Chapter 10: Blood Gas Monitoring

Chapter 10: Blood Gas Monitoring

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

MULTIPLE CHOICE

 

1. Which of the following are the most common sites for the percutaneous sampling of arterial blood for blood gas analysis?
2. Earlobe
3. Radial artery
4. Brachial artery
5. Side of the heel

a.	1 and 2	c.	3 and 4
b.	2 and 3	d.	1 and 4

 

 

ANS:  B

Specimens for arterial blood gas analysis can be drawn from a peripheral artery by means of a percutaneous needle puncture or from an indwelling intravascular cannula. Blood is most often drawn from the radial, brachial, or femoral arteries or the dorsalis pedis artery of the foot.

 

PTS:   1                    REF:   Page 319

 

2. Which of the following statements is true concerning capillary blood gases?

a.	They can be drawn from an earlobe.
b.	They coincide with arterial blood gases.
c.	They can be drawn from a peripheral artery.
d.	They require the performance of an Allen test.

 

 

ANS:  A

Capillary blood samples from an earlobe or the side of the heel can be substituted when arterial blood cannot be obtained, although the results may vary considerably from arterial blood gas values.

 

PTS:   1                    REF:   Page 319

 

3. When an Allen test result is negative, blood for blood gas analysis should be drawn from which of the following sites?

a.	Earlobe	c.	Brachial artery
b.	Radial artery	d.	Side of the heel

 

 

ANS:  C

Another sampling site, such as the brachial artery, should be chosen if the result of a modified Allen test is negative.

 

PTS:   1                    REF:   Page 319

 

4. The purpose of an Allen test is to check blood flow in the _____ artery.
5. ulnar
6. radial
7. brachial

4 posterior tibial

5. lateral plantar

a.	1, 2, and 3	c.	1, 4, and 5
b.	2, 3, and 4	d.	3, 4, and 5

 

 

ANS:  C

An Allen test should always be done before a radial artery puncture is performed to ensure that there is collateral circulation in the ulnar artery. An Allen type of test should be performed to ensure collateral circulation in the posterior tibial and lateral plantar arteries when drawing arterial blood from the dorsal artery of the foot.

 

PTS:   1                    REF:   Page 319

 

5. Which is the correct sequence of events when one is obtaining arterial blood from the radial artery of a patient?
6. Perform the modified Allen test.
7. Remove any air bubbles from the sample.
8. Apply direct pressure to the puncture site.
9. Clean the puncture site with a suitable antiseptic solution.
10. Use a 23-gauge needle and a plastic syringe containing an anticoagulant.

a.	1, 4, 3, 5, 2	c.	1, 4, 5, 3, 2
b.	4, 1, 5, 2, 3	d.	1, 5, 2, 4, 3

 

 

ANS:  C

Collateral circulation must be ensured before the puncture by performing a modified Allen test. After the test shows sufficient collateral circulation, the site should be prepared for the puncture by cleaning with a suitable antiseptic solution. Blood samples should be obtained with a small-gauge needle (i.e., 23 to 25 gauge). After blood has been withdrawn and the needle removed, direct pressure should be applied to the puncture site to prevent the formation of a hematoma. Air bubbles should then be removed because their presence can produce erroneous measurements.

 

PTS:     1          REF:    Pages 319-320