Arterial stick

An arterial stick is collection of blood from an artery for laboratory testing.

Blood sample - arterial

Usually the blood is drawn from the wrist. However, it may also be drawn from the inside of the elbow, groin, or other artery. A heartbeat (pulse) is felt by pressing on the area above an artery.

The area is cleaned with antiseptic and a needle inserted. A small amount of anesthetic may be injected or applied before the needle is inserted. The blood will easily flow into the specially prepared (heparinized) syringe.

The needle is removed after there is a sufficient sample of blood. Pressure is applied to the puncture site for 5 - 10 minutes to stop the bleeding. The person will be monitored during this time to make sure the bleeding stops.

Preparation varies with the specific test performed.

Puncture of the artery may be somewhat more uncomfortable than puncture of a vein, and requires firm pressure over the site after it is drawn.

When the needle is inserted, most people feel moderate discomfort or pain. Afterward, there may be some throbbing. The arterial stick is more painful than venipuncture because arteries are deeper than veins, have thicker walls, and have more nerves.

Blood transports oxygen, food, waste products, and other materials within the body. It is also regulates body temperature, fluids, and acid-base equilibrium.

Blood is made up of a fluid portion (plasma) and a cellular portion. Plasma contains various substances dissolved in the fluid. The cellular portion consists primarily of red blood cells, but also includes white blood cells and platelets.

Because blood serves multiple functions within the body, tests on the blood or its components may give valuable clues in the diagnosis of a multitude of medical conditions.

Arterial blood differs from venous blood primarily in its content of dissolved gases. Testing of arterial blood shows the make-up of the blood before any of its contents are used by the body tissues.