Cardiac Output Monitoring


The primary purpose of cardiac output monitoring is to determine the overall hemodynamic status of the patient, and to evaluate the patient's response to therapy.


1. Thermodilution catheter.
2. Cardiac output table.
3. Closed system for room temperature injectate.




1. Check that the thermodilution catheter is positioned properly in the pulmonary artery (PA) and that balloon is deflated. 1. There is a possibility of ventricular dysrhythmias because of current leakage if thermister is in right ventricle and connected to computer.
2. Configure the monitor for C.O. measurements:

a. Auto mode: on

b. Inject volume: 5 or 10 cc

c. Inject temp: In-line

d. Catheter 1. Baxter or 2. Other

e. Size (5, 6, 7, 7.5, or 8)

2. Cardiac output measurements will be inaccurate if information in computer differs from what is on the patient. Consult manufacturer’s insert on PA catheters for appropriate computation constant.
3. Ensure that the closed injectate system is attached to the stopcock of the proximal port on the PA catheter. 3. Cardiac output measurements will be inaccurate if connected to wrong port.
4. Withdraw 5 or 10cc of injectate into closed system syringe. 4. The amount used must be exact or output measurements are inaccurate. D5W is usually used; however, NS may be used if glucose tends to be of concern.
5. Observe for "Inject when ready" message displayed. Inject bolus as rapidly as possible (no slower than 10ml/4sec). 5. If the bolus is given too slowly an inaccurate output will be obtained.
6. Obtain average of three sequential measurements. 6. Each should be within 10% of the median.



1. Do not disconnect the object data system between measurements.
2. Change they inject a solution in accordance with your local infection control policies and procedures.
3. Follow-up electrical safety guidelines.
4.Always maintain stricter septic technique.
5.Check to make sure that the credit constant for use with the close system is used as well as inject a volume and temperature.


1. Dysrhythmias.
2. Pulmonary Emboli or Infarctions.
3. Cardiac arrest.
4.Electrical Microshock.
5. Air emboli.
6. Infection.


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