Improvement in human tumour oxygenation with carbogen of varying carbon dioxide concentrations

Abstract

Listen

Translate article

Background and purpose: Carbogen (95%O 2, 5%CO 2) is being used in clinical trials as a hypoxic radiosensitiser. Tolerance to carbogen can be a problem, this study compares tumour oxygenation during inhalation of hyperoxic gas containing either 2% or 5% CO 2. Materials and methods: Tumour pO 2 was measured in 16 patients using the Eppendorf pO 2 histograph. Results: After breathing gas containing either 5% or 2% CO 2 an increase in median pO 2 was measured in every tumour, the frequency of low pO 2 values (≤10 mmHg) fell from 47% to 29% in the 5% group and from 55% to 17% in the 2% group. Conclusions: This study confirms that breathing 2% CO 2 and 98% O 2 is well tolerated and effective in increasing tumour oxygenation.