EFFECT OF PREEMPTIVE CAUDAL DEXMEDETOMIDINE - BUPIVACAINE MIXTURE IN ADULT PATIENTS UNDERGOING SINGLE LEVEL LUMBAR LAMINECTOMY: A PROSPECTIVE RANDOMIZED STUDY

Post-operative pain after Laminectomy is a great challenge. Caudal Bupivacaine analgesia is an option but with short time. Dexmedetomidine a selective alpha 2 agonist with α2:α1 action of 1600:1 has sedative and analgesic properties and used before via epidural and caudal roots safely and effectively. Methods: Our study was done on 50 patients ASA I and II scheduled for elective single level lumbar hemi partial Laminectomy. Patients were divided into two groups: group B (n=25) received caudal 20 ml of isobaric Bupivacaine 0.25% while group BD (n=25) received same volume of isobaric Bupivacaine 0.25% mixed with Dexmedetomidine 1 mcg/kg, caudal injections were done after general anesthesia and 20 minutes before skin incision . The following parameters were recorded: Hemodynamic changes (pulse and blood pressure), end-tidal Sevoflurane, BIS, narcotic need intra and post operatively, PCA boluses, OAA/S sedation score, and finally time to first void. Results: There were no statistical differences between groups according to the hemodynamic parameters except intra and post operative bradycardia in the BD group till 8 hours post operatively. BD group had less Fentanyl supplementation intraoperatively, lower BIS, and less end-tidal Sevoflurane. Postoperatively BD group had longer time needed for the first post operative analgesia than B group with mean and standard deviation of 495.200 +/- 95.224, and 262.000 +/- 22.913 minutes respectively. Total morphine consumption was higher in the B group than the BD group with mean and standard deviation of 31.760 +/- 1.269, and 25.300 +/- 0.764 mg respectively. PCA boluses and VAS for pain were higher in the B group than the B group. Time to 1st void was longer in the BD group than the BD group with mean and standard deviation of 448.000 +/- 36.286 and 210 +/- 10.801 minutes respectively. Conclusions: Addition of Dexmedetomidine 1mcg/Kg to Bupivacaine caudally for cases of single level lumbar hemi partial Laminectomy preoperatively leads to better analgesia both intra and post-operatively as shown by less need for analgesia supplementation, together with lower intra-operative BIS. Also patients with Dexmedetomidine had higher level of post operative sedation and longer first void interval, with minimal hemodynamic affection in the form of bradycardia.