Tissue capnometry: does the answer lie under the tongue?
Increases in tissue partial pressure of carbon dioxide (PCO(2)) can reflect an abnormal oxygen supply to the cells, so that monitoring tissue PCO(2) may help identify circulatory abnormalities and guide their correction. Gastric tonometry aims at monitoring regional PCO(2) in the stomach, an easily accessible organ that becomes ischemic quite early when the circulatory status is jeopardized. Despite substantial initial enthusiasm, this technique has never been widely implemented due to various technical problems and artifacts during measurement. Experimental studies have suggested that sublingual PCO(2 )(P(sl)CO(2)) is a reliable marker of tissue perfusion. Clinical studies have demonstrated that high P(sl)CO(2) values and, especially, high gradients between P(sl)CO(2) and arterial PCO(2) (DeltaP(sl-a)CO(2)) are associated with impaired microcirculatory blood flow and a worse prognosis in critically ill patients. Although some questions remain to be answered about sublingual capnometry and its utility, this technique could offer new hope for tissue PCO(2) monitoring in clinical practice.
Maciel
Alexandre Toledo
AT
Department of Intensive Care, Erasme University Hospital, Free University of Brussels, Route de Lennik 808, 1070 Brussels, Belgium.
Creteur
Jacques
J
Vincent
Jean-Louis
JL
D000818:Animals; D019296:Capnography / Q000379:methods*; D003422:Critical Care; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods; D008991:Monitoring, Physiologic / Q000379:methods*; D009060:Mouth Floor / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology; D013270:Stomach / Q000098:blood supply*