Observational case-control study of non-invasive ventilation in patients with ARDS

Background. The application of non-invasive pressure support ventilation (NIPSV) in patients with acute lung injury or ARDS remains controversial despite recent promising results. Data in rather homogeneous ARDS groups is lacking. Objective. To compare the outcome of NIPSV-treated patients satisfying the diagnostic criteria for primary (pulmonary) ARDS (ARDSp) and presenting without distant organ failures at admission, with those of a matched control group treated in the same ICU with endotracheal mechanical ventilation (ETMV). Methods. We applied NIPSV in 12 immunocompetent and collaborative patients who met the above cited criteria. NIPSV failure rate, short-term oxygenation, length of stay, mortality rate and complications were analyzed and compared with a control group of 12 intubated ARDSp-patients matched for age, SAPS II, PaO2/FiO2 and pH at admission. Results. NIPSV failed in 4 patients developing distant organ failures. Compared to the ETMV control group, NIPSV success patients had reduced cumulative time on ventilation (p = 0.001) and length of ICU stay (p = 0.004). After the first 60’ of ventilation, oxygenation improved more in the NIPSV than in the ETMV group (146 ± 52 mmHg vs 109 ± 34 mmHg; p = 0.05). The overall ICU mortality rate did not differ significantly between the groups but tended to be higher in the NIPSV group. Conclusions. In ARDSp patients without distant organ failures at admission and during the disease course, NIPSV might be a suitable alternative to invasive ventilation; however, the real effects on outcome of NIPSV applied to stable homogeneous subgroups of ARDS patients merit further investigations in randomised studies.