Rhabdomyolysis: Difference between revisions

Revision as of 02:44, 3 March 2011

Background

Muscle necrosis and the release of intracellular muscle constituents into the circulation
Causes
- 1. Traumatic or muscle compression
  - a. Crush injury
  - b. Immobilization
  - c. Compartment syndrome
- 2. Nontraumatic exertional
  - a. Exercise + hot weather
  - b. Exercise + sickle cell
  - c. Exercise + hypokalemia
  - d. Hyperkinetic states
    - Seizure
    - DTs
    - Stimulant overdose
    - Malignant hyperthermia
    - NMS
- 3. Nontraumatic nonexertional
  - a. Drugs and toxins
    - Coma induced by sedatives
    - Statins
    - Colchicine
    - CO poisoning
  - b. Infection
    - Viral myositis - Influenza, Coxsackie, EBV, HSV, HIV, CMV
    - Bacterial pyomyositis
    - Septicemia
  - c. Endocrine
    - Hypothyroidism
  - d. Inflammatory myopathies
    - Moderate CK elevations only (rhabdo only described in case reports)
  - e. Miscellaneous
    - Status asthmaticus
    - TSS
    - Mushroom ingestion

Diagnosis

Clinical

Myalgias
- May progress to weakness
Red/brown urine
Renal failure

Laboratory

Elevated total CK (typically > 10K)
- CK-MB may be entirely normal or may be mildly elevated (reflects small amount found in skeletal tissue)
Myoglobinuria
- Is cleared much faster than CK (may see elevated CK with no myoglobinuria)
Transaminitis
Creatinine increase (if renal failure)
Electrolyte Abnormalities
- Hyperkalemia
- Hyperphosphatemia
- Hypocalcemia
- Hyperuricemia
- Metabolic acidosis

Treatment

1. Aggressive IVF

Start with 1-2 L/hr
Once diuresis occurs maintain urine output of 200-300 mL/hr

2. Bicarb?

If IVF establishes diuresis consider adding 75 mmol of NaHCO3 to 1L of 1/2NS
- Goal urine pH is > 6.5
- Monitor for hypocalcemia closely!
- If urine pH is not > 6.5 after 3-4 hrs or symptomatic hypocalcemia results d/c

3. Mannitol?

Consider if unable to establish diuresis with volume repletion
- Must check plasma osmolaity and plasma osmolal gap q4-6hr
  - D/c if osmolal gap > 55 mosmol/kg
If mannitol establishes diuresis continue until urine discoloration clears and CK decreases to <10K

4. Hypocalcemia

Only treat if symptomatic or severely hyperkalemic! (pts often have rebound hypercalcemia)

Evidence Based Questions

No randomized, controlled trial has supported the evidence-based use of mannitol, and some clinical studies suggest no beneficial effects. In addition, high accumulated doses of mannitol (>200 g per day or accumulated doses of >800 g) have been associated with acute kidney injury due to renal vasoconstriction and tubular toxicity, a condition known as osmotic nephrosis. However, many experts continue to suggest that mannitol should be used to prevent and treat rhabdomyolysis-induced acute kidney injury and relieve compartmental pressure. During the time mannitol is being administered, plasma osmolality and the osmolal gap (i.e., the difference between the measured and calculated serum osmolality) should be monitored frequently and therapy discontinued if adequate diuresis is not achieved or if the osmolal gap rises above 55 mOsm per kilogram.

A. Bozch X et al. Rhabdomyolysis and Acute Kidney Injury. NEJM 2009; 361: 62-72

Source

KajQuestions

Authors:

@@ Line 61: / Line 61: @@
 ==Treatment==
 . Aggressive IVF
-* Often up to 10L per day)
+* Start with 1-2 L/hr
+* Once diuresis occurs maintain urine output of 200-300 mL/hr
+. Bicarb?
-     -type of fluid = controversial     -NaBicarb (to alkalize urine)          -may exacerbate the symptoms of the initial hypocalcemic phase of rhabdomyolysis.          -urine pH and serum bicarbonate, calcium, and potassium levels should be monitored          -if urine pH does not rise after 4 to 6 hours of treatment or if symptomatic hypocalcemia develops, alkalinization should be discontinued and hydration continued with NS2) Monitor electrolytes     -correct hyperkalemia     -early hypocalcemia should NOT be treated unless symptomatic or severe hyperkalemia present     -Calcium-containing chelators should be used with caution to treat hyperphosphatemia, since the calcium load could increase the precipitation of calcium phosphate in injured muscle.==Disposition==
+* If IVF establishes diuresis consider adding 75 mmol of NaHCO3 to 1L of 1/2NS
+** Goal urine pH is > 6.5
+** Monitor for hypocalcemia closely!
-Insert
+** If urine pH is not > 6.5 after 3-4 hrs or symptomatic hypocalcemia results d/c
+. Mannitol?
+* Consider if unable to establish diuresis with volume repletion
+** Must check plasma osmolaity and plasma osmolal gap q4-6hr
+*** D/c if osmolal gap > 55 mosmol/kg
+* If mannitol establishes diuresis continue until urine discoloration clears and CK decreases to <10K
+. Hypocalcemia
+* Only treat if symptomatic or severely hyperkalemic! (pts often have rebound hypercalcemia)
 ==Evidence Based Questions==