149. Opioid sparing anesthesia for lumbar spinal fusion surgery reduces opioid consumption, blood loss and operative time: A propensity matched analysis

Abstract

<h3>BACKGROUND CONTEXT</h3> The recent opioid crisis in the US highlights opioid related side-effects and the dire need to reduce opioid exposure with alternative approaches. Prior studies reported that as many as 25% of opioid naive patients undergoing lumbar fusion surgery are still consuming opioids at 2 years postoperative. Currently, opioids are a primary component of anesthesia during spinal surgery. We developed an opioid sparing anesthesia (OSA) protocol for lumbar spinal fusion surgery to mitigate opioid exposure. <h3>PURPOSE</h3> To compare surgical, peri- and postoperative process measures and in-hospital opioid consumption in patients receiving OSA vs traditional anesthesia. <h3>STUDY DESIGN/SETTING</h3> Retrospective, single center propensity-matched observational cohort study. <h3>PATIENT SAMPLE</h3> Patients who underwent 1-4 level lumbar fusion for degenerative conditions. <h3>OUTCOME MEASURES</h3> Daily and total opioid consumption in morphine milligram equivalents (MME). <h3>Methods</h3> Patients undergoing < 5-level lumbar fusion for degenerative conditions were identified. Patients taking opioids preoperatively were excluded. Patients receiving OSA were propensity-matched to non-OSA patients based on sex, smoking status, BMI, ASA grade and revision vs primary procedure. Preoperatively patients receive an oral regimen of cyclobenzaprine (10mg), gabapentin (300-600mg), acetaminophen (650-1g), Celebrex (200mg), and/or methadone (5-10mg). The intraoperative OSA protocol includes a combination of IV propofol, lidocaine, ketamine, magnesium, dexmedetomidine, and esmolol as needed. Anesthesia was maintained with inhalational agents or TIVA. Postoperatively patients received a bilateral transverse abdominis plane or erector spinae block with 0.25% Ropivacaine/4mg decadron mixture. A standard opioid escalation protocol was also utilized in the hospital postoperatively. We evaluated surgical parameters (EBL and OR Time), immediate perioperative parameters (emergence time, PACU time, pain score on transfer in/out of PACU), and length of stay (LOS). <h3>Results</h3> Of 143 OSA patients meeting inclusion criteria, 134 OSA patients were successfully propensity matched to 134 non-OSA patients. Consistent with propensity matching, there was no difference in baseline demographic parameters between cohorts. Patients undergoing OSA had reduced EBL (197mL vs 324mL, p=0.000) and OR time (153min vs 193min, p=0.000) compared to non-OSA. Emergence time (9.9min vs 11.6min, p=0.151) and PACU time (90min vs 88min, p=0.688) was similar between cohorts. There was no difference in LOS (3.3day vs 3.5 days, p=0.599). Daily opioid consumption was reduced from POD 1 (114MME vs 139MME, p=0.002) and maintained each day with decreased total consumption (195MME vs 272MME, p=0.002). Pain score on transfer out of PACU was decreased for OSA patients as well (4.8 vs 6.0, p=0.000). <h3>Conclusions</h3> In a matched comparison of OSA vs traditional anesthesia for 1-4 lumbar spinal fusions in degenerative conditions we found a reduction in EBL, OR Time, PACU pain scores, and daily/total opioid in hospital consumption. The findings of this pilot study justify ongoing efforts to optimize OSA and undertake larger prospective studies of OSA protocols. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.