Rhabdomyolysis — Viva

Q1: Definition, classification and causes (3 min)

Define rhabdomyolysis as skeletal muscle breakdown with leakage of contents (myoglobin, CK, potassium, phosphate). Stahl: mild disease is acute muscle weakness, myalgia and swelling plus CK over 1000 IU/L or over 5 times ULN; myoglobinuria and AKI mark severe disease. Zutt's alternative is CK at least 10 times ULN with a rapid fall. Melli: toxins (illicit drugs, alcohol, prescribed drugs) 46%; multiple factors 60%; no cause 7%. Cervellin still lists direct muscle injury as the most common cause of muscle injury, plus hereditary enzyme disorders, drugs, toxins, endocrinopathies, MH, NMS, heatstroke, hypothermia, electrolyte change, DKA/HHS, thyroid disease and infection.^[1][2][3][5]

Q2: Pathophysiology (3 min)

Warren: common final pathway is uncontrolled free intracellular calcium and calcium-dependent proteases destroying myofibrils. Zutt: ARF from ATN due to mechanical obstruction by myoglobin is the most common complication, particularly if sCK is over 16 000 IU/L. Petejova: the belief that AKI is simply myoglobin-as-toxin is oversimplified. Veenstra: hyperkalaemia at or above 5.5 mmol/L in 13% of severe cases, all with impaired renal function; hypocalcaemia at or below 2.00 mmol/L in 41%.^{[3][4][9][11]}

Q3: Clinical presentation and diagnosis (2 min)

Cervellin: classic triad of pain, weakness and dark urine, although more than 50% do not complain of pain or weakness. Zutt: the full triad is seen in less than 10%. Laboratory diagnosis rests essentially on CK. Melli: urine myoglobin positive in only 19% — a negative qualitative assay does not exclude rhabdomyolysis.^[2][3][5]

Q4: Resuscitation and definitive management (3 min)

Cornerstone: early vigorous fluid. Cervellin: 1.5–2 L saline immediately then 1.5–2 L/h. Better: at least 12 L/day alkaline solution started at the scene. Geldermann: IV calcium salts for ECG changes or potassium at or above 6.5 mmol/L. Petejova: do not start RRT on myoglobin or CK concentration. McQueen: decompress when diastolic minus compartment pressure falls under 30 mmHg; an absolute 30 mmHg threshold over-triages.^{[2][7][9][17][18]}

Q5: Complications, pitfalls and special situations (2 min)

Better: early mortality from hypovolaemic shock, hyperkalaemia, acidosis and myoglobinuric AKI — not a single ranked cause of death. Das: do not treat early hypocalcaemia on the number alone; rebound hypercalcaemia in recovery is rare but serious. SEARCH: stop the statin; SLCO1B1 rs4149056 C allele OR 4.5 per copy on simvastatin 80 mg. Recurrent episodes, exercise intolerance or a family history of neuromuscular disease need investigation for an underlying genetic disorder (Zutt; Melli 11% recurrent, 10% myopathy).^{[3][5][7][14][23]}

References12ShowHide

1. [1]Stahl K, Rastelli E, Schoser B A systematic review on the definition of rhabdomyolysis J Neurol, 2020.PMID 30617905
2. [2]Cervellin G, Comelli I, Lippi G Rhabdomyolysis: historical background, clinical, diagnostic and therapeutic features Clin Chem Lab Med, 2010.PMID 20298139
3. [3]Zutt R, van der Kooi AJ, Linthorst GE, et al. Rhabdomyolysis: review of the literature Neuromuscul Disord, 2014.PMID 24946698
4. [4]Veenstra J, Smit WM, Krediet RT, et al. Relationship between elevated creatine phosphokinase and the clinical spectrum of rhabdomyolysis Nephrol Dial Transplant, 1994.PMID 7970089
5. [5]Melli G, Chaudhry V, Cornblath DR Rhabdomyolysis: an evaluation of 475 hospitalized patients Medicine (Baltimore), 2005.PMID 16267412
6. [7]Better OS, Abassi ZA Early fluid resuscitation in patients with rhabdomyolysis Nat Rev Nephrol, 2011.PMID 21587227
7. [9]Petejova N, Martinek A Acute kidney injury due to rhabdomyolysis and renal replacement therapy: a critical review Crit Care, 2014.PMID 25043142
8. [11]Warren JD, Blumbergs PC, Thompson PD Rhabdomyolysis: a review Muscle Nerve, 2002.PMID 11870710
9. [14]Link E, Parish S, Armitage J, et al. SLCO1B1 variants and statin-induced myopathy — a genomewide study N Engl J Med, 2008.PMID 18650507
10. [17]Geldermann N, Dzimiera J, Fischer H, et al. Acute hyperkalaemia in emergency care: evidence-based approaches Emerg Med J, 2026.PMID 41506858
11. [18]McQueen MM, Court-Brown CM Compartment monitoring in tibial fractures. The pressure threshold for decompression J Bone Joint Surg Br, 1996.PMID 8898137
12. [23]Das A, Silva J, Miyata K, et al. Rhabdomyolysis-induced resistant hypercalcemia during the recovery phase of acute kidney injury Cureus, 2026.PMID 42306390