ABSTRACT
A vast descriptive literature has been accumulated on the respiratory effects
of general anesthetics. However, progress in the identification of mechan-
isms by which anesthetics depress the brainstem respiratory center and alter
respiratory rhythm and pattern generation has been slow. This chapter is
divided into five parts. Section II summarizes the most important descriptive
aspects of the effect of general anesthesia on respiratory rate and depth as
reflected in tidal volume, phrenic nerve activity, and respiratory neuron
activity. Section III presents the current knowledge of anesthetic effects
on fast synaptic neurotransmission as is relevant for respiratory neuro-
transmission. In section IV an overview of the brainstem respiratory
network and the neurotransmission within will be provided. We introduce
a prototype respiratory oscillator model that can predict some of the
observed effects of anesthetics on respiratory rate. We conclude in section V
with three important paradigms that provide an approach to bridge in vitro
and in vivo data in order to assess the clinical relevance of the postulated
anesthetic mechanisms. This chapter does not attempt to be comprehensive,
but it provides a concise update on anesthetic and central respiratory mechanisms and highlights promising areas of respiratory and anesthetic research. We hope it will serve to stimulate further research. Please refer to Table 15.1 for frequently used abbreviations.
