significant. This finding was contrasted to 3 of other studies.Phenylephrine increases systemic blood pressure by increasing the systemic vascular resistance.Phenylephrine causes bradycardia in response to a physiological baroreceptor reflex.This study had a few limitations. First, this study was conducted only among the maternal population who underwent lower segment cesarean section; hence, it is uncertain whether the type of surgery had any influence on the results. The presence of other factors, such as anxiety, could contribute to shivering, which we did not consider in our study. In addition, the primary outcome (shivering) was measured at 15-minute intervals in our study, but changes might have occurred between measurements, which may have influenced the trend of the results. Finally, we did not determine the optimal phenylephrine dose required to effectively reduce perioperative shivering. We recommend that phenylephrine be studied in different population groups with regard to perioperative shivering. Further studies are required to determine the optimal dose of phenylephrine to prevent shivering.