Assessment of Output of the Respiratory Controller

Abstract

The respiratory controller in this context is considered to be the central nervous system pattern generator that produces a signal that in turn activates muscles of the respiratory pump. By its “output” we mean the strength of the signal. In fact, the signal varies constantly through the respiratory cycle in amplitude and in distribution among the various respiratory muscles. This review discusses advantages and limitations of commonly used methods of assessing output including electromyograms, occlusion pressure, minute ventilation, and recruitment of muscles beyond the diaphragm and intercostal muscles. Principles are reviewed for choosing and interpreting these measurements for analysis of clinical problems, and applied to the examples of obstructive sleep apnea, COPD, generalized weakness of respiratory muscles, and phrenic nerve palsy.

Key Words:

respiratory centre output - control of breathing - electromyogram - respiratory muscles - occlusion pressure - galen