ELECTROPHYSIOLOGY OF RESPIRATION

Neurological respiratory insufficiency may be the primary cause of adm ission to an intensive care unit or may develop during care in an inte nsive care ward. Severe respiratory insufficiency due to nervous syste m causes either involves a lack of central drive or weakness of the re spiration muscles. The former are induced by a wide variety of encepha lopathies and the latter by diseases of anterior horn cells, periphera l nerve, the neuromuscular junction, or muscles of the chest wall or d iaphragm. In an intensive care unit, it is often nor possible clinical ly to determine whether there is a lack of central drive or a neuromus cular problem. It is now possible by electrophysiological methods to p inpoint the site of nervous system cause of respiratory insufficiency. This review will describe the various electrophysiological techniques currently available and describe how they have been successfully appl ied in investigating some conditions that cause severe respiratory fai lure.