1. 2021;24;577-586Patterns of Use of Opioid Sparing Adjuncts for Perioperative Pain Management of Patients on Chronic Opioids
   Retrospective Study
   Sargis Ohanyan, MD, Devina Shiwlochan, MD, David Yanez, PhD, Colin-Beals Reid, MD, Kanishka Rajput, MD, and Robert Chow, MD.

BACKGROUND: Perioperative pain management of patients on chronic opioids is challenging. Although experts recommend regional anesthesia and multimodal analgesics for their opioid sparing effects, their use and predictors of use are unknown.

OBJECTIVES: To examine the patterns and predictors of use of regional anesthesia and multimodal analgesics for perioperative pain control of patients on chronic opioids. A secondary objective was to examine the association of patient and surgical factors with 24-hour postoperative opioid use.

STUDY DESIGN: Retrospective cross sectional.

SETTING: Single center tertiary care academic hospital.

METHODS: We studied patients with chronic opioid use undergoing painful operations such as abdominal, gynecologic, breast, orthopedic, spine, amputation, and laparoscopic surgeries. Chronic opioid use was identified using the narcotic score – a score generated from the state prescription drug monitoring database via the NarxCare platform. A narcotic score >= 320 corresponding to a preoperative home dose of approximately 40 milligram morphine equivalents (MMEs) daily, was chosen as a cutoff since the risk of overdose death increases above 40 MMEs. We reported the use of regional anesthesia and >= 3 multimodal analgesics in this cohort (n = 155) and examined the association of this use with patient and surgical factors such as preoperative narcotic score, age, race, comorbidity index, operative timetime, and intraoperative opioid use. In addition, we examined the association of patient and surgical factors with 24-hour postoperative opioid use.

RESULTS: Out of 2470 patients undergoing painful surgeries between July 2017and- December 2018, 155 patients had a narcotic score >= 320. The median narcotic score was 411 (interquartile range (IQR) 351-520), the median preoperative home MME dose was 67.5 (IQR 32-180) mg daily. Regional anesthesia was used in only 9.7% of cases and was associated with intraoperative opioid used, but not the preoperative narcotic score. Patients receiving 1 SD more MMEs intraoperatively had a higher odds of receiving regional anesthesia (OR = 1.57, 95% CI [1.06, 2.32]). Three or more multimodals were used in 83% of cases. Every 10-point increase in narcotic score and every additional hour of operative time was associated with higher odds of receiving >= 3 multimodals (OR = 1.05, 95% CI [1.00, 1.11] and OR = 1.49, 95% CI [1.11, 1.99] respectively). Total 24 hour post-operative opioid dose was associated with narcotic score, with an 8.6 higher mean MME for every 10-point increase in narcotic score (mean difference = 8.6, 95% CI [4.1, 13.1]). It was also moderately associated with age, where patients an year older received 4.7 MMEs less (mean difference = - 4.7, 95% CI [-9.3, -0.5]).

LIMITATIONS: This was a single center retrospective observational study. We could not adjust for inter-physician or inter-surgery effect on use of regional anesthesia or multimodal analgesics. Since this was one of the first studies to use narcotic scores to identify patients on chronic opioids, comparing the outcomes of interest to a control group was beyond the scope of the current study. Narcotic scores need to be validated to identify chronic opioid use.

CONCLUSIONS: Despite consensus guidelines, regional anesthesia remains underutilized. Multimodals are used frequently and are modestly associated with preoperative narcotic scores.

KEY WORDS: Chronic opioid use, preoperative opioid use, postoperative pain, regional anesthesia, multimodal analgesics, opioid sparing adjuncts, narcotic scores, NARX score

IRB approval: Institutional Review Board (IRB) approval was obtained per the University’s institutional guidelines.