NONINVASIVE MECHANICAL VENTILATION IN ACUTE RESPIRATORY-FAILURE DUE TO CHRONIC OBSTRUCTIVE PULMONARY-DISEASE - CORRELATES FOR SUCCESS

Background - Non-invasive mechanical ventilation is increasingly used in the treatment of acute respiratory failure in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to id entify simple parameters to predict the success of this technique. Met hods - Fifty nine episodes of acute respiratory failure in 47 patients with COPD treated with non-invasive mechanical ventilation were analy sed, considering each one as successful (78%) or unsuccessful (22%) ac cording to survival and to the need for endotracheal intubation. Resul ts - Pneumonia was the cause of acute respiratory failure in 38% of th e unsuccessful episodes but only in 9% of the successful ones. Success with non-invasive mechanical ventilation was associated with less sev erely abnormal baseline clinical and functional parameters, and with l ess severe levels of acidosis assessed during an initial trial of non- invasive mechanical ventilation. Conclusions - The severity of the epi sode of acute respiratory failure as assessed by clinical and function al compromise, and the level of acidosis and hypercapnia during an ini tial trial of non-invasive mechanical ventilation, have an influence o n the likelihood for success with non-invasive mechanical ventilation and may prove to be useful in deciding whether to continue with this t reatment.