Bedside quantification of dead-space fraction using routine clinical data in patients with acute lung injury: secondary analysis of two prospective trials

Table 3 The predictive value of estimated dead-space fraction at day 1 and day 3 of ALI/ARDS in the ARDS-network validation cohort, outcome hospital mortality

Mortality	Odds ratio	95% CI
Day 1
(Per 0.05 increment of dead space fraction)
Univariate analysis
VdVt	1.11	1.06	1.16
Multivariate analysis
Base Model (Shock + APACHE III predicted mortality), n = 1616	1.09	1.04	1.14
Base model + PaO₂/FiO₂, n = 1,610	1.07	1.03	1.13
Base model + OI, n = 1,492	1.08	1.03	1.14
Base model + PaO₂/FiO₂ + PEEP, n = 1,610	1.08	1.03	1.14
Base model + PaO₂/FiO₂ + PEEP, n = 1,492	1.09	1.04	1.15
Base model + Vt, n = 1,616	1.10	1.06	1.16
Day 3
(Per 0.05 increment of dead space fraction)
Univariate analysis
VdVt	1.18	1.12	1.24
Multivariate analysis
Base Model (Shock + APACHE III predicted mortality), n = 1,369	1.14	1.09	1.21
Base model + PaO₂/FiO₂, n = 1,369	1.12	1.06	1.18
Base model + OI, n = 1,241	1.10	1.04	1.17
Base model + PaO₂/FiO₂ + PEEP, n = 1,367	1.10	1.04	1.16
Base model + PaO₂/FiO₂ + PEEP, n = 1,241	1.10	1.04	1.17
Base model + Vt, n = 1,283	1.16	1.10	1.23

ALI, acute lung injury; APACHE, acute physiology and chronic health evaluation; ARDS, acute respiratory distress syndrome; CI, confidence interval; FiO2, fraction of inspired oxygen; PaO2, partial pressureof arterial pressure; PEEP, positive end-expiratory pressure; OI, oxygenation index; VdVt, dead space fraction; Vt, tidal volume.

ISSN: 1364-8535