Rates of carbon monoxide elimination in males and females

Physiological Reports

Gerald S. Zavorsky²  Janet Tesler³  Joshua Rucker¹  Ludwik Fedorko³  James Duffin³ 

[1] Department of Anesthesia, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada;ORCID:orcid.org/0000-0002-4473-1601;Department of Physiology, University of Toronto, Toronto, Ontario, Canada

关键词: Alveolar ventilation;    carboxyhemoglobin;    gender differences;   

DOI  :  10.14814/phy2.12237

来源: Wiley

【 摘 要 】

Abstract

The purpose of this study was to verify the previously reported shorter half-time of elimination (t_½) of carbon monoxide (CO) in females compared to males. Seventeen healthy subjects (nine men) completed three sessions each, on separate days. For each session, subjects were exposed to CO to raise the carboxyhemoglobin percentage (COHb) to ~10%; then breathed in random order, either (a) 100% O₂ at poikilocapnia (no CO₂ added), or (b) hyperoxia while maintaining normocapnia using sequential gas delivery, or (c) voluntary hyperpnea at~4x the resting minute ventilation. We measured minute ventilation, hemoglobin concentration [Hb] and COHb at 5 min intervals. The half-time of reduction of COHb (t_½) was calculated from serial blood samples. The total hemoglobin mass (Hb_TOT) was calculated from [Hb] and estimated blood volume from a nomogram based on gender, height, and weight. The t_½ in the females was consistently shorter than in males in all protocols. This relationship was sustained even after controlling for alveolar ventilation (P < 0.05), with the largest differences in t_½ between the genders occurring at low alveolar ventilation rates. However, when t_½ was further normalized for Hb_TOT, there was no significant difference in t_½ between genders at alveolar ventilation rates between 4 and 40 L/min (P = 0.24). We conclude that alveolar ventilation and Hb_TOT are sufficient to account for a major difference in CO clearance between genders under resting (nonexercising) conditions.

【 授权许可】

CC BY   
© 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

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