THE USE OF LYMPH FOR THE MEASUREMENT OF GAS TENSIONS IN INTERSTITIAL FLUID AND TISSUES*

Abstract

The concentrations of the respiratory gases in interstitial fluid and tissues were estimated by measurements of the gaseous tensions of lymph collected from various lymphatic ducts. This approach assumes that lymph is interstitial fluid which has bathed tissues prior to its entry into the lymphatic tree and that it undergoes no modification in gas tensions between its site of origin and collection. Lymph from the liver, small bowel and muscle yielded CO2 tensions which were uniformly higher than those of venous blood and O2 tensions which were not only lower than venous blood, but averaged 8 mm Hg. It was demonstrated that these gas tensions in lymph could not be attributed to the metabolism of the tissues of the larger lymphatic vessels or to an unsteady state of gas exchange. The low O2 tensions of the lymph, together with high lactate values, indicate not only that the bulk of the tissues represented in the lymph operate at O2 tensions far lower than those of venous blood, but also that in some parts of the tissues, the tissue O2 tensions approximate O mm Hg.