It is essential to distinguish 'central' apnoeas due to a loss of respiratory drive from those that are due to impaired respiratory mechanics or to widespread respiratory muscle weakness so that even a normal respiratory drive cannot be translated into detectable respiratory movements (Fig. 11.3). This latter group are better considered as 'pseudocentral' or 'peripheral' apnoeas, rather than due to any central abnormality . They are characteristic of neuromuscular disorders that cause diaphragmatic weakness so that in REM sleep no functioning inspiratory chest wall muscles are left (Table 11.1). Impaired respiratory mechanics in, for instance, emphysema may also cause even a normal drive only to be able to develop a small tidal volume (hypopnoea) or even no detectable airflow.
Was this article helpful?