Incidence of local anesthetic systemic toxicity in patients receiving bupivacaine infiltration analgesia for total joint arthroplasty under general anesthesia: a retrospective single-center study.

Background: Local infiltration analgesia (LIA) is a crucial component of multimodal analgesia that enhances recovery after total hip arthroplasty (THA) and knee arthroplasty (TKA). However, LIA can cause fatal local anesthetic systemic toxicity (LAST). The incidences of LIA-induced LAST in different surgeries and anesthetic agents have not been well investigated.

Methods: This observational study enrolled 1,267 adult patients who received LIA with bupivacaine for primary THA or TKA under general anesthesia at a single medical center between January 2020 and October 2021. LAST incidence was graded by severity: severe (refractory seizure or arrhythmia requiring lipid rescue), major (seizure or arrhythmia requiring prompt medication), and minor (all other) events. Patient demographics, surgical and anesthesia details, recovery profiles, and LAST incidences were recorded and analyzed.

Results: The incidence of severe LAST events was 2.41 per 1000 in unilateral THA, 0 in TKA, and 3.16 per 1000 in the entire cohort. The odds ratio of developing major LAST events was 4.35 in patients undergoing unilateral THA compared with those undergoing unilateral TKA in a matched comparison. Patients who underwent bilateral THA had the highest risk of developing LIA-induced LAST. Additionally, patients using propofol infusion for anesthesia maintenance had a lower risk of seizures and tremors than those using sevoflurane inhalation. The odds ratio of major LAST events was 0.47 in matched comparisons.

Conclusions: LIA was associated with a significantly higher risk of LAST in the THA group than in the TKA group. Propofol maintenance reduces the likelihood of seizures and tremors compared with sevoflurane inhalation. Exploring strategies to reduce the incidence of LIA-induced LAST is essential to improve perioperative patient safety.