Aggressive treatment with noninvasive ventilation for mild acute hypoxemic respiratory failure after cardiovascular surgery: Retrospective observational study

BACKGROUND Acute hypoxemic respiratory failure (AHRF) is one of the most serious complications after cardiovascular surgery. It remains unclear whether noninvasive ventilation (NIV) has potential as an effective therapy for AHRF after cardiovascular surgery, although many reports have described the use of NIV for AHRF after extubation. The aim of this study was to investigate the effectiveness of NIV in the early stage of mild AHRF after cardiovascular surgery. METHODS We retrospectively analyzed all patients admitted to the intensive care unit after cardiovascular surgery, whose oxygenation transfer (PaO(2)/FIO(2)) deteriorated mildly after extubation, and in whom NIV was initiated. A two-way analysis of variance and the Bonferroni multiple comparisons procedure, the Mann-Whitney test, Fisher's exact test or the χ(2)test was performed. RESULTS A total of 94 patients with AHRF received NIV, of whom 89 patients (94%) successfully avoided endotracheal intubation (successful group) and five patients required reintubation (reintubation group). All patients, including the reintubated patients, were successfully weaned from mechanical ventilation and discharged from the intensive care unit. In the successful group, PaO(2)/FIO(2) improved and the respiratory rate decreased significantly within 1 h after the start of NIV, and the improvement in PaO(2)/FIO(2) remained during the whole NIV period. CONCLUSION We conclude that NIV is beneficial for mild AHRF after cardiovascular surgery when it is started within 3 h after mild deterioration of PaO(2)/FIO(2). We also think that it is important not to hesitate before performing reintubation when NIV is judged to be ineffective.