Intravenous clonidine reduces the frequency and severity of shivering and pain after urological surgeries

ABSTRACT

This study aimed to evaluate the therapeutic yield of ketamine and clonidine in patients assigned for various urological surgeries. The study comprised 90 patients; 54 males and 36 females with mean age of 43.5 +/- 8.3 years. Patients were randomly allocated into 3 equal groups to receive saline [Control group]; ketamine 0.5 mg/kg or clonidine 3 microg/kg injected intravenously 20 min before the end of surgery. Anesthetic management of all patients was standardized and recovery times were measured from completion of wound dressing to eligibility for discharge from the recovery room; defined as a modified Aldrete score of >/= 9. Post-anesthetic shivering [PAS] was graded on admission to the post-anesthetic recovery room [T0], and 10 min [T10], 20 min [T20] and 30 min [T30] thereafter using a four-point scale. Pain was assessed using a 0-10cm visual analogue scale [VAS] hourly for 6 hours and then 3-hourly for the first 24-hrs after surgery, VAS scores were expressed collectively as 3-hours VAS score. Meperidine, 20 mg IV injection was given for PAS >/= 2 and/or VAS >/= 4. Any possible side-effects of the study drugs were recorded. Patients received clonidine consumed longer time till had Aldrete score of >/= 9 that had significant compared to saline and non-significant compared to ketamine group with a non-significantly longer time with ketamine compared to saline. No PAS was recorded in 40 patients [44.4%] with a total frequency of PAS of 55.6%. Clonidine significantly reduced the frequency and score of PAS with a significant reduction of the need for and the numbers of requests of PAS rescue treatment in comparison to saline and ketamine with a significant difference in favor of ketamine. Clonidine significantly reduced VAS scores and spared the need for rescue analgesia compared to both placebo and ketamine with a significant difference in favor of ketamine. It could be concluded that clonidine administration prior to end of surgery provided superior postoperative outcome compared to ketamine and manifested as reduced frequency and severity of both PAS and pain with significant reduction of the need for rescue treatment