| Subject | Contents |
| Definition | A test performed to detect the presence of myoglobin in urine. Myoglobin is an oxygen-binding protein found in cardiac and skeletal muscle. Exercising muscle uses up available oxygen as it metabolizes available fuel (that is, glucose and fatty acids) for energy. The presence of myoglobin in muscle provides an extra reserve of oxygen so that exercising muscles can maintain a high level of activity for a longer period of time. When skeletal muscle is damaged, the myoglobin is released into the bloodstream. It is filtered out of the bloodstream by the kidneys. In large quantities, myoglobin can occlude the structures of the kidney as well as break down into potentially toxic compounds, causing kidney failure . |
| Alternative Names | Urine myoglobin |
| How the test is performed | Child or adult: A "clean-catch" (midstream) urine sample must be obtained. To perform a clean-catch, men or boys should wipe clean the head of the penis . Women or girls need to wash the area between the lips (labia) of the vagina with soapy water and rinse well. As you start to urinate, allow a small amount to fall into the toilet bowl first (this clears the urethra of contaminants), and then catch about 1 to 2 ounces of urine in the container. Give the container to the health care provider or assistant. Infant: Thoroughly wash the area around the urethra (opening where the urine flows from). Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on your infant. For males, the entire penis can be placed inside the bag and the adhesive attached to the skin. For females, the bag is placed over the labia. Place a diaper over the infant (bag and all). Check your baby frequently and remove the bag after the infant has urinated into it. For active infants, this procedure may take a couple of attempts-lively infants can easily displace the bag. The urine is then poured into a container for transport back to the health care provider. |
| How to prepare for the test | No special preparation is necessary for this test, but if the collection is being taken from an infant, a couple of extra collection bags may be necessary. |
| How the test will feel | The test involves only normal urination which should cause no discomfort. |
| Why the test is performed | Myoglobin levels may be obtained when muscle damage, including skeletal and heart muscle damage, is suspected. |
| Normal Values | The urine sample is normally negative for myoglobin. |
| What abnormal results mean | The presence of myoglobin in the urine may indicate:malignant hyperthermia (very rare) muscular dystrophymyocardial infarctionrhabdomyolysis (result of skeletal muscle damage from multiple causes) skeletal muscle inflammation ( myositis ) skeletal muscle ischemia (blood deficiency) skeletal muscle trauma |
| What the risks are | There are no risks. |
| Special considerations | |
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