Ventimask in exacerbation of chronic obstructive pulmonary disease and mild acidosis before starting with bilevel positive airway pressure

摘要

Patients with chronic obstructive pulmonary disease (COPD) during an episode of acute or acute on chronic respiratory failure due to infection present a special problem with regard to the relief of hypoxia. In a prospective, randomized, multicenter controlled trial, we evaluated the efficacy of oxygen delivery by Ventimask compared with Venturi mask in patients affected by exacerbation of COPD and mild acidosis before starting with non-invasive bilevel-positive airway pressure (PAP). The study involved 80 patients with exacerbation of COPD divided in two groups: Group A=40 patients randomized to Ventimask plus standard therapy and Group B=40 patients randomised to Ventury mask plus standard therapy. The primary endpoint was to evaluate the efficacy of oxygen therapy with Ventimask compared with Venturi mask in terms of avoiding the need for non-invasive bilevel-PAP during the 1st h and reducing PaCO2 retention. Twenty-five patients (62%) started with bilevel-PAP in Group A and 28 (70%) in Group B (not significant). There were no significant changes in arterial blood gases values between the two groups. In Group A, pH and PaCO2 were 7.32±0.11 and 68.5±13.6 mmHg at admission, and 7.33±0.05 and 64.8±4.9 mmHg after 1 h (not significant). In Group B, pH and PaCO2 were, respectively, 7.32±0.11 and 65.7±13.6 mmHg at admission, and 7.33±0.03 and 64.0±5.5 mmHg after 1 h (not significant). Our conclusion did not show any significant differences between the two oxygen masks delivery in terms of preventing the need of bilevel-PAP and reducing PaCO2, despite the trend towards a reduction of the utilization of non-invasive positive pressure ventilation was in favor of Ventimask.