a) To describe the introduction of noninvasive means to provide positive-pressure ventilation in acute respiratory failure; b) to describe the physiologic response to noninvasive ventilation; c) to review the current published literature on using noninvasive ventilation in patients with acute hypercapnic and/or hypoxemic respiratory failure; d) to describe the technique of applying mask ventilation and current recommendations for using noninvasive ventilation in patients with acute respiratory failure; and e) to discuss the advantages and disadvantages of noninvasive ventilation.Data Sources
All relevant articles published in the English medical literature from 1988 through August 1994 were retrieved through a MEDLINE search, as well as from the authors' experience.Study Selection
Studies were selected based on the use of positive-pressure mechanical ventilation delivered, using facial or nasal masks in various acute settings of respiratory failure.Data Extraction
The authors extracted all applicable data.Data Synthesis
Studies were analyzed according to the type of respiratory failure (hypercapnic vs. hypoxemic) and the underlying conditions where noninvasive ventilation seemed to be a better alternative. The results were evaluated based on types of masks used and modes of ventilation. Outcome measures were compared based on studies that randomized patients with acute respiratory failure to receive noninvasive ventilation vs. conventional therapy. Complications of noninvasive ventilation, mainly local, were compared with those complications seen with endotracheal intubation in acute respiratory failure patients.Conclusions
Noninvasive ventilation is a safe and effective means of ventilatory support for many patients with acute respiratory failure, particularly those patients with hypercapnic respiratory failure. Noninvasive ventilation is well tolerated, principally because it allows the patient to be in control and to continue verbal communication, and should be strongly considered in managing terminally ill patients with potentially reversible causes of respiratory failure. The duration of mechanical ventilation and its associated complications are significantly decreased in hypercapnic respiratory failure with noninvasive ventilation.