Rhabdomyolysis: Difference between revisions

No edit summary
(Strip excess bold)
 
(71 intermediate revisions by 14 users not shown)
Line 1: Line 1:
==Background ==
==Background==
#Muscle necrosis and release of intracellular muscle constituents into the circulation
*Breakdown of skeletal muscle releasing intracellular contents into the circulation
#Recurrent episodes suggests inherited metabolic disorder
*Key toxins: myoglobin (nephrotoxic), creatine kinase (CK), potassium, phosphate, uric acid
#Alcohol and drugs play a role in up to 80% of cases
*Acute kidney injury (AKI) occurs in 15-40% of cases<ref name="bosch">Bosch X, et al. Rhabdomyolysis and acute kidney injury. ''N Engl J Med''. 2009;361(1):62-72. PMID 19571284.</ref>
*Overall mortality ~5%; higher with AKI, DIC, or [[Compartment syndrome|compartment syndrome]]


==DDx==
==Etiology==
[[Colored Urine (DDx)]]
*Trauma / Crush injury (most common worldwide)
 
*'''Exertional''' (exercise, seizures, agitation, status epilepticus)
==Causes==
*Drug/toxin-induced
===Trauma or muscle compression===
**Statins (especially with interacting drugs)
#Crush injury
**[[Cocaine toxicity|Cocaine]], [[Amphetamine toxicity|amphetamines]], MDMA, [[Ethanol toxicity|alcohol]]
#Immobilization
**[[Neuroleptic malignant syndrome|NMS]], [[Serotonin syndrome]], [[Malignant hyperthermia]]
#Compartment syndrome
*Prolonged immobilization (found down, intraoperative)
===Nontraumatic Exertional===
*[[Hypokalemia]], [[Hypophosphatemia]], [[Hyponatremia]]
#Exercise + hot weather
*[[Heat stroke]]
#Exercise + sickle cell
*Infections (influenza, COVID-19, Legionella)
#Exercise + hypokalemia
*Hypothermia, [[Electrical injury|electrical injuries]]
#Hyperkinetic states
##Seizure
##DTs
##Stimulant overdose
##Malignant hyperthermia
##Neuroleptic malignant syndrome
===Nontraumatic Nonexertional===
#Drugs and toxins
##Coma induced by sedatives
##Alcohol
###Coma-induced muscle compression
###Direct toxic effect
###Nutritional compromise increases risk (hypoK, hypoMg, HypoPhos)
##Statins
##Colchicine 
##CO poisoning
#Infection
##Viral myositis - Influenza, Coxsackie, EBV, HSV, HIV, CMV
##Bacterial pyomyositis
##Septicemia
#Endocrine
##Hypothyroidism
#Inflammatory myopathies
##Moderate CK elevations only (rhabdo only described in case reports)
#Miscellaneous
##Status asthmaticus
##TSS
##Mushroom ingestion


==Clinical Features==
==Clinical Features==
#Myalgia, stiffness, weakness, malaise, low-grade fever, dark urine
*Classic triad: myalgias, weakness, dark urine (tea/cola-colored)
##Musculoskeletal symptoms may be present in only half of cases
**Full triad present in <10% of cases
#N/V, abd pain, tachycardia in severe cases
*Muscle tenderness, swelling, and stiffness
#Mental status changes secondary to urea-induced encephalopathy
*May be asymptomatic with only lab abnormalities
 
*Complications:
==Diagnosis==
**[[Hyperkalemia]] (can cause [[Cardiac dysrhythmia|cardiac dysrhythmias]]) — '''life-threatening'''
#Total CK
**[[Acute kidney injury]] (oliguria, anuria)
##Most consider if fivefold or greater increase above upper limit of normal
**[[Compartment syndrome]]
##Serum CK begins to rise 2-12hr after injury, peaks w/in 24-72hr
**[[DIC]]
##Degree of CK elevation correlates w/ muscle injury, but NOT renal failure
**Hypocalcemia (early), hypercalcemia (recovery phase)
#CK-MB
**Metabolic acidosis
##May be normal or mildly elevated (<5% of total)
#Myoglobinuria
##UA = +blood, but no RBCs
###Sn = 80%
##Myoglobin is cleared w/in 1-6hr (often see elevated CK with no myoglobinuria)
##Is pathognomonic
 
