Deck 8: Invasive Blood Gas Analysis and Monitoring

Question 1

In addition to the dorsalis pedis,which of the following arteries is involved when the modified Allen's test is performed using a foot as the potential arterial puncture site?

A)Axillary artery
B)Femoral artery
C)Posterior tibial artery
D)Dorsalis pedis

Answer 1

C
The modified Allen's test can also be used to verify collateral circulation when using one of the arteries of the foot as a puncture site,by elevating the foot and compressing the dorsalis pedis and posterior tibial arteries.Collateral circulation is confirmed by releasing pressure from the artery that will not be punctured and assessing the nail beds and sole of the foot for return of blood flow.

Question 2

With an umbilical artery catheter (UAC)in the "low position," which of the following blood vessels should be avoided?

A)Celiac artery
B)Superior mesenteric artery
C)Renal artery
D)Descending aorta

Answer 2

C
The low position is usually at the third to fourth lumbar (L3 to L4)space,between the renal artery and aortic intersection and above the takeoff of the inferior mesenteric artery.The UAC is placed to avoid the large tributaries supplied by these vessels in an effort to minimize trauma and hemodynamic disturbances of vital organs.

Question 3

How would tricuspid stenosis be expected to influence a patient's CVP value?

A)Elevate it above normal
B)Cause it to fall below normal
C)Produce fluctuations in the CVP value
D)Have no effect in the CVP value

Answer 3

A
Increased CVP values may result from:
•Hypervolemia,as with sudden fluid shifts or volume overload
•Interference with the ability of the right ventricle to pump blood,such as in tricuspid valve regurgitation or tricuspid stenosis,right ventricular failure or infarction,increased pulmonary vascular resistance,or cardiac tamponade
•Increased systemic vasoconstriction
•Left ventricular failure

Question 4

A 12-hour-old infant is experiencing respiratory distress,and the neonatologist orders a heel stick to assess the infant's oxygenation status.What action should the therapist take at this time?

A)Perform the heel stick as ordered.
B)Instead of using the newborn's heel,the therapist should use a finger as the site.
C)Inform the physician that this procedure is inappropriate at this time.
D)Explain to the doctor that an arterial puncture procedure is appropriate.

Question 5

Which of the following pulmonary artery catheter waveforms represents the catheter's normal location?
A.


B.


C.


D.

A)Right atrium
B)Right ventricle
C)Pulmonary artery
D)Wedged position

Question 6

Which of the following factors would adversely affect the correlation between arterial puncture measurements and those from a capillary sample?

A)Hypotension
B)Hyperventilation
C)Hypoxemia
D)Hyperthermia

Question 7

Calculate a patient's total arterial oxygen content given the following data:
•Arterial oxygen tension (PaO₂),100 mm Hg
•Arterial carbon dioxide tension (PacO₂),45 mm Hg
•Arterial oxygen saturation (SaO₂),97.5%
•Hemoglobin concentration ([Hb]),15 g/dL
•Cardiac output,4.5 L/minute
•Stroke volume,55 mL/beat

A)19.9 vol%
B)18.7 vol%
C)16.6 vol%
D)14.9 vol%

Question 8

A respiratory therapist has been ordered to obtain a blood gas sample from a nonintubated premature baby.After selecting the best site to obtain the sample,what should the RT suggest to ameliorate the pain associated with the procedure?

A)Administer a small dose of fentanyl
B)Inject lidocaine at the injection site
C)Give a pacifier dipped in 24% sucrose
D)Administer a lidocaine drip

Question 9

On the basis of the following waveform,in which of the following anatomic locations is the distal tip of the pulmonary artery catheter located?

A)Right atrium
B)Right ventricle
C)Pulmonary artery
D)Wedged position

Question 10

Which of the following factors influence the central venous pressure (CVP)measurement?
I)Bicuspid valve function
II)Right ventricular pressure
III)Intravascular volume
IV)Systemic venous return

A)I and III only
B)II and III only
C)II and IV only
D)II,III,and IV only

Question 11

A 3-kg neonate has lost 30% of his circulating blood volume.Approximately how much fluid should be infused to compensate for this loss?

A)30 mL
B)60 mL
C)90 mL
D)120 mL

Question 12

On the basis of the following waveform,in which of the following anatomic locations is the distal tip of the pulmonary artery catheter located?

A)Right atrium
B)Right ventricle
C)Pulmonary artery
D)Wedged position

Question 13

On the basis of the position of the three-way stopcock shown here,identify which of the following activities related to arterial line blood sampling is occurring.

A)The therapist is aspirating blood diluted with infusion fluid.
B)The therapist is withdrawing blood from the arterial line.
C)The therapist is keeping the stopcock in its normal operational position.
D)The therapist is infusing fluid back into the system after having removed a blood sample.

Question 14

Which of the following is one of the most common arrhythmias observed as a complication from the insertion of a pulmonary artery catheter?

A)Premature ventricular contraction
B)S3 gallop
C)Atrial fibrillation
D)Paroxysmal atrial contraction

Question 15

If a blood gas sample is not obtained from an arterial stick in a premature baby without central access,which of the following sites should be considered because this blood vessel is larger than the radial artery at this age?

A)Dorsalis pedis
B)Temporal
C)Posterior tibial
D)Femoral

Question 16

The neonatal intensive care unit (NICU)respiratory therapy supervisor is observing a therapist obtain an arterial blood sample from an infant's radial artery and notices that the therapist has the bevel of the needle pointed upward,entering the patient's skin at a 45-degree angle and in a direction against the arterial flow.What should the supervisor do at this time?

A)Continue to observe the procedure.
B)Inform the therapist to turn the bevel downward.
C)Tell the therapist to penetrate the infant's skin at about a 60-degree angle.
D)Advise the therapist to insert the needle in the same direction as the blood flows.

Question 17

In addition to applying direct pressure to the puncture site immediately after the arterial puncture procedure,what can the therapist do to minimize the risk of hematoma formation in a patient who requires frequent radial arterial punctures?

A)Have the patient maintain the arm in an elevated position for a couple of hours after the radial puncture.
B)Have the patient shake the arm periodically throughout the day.
C)Alternate arms used for arterial puncture and use other sites as well.
D)Apply a bandage to the puncture site.

Question 18

On the basis of the following waveform,in which of the following anatomic locations is the distal tip of the pulmonary artery catheter located?

A)Right atrium
B)Right ventricle
C)Pulmonary artery
D)Wedged position

Question 19

Which of the following arteries is considered the optimal puncture site for obtaining arterial blood samples from neonatal and pediatric patients?

A)Radial artery
B)Axillary artery
C)Ulnar artery
D)Popliteal artery

Question 20

A patient has a systolic blood pressure of 100 mm Hg and a diastolic pressure of 75 mm Hg.What is this patient's mean arterial pressure?

A)25 mm Hg
B)58 mm Hg
C)83 mm Hg
D)175 mm Hg

Question 21

Which of the following conditions can cause methemoglobinemia?

A)Anemia
B)Inhalation of nitric oxide (NO)
C)Use of dobutamine
D)High fraction of inspired oxygen