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 mechanical ventilation before extracorporeal life support and survival in patients with respiratory failure, Design: Retrospective review, Setting: Surgical intensive care unit at a university medical center, Patients: Thirty-six consecutive adult patients with severe respiratory failure managed with extracorporeal life support, Interventions: Extracorporeal life support was utilized in 36 acute respiratory failure adult patients with a variety of diagnoses and an estimated mortality rate of >90%, Management protocols were followed before and during extracorporeal life support, The 36 patients were physiologically similar before extracorporeal life support was initiated: shunt of 48 +/- 17%; FIO2 of 1.0 +/- 0.1; peak inspiratory pressure of 56 +/- 16 cm H2O; positive end expiratory pressure of 14 +/- 6 cm H2O; and respiratory rate of 23 +/- 10 breaths/ min, Ventilation was utilized for 1 to 17 days before extracorporeal life support, Typical lung rest settings during extracorporeal life support were Ro(2) of 0.40, peak inspiratory pressure of 30 cm H2O, positive end-expiratory pressure of 10 cm H2O, and respiratory rate of 6 breaths/min, Death was almost always secondary to endstage pulmonary failure, Measurements and Main Results: Survival (hospital discharge) in these 36 patients was inversely associated with the number of days of preextracorporeal life support ventilation, with a 50% mortality rate predicted by logistic regression after 5 days of mechanical ventilation, The overall survival rate was 18(50.0%) of 36 patients, Conclusion: In severe acute respiratory failure treated with lung rest and extracorporeal life support, a predicted 50% mortality rate was associated with 5 days of preextracorporeal life support mechanical ventilation.