1285. The Impact of Preventative Multimodal Analgesia on Postoperative Opioid Requirement and Pain Control in Patients Undergoing Lumbar Fusions

Authors: Sharad Rajpal, MD, FAANS ; Steven Hobbs, PhD; Ewell Nelson, MD; Christopher Zielenski, PhD; Sigita Burneikiene, MD; Alan Villavicencio, MD; Vinod Kantha (Boulder, CO)

Introduction: Preventive multimodal analgesia (PMA) addresses multiple sources and pathways of acute and chronic pain by interfering with peripheral and central sensitization and should provide a way to achieve safer and more effective pain management with reduced opioid medication use. The main objectives of this study were to determine the impact of PMA on postoperative opioid requirements and analgesic effectiveness in patients undergoing lumbar fusion surgery. Methods: A prospective observational study with a historical reference group was performed. The study compared postoperative opioid requirement and analgesic effect in a total of 103 patients undergoing elective, one- or two-level transforaminal lumbar interbody fusion (TLIF) surgeries for symptomatic lumbar degenerative disc disease. The PMA patient group included 52 consecutive patients who received 1000 mg of acetaminophen, 300 – 900 mg of gabapentin, and 200 – 400 mg of celecoxib one hour before the procedure. The reference group included 51 patients who received 15 mg of morphine-equivalent dose (MED) preoperatively. Multiple linear regression was used to evaluate the influence of PMA on pain, MED and acetaminophen use over 4 postoperative days (PODs), while controlling for all variables likely to influence these outcomes, including age, sex, baseline opioid use, duration of surgery, post-operative intrathecal morphine use and administration of muscle relaxants and anticonvulsants. Results: The differences in opioid requirement and postoperative pain scores were statistically significant on all four postoperative days. The effect size varied from -0.54 to -0.99 for the postoperative opioid requirement and from -0.59 to -1.16 for postoperative pain indicating that these measures were reduced by about ½ to 1 standard deviation in the PMA patient group. Conclusion: PMA is a highly effective method for postoperative pain management in patients undergoing lumbar fusion surgeries, which not only improves pain control, but also reduces opioid requirement.