SPLANCHNIC TISSUE OXYGENATION: ESTIMATION BY THORACIC DUCT LYMPH PO2

Internal respiration or gas exchange of oxygen and carbon dioxide between capillary blood and tissue cells involves diffusion through intervening tissue fluid (8) and depends on the partial pressure or fugacity gradient of these dissolved gases in plasma and extracellular fluid (2). Excess interstitial fluid from the small bowel and liver is transported mainly to the thoracic duct, and in animals at rest or under anesthesia forms the bulk of thoracic duct lymph (4, 11). Therefore, thoracic duct lymph oxygen tensions were stuied in patients at rest and in experimental animals under anesthesia to assess oxygen exchange in splanchnic tissues.