Home mechanical ventilation.

Mechanical ventilation originated as an in-hospital service but there is now an increasing demand for provision at home [1]. This is a consequence of social pressures, a better understanding of the significance of nocturnal hypoventilation in the pathogencsis of respiratory failure, and an awareness of respiratory muscle fatigue. It is important to recognize that there are two quite different circumstances in which respiratory support may be needed: 1) the patient with a complete inability to breathe, for example after high cervical cord transection; 2) the patient unable to sustain adequate spontaneous ventilation indefinitely, in whom assistance during sleep is all that is required.