Treatment of acute exacerbations with non-invasive ventilation in chronic hypercapnic COPD patients with pulmonary hypertension.

ABSTRACT

BACKGROUND AND OBJECTIVES: Chronic Obstructive Pulmonary Disease (COPD) is a slowly progressive airways disorder characterized by not fully reversible airflow obstruction, often presenting exacerbations of respiratory symptoms requiring hospitalization. Non-Invasive Ventilation (NIV) has been shown to be an effective adjunct to standard medical therapy in the treatment of acute respiratory failure. Secondary pulmonary hypertension leads to a rapid progression of the disease. AIM: To evaluate the effect of NIV treatment in patients with acute exacerbation of COPD, with or without respiratory acidosis, and its effect in patients with pulmonary hypertension. PATIENTS AND METHODS: We enrolled 61 consecutive subjects (M 41; F 20) with COPD admitted to our respiratory ward for acute respiratory exacerbation. Patients were divided into two groups on the basis of arterial pH (group A 26 individuals with pH <7.35; group B 35 with pH > or =7.35) and treated with optimal medical therapy (oxygen-therapy, systemic corticosteroids, bronchodilators, antibiotics) and NIV. Moreover, we evaluated functional autonomy thought Six Minute Walking Test (6 mWT), and pulmonary arterial pressure (by transthoracic echocardiography). RESULTS: In group A NIV treatment was associated to a total regression of uncompensated respiratory acidosis (pH 7.36 vs. 7.29). In both groups we observed a significant reduction of PaCO2 (group A 77.14 +/- 10.4 vs. 45.1 +/- 2.8 mmHg; group B 70.1 vs. 44 +/- 3.9 mmHg) and an improvement in PaO2 (group A 51.2 +/- 10.3 vs 84.2 mmHg; group B 59 +/- vs. 87 +/- 3.3 mmHg). Total average duration of NIV administration was longer in Group A than in Group B (81.14 hours vs 55.83 hours). At the end of NIV treatment, we observed improvement in the autonomy of walking (175.1 meters vs 118.4 meters) in both groups. Patients with severe pulmonary hypertension (PASP > or =55 mmHg) showed a lower reduction of PaCO2 (47.8 vs. 43.7 mmHg) and a minor improvement of arterial pH (7.37 vs. 7.41) compared to patients with a lower value of pulmonary hypertension. CONCLUSIONS: In this study we showed that NIV is useful in patients with or without uncompensated respiratory acidosis, through the improvement of symptoms, blood gases parameters, and walking autonomy. Patients with severe pulmonary hypertension are associated with poorer response to NIV treatment.