Real-time monitoring of blood carbon dioxide tension by fluorosensor.

A new intravascular fluorosensor was developed and validated for inline P(CO)₂monitoring. The P(CO)₂sensor was based on the fluorescent indicator 1-hydroxypyrene-3,6,8-trisulfonate. The P(CO)₂sensor was then immersed in various solutions in vitro and carotid artery bypass of rabbits in vivo for testing. Changes of P(CO)₂in solutions and blood were created by bubbling CO2/N2 and hyperventilation/hypoventilation, respectively. The changes of fluorescent intensity over P(CO)₂ range of 14-150 mmHg was linear. The resolution of the whole sensor system was 1 mmHg, with a bias ± SD of -0.1 ± 2.9 mmHg and precision ± SD of 2.1 ± 1.9 mmHg. The sensor signal has been stable during measurement for at least 25h and was insensitive to fluctuations of ions concentration and osmosis at pathophysiological limits. The performance of the sensor is in agreement with blood gas analyzer in a wide range of P(CO)₂and it is qualified for continuous intravascular measurement of blood P(CO)₂at various conditions.