Abstract
BACKGROUND: Predicting mortality has become a necessary step for selecting patients for clinical trials and defining outcomes. We examined whether stratification by tertiles of respiratory and ventilatory variables at the onset of acute respiratory distress syndrome (ARDS) identifies patients with different risks of death in the intensive care unit.
METHODS: We performed a secondary analysis of data from 220 patients included in 2 multicenter prospective independent trials of ARDS patients mechanically ventilated with a lung-protective strategy. Using demographic, pulmonary, and ventilation data collected at ARDS onset, we derived and validated a simple prediction model based on a population-based stratification of variable values into low, middle, and high tertiles. The derivation cohort included 170 patients (all from one trial) and the validation cohort included 50 patients (all from a second trial).
RESULTS: Tertile distribution for age, plateau airway pressure (Pplat), and PaO2/FIO2 at ARDS onset identified subgroups with different mortalities, particularly for the highest-risk tertiles: age (> 62 years), Pplat (> 29 cm H2O), and PaO2/FIO2 (< 112 mm Hg). Risk was defined by the number of coexisting high-risk tertiles: patients with no high-risk tertiles had a mortality of 12%, whereas patients with 3 high-risk tertiles had 90% mortality (P < .001).
CONCLUSIONS: A prediction model based on tertiles of patient age, Pplat, and PaO2/FIO2 at the time the patient meets ARDS criteria identifies patients with the lowest and highest risk of intensive care unit death.
- acute respiratory distress syndrome
- ARDS
- age
- mortality
- PaO2/FIO2
- plateau airway pressure
- prediction
- tertiles
Footnotes
- Correspondence: Jesús Villar MD PhD, Multidisciplinary Organ Dysfunction Evaluation Research Network, Hospital Universitario Dr Negrin Barranco de la Ballena, s/n 4th Floor, South Wing, 35010 Las Palmas de Gran Canaria, Canary Islands, Spain. E-mail: jesus.villar54{at}gmail.com.
↵* Members of the Hospitales Españoles Para el Estudio de la Lesión Pulmonar (HELP) Network are listed in the supplementary materials at http://www.rcjournal.com.
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This research was partly supported in part by grant 07/0113 from Fondo de Investigación Sanitaria, Madrid, Spain, and by the Asociación Científica Pulmón y Ventilación Mecánica, Las Palmas, Spain.
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To avoid potential conflict of interest, Editor in Chief Dean R Hess was blinded to the peer review process, deferring to Deputy Editor Richard D Branson MSc.
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See the Related Editorial on Page 533
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