CABT Patient Monitoring 2 — Questions and Answers
Question 1: Which waveform component of an arterial blood pressure tracing represents the dicrotic notch?
- Closure of the aortic valve (Correct answer)
- Opening of the mitral valve
- Peak systolic pressure
- End-diastolic pressure
Correct answer: Closure of the aortic valve
The dicrotic notch on the arterial waveform corresponds to the closure of the aortic valve at the end of systole.
Question 2: A pulse oximeter reading is most likely to be unreliable in a patient with:
- Severe peripheral vasoconstriction (Correct answer)
- Mild anemia
- A heart rate of 90 bpm
- Normal oxygen saturation
Correct answer: Severe peripheral vasoconstriction
Severe peripheral vasoconstriction reduces pulsatile blood flow to the extremities, making it difficult for the pulse oximeter to detect an accurate signal.
Question 3: What is the primary purpose of the 'alarm limit' feature on patient monitors?
- To alert clinicians when a parameter exceeds safe boundaries (Correct answer)
- To silence nuisance alarms automatically
- To record data for retrospective analysis
- To calibrate sensors periodically
Correct answer: To alert clinicians when a parameter exceeds safe boundaries
Alarm limits are set to notify clinicians when physiological parameters deviate outside acceptable ranges, enabling timely intervention.
Question 4: Which lead configuration is standard for continuous 3-lead ECG monitoring in the ICU?
- Leads I, II, and III
- Leads V1, V4, and V6
- Leads aVR, aVL, and aVF
- Leads II, V1, and V5 (Correct answer)
Correct answer: Leads II, V1, and V5
Leads II, V1, and V5 are commonly used in ICU monitoring as they best detect arrhythmias and ischemic changes.
Question 5: In capnography, an abnormally elevated ETCO2 value most often indicates:
- Hypoventilation or increased CO2 production (Correct answer)
- Hyperventilation
- Correct endotracheal tube placement failure
- Pulmonary embolism
Correct answer: Hypoventilation or increased CO2 production
Elevated end-tidal CO2 is typically caused by hypoventilation or conditions that increase CO2 production such as fever or sepsis.
Question 6: When zeroing an invasive arterial pressure transducer, the stopcock reference port should be positioned at the level of the:
- Phlebostatic axis (mid-axillary line at the 4th intercostal space) (Correct answer)
- Top of the patient's head
- Level of the catheter insertion site
- Patient's feet
Correct answer: Phlebostatic axis (mid-axillary line at the 4th intercostal space)
The phlebostatic axis approximates the level of the right atrium and is the standard reference point for zeroing hemodynamic transducers.
Question 7: Which biomedical device parameter would be most affected by motion artifact during monitoring?
- Pulse oximetry SpO2 reading (Correct answer)
- Static body temperature
- Invasive arterial blood pressure mean
- Exhaled CO2 concentration
Correct answer: Pulse oximetry SpO2 reading
Pulse oximetry relies on detecting pulsatile light absorption changes and is highly susceptible to motion artifact that mimics or obscures the pulse signal.
CABT Patient Monitoring 2
Which waveform component of an arterial blood pressure tracing represents the dicrotic notch?