New non invasive ventilator strategy applied to COPD patients in acute ventilator failure.

INTRODUCTION: There is no evidence in the literature regarding the combined use of positive ventilation with negative ventilation. A recent study reported that the two techniques can be combined in patients with ARDS, who undergo ventilatory support for severe acute respiratory failure (ARF). There is experience of non-invasive ventilation in patients with chronic respiratory diseases and ARF. The aim of this study was to test the efficacy of a non-invasive ventilatory strategy based on the combined use of negative (N) and positive ventilation (P) in bi-level mode (PN).

METHODS: We enrolled 8 patients with severe COPD exacerbations and exacerbated chronic respiratory failure admitted in a monitored setting of an intermediate-intensive respiratory Unit.

RESULTS: Patients underwent combined positive/negative ventilation and at different times, in place of the two singular ventilation modes (P and N). After each cycle, in the combined P/N ventilatory mode, gas exchanges were significantly increased compared to the two singular P/N mode: pH (7.42 vs 7.40 and 7.40); PCO2 (85.01 vs 72.05 and 66.81 mmHg); FiO2/PO2 (488.75 vs 352.62 and 327.87). All patients well tolerated the application of the double ventilation mode.

CONCLUSIONS: In conclusion, the use of dual mode ventilation appears well tolerated and superior to the individual modes in patients with COPD exacerbations and ARF.