 
 
#Transaminitis
#Creatinine increase (if renal failure)
#Electrolyte Abnormalities
##Hyperkalemia
##Hyperphosphatemia
##Hypocalcemia
## Hyperuricemia
## Metabolic acidosis
 
==Workup==
#Investigate cause
#Total CK
#UA
#CBC
#Chemistry
#Uric acid
#LFTs
#DIC panel
##Coags, FSP, fibrinogen
 
 
 
 
===Follow===
##Urine pH
##Potassium
 
 


==Treatment==
==Evaluation==
# Aggressive IVF
*Creatine kinase (CK) — diagnostic marker
## Start with 1-2 L/hr
**CK >5x upper limit of normal (typically >1,000 U/L) diagnostic
## Once diuresis occurs maintain urine output of 200-300 mL/hr (3mL/kg)
**CK >5,000 U/L: significant risk of AKI
## Frequently need ~10 L/day
**Peak CK at 24-72 hours; monitor serial levels
# Bicarb^
*Urinalysis: urine dipstick positive for "blood" but no RBCs on microscopy (myoglobinuria)
## Indication = Urine pH is <6.5
*BMP: potassium (may be severely elevated), creatinine, BUN, calcium, phosphate, bicarbonate
## After initial IVF, give 75mmol NaHCO3 in 1L 1/2NS
*CBC, LDH, uric acid, coagulation studies
### Alternative regimen = 100mmol NaHCO3 in 1L 1/2NS, alternated with 1L NS (no NaHCO3), repeat
*ECG — evaluate for [[Hyperkalemia|hyperkalemia]] changes (peaked T waves, wide QRS)
### Goal urine pH is >6.5
*Consider compartment pressures if clinical concern
### Monitor for hypocalcemia closely!
### If urine pH is not > 6.5 after 3-4 hrs or symptomatic hypocalcemia results d/c
# Mannitol^^
## Consider if unable to establish diuresis after significant 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


^Degrees of controversy
==Management==
===Aggressive IV Fluid Resuscitation===
*Cornerstone of treatment
*Normal saline at 200-300 mL/hr (or 1-2 L/hr initially if severely hypovolemic)<ref name="scharman">Scharman EJ, et al. Prevention of kidney injury following rhabdomyolysis: a systematic review. ''Ann Pharmacother''. 2013;47(1):90-105. PMID 23324509.</ref>
*Target urine output 200-300 mL/hr until CK trending down and urine clears
*Monitor for fluid overload, especially in elderly and those with cardiac/renal disease
*Bicarbonate drip (150 mEq NaHCO3 in 1 L D5W) may be considered to alkalinize urine (target urine pH >6.5) — evidence is limited


==Complications==
===Treat Hyperkalemia===
#[[Acute Renal Failure]]
*See [[Hyperkalemia]] for detailed management
#[[Hyperkalemia]]
*Calcium gluconate 10% 10 mL IV for cardiac membrane stabilization if ECG changes
##Treat aggressively
*Insulin 10 units regular IV + D50W 50 mL IV
#[[Hypocalcemia]] (initial phase)
*[[Sodium bicarbonate]], [[Albuterol]] nebulizer, [[Kayexalate]] or patiromer
##Treat only if symptomatic or severely hyperkalemic (often have rebound hypercalcemia)
*Emergent [[Hemodialysis|dialysis]] if refractory
#[[Hypercalcemia]] (recovery phase)
#[[Hyperphosphatemia]]
##Treat cautiously (treatment may worsen calcium precipitation in muscle)
#[Diss


==Evidence Based Questions==
===Other===
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.
*Treat underlying cause (cool if [[Heat stroke|hyperthermic]], correct electrolytes)
*Avoid nephrotoxins (NSAIDs, contrast dye, aminoglycosides)
*[[Compartment syndrome]]: emergent fasciotomy if pressures >30 mmHg or clinical diagnosis
*Monitor for and treat [[DIC]] if present


