Predictability of PaO2 in different inert gas-oxygen environments
Tóm tắt
Recent experimentation with metabolic changes in rats exposed to thermally isoconductive environments has involved the use of inert gas-oxygen mixtures with different total pressures (PT) and inspired oxygen fractions (F1O2). To determine the FIO2 for each mixture that would result in similar arterial oxygen pressures (P
a
O2) and saturations (OS), arterial blood of dogs breathing the mixtures through a mask was analyzed for pH,PO2,PCO2, and OS. Using PIO2's calculated from the alveolar gas equation as a theoretical basis, the oxygen partial pressure for the helium mixture had to be increased by 5.6% while that in argon decreased by 10.2% below the computed values to obtain P
a
O2's acceptably similar to those resulting from air exposure. No consistent variation in pH, P
a
CO2, and OS were apparent. Based on the data presented, which were obtained under highly specialized conditions, it appears that the use of helium and argon as diluent gases may significantly affect arterial oxygen tension.
Tài liệu tham khảo
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