Mepivacaine vs Bupivacaine Spinal Anesthesia in Total Hip Arthroplasty at an Ambulatory Surgery Center

BackgroundMepivacaine spinal anesthetic may facilitate more rapid postoperative recovery in joint arthroplasty than bupivacaine. This study compared recovery, pain, and complications between the 2 anesthetics in anterior-approach total hip arthroplasty (THA) at a free-standing ambulatory surgery center (ASC).MethodsThis retrospective cohort study of 282 consecutive patients with mean age 55.7 ± 8.8 years and body mass index 30.6 ± 5.3 who underwent THA at an ASC from November 2018 to July 2020 compares mepivacaine (n = 141) vs bupivacaine (n = 141) spinal anesthesia, a transition made in March 2019. The main outcomes were length of stay in the postoperative unit (post acute care unit) prior to same-day discharge (SDD), time to controlled void, and ambulation. Secondarily, postoperative pain scores (0-10) with morphine equivalents were required and any postoperative complications were compared.ResultsMepivacaine decreased mean post acute care unit stay (4.0 vs 5.7 hours, P < .001), time to void (3.1 vs 4.9 hours, P < .001), and ambulation (3.2 vs 4.5 hours, P < .001). No patients needed urinary catheterization or overnight stay. Two patients in the bupivacaine group had transient neurologic symptoms, consisting of foot drop and spinal headache, compared to none with mepivacaine (P = .498). Mepivacaine patients had increased postoperative pain at 2 hours (1.7 vs 0.9, P < .001), at discharge (1.1 vs 0.5, P = .004), and morphine equivalent doses received (7.8 vs 3.7 mg, P < .001).ConclusionMepivacaine spinal anesthesia for anterior-approach THA safely facilitated more rapid SDD from the ASC through decreased times to controlled void and ambulation with only minor increase in pain when compared to bupivacaine.Level of EvidenceLevel III – Retrospective comparative cohort study.