A strategy of mechanical ventilation that limits tidal volume while permitting hypercapnia has been recommended for patients with the acute respiratory distress syndrome. We attempted to evaluate the effects of protective-ventilatory strategy on the outcome of the acute respiratory distress syndrome.

The study was performed on 31 patients over 16 years old who were under the mechanical ventilation with the diagnosis of acute lung injury (ALI)/ARDS in the Surgical ICU. Pulmonary artery catheter was inserted after start of ventilation. A tidal volume (VT) of 10 to 12 ml per kg and positive end expiratory pressure (PEEP) 10 cmH₂O or less was used in conventional group (n = 15), and VT of 6 to 8 ml/kg and PEEP 15 cmH₂O or less was used in protective group (n = 16). Arterial blood gas analysis, hemodynamic parameters and metabolic parameters were recorded 1, 3, 5 and 7 day interval.

1) VT, PEEP and respiratory rate showed statistical differences between groups (10.5 ± 1.2 vs. 6.7 ± 0.8 ml/kg, 7.7 ± 3.3 vs. 13.3 ± 3.1 cmH₂O, 15.0 ± 3.7 vs. 20.3 ± 4.1 rate/min), but minute volume didn't showed significant difference in between groups. 2) Mortality was 46% in the conventional group and 25% in protective group (P < 0.001). 3) Significant difference was identified in PaO₂/FiO₂ (176.9 ± 81.7 vs. 274.7 ± 83.5), wedge pressure (11.1 ± 3.7 vs. 16.2 ± 3.9 mmHg) and mean pulmonary artery pressure (23.0 ± 4.5 vs. 30.2 ± 6.5 mmHg) during study periods. 4) The incidence of barotrauma and dialysis for renal failure were similar in the both groups.

Protective ventilatory strategy with low VT and high PEEP shows low mortality in ALI/ARDS patients, it is recommended method for the ALI/ARDS patients.