The nurse prepares the client for insertion of a pulmonary artery catheter (Swan-Ganz catheter). The nurse teaches the client that the catheter will be inserted to provide information about:
A. Stroke volume
B. Cardiac output
C. Venous pressure
D. Left ventricular functioning
Correct Answer: D. Left ventricular functioning
The catheter is placed in the pulmonary artery. Information regarding left ventricular function is obtained when the catheter balloon is inflated. Pulmonary artery catheterization remains an excellent tool for the assessment of patients with pulmonary hypertension, cardiogenic shock, or unexplained dyspnea. It can be used to assess right-sided cardiac chamber filling pressures, to estimate cardiac output, to evaluate intracardiac shunts, to evaluate cardiac valves, or to assess vascular resistance.
Option A: Stroke volume is calculated using measurements of ventricle volumes from an echocardiogram and subtracting the volume of the blood in the ventricle at the end of a beat (called end-systolic volume) from the volume of blood just prior to the beat (called end-diastolic volume).
Option B: Cardiac output (CO) is the product of the heart rate (HR), i.e. the number of heartbeats per minute (bpm), and the stroke volume (SV), which is the volume of blood pumped from the ventricle per beat; thus, CO = HR × SV.
Option C: The central venous pressure is measured by a central venous catheter placed through either the subclavian or internal jugular veins. The central venous pressure can be monitored using a pressure transducer or amplifier.
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