A FATAL PERIOPERATIVE STORM: SYNERGISTIC STATIN-HALOGENATED MYOTOXICITY WITH REFRACTORY HYPERKALAEMIA AND ACUTE KIDNEY INJURY - A CASE REPORT AND PROPOSED CLINICAL REASONING FRAMEWORK

Background: Statins and halogenated volatile anaesthetics are independently myotoxic, but their concurrent perioperative interaction remains poorly characterised.Current guidelines recommend perioperative statin continuation in coronary patients, yet the resulting pharmacological intersection with inhalational anaesthesia has not been integrated into routine risk stratification. Case Presentation: A 66-year-old woman receiving long-term high-intensity atorvastatin (40 mg/day), with poorly controlled type 2 diabetes (HbA1c 9.0%), recent inferior ST-elevation myocardial infarction with drug-eluting stent, and ischaemic cardiomyopathy (LVEF 35%), underwent uneventful 180-minute open reduction- internal fixation of an AO/OTA 13-C2 distal humeral fracture under sevoflurane in left lateral decubitus. Twenty two hours postoperatively, after an asymptomatic interval, she abruptly developed circulatory collapse, diffuse myalgia, anuria and obtundation. Investigations revealed massive rhabdomyolysis (creatine phosphokinase 31,010 IU/L), severe hyperkalaemia (8.0 mmol/L), KDIGO stage 3 acute kidney injury, severe metabolic acidosis (pH 7.20), and high-sensitivity troponin I 13,000 pg/mL with unchanged left-ventricular function. Despite intensive multimodal therapy and emergent intermittent haemodialysis, rebound hyperkalaemia and refractory cardiac arrest occurred 35 hours after surgery.