Assessment of respiratory function in the intensive care unit.

Disorders of both the central and peripheral nervous systems are important causes of respiratory insufficiency. However, simple clinical observations and pulmonary function measurements may fail to identify the location and type of disorder. This can often be accomplished by the newly-developed technique of phrenic nerve conduction and needle electromyography of the diaphragm which delineate the various disturbances of central drive, axonal or demyelinating neuropathies of the phrenic nerves and certain myopathies. These studies have been preformed safely and with little discomfort on adults, children or infants, and in out-patient and general ward settings. We have found they are of particular value in the intensive care unit.