Definition
One of the methods of collecting blood is arterial puncture. Obtainingarterial blood sample requires percutaneous puncture of the brachial, radial or femoral artery or the extraction of a sample from an arterialline. Once collected, the sample withdrawn can be used to analyze the patient’s arterial blood gas (ABG) values. Determining if a patient is acidic or alkaline and assessing the oxygenation status of the patient is made possible by obtaining a blood sample through arterial puncture. The procedure is quite similar to venipuncture however, it should be done with no exposure to air to prevent the escape of gas from thearterial line and avoid intracellular fluid shift to extracellular.
Indications
Arterial punctures are usually performed for the following purposes:
- Arterial blood gas sampling or assessment of the patient’s acid-base balance (ph)
- Ventilatory status assessment (PaCO2) or frequent need for blood sampling such as in cases of prolonged resuscitation
- Oxygenation status assessment (PaO2)
Important Considerations
In extracting blood samples from the arterial line, the nurse should keep the following factors in mind for successful outcomes.
- The arteries that are easier to palpate, stabilize and puncture are those that are superficial. It is also less painful for the patient if the punctured arteries are surrounded by insensitive body tissues such as muscle, tendon and fat.
- Potential complications of arterial puncture are vascular spasm, clotting of the vessel or bleeding that may result to possible hematoma and vascular compression.
- In cases where complication occurred, the artery should have a good collateral blood flow. It is the radial artery that meets these criteria and usually the brachial artery is the best second choice.
Equipment
- 10 ml glass syringe or plastic leur-lock syringe
- 1 ml ampule of aqueous heparin
- 20 G needle – for drawing the heparin to the syringe
- 22 G needle
- Gloves
- Alcohol pad
- Two 2” x 2” gauze pads
- Rubber cap for syringe hub or rubber stopper for needle
- Ice-filled plastic bag
- Label
- Laboratory request form
- Adhesive bandage
- Optimal: 1% lidocaine solution