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THE MORNING REPORT

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Jaclyn Angielczyk, MD
Sep 20, 2023

Rhabdomyolysis - the other red meat

History:

49 year old male, past medical history of polysubstance abuse presents via ambulance after he was found down, concern for possible drug overdose. States he does not remember what happened, but that he remembers, "snorting heroin and maybe fentanyl this morning". Patient complains of bilateral lower extremity pain and the inability to move his legs. Denies IV drug use.


Physical:

Vitals: HR 105, RR 18, SpO2 92%, BP 92/58

General: Drowsy, A&O x3

Cardiac: tachycardia, normal S1, S2. no murmurs, rubs, gallops.

Pulmonary: lungs clear to auscultation. equal chest rise

Abdomen: soft, nontender, nondistended.

Musculoskeletal: Lower extremities soft, nontender, bilateral PDs intact, pain with passive leg movement. Cannot move legs secondary to pain.


Labs




Rhabdomyolysis

Definition and pathophysiology:

  • Muscle injury that results in leakage of extracellular calcium ions that cause interaction of actin and myosin that causes muscle destruction and fiber necrosis

  • Subsequently causes leakage of potassium, phosphate, myoglobin, and CK to leak into circulation

  • Myoglobin causes renal tubular obstruction leading to renal damage

  • Hyperphosphatemia binds to calcium causing hypocalcemia and calcium phosphate crystals further causing renal damage

  • Hyperkalemia leads to increase risk of cardiac arrhythmias

Causes:

  • Medications

    • Statins and Fibrates

    • Colchicine

    • TCAs, SSRIs, SNRIs, antipsychotics

    • antibiotics such as daptomycin, Bactrim, quinolones, amphotericin, HIV medications

    • Propofol

    • Antihistamines

    • Sympathomimetics

    • alcohol

    • Venomous exposures (snakes such as crotalids, spiders such as brown recluse spiders)

  • Physical injuries

    • Trauma

    • Compartment syndrome

    • Surgery (especially vascular & orthopedic surgeries)

    • Coma

    • Ischemic Limbs

    • Electrical injuries/burns

  • Excessive muscle activity

    • Marathon running

    • Status epilepticus

    • Status asthmaticus

    • Serotonin syndrome

    • Neuroleptic malignant syndrome

    • Excessive exercise against high resistance

  • Dysthermia & electrolyte abnormalities

    • Hyperthermia / Hypothermia

    • Hypophosphatemia

    • Hypocalcemia

    • Hypokalemia

    • Hypernatremia / Hyponatremia

    • Hyperosmolarity

    • Hypothyroidism / hyperthyroidism

Signs and Symptoms

  • Muscle pain (23%)

  • Swelling / cramping

  • Muscle weakness (12%)

  • Brown / cola colored urine (myoglobinuria)

Laboratory Abnormalities


  • Elevated Uric acid & LDH

  • Isolated elevated AST

  • UA positive for Heme, however, no RBCs

Diagnosis



Treatment

  1. Evaluate and treat any underlying problems (compartment syndrome, ischemic limb), and discontinue any causative medications.

  2. Electrolyte management

    1. Hyperkalemia: CB DIAL K

      1. Calcium - stabilizes cardiac membrane reducing risk for arrhythmias

      2. Bicarbonate - Alkalizes blood shifting potassium into cells

      3. Dialysis - removes K from body

      4. Insulin - shifts potassium into cells

      5. Lasix - diuresis potassium

      6. K binding agents - Sodium polystyrene sulfonate, patiromer, sodium zirconium cyclosilicate

    2. Do not treat hypocalcemia (may worsen muscle injury)

  3. Fluid resuscitation

    1. Bicarbonate for metabolic acidosis

  4. Consider emergent CRRT for refractory cases


Prognosis

References



Jaclyn Angielczyk, MD

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