Reduction of Opioid Use With Enhanced Recovery Program for Total Knee Arthroplasty

Perioperative Opioid Use

Of the SOC patients, 99.0% received narcotics intraoperatively (range, 0-198 mg MED), and 74.5% received narcotics during PACU recovery (range, 0-141 mg MED). The total oral MED during the hospital stay for the SOC patients ranged from 10 to 2,946 mg. Of the ERAS patients, 86% received no narcotics during surgery (range, 0-110 mg MED), and 98% received no narcotics during PACU recovery (range, 0-65 mg MED). The total oral MED during the hospital stay for the ERAS patients ranged from 10 to 240 mg.

The MED used was significantly lower for the ERAS patients than it was for the SOC patients during surgery (10.5 mg vs 57.4 mg, P = .0001, FDR = .0002) and in the PACU (1.3 mg vs 13.6 mg, P = .0002, FDR = .0004), during the inpatient stay (66.7 mg vs 169.5 mg, P = .0001, FDR = .0002), and on hospital discharge (419.3 mg vs 776.7 mg, P = .0001, FDR = .0002). However, there was no significant difference in the total MED prescriptions filled between patients on the ERAS protocol vs those who received SOC during the 3-month period after hospital discharge (858.3 mg vs 1126.1 mg, P = .29, FDR = .29)(Table 3).

Finally, the logistic regression analysis, adjusting for the covariates demonstrated that the ERAS patients were less likely to take narcotics at 6 months following hospital discharge (OR, 0.23; P = .013; FDR = .018) and less likely to have postoperative nausea and vomiting (OR, 0.18; P = .019; FDR = .02) than SOC patients. There was no statistically significant difference between complication rates for the SOC and ERAS groups, which were 11.2% and 5.0%, respectively, with an overall complication rate of 9.1% (P = .09)(Table 4).

Discussion

Orthopedic surgery has been associated with long-term opioid use and misuse. Orthopedic surgeons are frequently among the highest prescribers of narcotics. According to Volkow and colleagues, orthopedic surgeons were the fourth largest prescribers of opioids in 2009, behind primary care physicians, internists, and dentists.¹⁷ The opioid crisis in the United States is well recognized. In 2017, > 70,000 deaths occurred due to drug overdoses, with 68% involving a prescription or illicit opioid. The Centers for Disease Control and Prevention has estimated a total economic burden of $78.5 billion per year as a direct result of misused prescribed opioids.¹⁸ This includes the cost of health care, lost productivity, addiction treatment, and the impact on the criminal justice system.

The current opioid crisis places further emphasis on opioid-reducing or sparing techniques in patients undergoing TKA. The use of liposomal bupivacaine for intraoperative periarticular injection is debated in the literature regarding its efficacy and whether it should be included in multimodal protocols. Researchers have argued that liposomal bupivacaine is not superior to regular bupivacaine and because of its increased cost is not justified.^19,20 A meta-analysis from Zhao and colleagues showed no difference in pain control and functional recovery when comparing liposomal bupivacaine and control.²¹ In a randomized clinical trial, Schroer and colleagues matched liposomal bupivacaine against regular bupivacaine and found no difference in pain scores and similar narcotic use during hospitalization.²²

Studies evaluating liposomal bupivacaine have demonstrated postoperative benefits in pain relief and potential opioid consumption.²³ In a multicenter randomized controlled trial, Barrington and colleagues noted improved pain control at 6 and 12 hours after surgery with liposomal bupivacaine as a periarticular injection vs ropivacaine, though results were similar when compared with intrathecal morphine.²⁴ Snyder and colleagues reported higher patient satisfaction in pain control and overall experience as well as decreased MED consumption in the PACU and on postoperative days 0 to 2 when using liposomal bupivacaine vs a multidrug cocktail for periarticular injection.²⁵

The PILLAR trial, an industry-sponsored study, was designed to compare the effects of local infiltration anesthesia with and without liposomal bupivacaine with emphasis on a meticulous standardized infiltration technique. In our study, we used a similar technique with an expanded volume of injection solution to 140 ml that was delivered throughout the knee in a series of 14 syringes. Each needle-stick delivered 1 to 1.5 ml through a 22-gauge needle to each compartment of the knee. Infiltration technique has varied among the literature focused on periarticular injections.

In our experience, a standard infiltration technique is critical to the effective delivery of liposomal bupivacaine throughout all compartments of the knee and to obtaining reproducible pain control. The importance of injection technique cannot be overemphasized, and variations can be seen in studies published to date.²⁶ Well-designed trials are needed to address this key component.

There have been limited data focused on the veteran population regarding postoperative pain-management strategies and recovery pathways either with or without liposomal bupivacaine. In a retrospective review, Sakamoto and colleagues found VA patients undergoing TKA had reduced opioid use in the first 24 hours after primary TKA with the use of intraoperative liposomal bupivacaine.²⁷ The VA population has been shown to be at high risk for opioid misuse. The prevalence of comorbidities such as traumatic brain injury, posttraumatic stress disorder, and depression in the VA population also places them at risk for polypharmacy of central nervous system–acting medications.²⁸ This emphasizes the importance of multimodal strategies, which can limit or eliminate narcotics in the perioperative period. The implementation of our ERAS protocol reduced opioid use during intraoperative, PACU, and inpatient hospital stay.

While the financial implications of our recovery protocol were not a primary focus of this study, there are many notable benefits on the overall inpatient cost to the VHA. According to the Health Economics Resource Center, the average daily cost of stay while under VA care for an inpatient surgical bed increased from $4,831 in 2013 to $6,220 in 2018.²⁹ Our reduction in length of stay between our cohorts is 44.5 hours, which translates to a substantial financial savings per patient after protocol implementation. A more detailed look at the financial aspect of our protocol would need to be performed to evaluate the financial impact of other aspects of our protocol, such as the elimination of patient-controlled anesthesia and the reduction in total narcotics prescribed in the postoperative global period.