Sequential V(A)/Q distributions in the normal rabbit by micropore membrane inlet mass spectrometry

• Published in: Journal of applied physiology (1985) Vol. 89; no. 5; pp. 1699 - 1708
• Main Authors: Baumgardner, J E, Choi, I C, Vonk-Noordegraaf, A, Frasch, H F, Neufeld, G R, Marshall, B E
• Format: Journal Article
• Language: English
• Published: United States 01.11.2000
• Subjects: Acetone - analysis; Anesthetics, Inhalation - analysis; Animals; Blood Gas Analysis - instrumentation; Blood Gas Analysis - methods; Enflurane - analysis; Ether - analysis; Female; Isoflurane - analogs & derivatives; Isoflurane - analysis; Krypton - analysis; Mass Spectrometry - instrumentation; Mass Spectrometry - methods; Membranes, Artificial; Noble Gases - analysis; Partial Pressure; Pulmonary Artery - physiology; Rabbits; Sensitivity and Specificity; Solubility; Sulfur Hexafluoride - analysis; Ventilation-Perfusion Ratio
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.2000.89.5.1699

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 (r(2) 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 (V(A)/Q) with the use of linear regression techniques. Distributions of V(A)/Q were unimodal and broad, consistent with prior reports in the normal rabbit. Total blood sample volume for each VA/Q 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.