| abstract |
Methods and devices are provided for assessing impairment of blood circulation in a patient, such as that in perfusion failure, by measurement of pCO 2 (partial pressure of carbon dioxide) in the upper digestive and/or respiratory tract of the patient. The method comprises introducing a carbon dioxide sensor into the upper digestive and/or respiratory tract of a patient, without passing the sensor down through or beyond the patient's epiglottis. Specifically, a carbon dioxide sensor is placed adjacent a mucosal surface within the upper digestive and/or respiratory tract, preferably within the patient's mouth or inside the patient's nose. By avoiding passage through the mouth into the throat and esophagus, discomfort is substantially avoided and the potential for injury minimized. Previously, the belief in the art was that increased partial pressure of carbon dioxide was a localized phenomenon during perfusion failure; however, applicants have now discovered that increases in tissue CO 2 occur throughout the body during perfusion failure, and the method and device of the invention are premised on this discovery. |