Evaluation of cardiac output by 5 arterial pulse contour techniques using trend interchangeability method

Area of Science:

• Cardiovascular physiology
• Medical device technology
• Clinical monitoring

Background:

• Cardiac output (CO) measurement is crucial for patient management.
• Pulse contour analysis (PCA) offers continuous, minimally invasive CO monitoring.
• Existing methods for comparing CO measurements have limitations, risking misinterpretation.

Purpose of the Study:

• To introduce and validate a novel trend interchangeability method for assessing CO measurement agreement.
• To objectively evaluate the interchangeability of five arterial PCA techniques against bolus thermodilution in cardiac surgery.

Main Methods:

• Development of a new trend interchangeability method classifying changes as interpretable/uninterpretable and interchangeable/non-interchangeable/gray zone.
• Application of the method to compare 5 PCA techniques (Wesseling, LiDCO, PiCCO, Hemac, Modelflow) with bolus thermodilution in 24 cardiac surgery patients.
• Analysis of 172 CO variations to determine interchangeability rates.

Main Results:

• Over 50% (51%) of CO variations were deemed uninterpretable by the new method.
• Among interpretable variations, only 21-36% were interchangeable between PCA techniques and the reference method.
• No tested PCA technique demonstrated interchangeability with bolus thermodilution for CO changes in this cohort.

Conclusions:

• The novel trend interchangeability method provides an objective assessment of CO measurement agreement.
• Current arterial pulse contour cardiac output techniques show limited interchangeability with bolus thermodilution in cardiac surgery.
• Further research using this method is recommended to assess interchangeability between different CO measurement techniques.