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.