NONINVASIVE POSITIVE PRESSURE VENTILATION TO TREAT RESPIRATORY-FAILURE

Purpose: To review the clinical use of noninvasive positive pressure ventilation, including its efficacy with acute and chronic forms of respiratory failure, its mechanism of action, and its implementation. Data Sources: Studies were identified through a MEDLINE search using the keywords respiratory failure and mechanical ventilation and through a manual review of reference lists of published articles. Study Selection: All original studies relating to the use of noninvasive positive pressure ventilation in respiratory failure were included. Because of the paucity of controlled trials, cohort studies were not excluded. Data Extraction: Study design, numbers and diagnoses of patients, ventilator modes, and success and complication rates were extracted and compiled. Results: For acute respiratory failure, studies report improved gas exchange and avoidance of intubation in 60% to 80% of patients with chronic obstructive pulmonary disease, restrictive thoracic disease, congestive heart failure, pneumonia, or postoperative extubation failure. However, the patients were highly selected, and relatively few studies have been published, only one of which was a randomized controlled trial. For chronic respiratory failure due to restrictive thoracic disease, all studies report improved gas exchange and symptoms of hypoventilation after prolonged nocturnal use, although no study was controlled. Some cohort studies of patients with severe chronic obstructive pulmonary disease yielded favorable results, but longer-term, randomized, controlled studies showed minimal, if any, benefit. Conclusion: Noninvasive positive pressure ventilation is effective in the treatment of chronic respiratory failure due to restrictive thoracic diseases. The routine use of such treatment for chronic respiratory failure due to chronic obstructive pulmonary disease and for acute respiratory failure needs to be studied in randomized controlled trials in better-defined patient subsets.