Description of test Technician, doctor or nurse applies a tourniquet or blood-pressure cuff to the upper arm if blood is collected from a vein. Skin over the vein to be stuck is cleaned with alcohol or other antiseptic on a piece of cotton. When blood is drawn from a vein, the operator feels the vein to be used then punctures both the skin and vein in one quick stroke. The needle used is a sterile, disposable needle attached to a sterile, disposable syringe. Tubes are treated with an anti-coagulant chemical to prevent clotting.
Operator collects a baseline blood sample.
An intravenous catheter is inserted to avoid repeated venepunctures. Arginine is started intravenously in a different vein and continues for 30 minutes. After 30 minutes, solution is discontinued. After the test Immediate post-test care Apply pressure to the puncture site with cotton provided by the laboratory. If a vein has been punctured, raise your entire arm over your head while applying pressure.