Collection of bone marrow. Small Animal Diagnostic and Treatment Techniques

femoral artery puncture

Femoral arterial puncture is performed to obtain arterial blood for blood gas analysis. Supplies needed include a small gauge needle (23 to 25 gauge), a 3ml syringe, heparin (1,000 units/ml), and a rubber stopper or cork.

Heparin is aspirated into the syringe and then evacuated back into the bottle so only the amount of heparin that coats the needle and barrel of the syringe remains

Palpate the femoral pulse in the inguinal region with 2 fingers and aspirate between your fingers. Arterial blood obtained from a normally oxygenated patient has a bright red color. The femoral artery is anterior to the femoral vein so if the sample procured appears dark in color and you suspect it is venous in origin, move anterior to the first puncture site for the next attempt. Blood gas values of the suspected venous sample can be compared to a blood sample

obtained from another vein. If the blood gas values are the same, the femoral sample was obtained from the vein, rather than the artery. Digital pressure should be applied to the arterial puncture site for several minutes to prevent development of a hematoma.

	All air should be evacuated from the blood sample as gases will diffuse to and from the sample. Blood gas samples can only be held for about 10 minutes at room temperature without significant changes in sample values. Storage in an ice water bath may extend this time to about six hours.
	The needle should be capped or corked to prevent diffusion of gases between room air and the blood sample.