Postoperative Continuous Paravertebral Anesthetic Infusion for Pain Control in Lumbar Spinal Fusion Surgery

Study Design. A retrospective, case-control study was conducted to analyze postoperative outcomes in patients who received local anesthetic infusion pumps after lumbar spinal fusion procedures. Data were collected prospectively via nursing protocol and third party assessment, and analyzed retrospectively. Objective. To review the safety and efficacy of continuous infusion of local anesthetic into the subfascial aspects of the wound after lumbar fusion surgery for treatment of postoperative pain, and to determine whether other outcome measures such as postoperative nausea and vomiting, ambulation and length of hospitalization were affected by the presence of the device. Summary of Background Data. Patients who undergo lumbar spine fusion procedures frequently experience significant, debilitating pain related to their surgery. This pain may delay postoperative mobilization, increase length of hospitalization, and require prolonged use of high doses of narcotics. Use of a local anesthetic continuous-infusion pump after surgery may lead to improvements in these outcome variables. Methods. After posterior lumbar spine fusion procedures, 26 consecutive patients received the ON-Q PainBuster, which infused 0.5% marcaine via an elastomeric pump into the subfascial aspects of the wound. Retrospective analysis compared each of these patients with a case-matched control patient. Data included pain scores and opiate use during the first 5 postoperative days (PODs), length of hospital stay, and complications. Variables such as age, American Society of Anesthesiologists (ASA) physical status, and surgical procedure were similar between matched cases. One patient was excluded because of active heroine abuse. Results. Patients with the ON-Q PainBuster used 41.2% less narcotics on POD 1, 50.1% less on day 2, and 47.1% less on day 3 compared with the control patients. Differences in opiate usage were not statistically significant on POD 4 (45.5% less) and 5 (50.3% less). A lower average pain score was observed among patients with the ON-Q PainBuster on each POD: 39.1% less pain on POD 1, 34.0% on day 2, 45.1% on day 3, 29.5% on day 4, and 43.6% on day 5. No differences were observed in length of hospital stay or complication rate. Conclusion. Patients who received the ON-Q PainBuster used less narcotic medications than case-matched patients during the first 3 PODs, and reported lower pain scores during the first 5 PODs. No complications attributable to the device were noted. These results suggest that continuous infusion of local anesthetic into the wound during the immediate postoperative period is a safe and effective technique that results in lower pain scores and narcotic use. Further data may reveal additional benefits such as lower incidence of nausea and vomiting and decreased times to mobility and functional independence.