Background: Blood loss in spine surgery is an important issue, even though it has been understudied compared to hip and knee arthroplasty surgery. In this study we have evaluated the effect of oral clonidine as premedication on blood loss in lumbar spine fusion surgery under propofol and remifentanil anesthesia.
Materials and Methods: In this prospective double-blinded randomized clinical trial, 30 patients undergoing lumbar spine posterior fusion surgery were randomly allocated into 2 groups. The study group (Clonidine group) received 200micg 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 target mean arterial pressure for controlled hypotension with remifentanil were the same in the 2 groups. We compared the amount of blood loss, dose of remifentanil /hour administered, need for nitroglycerine to reach the target mean arterial pressure when remifentanil was not enough, duration of operation and surgeon's satisfaction of a bloodless field between the 2 groups.
Results: There was no statistically significant difference between the study groups in demographic characteristics (age (p=0.115), sex (p=0.439), weight (p=0.899)) operation time (p=0.2) and American Society of Anesthesiologists physical status score of the patients (p=0.390).Intra-operative blood loss and remifentanil dosage administered per hour in the clonidine group were significantly less than the control group (p=0.002 and p=0.001 respectively). But there was no significant difference in surgeon's satisfaction between the two groups (p=0.169).
Conclusion: Clonidine as an oral premedication can reduce surgical blood loss in lumbar spine posterior fusion surgery, even at the same levels of mean arterial pressure with the control group. Its use can be studied in more complicated spine surgeries such as scoliosis and spinal deformity surgeries.