CVT Hemodynamic Monitoring 2 — Questions and Answers
Question 1: A patient's pulmonary capillary wedge pressure (PCWP) is 22 mmHg. This finding most likely indicates:
- Left ventricular failure (Correct answer)
- Right ventricular failure
- Hypovolemia
- Pulmonary embolism
Correct answer: Left ventricular failure
An elevated PCWP above 18 mmHg reflects increased left atrial pressure, indicating left ventricular failure or fluid overload.
Question 2: During thermodilution cardiac output measurement, which factor would cause a falsely HIGH cardiac output reading?
- Injecting cold injectate too slowly (Correct answer)
- Tricuspid regurgitation
- Atrial septal defect
- Pulmonary hypertension
Correct answer: Injecting cold injectate too slowly
Injecting the cold injectate too slowly allows it to warm before reaching the thermistor, producing a smaller temperature change and falsely elevated CO calculation.
Question 3: Which hemodynamic parameter is calculated using the formula: (MAP - RAP) / CO × 80?
- Systemic vascular resistance (SVR) (Correct answer)
- Pulmonary vascular resistance (PVR)
- Cardiac index (CI)
- Stroke volume index (SVI)
Correct answer: Systemic vascular resistance (SVR)
SVR = (MAP − RAP) / CO × 80, expressed in dyne·sec·cm⁻⁵, quantifying afterload to the left ventricle.
Question 4: A patient has a cardiac output of 4 L/min and a body surface area of 2.0 m². What is the cardiac index?
- 2.0 L/min/m² (Correct answer)
- 8.0 L/min/m²
- 0.5 L/min/m²
- 4.0 L/min/m²
Correct answer: 2.0 L/min/m²
Cardiac index = CO / BSA = 4 / 2.0 = 2.0 L/min/m², which is at the lower limit of normal (normal: 2.2–4.0).
Question 5: Which waveform component of the arterial pressure tracing represents the closure of the aortic valve?
- Dicrotic notch (Correct answer)
- Anacrotic notch
- Peak systolic pressure
- End-diastolic pressure
Correct answer: Dicrotic notch
The dicrotic notch is a brief pressure rise followed by a dip on the descending limb, marking aortic valve closure at the end of systole.
Question 6: When zeroing an arterial line transducer, the stopcock should be positioned at the level of the:
- Phlebostatic axis (right atrium) (Correct answer)
- Femoral artery insertion site
- Top of the patient's head
- Mid-axillary line at the diaphragm
Correct answer: Phlebostatic axis (right atrium)
The phlebostatic axis (4th intercostal space, mid-axillary line) approximates the right atrium and is the standard reference for zeroing vascular pressure transducers.
Question 7: A CVT observes a pulmonary artery waveform that has changed to a wedge (PCWP) waveform without balloon inflation. The most appropriate immediate action is to:
- Notify the physician of catheter migration (Correct answer)
- Inflate the balloon to confirm wedge position
- Recalibrate the transducer
- Flush the catheter with heparin
Correct answer: Notify the physician of catheter migration
Spontaneous wedging indicates the catheter has migrated distally and poses a risk of pulmonary infarction, requiring immediate physician notification.
CVT Hemodynamic Monitoring 2
A patient's pulmonary capillary wedge pressure (PCWP) is 22 mmHg.
This finding most likely indicates: