Nocturnal assisted ventilation using bilevel positive airway pressure: the effect of expiratory positive airway pressure.

Increasing expiratory positive airway pressure (EPAP) has theoretical advantages during overnight nasal ventilation. We wanted to evaluate the effect of the addition of EPAP upon the control of nocturnal hypoventilation. Seven patients with neuromuscular/skeletal (NMS) disorder (mean +/- SD forced vital capacity (FVC) 1.

A comparison of different modes of noninvasive ventilatory support: effects on ventilation and inspiratory muscle effort.

The aims of noninvasive ventilation include the correction of hypoventilation and unloading of inspiratory muscles. Volume cycled flow generators, bi-level positive airway pressure and continuous positive airway pressure techniques have all been used with face and nasal masks. We have compared these modes of ventilatory support, administered by a nasal mask in stable, awake outpatients with chronic obstructive pulmonary disease or neuromusculo-skeletal disease in respect of their effects on ventilation, inspiratory muscle effort and oxygen saturation.

Inspiratory muscle effort during nasal intermittent positive pressure ventilation in patients with chronic obstructive airways disease.

Effective intermittent positive pressure ventilation can be achieved noninvasively using a nasal mask, but patient comfort may be compromised and respiratory effort increased unless the trigger threshold is low and the response time of the ventilator short. The effect of nasal ventilation upon inspiratory muscle effort and the functional characteristics of the trigger of a purpose-built ventilator were evaluated in five patients with chronic obstructive airways disease. A measure of inspiratory muscle effort, the average pressure time integral per minute, decreased by at least 80% in four patients and by 50% in one.