Study objectives: To compare in-hospital
mortality of patients with ARDS ventilated with either
pressure-controlled ventilation (PCV) or volume-controlled ventilation
(VCV) with a square-wave inspiratory flow.
Multicenter and randomized trial.
medical-surgical ICUs located in tertiary-care hospitals.
Patients: Seventy-nine patients having ARDS, as
defined by the American-European Consensus Conference.
Interventions: Patients were randomly assigned to be
ventilated with either PCV (n = 37) or VCV (n = 42). In both
instances, inspiratory plateau pressure was limited to ≤ 35 cm
Measurements and results: There were
no significant differences among the studied groups at the moment of
randomization, although there was a trend toward greater renal failure
in patients assigned to VCV. Ventilatory settings and blood gases did
not significantly differ over time between the two groups. 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,
respectively). The development of renal failure during the study period
was also significantly more frequent among VCV patients (64% vs 32%,
respectively). Multivariate analysis showed that factors
independently associated with an increased 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 developed in patients of the
VCV group was strongly associated with a higher mortality rate. The
development of organ failures was probably not related to the