RANDOMIZED CLINICAL-TRIAL OF PRESSURE-CONTROLLED INVERSE RATIO VENTILATION AND EXTRACORPOREAL CO2 REMOVAL FOR ADULT-RESPIRATORY-DISTRESS-SYNDROME

The impact of a new therapy that includes pressure-controlled inverse ratio ventilation followed by extracorporeal CO2 removal on the surviv al of patients with severe ARDS was evaluated in a randomized controll ed clinical trial. Computerized protocols generated around-the-clock i nstructions for management of arterial oxygenation to assure equivalen t intensity of care for patients randomized to the new therapy limb an d those randomized to the control, mechanical ventilation limb. We ran domized 40 patients with severe ARDS who met the ECMO entry criteria. The main outcome measure was survival at 30 days after randomization. Survival was not significantly different in the 19 mechanical ventilat ion (42%) and 21 new therapy (extracorporeal) (33%) patients (p = 0.8) . All deaths occurred within 30 days of randomization. Overall patient survival was 38% (15 of 40) and was about four times that expected fr om historical data (p = 0.0002). Extracorporeal treatment group surviv al was not significantly different from other published survival rates after extracorporeal CO2 removal. Mechanical ventilation patient grou p survival was significantly higher than the 12% derived from publishe d data (p = 0.0001). Protocols controlled care 86% of the time. Averag e Pa-O2 was 59 mm Hg in both treatment groups. Intensity of care requi red to maintain arterial oxygenation was similar in both groups (2.6 a nd 2.6 PEEP changes/day; 4.3 and 5.0 Fl(O2) changes/day). We conclude that there was no significant difference in survival between the mecha nical ventilation and the extracorporeal CO2 removal groups. We do not recommend extracorporeal support as a therapy for ARDS. Extracorporea l support for ARDS should be restricted to controlled clinical trials.