Noninvasive vs conventional mechanical ventilation in acute respiratory failure: a multicenter, randomized controlled trial.

STUDY OBJECTIVE: Noninvasive mechanical ventilation (NIMV) is beneficial for patients with acute respiratory failure (ARF) when added to medical treatment. However, its role as an alternative to conventional mechanical ventilation (CMV) remains controversial. Our aim was to compare the efficacy and resource consumption of NIMV against CMV in patients with ARF.

DESIGN: A randomized, multicenter, controlled trial.

SETTING: Seven multipurpose ICUs.

PATIENTS: Sixty-four patients with ARF from various causes who fulfilled criteria for mechanical ventilation.

INTERVENTION: The noninvasive group received ventilation through a face mask in pressure-support mode plus positive end-expiratory pressure; the conventional group received ventilation through a tracheal tube.

MEASUREMENTS AND RESULTS: Avoidance of intubation, mortality, and consumption of resources were the outcome variables. Thirty-one patients were assigned to the noninvasive group, and 33 were assigned to the conventional group. In the noninvasive group, 58% patients were intubated, vs 100% in the conventional group (relative risk reduction, 43%; p < 0.001). Stratification by type of ARF gave similar results. In the ICU, death occurred in 23% and 39% (p = 0.09) and complications occurred in 52% and 70% (p = 0.07) in the noninvasive and conventional groups, respectively. There were no differences in length of stay. The Therapeutic Intervention Score System-28, but not the direct nursing activity time, was lower in the noninvasive group during the first 3 days.

CONCLUSIONS: NIMV reduces the need for intubation and therapeutic intervention in patients with ARF from different causes. There is a nonsignificant trend of reduction in ICUs and hospital mortality together with fewer complications during ICU stay.