Added Value of Local Clonidine for Spine Postoperative Pain Control, in Addition to Bupivacaine

Randomized Double-blind Trial Comparing the Post-operative Analgesic Efficacy of Local Wound Infiltration With Bupivacaine Alone to Bupivacaine With Clonidine in Posterior Spine Surgeries

The objective of this prospective randomized double-blind study is to evaluate the added analgesic value of clonidine to the conventional local bupivacaine wound infiltration in posterior spine surgery.

Patients candidates to posterior spine surgery (Micro-discectomy, Lumbar laminectomy with or without fusion, cervical laminectomy) are asked to participate to this prospective study. After verification of inclusion and exclusion criteria, patients consenting to enter the study are randomly assigned to one of the following subgroups: 1-Pre-incisional wound infiltration with 20 mL of bupivacaine 0.25%. 2- Pre-incisional wound infiltration with 150 μg of clonidine with 20 mL of bupivacaine 0.25%. Demographic parameters, co-morbidities and other pre and per operative medical data are noted. In the post-operative period, patients received a standardized post-operative analgesic protocol (NSAI and paracetamol). Patients are asked to fill their pain diary using Visual Analog Scale (VAS) from day 0 till day 8 after surgery. Morphine rescue consumption is noted. Finally, the percentage of global subjective patient satisfaction regarding the post-operative wound pain is noted from 0 to 100.

Pain is assessed on numeric rating scale (NRS) 8times/day during the first 3 days, 3times/day during the next 6days and one mean value during the night. The mean intensity of daily pain is obtained from the different values mentioned during day and night corrected by the duration covered by every value. It may vary from 0 to 10.

The AUC during an interval (in days) is calculated by adding the different values of pain assessed during day and night multiplied by the duration (in hours) of sufferance from this amount of pain. The AUC during an interval is proportional to the mean intensity of pain suffered during the same interval. It is expressed in pain unit multiplied by hour

The unit of rescue opiates consumption equals the administration of 5mg of morphine subcutaneously. The minimum interval between 2 rescue opiates consumption is 6 hours. Thus, the rescue opiates consumption may vary from 0 to 4/day.

Inclusion Criteria: First (not recurrent) posterior spinal surgery at the operated site American Society of Anesthesiologists class I or II (operative risk) Exclusion Criteria: Allergy to local anesthetics or to clonidine Pregnancy Raynaud's syndrome Thromboangiitis obliterans History of substance abuse Current treatment with corticosteroids

Abdel Hay J, Kobaiter-Maarrawi S, Tabet P, Moussa R, Rizk T, Nohra G, Okais N, Samaha E, Maarrawi J. Bupivacaine Field Block With Clonidine for Postoperative Pain Control in Posterior Spine Approaches: A Randomized Double-Blind Trial. Neurosurgery. 2018 Jun 1;82(6):790-798. doi: 10.1093/neuros/nyx313.