A. Bozch X et al. Rhabdomyolysis and Acute Kidney Injury. NEJM 2009; 361: 62-72
==Disposition==
*Admit patients with:
**CK >5,000 U/L
**AKI (elevated creatinine)
**[[Hyperkalemia]] or other electrolyte derangements
**Ongoing symptoms or rising CK
*Discharge may be considered for mild rhabdomyolysis (CK <5,000, normal renal function, normal K) with close follow-up and oral hydration


==See Also==
==See Also==
Insert
*[[Hyperkalemia]]
*[[Acute kidney injury]]
*[[Compartment syndrome]]
*[[Crush injury]]
*[[Heat stroke]]


==Source==
==References==
KajQuestions
<references/>


[[Category:GU]]
[[Category:Renal]]
[[Category:Orthopedics]]

Latest revision as of 09:31, 22 March 2026

Background

  • Breakdown of skeletal muscle releasing intracellular contents into the circulation
  • Key toxins: myoglobin (nephrotoxic), creatine kinase (CK), potassium, phosphate, uric acid
  • Acute kidney injury (AKI) occurs in 15-40% of cases[1]
  • Overall mortality ~5%; higher with AKI, DIC, or compartment syndrome

Etiology

Clinical Features

  • Classic triad: myalgias, weakness, dark urine (tea/cola-colored)
    • Full triad present in <10% of cases
  • Muscle tenderness, swelling, and stiffness
  • May be asymptomatic with only lab abnormalities
  • Complications:

Evaluation

  • Creatine kinase (CK) — diagnostic marker
    • CK >5x upper limit of normal (typically >1,000 U/L) diagnostic
    • CK >5,000 U/L: significant risk of AKI
    • Peak CK at 24-72 hours; monitor serial levels
  • Urinalysis: urine dipstick positive for "blood" but no RBCs on microscopy (myoglobinuria)
  • BMP: potassium (may be severely elevated), creatinine, BUN, calcium, phosphate, bicarbonate
  • CBC, LDH, uric acid, coagulation studies
  • ECG — evaluate for hyperkalemia changes (peaked T waves, wide QRS)
  • Consider compartment pressures if clinical concern

Management

Aggressive IV Fluid Resuscitation

  • Cornerstone of treatment
  • Normal saline at 200-300 mL/hr (or 1-2 L/hr initially if severely hypovolemic)[2]
  • Target urine output 200-300 mL/hr until CK trending down and urine clears
  • Monitor for fluid overload, especially in elderly and those with cardiac/renal disease
  • Bicarbonate drip (150 mEq NaHCO3 in 1 L D5W) may be considered to alkalinize urine (target urine pH >6.5) — evidence is limited

Treat Hyperkalemia

Other

  • Treat underlying cause (cool if hyperthermic, correct electrolytes)
  • Avoid nephrotoxins (NSAIDs, contrast dye, aminoglycosides)
  • Compartment syndrome: emergent fasciotomy if pressures >30 mmHg or clinical diagnosis
  • Monitor for and treat DIC if present

Disposition

  • Admit patients with:
    • CK >5,000 U/L
    • AKI (elevated creatinine)
    • Hyperkalemia or other electrolyte derangements
    • Ongoing symptoms or rising CK
  • Discharge may be considered for mild rhabdomyolysis (CK <5,000, normal renal function, normal K) with close follow-up and oral hydration

See Also

References

  1. ↑ Bosch X, et al. Rhabdomyolysis and acute kidney injury. N Engl J Med. 2009;361(1):62-72. PMID 19571284.
  2. ↑ Scharman EJ, et al. Prevention of kidney injury following rhabdomyolysis: a systematic review. Ann Pharmacother. 2013;47(1):90-105. PMID 23324509.
Retrieved from "https://www.wikem.org/w/index.php?title=Rhabdomyolysis&oldid=389287"