Validation study of PulseCO system for continuous cardiac output measurement

Area of Science:

• Cardiovascular Physiology
• Medical Device Technology

Background:

• Ultrasonic flow probes optimize biventricular pacing post-cardiopulmonary bypass, but require removal.
• The PulseCO system offers potential for extended cardiac output (CO) monitoring into the postoperative period.
• Controlled validation studies for the PulseCO system are lacking.

Purpose of the Study:

• To validate the accuracy and identify limitations of the PulseCO system for measuring cardiac output in a porcine model.
• To compare PulseCO measurements against a gold standard ultrasonic flow probe during controlled hemodynamic conditions.

Main Methods:

• Six anesthetized pigs underwent instrumentation for right heart bypass.
• Cardiac output was manipulated and measured using both an aortic ultrasonic flow probe and the PulseCO system via a femoral arterial line.
• Hemodynamic conditions were altered using cardiac pacing, phenylephrine, and nitroprusside infusions.

Main Results:

• Both PulseCO and ultrasonic flow probes demonstrated high accuracy in measuring cardiac output (R2 values ranging from 0.79 to 0.99).
• PulseCO falsely indicated increased CO during cardiac pacing (p = 0.014).
• PulseCO provided false readings of increased CO with phenylephrine (p = 0.014) and decreased CO with nitroprusside (p = 0.003).

Conclusions:

• The PulseCO system is a potentially useful tool for assessing acute changes in cardiac output.
• Clinicians must be aware of PulseCO's limitations, particularly its susceptibility to errors during altered heart rates or blood pressure.
• Further research is needed to refine the system's accuracy under various physiological conditions.