Use of clonidine in hernia patients: Intramuscular versus surgical site

Background and Objectives. This study was designed to determine if administ ration of clonidine in hernia patients enhances analgesia. It was also desi gned to determine whether administration directly in the surgical site furt her improves the analgesia. Methods. A randomized, double-blinded study was undertaken at a tertiary fare hospital. Forty-five outpatients undergoing unilateral inguinal hernia repair by one of two surgeons (D.P. or M.A.) und er local anesthesia with monitored anesthesia care were evaluated. Patients were invited to participate in this investigation at the time of the preop erative surgical visit. Patients who had a contraindication to the use of c lonidine or who refused repair under local anesthesia with sedation were ex cluded. Patients were randomized to one of three groups: (a) clonidine 0.5 mu g/kg intramuscularly and saline in the surgical site (mixed with the loc al anesthetic); (b) clonidine 0.5 mu g/kg in the surgical site and saline i ntramuscularly; or (c) saline in both the surgical site and intramuscularly . The outcome measures included visual analog pain scores twice in the hosp ital, pain scores at rest and with movement 24 hours postoperatively, the t ime to first analgesic, and total analgesic requirement. Results. The pain scores were lower in both clonidine groups at 2 hours postoperatively than in the control group (P <.03). No difference was observed with respect to t he time to first analgesic, 24-hour analgesic use, or 24-hour pain scores a mong the groups. Conclusions. When clonidine is administered to patients un dergoing hernia repair, the 2-hour pain scores are lowered. No difference w as exhibited when clonidine was administered intramuscularly or directly in to the hernia site.