No longer in routine clinical use.
Blood or urine was historically tested for the presence of myoglobin, a red protein found in muscles. Myoglobin traps oxygen allowing muscle cells to work properly. When muscle is injured, myoglobin is released into the blood and appears in the urine.
How is the sample collected for testing?
A blood sample is taken by needle from a vein in the arm or a random urine sample.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
How is it used?
Myoglobin was once the primary test to for people with suspected muscle injury. It has been replaced by creatine kinase (CK), which is more sensitive, specific and the concentration remains elevated in the bloodstream for longer following the injury.
When is it requested?
What does the test result mean?
Is there anything else I should know?
The excretion of myoglobin by the kidney can lead to renal failure.
Myoglobin is no longer requested in people with chest pain who are suspected of having had a heart attack, having been superseded by troponin, a test which is specific for heart muscle and which also remains elevated for longer in the bloodstream.
How does myoglobin cause kidney failure?
Myoglobin released from damaged muscle into plasma is filtered by the kidneys into the urine but can precipitate in the kidney tubules, obstructing urine formation. This is a particular risk if shock lowers blood pressure and reduces the rate of urine production. Infusion of fluid into a vein can help increase the rate of urine production and myoglobin loss therefore reducing the risk of kidney failure.