Study of the Interactive Effects of Stresses from Respirator Wear and Simultaneous Exposure to Toxic Anticholinesterase Agents

摘要

The cardiopulmonary effects of a peripheral cholinesterase inhibitor (0.025 mg neostigmine i.v. per kg) and inspiratory resistance loading comparable to the inspiratory resistance of a protective respirator mask, were studied comprehensively in 6 intact, awake dogs at rest and during exercise. The aim of this study was to test the hypothesis that both exercise and inspiratory resistance loading enhance the toxic effect of sublethal doses of CHEI agents. This study was also carried out in order to establish the methodological and physiological foundations for further in depth analysis of the pathophysiological and compensatory mechanism involved, and to explore possible and therapeutic interventions in the treatment of CHEI-exposed subjects. Mild peripheral cholinesterase inhibition endangers the mammal organism mainly by the fact that the increased metabolic needs of the respiratory muscles are not met as a result of diminished blood flow and perfusion pressure, and compromised gas exchange in the lung. The mechanical resistance load of a protective respirator, and the increased work of breathing associated with exercise, serve to aggravate these conditions to an extent that may lead to incipient respiratory muscle fatigue, and ultimately to peripheral respiratory failure if these stress conditions would be allowed (or required) to persist.