Intravascular pH-ISFET, a method of the future

Area of Science:

• Biomedical Engineering
• Medical Devices
• Critical Care Medicine

Background:

• Blood pH is a vital parameter reflecting metabolic and cardiorespiratory function.
• Current point-to-point pH measurements have limitations due to delayed results.
• Continuous monitoring is crucial for managing rapidly changing physiological conditions in intensive care.

Purpose of the Study:

• To evaluate the feasibility and accuracy of an intravascular pH monitoring system utilizing ion-selective field-effect transistor (ISFET) technology.
• To assess the performance of the pH-ISFET system in animal models and critically ill human patients.

Main Methods:

• Development and testing of miniaturized pH-ISFET catheters for intravascular insertion.
• Simultaneous measurements using pH-ISFET catheters and a standard blood-gas analysis system (Radiometer ABL2) in canine experiments.
• Clinical trials in intensive care unit patients post-coronary artery bypass grafting.

Main Results:

• In canine studies (N=12), the pH-ISFET system demonstrated high accuracy compared to ABL2 measurements (n=132), with a mean delta pH of 0.016 ± 0.024 and a maximum deviation of 0.06.
• The system showed a short response time and suitability for miniaturization.
• Clinical trials confirmed the system's effectiveness in monitoring intravascular pH in critically ill patients.

Conclusions:

• The developed pH-ISFET system offers a reliable method for continuous intravascular pH monitoring.
• This technology is well-suited for use in intensive care units, providing timely physiological data.
• The pH-ISFET system has the potential to improve patient management in critical care settings.