Is it possible to predict the success of non-invasive positive pressure ventilation in acute respiratory failure due to COPD?

There is now sufficient evidence that non-invasive positive pressure ventil ation (NIPPV) in selected patients with severe hypercapnic acute respirator y failure due to chronic obstructive pulmonary disease (COPD) is more effec tive than pharmacological therapy alone. The aim of this study was to ident ify prognostic factors to predict the success of this technique. Fifty-nine consecutive patients with COPD admitted to a respiratory ward for 75 episo des of acute respiratory failure treated with NIPPV were analysed: success( 77%) or failure (23%) were evaluated by survival and the need for endotrach eal intubation. There were no significant differences in age, sex, cause of relapse and lung function tests between the two groups. Patients in whom N IPPV was unsuccessful were significantly underweight, had an higher Acute P hysiology and Chronic Health Evaluation (APACHE) II score, and a lower seru m level of albumin in comparison with those in whom NIPPV was successful. T hey demonstrated significantly greater abnormalities in pH and Pa-CO2 at ba seline and after 2h of NIPPV. The logistic regression analysis demonstrated that, when all the variables were tested together, a high APACHE II score and a low albumin level continued to have a significant predictive effect. This analysis could predict the outcome in 82% of patients. In conclusion, our study suggests that low albumin serum levels and a high APACHE II score may be important indices in predicting the success of NIPPV.