• Rhabdomyolysis can result from a variety of traumatic and non-traumatic mechanisms that cause muscle injury and release intracellular muscle constituents into the circulation.
• Can result in life threatening acute renal failure, electrolyte and metabolic abnormalities, fluid shifts and disseminated intravascular coagulation (DIC).
• Early recognition and appropriate resuscitation can therefore be lifesaving.
• Many patients will likely need to be admitted for treatment and monitoring of potential complications. Depending on your setting, much of the initial management may occur in the ED.
• See the Rhabdomyolysis – Diagnosis for presentation details.

Management Overview

1. Finding and treating the underlying cause,
2. Prevention of renal failure, and
3. The management of life or limb-threatening complications (may require intubation; cardiac arrest from hyperkalemia, hypocalcemia and acidosis).
4. Essentially if the kidney function is normal and the CK is less than 5K, give a couple of liters NS and forget about it.
5. If the eGFR is 30 – 60, or CK 5K to 10K recheck after a few litres NS, and values are improving, can discharge home in 6 – 12 hours assuming no other problems.
6. If the eGFR of CK doesn’t improve after recheck, admit.
7. If eGFR is less than 30 or CK > 10K, may as well admit since that isn’t going to get better in 12 hours.
8. Use bicarb for elevated K or acidosis and such patients should be admitted.

More specifically

Volume Administration

• Volume expansion (bordering on hypervolemia) is critical to avoiding myoglobin-induced acute renal failure.
• Initiate aggressive fluid resuscitation early in treatment:
  • Choice of crystalloid type is controversial.
  • One recommended approach is to start volume repletion with normal saline at an initial rate from 200 to 1500 ml per hour depending on severity of rhabdomyolysis.
  • Target fluid rate to achieve a urine output of approximately 3 ml/kg/hr
  • Regularly check a serum pH to monitor for an iatrogenically induced hyperchloremic metabolic acidosis if using a large volume of normal saline.
  • Consider switching to Ringers Lactate or Plasmalyte after 2-4 litres fon saline.
  • IV fluids should be continued until CK concentration decreases to less than 1000 U/L.

Alkalization

• Bicarbonate administration is considered because urine alkalization, in theory, prevents heme-protein precipitation with Tamm-Horsfall proteins. There is no clear clinical evidence however that an alkaline diuresis is more effective than a saline diuresis in preventing AKI.
• Probably more benefit for hyperkalemia/acidosis.
• Check urine pH. If less than 6.5, consider urine alkalization with the following:
  • Sodium bicarbonate (150 mL [3 amps] of 8.4 percent sodium bicarbonate mixed with 1 L of 5 percent dextrose) via an intravenous line separate from that used for the isotonic saline infusion. The initial rate of infusion is 200 mL/hour; the rate is adjusted to achieve a urine pH of >6.5.
  • Bicarbonate may be given only if hypocalcemia is not present, arterial pH is less than 7.5 and serum bicarbonate is less than 30 mmol/L.
• If bicarbonate is given, the arterial pH and serum calcium should be monitored every two hours during the infusion.

Additional Medications

• Hyperkalemia: calcium gluconate/chloride, insulin-dextrose, B-2 agonists, NaHCO3.
• Loop diuretics may be indicated if volume overload is present.
• Administration of mannitol is not routinely recommended. If given, it should only be administered after volume replacement and avoided in patient with oliguria.
• May need hemodialysis but plasma exchange has not been shown to be beneficial.

 Complications

• Regularly monitor electrolytes for potentially life-threatening abnormalities.
  • Common electrolyte derangements in rhabdomyolysis include hyperkalemia, hyperphosphatemia, hypocalcemia and hyperuricemia.
  • Treatment electrolyte abnormalities are reviewed in another PECS.
• Monitor for compartment syndrome in affected extremities.
• Monitor for signs and symptoms of disseminated intravascular coagulation.

Consider Renal Replacement Therapy

• As with non-rhabdomyolysis related causes of renal failure, monitor for indications for emergent dialysis including
  • Uncorrectable metabolic acidosis
  • Life-threatening hyperkalemia and other electrolyte disturbances despite medical management
  • Manifestations of uremia, and anuria or oliguria
  • Fluid overload.

Disposition

• Most patients with rhabdomyolysis will likely require admission for parenteral fluid resuscitation, monitoring for complications as outlined above and treatment of coexisting injuries.

Prognosis

• Most patients with rhabdomyolysis will recover sufficient kidney function to be dialysis independent, and many recover to normal or near normal kidney function.
• The McMahon score for Rhabdomyolysis can be used as a predictive tool for morality and AKI
  • mdcalc.com

• The kidney function is normal and the CK is less than 5K, give a couple of litres NS and can discharge assuming underlying cause addressed.
• If the eGFR is 30 – 60, or CK 5,000-10,000:
  • recheck after a few litres NS, and if values are improving, can discharge home in 6 – 12 hours assuming no other problems.

1. Bosch X, Poch E, Grau JM. Rhabdomyolysis and acute kidney injury. N Engl J Med. 2009;361(1):62–72.
   
   
2. Khan FY. Rhabdomyolysis: a review of the literature. Neth J Med 2009; 67:272.
   
   
3. Perazella, Mark. Prevention and treatment of heme pigment-induced acute kidney injury.In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. (Accessed on November 21, 2020.)
   
   
4. Walls, Ron. Rosen’s Guide To Emergency Medicine 9th edition. Philadelphia, Elsevier INC, 2018.