Effect of Clonidine Premedication on Blood Loss in Spine Surgery

BACKGROUND Blood loss in spine surgery is an important issue, even though it has been understudied compared with hip and knee arthroplasty. OBJECTIVES In this study, we evaluated the effect of oral clonidine as premedication on blood loss in lumbar spine fusion surgery under anesthesia with propofol and remifentanil. PATIENTS AND METHODS In this double-blind, randomized clinical trial, 30 patients who were undergoing lumbar spine posterior fusion surgery due to traumatic fracture were allocated randomly into 2 groups. The study group (clonidine group) received a 200-μg oral clonidine tablet 60-90 minutes before anesthesia, and the control group received placebo at the same time. Induction and maintenance of anesthesia and the mean target arterial pressure for controlled hypotension with remifentanil were the same in the 2 groups. We compared the amount of intraoperative blood loss, dose of remifentanil/hour administered, need for nitroglycerine to reach the mean target arterial pressure when remifentanil was insufficient, duration of operation, and surgeon's satisfaction of a bloodless field between groups. RESULTS There was no statistically significant difference between groups in age (P = 0.115), sex (P = 0.439), weight (P = 0.899), operation time (P = 0.2), or American Society of Anesthesiologists physical status score (P = 0.390). Intraoperative blood loss and remifentanil dose administered per hour in the clonidine group were significantly less than in the control group (P = 0.002 and P = 0.001, respectively), but there was no significant difference in surgeon's satisfaction between groups (P = 0.169). CONCLUSIONS As an oral premedication, clonidine can reduce surgical blood loss in lumbar spine posterior fusion surgery, even at the same levels of mean arterial pressure (MAP) with the control group. Its use can be studied in more complicated spine surgeries, such as scoliosis and spinal deformity surgeries.