Transitioning from intrathecal bupivacaine to mepivacaine for same-day discharge total joint arthroplasty: a quality improvement study

IntroductionSame-day discharge total knee and hip arthroplasty is becoming more common. Anesthetic approaches that optimize readiness for discharge are important. Based on an institutional change from low-dose bupivacaine to mepivacaine, we aimed to assess the impact on postanesthesia care unit (PACU) recovery in a quaternary care, academic medical center. MethodsIn this quality improvement retrospective study, a single surgeon performed 96 combined total knee and hip arthroplasties booked as same-day discharge from September 20, 2021 to December 20, 2021. Starting on November 15, 2021 the subarachnoid block was performed with isobaric mepivacaine 37.5-45 mg instead of hyperbaric bupivacaine 9-10.5 mg. We compare these cohorts for time to discharge from PACU, perioperative oral morphine milligram equivalent (OMME) administration, PACU pain scores, conversion to general anesthesia (GA), and overnight admission. ResultsWe found the use of isobaric mepivacaine as compared with hyperbaric bupivacaine for intrathecal block in same-day discharge total joint arthroplasty was associated with decreased length of PACU stay at our academic center (median 4.03 vs 5.33 hours; p=0.008), increased perioperative OMME (mean 22.5 vs 11.4 mg; p<0.001), increased PACU pain scores (mean 6.29 vs 3.41; p<0.01) and no difference in conversion to GA or overnight admission. ConclusionsIntrathecal mepivacaine was associated with increased perioperative OMME consumption and PACU pain scores, but still realized a decreased PACU length of stay.