Abstract
We developed micropore membrane inlet mass spectrometer (MMIMS) probes to rapidly measure inert-gas partial pressures in small blood samples. The mass spectrometer output was linearly related to inert-gas partial pressure (r2 of 0.996-1.000) and was nearly independent of large variations in inert-gas solubility in liquid samples. We infused six inert gases into five pentobarbital-anesthetized New Zealand rabbits and used the MMIMS system to measure inert-gas partial pressures in systemic and pulmonary arterial blood and in mixed expired gas samples. The retention and excretion data were transformed into distributions of ventilation to-perfusion ratios (V̇(A)/Q̇) with the use of linear regression techniques. Distributions of V̇(A)/Q̇ were unimodal and broad, consistent with prior reports in the normal rabbit. Total blood sample volume for each V̇(A)/Q̇ distribution was 4 ml, and analysis time was 8 min. MMIMS provides a convenient method to perform the multiple inert-gas elimination technique rapidly and with small blood sample volumes.
Original language | English |
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Pages (from-to) | 1699-1708 |
Number of pages | 10 |
Journal | Journal of Applied Physiology |
Volume | 89 |
Issue number | 5 |
Publication status | Published - 1 Jan 2000 |
Keywords
- Inert gases
- Multiple inert-gas elimination technique
- Solubility
- Stirring effect