Evaluation the Effect of Intrathecally Fentanyl Added to Lidocaine on Interception of Shivering in Abdominal Hysterectomy: Randomized Clinical Trial

Background Shivering is a frequent phenomenon in postoperative period. Post spinal shivering causes a major distress for patients and may induce some complications. Investigations to control shivering could not mange it completely. Objectives The aim of this randomized single-blind study was to investigate how much the high dose (50 μg) of intrathecally administered fentanyl would influence the incidence and severity of shivering in patients undergoing abdominal hysterectomy. Methods In this prospective clinical trial, seventy healthy patients scheduled for abdominal hysterectomy under spinal anesthesia using 75 mg of hyperbaric 5% lidocaine were randomly allocated to receive an additional 50 μg (1 mL) of fentanyl intrathecally (group F) or normal saline 1 mL (groups).Then the level of shivering was measured with crossly and mahajon scale and analyzed with chi-square test using SPSS version 17 software. Results The incidence of shivering up to two hours after spinal anesthesia was 13 from 35 patients (37.2 %) in group F, and 27 from 35 patients (77.2%) in group S. The difference was statistically significant (P < 0.01). The shivering score was significantly lower in group F. There was no difference in the incidence of pharmacologic side effects. Conclusions Addition of 50 μg fentanyl to 75 mg of hyperbaric 5% lidocaine intrathecally can reduce the incidence and severity of shivering in patients who receive abdominal hysterectomy without increasing other side effects.