Myoglobinuria describes the presence of myoglobin (a muscle protein) in the urine .
Myoglobin is released if there is muscle injury or necrosis (rhabdomyolysis).
Causes of myoglobinuria include:
- trauma
- electrocution
- ischaemia
- immobility
- excessive exercise
- myositis
- drugs e.g. statins, fibrates
- toxins e.g. snake bite, carbon monoxide, alcohol, ecstasy
- inherited muscle disorders e.g. McArdle's disease
- malignant hyperpyrexia
- neuroleptic malignant syndrome
- metabolic causes e.g. hypokalaemia, hypophosphataemia
- coma
Clinical features:
- may be asymptomatic - depending on cause
- nospecific symptoms e.g. muscle tenderness, pain or swelling
Investigations:
- dipstick urine - positive for blood but negative for red blood cells on microscopy
- blood tests - increased creatinine, increased urea, increased potassium, reduced calcium, increased phosphate, increased urate, increased CK, increased LDH