ABSTRACT
PURPOSE: Postoperative shivering is commonly observed in patients after general anesthesia. A double-blind randomized controlled trial was conducted in patients undergoing day care knee arthroscopy to test the hypothesis that a single intraoperative dose of hydrocortisone would prevent or attenuate postoperative shivering. METHODS: One hundred and twenty patients were given a nitrous oxide-isoflurane-remifentanil anesthetic. Approximately ten minutes before the end of anesthesia, they were randomized to receive normal saline (Control group; n = 40); hydrocortisone 1 mg·kg(-1) iv (Hydrocortisone-1 group; n = 40), or hydrocortisone 2 mg·kg(-1) iv (Hydrocortisone-2 group; n = 40). Postoperative shivering was graded by a blinded observer using a five-point scale: Grade 0: none; Grade 1: one or more areas of piloerection but without visible muscular activity; Grade 2: visible muscular activity confined to one muscle group; Grade 3: same as Grade 2 but in more than one muscle group; and Grade 4: gross muscular activity involving the entire body. RESULTS: Shivering (Grades 1-4) was observed in 33 patients (82%) in the Control group, 13 patients (32%) in the Hydrocortisone-1 group (P < 0.001 compared with the Control group), and eight patients (20%) in the Hydrocortisone-2 group (P < 0.001 compared with the Control group). The overall incidence of shivering was similar in the Hydrocortisone-1 and Hydrocortisone-2 groups. CONCLUSIONS: This study shows that hydrocortisone (1-2 mg·kg(-1) iv) provides effective prophylaxis against postoperative shivering in patients undergoing day care knee arthroscopy under general anesthesia.
