IMPROVED METHOD AND APPARATUS FOR DETERMINING DIFFERENCES BETWEEN REGIONAL CO2 AND SYSTEMIC CO2 MEASUREMENTS

摘要

Methods and apparatus for determining the difference between a regional CO2 partial pressure of a selected body organ of a mammalian subject, such as the gut, and a systemic CO2 partial pressure of the subject. The regional CO2 partial pressure value is tonometrically obtained at body temperature using a gaseous sampling medium. A systemic CO2 partial pressure value is obtained from the blood. The systemic CO2 partial pressure value can be that for the body temperature or for a standard temperature. If the systemic CO2 partial pressure value is that for the body tempeature, the regional CO2 partial pressure value is compared to the systemic CO2 partial pressure value and the difference therebetween is provided as a CO2 partial pressure gap measurement. If the systemic CO2 partial pressure value is that for a standard temperature, one of the regional CO2 partial pressure value or the systemic CO2 partial pressure value is corrected for the difference between the body temperature and the standard temperature so that both the partial pressure values comprise CO2 partial pressure values at a common temperature. The values are thereafter compared to provide a CO2 partial pressure gap measurement. An end tidal CO2 partial pressure value may be used as the systemic CO2 partial pressure value.