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Direct measurement of hepatic tissue hypoxia by using a novel tc p O 2 / p CO 2 monitoring system in comparison with near‐infrared spectroscopy
Author(s) -
Yang Wenxuan,
Hafez Tariq,
Thompson Cecil S.,
Mikhailidis Dimitri P.,
Davidson Brain R.,
Winslet Marc C.,
Seifalian Alexander M.
Publication year - 2003
Publication title -
liver international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.873
H-Index - 110
eISSN - 1478-3231
pISSN - 1478-3223
DOI - 10.1034/j.1600-0676.2003.00818.x
Subject(s) - hypoxia (environmental) , liver tissue , partial pressure , oxygen , chemistry , hemoglobin , medicine , endocrinology , organic chemistry
Background/Aims: Hepatic hypoxia occurs during liver surgery and transplantation and it may also appear within liver tumours, correlating with prognosis and efficacy of the treatment. The present study measured liver tissue hypoxia by directly using near‐infrared spectroscopy (NIRS) and a novel tc p O 2 / p CO 2 monitoring system. Methods: Graded hypoxia was achieved in a rabbit model by a stepwise reduction of the fraction of inspired oxygen (FiO 2 ) from 0.3 to 0.0. Animals were allowed to recover from hypoxia at FiO 2 of 3.0 indicated by normalised arterial blood gas values. Hepatic tissue oxyhaemoglobin (HbO 2 ), deoxyhaemoglobin (Hb), cytochrome oxidase (Cyt Ox), oxygen partial pressure (pO 2 ) and carbon dioxide partial pressure (pCO 2 ) were measured continuously with the help of NIRS and a Clark‐type surface tc p O 2 / p CO 2 monitoring system, throughout the period of hypoxaemia. Results: There was an immediate reduction in hepatic HbO 2 with hypoxia and a simultaneous increase in hepatic Hb. Similarly, hepatic tissue pO 2 decreased significantly but tissue pCO 2 remained unchanged until the FiO 2 was below 0.1. Hepatic HbO 2 showed a positive correlation with tissue pO 2 ( r = 0.53, P < 0.001). Hepatic Hb showed a negative correlation with tissue pO 2 ( r = 0.47, P < 0.001). Hepatic Cyt Ox decreased significantly with an FiO 2 of 0.1 or less and showed a positive correlation with hepatic tissue pO 2 ( r = 0.64, P < 0.001). A significant correlation was found between hepatic tissue pO 2 and arterial blood pO 2 ( r = 0.44, P < 0.001). Arterial blood pCO 2 also correlated with hepatic tissue pCO 2 ( r = 0.53, P < 0.001) measured by the tc p O 2 / p CO 2 monitoring system. Conclusion: The data from the present study suggest that, like NIRS, the tc p O 2 / p CO 2 monitoring system can be reliably used for the direct monitoring of hepatic tissue oxygenation in vivo .