Effect of a preemptive caudal dexmedetomidine-bupivacaine mixture in adult patients undergoing a single-level lumbar laminectomy : a prospective randomized study

الملخص EN

Background Postoperative pain after laminectomy is a huge challenge.

Caudal bupivacaine analgesia is an option but for a short duration.

Dexmedetomidine, a selective a2 agonist with an a2 : a1 action of 1600 : 1, has sedative and analgesic properties and can be used before, through epidural and caudal roots, safely and effectively.

Methods Our study was carried out on 50 patients (American Society of Anesthesiologists Classification I and II) scheduled for an elective single-level lumbar hemipartial laminectomy.

Patients were divided into two groups: group B (n = 25) received caudal 20 ml of isobaric bupivacaine (0.25%), whereas group BD (n =25) received the same volume of isobaric bupivacaine (0.25%) mixed with dexmedetomidine 1 mcg/kg; caudal injections were administered after general anesthesia and 20 min before skin incision.

The following parameters were recorded: hemodynamic changes (pulse and blood pressure), end-tidal sevoflurane, bispectral index (BIS), narcotic need intraoperatively and postoperatively, patient-controlled analgesia boluses, the observer assessment of alertness/sedation score, and the time to first void.

Results There were no statistical differences between the groups in the hemodynamic parameters, except intraoperative and postoperative bradycardia in the BD group until 8 h postoperatively.

The BD group had less fentanyl supplementation intraoperatively, lower BIS, and less end-tidal sevoflurane.

Postoperatively, the BD group required a longer time for the first postoperative analgesia than B group, with a mean ± SD of 495.200 ±95.224 and 262.000 ±22.913 min, respectively.

The total morphine consumption was higher in the B group than the BD group, with a mean ± SD of 31.760± 1.269 and 25.300± 0.764 mg, respectively.

Patient-controlled analgesia boluses and visual analogue scale for pain were higher in the B group than the B group.

Time to first void was longer in the BD group than the BD group, with a mean ± SD of 448.000± 36.286 and 210 ± 10.801 min, respectively.

Conclusion The addition of dexmedetomidine 1 mcg/kg to bupivacaine caudally for cases of a single-level lumbar hemipartial laminectomy preoperatively leads to better analgesia both intraoperatively and postoperatively as shown by a reduced need for analgesia supplementation, together with lower intraoperative BIS.

Also, patients with dexmedetomidine had a higher level of postoperative sedation and a longer first-void interval, with minimal hemodynamic effect in the form of bradycardia