Cocaine-Induced Severe Rhabdomyolysis with Acute Kidney Injury: A Case Report of Massively Elevated Creatine Kinase Exceeding 1,000,000 U/L

Cocaine-associated rhabdomyolysis is a serious complication of stimulant intoxication characterized by skeletal muscle injury with the release of intracellular contents into the circulation, potentially resulting in acute kidney injury (AKI), severe electrolyte abnormalities, and other life-threatening complications.Fentanyl was also detected, but its contribution is difficult to determine.A 33-year-old male with a history of polysubstance use disorder presented after being found unresponsive on the floor with a posterior scalp laceration.He was combative during transport and arrived confused and obtunded.Urine drug screening was positive for cocaine and fentanyl (presumptive, unconfirmed); serum ethanol was 19 mg/dL.Initial laboratory evaluation demonstrated severe rhabdomyolysis with creatine kinase (CK) of 67,705 U/L, rising to a peak of 1,233,505 U/L on hospital day 2; pigmenturia suggestive of myoglobinuria; hyperkalemia (8.3 mEq/L); hypocalcemia (5.6 mg/dL); hyperphosphatemia (9 mg/dL); high anion gap metabolic acidosis (anion gap 21 mEq/L, lactate 18.8 mmol/L); and stage 3 AKI, with creatinine of 1.3 mg/dL on arrival, peaking at 5.7 mg/dL on hospital day 11.Electrocardiography demonstrated peaked Twave morphology consistent with hyperkalemia.Emergency management included intravenous calcium gluconate, insulin-dextrose therapy, sodium bicarbonate, fluid resuscitation, and emergent hemodialysis.Hemoadsorption therapy for myoglobin removal was considered but was unavailable.After improvement in mental status, left foot drop was recognized on hospital day 4. Evaluation revealed acute compartment syndrome (ACS) of the left lower extremity, requiring emergent anterior and lateral fasciotomy followed by multiple wound washouts, serial debridement, and wound vacuum-assisted closure exchanges.The patient was ultimately discharged on outpatient hemodialysis three times weekly, with wound care, surgical followup, and referral for substance use disorder counseling and harm reduction services.Renal recovery was documented about 12 weeks after presentation.This case highlights an extreme presentation of cocaine-associated rhabdomyolysis complicated by profound rhabdomyolysis-associated AKI, life-threatening metabolic derangements, and delayed recognition of ACS.Early recognition, fluid resuscitation, timely renal replacement therapy, and continued neurological surveillance beyond the acute metabolic phase are critical for optimizing outcomes.Clinicians should maintain a high index of suspicion for compartment syndrome and should not rely on classic signs in patients with severe rhabdomyolysis.