Prospective randomized trial comparing pressure-controlled ventilation andvolume-controlled ventilation in ARDS

Study objectives: To compare in-hospital mortality of patients with ARDs ve ntilated with either pressure-controlled ventilation (PCV) or volume-contro lled ventilation (VCV) with a square-wave inspiratory flow. Design: Multicenter and randomized trial. Setting: Twelve medical-surgical ICUs located in tertiary-care hospitals. Patients: Seventy-nine patients having ARDS, as defined by the American-Eur opean Consensus Conference. Interventions: Patients were randomly assigned to be ventilated with either PCV (n = 37) or VCV (n = 42). In both instances, inspiratory plateau press ure was limited to less than or equal to 35 cm H2O. Measurements and results: There were no significant differences among the s tudied groups at the moment of randomization, although there was a trend to ward greater renal failure in patients assigned to VCV. Ventilatory setting s and blood gases did not significantly differ over time between the two gr oups. Patients in the VCV group had both a significantly higher in-hospital mortality rate than those in the PCV group (78% vs 51%, respectively) and a higher number of extrapulmonary organ failures (median, 4 vs 2, respectiv ely). The development of renal failure during the study period was also sig nificantly more frequent among VCV patients (64% vs 32%, respectively). Mul tivariate analysis showed that factors independently associated with an inc reased mortality rate were the presence of two or more extrapulmonary organ failures (odds ratio [OR], 4.61%; 95% confidence interval [CI], 1.38 to 15 .40) and acute renal failure (OR, 3.96; 95% CI, 1.10 to 14.28) but not the ventilatory mode used. Conclusions: The increased number of extrapulmonary organ failures develope d in patients of the VCV group was strongly associated with a higher mortal ity rate. The development of organ failures was probably not related to the ventilatory mode.