Intravascular carbon dioxide monitoring using micro-flow colorimetry

Area of Science:

• Biomedical Engineering
• Medical Devices
• Analytical Chemistry

Background:

• Accurate intravascular blood gas monitoring is crucial for critical care.
• Existing methods for continuous CO2 measurement face limitations in stability and accuracy.
• A need exists for a reliable, real-time intravascular CO2 sensor.

Purpose of the Study:

• To investigate a novel intravascular carbon dioxide sensor.
• To evaluate the sensor's performance in vivo using a pig model.
• To assess the sensor's stability, response time, and accuracy.

Main Methods:

• Developed an intravascular CO2 sensor utilizing continuous reagent perfusion through silicone membrane tubing.
• Integrated the sensor into a catheter system for periodic blood withdrawal-reinfusion.
• Employed an optical cell to detect reagent color changes indicative of CO2 levels.
• Conducted in vivo trials on pigs to validate sensor performance.

Main Results:

• The sensor demonstrated stable performance with fast response times (2 min) and high signal-to-noise ratios.
• Achieved a resolution of +/-2 mmHg and minimal drift over 12 hours.
• In vivo pig model trials showed excellent correlation (0.998), precision (1.3 mmHg), and bias (1.7 mmHg).
• The sensor exhibited immunity to temperature variations, reduced blood flow, photobleaching, and leaching.

Conclusions:

• The developed intravascular CO2 sensor offers a promising solution for continuous blood gas monitoring.
• The sensor exhibits robust performance characteristics, including accuracy, stability, and rapid response.
• This technology has the potential to improve patient management in critical care settings.