Role of postoperative continuous subfascial bupivacaine infusion after posterior cervical laminectomy: Randomized control study

Introduction
One of the major drawbacks of posterior cervical decompression and rigid internal fixation is the severe postoperative neck pain created by extensive soft tissue and muscular dissection. The usual management of acute postsurgical pain consists of systemic opioids or non-steroidal anti-inflammatory drugs. Another satisfying method of postoperative pain relief is continuous local infusion of analgesic agents in posterior subfascial paravertebral space on both sides of the wound using epidural catheters.
Methods
Sixty patients scheduled for cervical laminectomy with fixation surgery via the posterior midline approach with postoperative epidural catheters placed subfascially on both sides of the wound. They were randomly divided into two groups, bupivacaine group with local infiltration of 0.5% bupivacaine at the rate 2 ml/h, and control group with saline infusion at a rate 2 ml/h. The patient controlled analgesia device (PCA) was given to all patients and set to deliver IV morphine in 1 mg boluses with a lock out at 10 min and a 4 h maximum 10 mg.
Results
The visual analog score was statistically significant lower in bupivacaine group compared to control group during the first 60 h postoperatively. While in 66 and 72 h postoperatively there was no statistical significant difference was observed between the two groups. The total doses of morphine delivered by PCA in the three postoperative days were statistically significantly higher in control group than bupivacaine group. The incidence of side effects related to narcotics was higher in control than bupivacaine group.
Conclusion
Bilateral subfascial continuous 0.5% bupivacaine infiltration through an ordinary epidural catheter at the rate 2 ml/h for three successive postoperative days is associated with better pain control, reduced narcotics, early ambulation and no serious side effects in the postoperative period in patients undergoing posterior cervical fixation.