Creatine phosphokinase test Health Article

Definition

Creatine phosphokinase (CPK) is an enzyme found mainly in the heart, brain, and skeletal muscle. This article discusses the test to measure the amount of CPK is the blood.

See also: CPK isoenzymes

Alternative Names

CPK test; Creatine kinase

How the test is performed

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

The blood sample is sent to a lab, where the amount of CPK is measured.

This test may be repeated over 2 or 3 days for if you are a patient in the hospital.

How to prepare for the test

Usually, no special preparation is necessary.

Tell your doctor about any medications you are taking. Drugs that can increase CPK measurements include amphotericin B, ampicillin, certain anesthetics, blood thinners, aspirin, clofibrate, dexamethasone, furosemide, alcohol, and cocaine.

How the test will feel

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.