PCU Hemodynamic Monitoring & Vascular Access 2 — Questions and Answers
Question 1: Which formula is used to calculate mean arterial pressure (MAP)?
- (Systolic BP + Diastolic BP) / 2
- (Systolic BP + 2 × Diastolic BP) / 3 (Correct answer)
- (2 × Systolic BP + Diastolic BP) / 3
- Systolic BP − Diastolic BP
Correct answer: (Systolic BP + 2 × Diastolic BP) / 3
MAP = (Systolic BP + 2 × Diastolic BP) / 3, reflecting that diastole occupies approximately two-thirds of the cardiac cycle.
Question 2: A PCU nurse observes that a patient's arterial waveform shows pulsus paradoxus with an inspiratory drop in systolic BP greater than 10 mmHg. Which condition should the nurse suspect?
- Hypertensive crisis
- Cardiac tamponade (Correct answer)
- Aortic stenosis
- Mitral valve regurgitation
Correct answer: Cardiac tamponade
Pulsus paradoxus greater than 10 mmHg is a hallmark sign of cardiac tamponade due to exaggerated ventricular interdependence during respiration.
Question 3: When caring for a patient with a pulmonary artery catheter (PAC), a pulmonary artery wedge pressure (PAWP) of 22 mmHg most likely indicates:
- Hypovolemia
- Left ventricular failure and elevated left-sided filling pressures (Correct answer)
- Normal left ventricular preload
- Right-sided heart failure only
Correct answer: Left ventricular failure and elevated left-sided filling pressures
Normal PAWP is 6–12 mmHg; a value of 22 mmHg indicates elevated left-sided filling pressures, consistent with left ventricular failure.
Question 4: Which complication is most specific to the use of a pulmonary artery catheter (PAC)?
- Pneumothorax during insertion
- Pulmonary artery rupture (Correct answer)
- Air embolism
- Bloodstream infection
Correct answer: Pulmonary artery rupture
Pulmonary artery rupture is a rare but life-threatening complication unique to PAC use, often associated with over-wedging or balloon over-inflation.
Question 5: A patient receiving a peripheral IV infusion develops pain, erythema, and a palpable cord along the vein. Which intervention is the priority?
- Slow the infusion rate
- Apply warm compresses and continue the infusion
- Discontinue the IV and remove the catheter (Correct answer)
- Increase the gauge of the IV catheter
Correct answer: Discontinue the IV and remove the catheter
Signs of thrombophlebitis require immediate discontinuation of the IV and removal of the catheter to prevent further vein damage and potential infection.
Question 6: Which of the following parameters directly reflects systemic vascular resistance (SVR)?
- Pulmonary artery diastolic pressure
- Cardiac output divided by heart rate
- The difference between MAP and CVP, divided by cardiac output (Correct answer)
- Pulmonary artery wedge pressure minus CVP
Correct answer: The difference between MAP and CVP, divided by cardiac output
SVR = (MAP − CVP) / Cardiac Output × 80, reflecting the resistance against which the left ventricle pumps.
Question 7: A patient with a central line develops sudden onset dyspnea, chest pain, and hypoxia during a tubing change. The nurse suspects air embolism. What is the immediate priority intervention?
- Administer 100% oxygen and place the patient in the left lateral Trendelenburg position (Correct answer)
- Place the patient in high Fowler's position and administer diuretics
- Initiate CPR and call a code
- Clamp the central line and place the patient supine
Correct answer: Administer 100% oxygen and place the patient in the left lateral Trendelenburg position
The left lateral Trendelenburg (Durant's maneuver) position traps air in the right ventricle apex, preventing pulmonary embolism, while 100% oxygen accelerates air reabsorption.
PCU Hemodynamic Monitoring & Vascular Access 2
Which formula is used to calculate mean arterial pressure (MAP)?