Physiology-Rhabdomyolysis Flashcards
What causes myocyte destruction in rhabdomyolysis?
Muscle injury -> ATP depletion -> Ion pump impairment -> Increase in intracellular Ca2+ -> Persistent contraction -> Protease activation -> Fiber necrosis
Why is rhabdomyolysis such a scary thing for the survival of the patient?
Large amounts of P, K, CK, myoglobin and urate leak into the ECF.
Why do patients with rhabdomyolysis see a drop in blood pressure?
The injured cells take in water from the ECF.
Wait a minute…I thought myoglobin carried oxygen…why does it cause kidney damage?
It is filtered by the glomerulus and clogs up the distal tubule. The heme group also causes oxidative damage.
What are the big causes of rhabdomyolysis?
Trauma, exercise, muscle hypoxia (drunk guy lying on arm), genetics, infections, body-temperature change, drugs, toxins and metabolic disorders.
How do rhabdo patients typically present?
Muscle pain, compartment syndrome, neuro defect and dark urine.
What lab values do you use in diagnosis of rhabdomyolysis?
Elevated CK. Myoglobinuria is transient and not required. Urine dipstick is + w/o presence of RBCs. Casts, proteinuria and acidic pH.
What early and late complications happen with rhabdomyolysis?
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How do we treat patients with rhabdomyolysis?
Promote renal tubular flow to clear myoglobin and correct electrolyte abnormalities….FLUID, FLUID and more FLUID (200-300mL/hour)
Why would you want to alkalinize the urine in a patient with rhabdo?
A higher pH minimizes cast formation
Why would you give a patient mannitol who has rhabdomyolysis?
Decrease cast formation and scavenge ROS.
Why would you put a patient on dialysis who has rhabdomyolysis?
Oliguria or anuria
