Troubleshooting - All Chapters

Question 1

Gas chromatograph:

If the sum of all gases analyzed is less than 100%, what should you do?

Answer 1

Increase the gain until the sum is 100%

Question 2

Infrared Absorption Analyzer:

What 2 things are most likely to affect your results?

Long ___ ___ and ___

Answer 2

long sample lines and moisture.

Question 3

There are “spikes” in your N2 readings from a geissler tube ionizer. What is the most likely cause?

Answer 3

moisture will cause spikes in a geissler tube ionizer.

Question 4

Your blood gas analyzer shows consistent “unstable”, “noisy” or “erratic” readings. What should you do?

Answer 4

You should replace the membranes. Unstable readings indicate worn or ruptures membranes.

Question 5

When troubleshooting a blood gas analyzer, what should you try to do before replacing membranes if given the option?

Answer 5

Check solution and gas cylinder levels, and replace if necessary.

Question 6

When troubleshooting galvanic fuel cell/Zirconium fuel cell O2 analyzers, what should you do if you cannot calibrate the cell?

Answer 6

Replace it.

Question 7

You are unable to calibrate a polarographic O2 analyzer. What would you check first to determine the problem?

Answer 7

Check the batteries and electrolyte level when troubleshooting a polarographic O2 analyzer during calibration.

Question 8

What will typically cause errors in turbine style pneumotachometers such as the Wright respirometer?

Answer 8

Moisture.

Question 9

What will cause a false high volume reading on a pressure differential pneumotachometer?

What will also cause a low reading on a pressure differential pneumotachometer after cleaning due to being present in the transducer lines?

Answer 9

Moisture.

Question 10

What will cause decreased resistance and result in a false low reading on a thermal element?

(This will probably not be on the test)

Answer 10

A hole in the mesh screen

Question 11

The alarm is sounding on an air/oxygen proportioner (blender). What should you do?

Answer 11

Check the gas source pressure. A blender will alarm is the inlet pressure is below 40psi.

Question 12

Your patient passes out during an FVC maneuver. What do you suspect?

Answer 12

Decreased venous return (a vaso-vagal response)

Question 13

If your patient produces an MVV that is less than FEV1 x 35, what do you suspect?

Answer 13

poor effort.

Question 14

How will a leak affect a DLCO test? Why?

Answer 14

DLCO will be falsely increased due to a leak. This is because the CO will diffuse through the leak. If the CO is lost in the leak, the test will show the diffusing value as increased.

Question 15

How should a patient perform a DLCO?

Answer 15

Exhale to RV
Quickly inhale to TLC
Hold breath for 10 seconds (8-12 is ok)
Exhale Rapidly

Question 16

What are the gas concentrations used in a DLCO test?

Answer 16

0.3% CO
10% helium
remainder is room air (21% O2 and balance N2)

Question 17

What DLCO test is the most commonly used in the clinical setting?

Answer 17

DLCO-SB (single breath)

Question 18

What DLCO test is the best method for patients who cannot follow instructions? What are the gas concentrations used? Describe the test.

Answer 18

DLCO-SS (steady state)

0.1%-0.2% CO, balance room air (21% O2 and remainder N2)

Patient rebreathes above gas concentration for 5-6 minutes. This test requires an ABG.

Question 19

Which DLCO should you use during an exercise test? Why?

Answer 19

The DLCO-IB (intrabreath)

This is best for exercise because there is no breath hold.

Question 20

Bonus Lung Test Question: (may be on the exam)

What do you need to do to get a “Membrane Diffusion Coefficient/Factor (Dm)

Answer 20

You should perform 2 different diffusion studies at 2 levels of oxygen (high and low).

This is so that you can extrapolate a line of values across different levels of O2 between your 2 measured points.

Question 21

What color is the dessicant CaSO4 (Drierite) when new? What color does it turn when it needs to be replaced?

Answer 21

CaSO4 (Drierite) is Blue when new, and Pink when it needs to be replaced.