Effects of perioperatively administered bupivacaine and bupivacaine-methylprednisolone on pain after lumbar discectomy

Abstract

Study design: A prospective, randomized, controlled trial that compared the efficacy of different protocols of local tissue infiltration with bupivacaine or bupivacaine-methylprednisolone at the surgical site for pain relief after lumbar discectomy.

Objective: To determine the efficacy of preemptive wound infiltration with bupivacaine and bupivacaine-methylprednisolone after lumbar discectomy.

Summary of background data: Patients usually have significant pain after lumbar discectomy. Wound infiltration with bupivacaine or bupivacaine-methylprednisolone is one method to address this.

Methods: Seventy-five patients were randomly allocated to 5 equal groups as follows: Group I (n = 15) had the musculus multifidi near the operated level infiltrated with 30 mL 0.25% bupivacaine and 40 mg methylprednisolone just before wound closure; Group II (n = 15) had the same region infiltrated with 30 mL 0.25% bupivacaine alone before closure; Group III (n = 15) had this region infiltrated with 30 mL 0.25% bupivacaine and 40 mg methylprednisolone before the incision was made; in Group IV (n = 15), this region infiltrated with 30 mL 0.25% bupivacaine alone before incision; and Group C (controls, n = 15) had this region infiltrated with 30 mL 0.9% NaCl just before wound closure. Demographics, vital signs, postoperative pain scores, and morphine usage were recorded.

Results: All 4 groups treated with bupivacaine or bupivacaine-methylprednisolone (by preemptive or preclosure wound infiltration) showed significantly better results than the control group for most parameters. The treated groups had lower parenteral opioid requirements after surgery, lower incidences of nausea, and shorter hospital stays. Further, the data indicate that, compared with infiltration of these drugs at wound closure, preemptive injection of bupivacaine or bupivacaine-methylprednisolone into muscle near the operative site provides more effective analgesia after lumbar discectomy.

Conclusion: In addition, our data suggest that preemptive infiltration of the wound site with bupivacaine alone provides similar pain control to preemptive infiltration of the wound site with bupivacaine and methylprednisolone combined.