Arterial puncture - Specimen collection:

Arterial puncture:  this requires special skill and usually performed only by physician.

The preferred site is radial artery at the wrist, the brachial artery at the elbow, and the femoral artery in the groin. Skin should be cleaned. No tourniquet is required for arterial puncture. The needle and the syringe should be flushed out with heparin solution both to ensure adequate anticoagulation and to eliminate trapping of air in the needle and in the dead space of the nozzle.       

Plastic syringes should be avoided. After collection of blood and if the sample is intended for blood gas analysis, the nozzle should be sealed and the syringe placed in ice water for immediate transfer to the laboratory.