Rhabdomyolysis (New for 2025)
>5x ULN
CK Level
Diagnostic threshold
200-300
Fluid Rate mL/hr
Aggressive IV crystalloid target
200-300
UO Target mL/hr
Goal urine output
Causes and Presentation
massive muscle breakdown with systemic falloutCrush injuries, compartment syndrome, prolonged immobilization
Prolonged seizures or status epilepticus
Extreme exertion, heat stroke, malignant hyperthermia
Statins (especially combined with fibrates or macrolide antibiotics)
CK elevated greater than 5 times the upper limit of normal
Dark cola-colored urine (myoglobinuria)
Muscle pain, weakness, and swelling
Urine dipstick positive for blood but no RBCs on microscopy
Complications and Treatment
AKI from myoglobin-induced tubular necrosis (primary concern)
Hyperkalemia from intracellular potassium release
Hypocalcemia from calcium sequestration in damaged muscle
DIC in severe cases
Compartment syndrome if swelling is severe
Aggressive fluid resuscitation 200-300 mL/hr targeting urine output 200-300 mL/hr
Key Values to Memorize
CK >5x upper limit
Fluids 200-300 mL/hr
UO goal 200-300 mL/hr
Myoglobin causes ATN
Watch K+ closely
New 2025 test topic
rhabdomyolysis is new for the 2025 CCRN, expect to see it
Practice CCRN exam-style questions with instant feedback
Practice CCRN QuestionsExam Traps
AKI from myoglobin is the major complication
When muscle cells die, they release myoglobin into the bloodstream. Myoglobin is toxic to renal tubules and causes acute tubular necrosis. The dark cola-colored urine is myoglobin, not blood. Preventing AKI with aggressive fluid resuscitation is the primary treatment goal.
Monitor and treat hyperkalemia
Massive muscle breakdown releases intracellular potassium into the blood. Hyperkalemia can cause lethal arrhythmias. Monitor potassium frequently and treat per standard hyperkalemia protocol. This is the most immediately life-threatening electrolyte disturbance in rhabdomyolysis.
Urine alkalinization is controversial
Adding sodium bicarbonate to IV fluids to alkalinize urine was once standard practice. Current evidence is mixed. Some centers still do it, but aggressive crystalloid resuscitation targeting high urine output is the universally agreed-upon priority.
New for November 2025 test plan
Rhabdomyolysis was added to the CCRN test plan for November 2025. It is a new topic that may appear on your exam. Know the pathophysiology, complications, and fluid management targets.
Cola-Colored Urine
Dark brown urine + sky-high CK = rhabdomyolysis. The color is myoglobin, not hemoglobin. Urine dip positive for blood without RBCs on microscopy.
Flood the Kidneys
Aggressive fluids 200-300 mL/hr targeting UO 200-300 mL/hr. Dilute the myoglobin before it destroys the tubules.
Muscle cells are being demolished, whether from a crush injury, prolonged seizures, extreme exertion, or certain medications. When these cells break apart, they dump their contents into the bloodstream, including myoglobin, potassium, and phosphorus.
Myoglobin is like demolition debris flowing into the plumbing system. The kidneys are the filtration plant, and myoglobin clogs and damages the filters (renal tubules). If enough debris reaches the plant, it shuts down entirely, which is acute kidney injury.
The treatment is to flood the plumbing with water (IV crystalloid) to dilute the debris and flush it through before it can clog the filters. The goal is massive urine output to keep the myoglobin moving through the kidneys instead of settling in the tubules.
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