Introduction: Depression of Ventilation by Hypoxia - A Comparison of the Phenomenon in Anaesthetized Cats and Conscious Humans
The ventilatory response to isocapnic hypoxia is biphasic: there is an initial brisk rise in ventilation at the onset of hypoxia which is then followed by a subsequent slow decline over a period of many minutes1. The mechanisms underlying this slow decline in ventilation are not fully understood, but many investigators have focussed on the effects of hypoxia on the brainstem, and in particular the modulations in neurotransmitter levels that hypoxia can produce - for a review see Neubauer et al2. Of necessity, much of this work has been performed on anaesthetized experimental animals. The purpose of this article is to review the similarities and the differences between the hypoxic ventilatory decline observed in anaesthetized cats and that observed in conscious humans.
KeywordsCarotid Body Ventilatory Response Hypoxic Ventilatory Response Sustained Hypoxia Conscious Human
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