Hypocalcemia or Hypercalcemia (see Hypocalcemia, [[Hypocalcemia]] and Hypercalcemia, [[Hypercalcemia]])
Patients are typically hypocalcemic during the oliguric phase of AKI (ATN): probably due to calcium deposition in the injured muscle tissues
Approximately 30% of patients are hypercalcemic during the recovery/diuretic phase of AKI (ATN): due to increased 1,25-Dihydroxyvitamin D3, which occurs during this phase
Abnormal Findings on Urinalysis
Large Blood Detected on Urinary Dipstick with Minimal RBC’s on Microscopy: as urinary dipstick detects myoglobin
Hypocalcemia (During Early Oliguric Phase of ATN): should not be treated unless patient has arrhythmias, hemodynamic instablity, hyperkalemia, or seizures
Administered calcium may complex with phosphate and produce metastatic calciification (especially intramuscularly)
Hypercalcemia (During Recovery/Diuretic Phase of ATN): no treatment necessary (as this occurs due to increased 1,25-Dihydroxyvitamin D3, which occurs during this phase)
hyperphosphatemia : usually not clinically significant (but will respond to urinary alkalinization with diuresis
Hyperuricemia: usually not clinically significant and does not require treatment
Expansion of extracellular volume is critical: injured myocytes sequester fluids
Expansion of intravascular volume increases the glomerular filtration rate, oxygen delivery, and dilutes myoglobin and other renal tubular toxins
Although there are no randomized trials of hydration in rhabdomyolysis, retrospective studies in crush injury patients indicate that early (pre-hospital) IVF hydration improves prognosis
Patients with CK >15,000 IU/L may require IVF resuscitation in excess of 6L
Urinary alkalization should be considered earlier in patients with acidemia, dehydration, or pre-existing renal disease
Although randomized trials are lacking, retrospective and animal studies support this practice
Bicarbonate infusion may precipitate hypocalcemia: must follow serial calcium during bicarbonate infusion
Invasive Monitoring (Central Venous Pressure, Swan-Ganz Catheterization, Arterial Line): may be required to assure adequate fluid resuscitation (especially in patients with cardiac or renal disease)
Role of Diuretics: lasix or mannitol may be considered in cases with oliguria despite adequate intravascular volume (however, these should be avoided in cases with inadequate intravascular volume)
Monitor Serial CK Levels + Myoglobinuria
Follow serial CK levels at least q6hrs
Aggressive IVF resuscitation should be continued until myoglobinuria is cleared
Hemodialysis
May be required in cases with AKI + refractory hyperkalemia/acidosis or pulmonary edema/congestive heart failure
Free-Radical Scavengers/Antioxidants
Examples: pentoxifylline, vitamin E, and vitamin C
Despite animal studies, these have an unclear role in management of rhabdomyolysis
Treatment of Fractures/Sites of Muscle Injury
Orthopedic treatment, as required
Management of Compartment Syndrome (see Compartment Syndrome, [[Compartment Syndrome]]): if present
Intracompartment pressure >30 mm Hg: requires fasciotomy
Prolonged elevated intracompartmental pressure may lead to further muscle injury and/or irreversible peripheral nerve injury
References
Factors predictive of acute renal failure in rhabdomyolysis. Arch Intern Med. Jul 1988;148(7):1553-7 [MEDLINE]
Rhabdomyolysis and secondary renal failure in critically ill surgical patients. Am J Surg 2004; 188:801– 806 [MEDLINE]
Hypocalcemia and hypercalcemia in patients with rhabdomyolysis with and without acute renal failure. J Clin Endocrinol Metab. 1986 Jul;63(1):137-42 [MEDLINE]
