ABG Blood Interpretation Notes

ABG Blood Interpretation Notes List 3 common arterial blood sampling sites. The arterial blood sample may be obtained from the radial, dorsalis pedis, brachial, or femoral arteries in the adult. Describe the procedure ...

ABG Blood Interpretation Notes List 3 common arterial blood sampling sites. The arterial blood sample may be obtained from the radial, dorsalis pedis, brachial, or femoral arteries in the adult. Describe the procedure for doing the modified Allen's Test. To perform this test, the clinician instructs the patient to make a tight fist. Then compress both the radial and ulnar arteries. Now instruct the patient to open and relax his fist, revealing a blanched palm and fingers. Then release the pressure over the ulnar artery while observing the patient's palm for changes in color. If collateral flow is adequate, the patient's hand will "pink up" within 10 to 15 seconds; this constitutes a positive Allen's test. A positive result documents that collateral blood flow is adequate and that the radial artery is an acceptable puncture site. If the test is negative (the palm does not pink up rapidly), the radial artery is not an acceptable site for puncture. In such cases, the other wrist is evaluated or the brachial artery is used for the puncture site. Why is it important to remove air bubbles from the sample? The oxygen and CO2 gas tensions of the bubbles may equilibrate with the blood and result in erroneous measurements. How long should pressure be applied to the puncture site? After the needle is withdrawn, the wound should be pressurized for a period of at least 3 to 5 minutes or longer, if clotting problems exist. List the measurements that are used to assess oxygen status acid-base balance adequacy of ventilation The measurements obtained from analysis of arterial and mixed venous blood samples are useful in evaluating the following: • Acid-base balance (pH, Paco2, HCO3−, base excess)