Near-patient testing for coagulopathy after cardiac surgery

Area of Science:

• Clinical chemistry
• Medical device evaluation
• Cardiovascular surgery

Background:

• Near-patient testing systems aim to provide rapid diagnostic results at the point of care.
• Accurate coagulation monitoring is crucial for patients undergoing cardiac surgery with cardiopulmonary bypass.

Purpose of the Study:

• To evaluate the accuracy and precision of the Hemochron Response near-patient testing system.
• To compare Hemochron Response measurements of prothrombin time (PT) and activated partial thromboplastin time (APTT) with laboratory assays.

Main Methods:

• Fifty patients undergoing cardiac surgery with cardiopulmonary bypass were studied.
• Prothrombin time (PT) and activated partial thromboplastin time (APTT) were measured using the Hemochron Response and laboratory assays.
• Measurements were taken before and after cardiopulmonary bypass, including after protamine administration.

Main Results:

• Before bypass, PT measurements showed good agreement (bias +0.34) with small limits of agreement.
• After bypass, PT measurements exhibited increased bias (-3.27) and wider limits of agreement.
• Activated partial thromboplastin time (APTT) measurements demonstrated wider bias and limits of agreement compared to PT, both before and after bypass.

Conclusions:

• The Hemochron Response system demonstrated good agreement for PT and clinically acceptable agreement for APTT pre-bypass.
• Post-bypass, both PT and APTT measurements showed increased bias and limits of agreement, potentially becoming clinically unacceptable.
• The accuracy of the Hemochron Response system may be compromised in the post-cardiopulmonary bypass setting.