Prophylactic granisetron for post-spinal anesthesia shivering in cesarean section: A randomized controlled clinical study.

Abstract

The serotonergic system is known to be involved in control of post-anesthetic shivering. Our hypothesis was that prophylactic granisetrone (serotonin antagonist) might reduce incidence of post-spinal anesthesia shivering in cesarean section. Parturient scheduled for elective cesarean delivery under spinal anesthesia were allocated to receive 0.9% saline (Group I, n=71), 1mg granisetron (Group II, n=69), or 0.7mg granisetron (Group III, n=72) before the spinal block. Assessment parameters included; hemodynamics, tympanic membrane temperature, neonatal Apgar score, shivering score, patient satisfaction scores about shivering prophylaxis and adverse effects. Clinically significant shivering was recorded in 55/71 patients (77.5%) in group I, 11/69 (15.9%) in group II and 21/72 (29.2%) in group III (P=0.000). The intensity of shivering was significantly lower in patients who received granisetron 1mg compared with granisetron 0.7mg or saline (P=0.000). Patients who received prophylactic granisetron 1mg reported lower mean intraoperative arterial pressure and heart rate values and consumed higher doses of iv ephedrine compared with 0.7mg granisetron or saline placebo (P<0.05). Pruritus significantly decreased from (22.5%) in control group to (0%) in granisetron groups (P=0.000). Nausea was reported in 8 vs 10 and four in group I, II and III, respectively (P<0.03). Sixteen vs eight and six patients vomited in group I, II, and III, respectively (P<0.03). Higher patient satisfaction scores were recorded in group II (9.83±0.29, P<0.03) and III (9.14±1.04, P<0.04), compared with control group (8.23±1.14). Prophylactic granisetron effectively reduced incidence and severity of perioperative shivering in a dose dependent manner, compared to placebo controls.