MORTALITY IS DIRECTLY RELATED TO THE DURATION OF MECHANICAL VENTILATION BEFORE THE INITIATION OF EXTRACORPOREAL LIFE-SUPPORT FOR SEVERE RESPIRATORY-FAILURE

Objective: To investigate the relationship between the period of mecha nical ventilation before extracorporeal life support and survival in p atients with respiratory failure, Design: Retrospective review, Settin g: Surgical intensive care unit at a university medical center, Patien ts: Thirty-six consecutive adult patients with severe respiratory fail ure managed with extracorporeal life support, Interventions: Extracorp oreal life support was utilized in 36 acute respiratory failure adult patients with a variety of diagnoses and an estimated mortality rate o f >90%, Management protocols were followed before and during extracorp oreal life support, The 36 patients were physiologically similar befor e extracorporeal life support was initiated: shunt of 48 +/- 17%; FIO2 of 1.0 +/- 0.1; peak inspiratory pressure of 56 +/- 16 cm H2O; positi ve end expiratory pressure of 14 +/- 6 cm H2O; and respiratory rate of 23 +/- 10 breaths/ min, Ventilation was utilized for 1 to 17 days bef ore extracorporeal life support, Typical lung rest settings during ext racorporeal life support were Ro(2) of 0.40, peak inspiratory pressure of 30 cm H2O, positive end-expiratory pressure of 10 cm H2O, and resp iratory rate of 6 breaths/min, Death was almost always secondary to en dstage pulmonary failure, Measurements and Main Results: Survival (hos pital discharge) in these 36 patients was inversely associated with th e number of days of preextracorporeal life support ventilation, with a 50% mortality rate predicted by logistic regression after 5 days of m echanical ventilation, The overall survival rate was 18(50.0%) of 36 p atients, Conclusion: In severe acute respiratory failure treated with lung rest and extracorporeal life support, a predicted 50% mortality r ate was associated with 5 days of preextracorporeal life support mecha nical ventilation.