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

Table 2 The predictive value of estimated dead-space fraction at day 1 and day 3 of ALI/ARDS in the Mayo validation cohort, outcome hospital mortality

Mortality	Odds ratio	95% CI
Day 1
(Per 0.05 increment of dead space fraction)
Univariate analysis
VdVt	1.33	1.09	1.69
Multivariate analysis
Base model (Shock + APACHE III predicted mortality), n= 108	1.28	1.04	1.64
Base model + PaO₂/FiO₂, n = 108	1.26	1.08	1.61
Base model + OI, n = 107	1.25	1.02	1.61
Base model + PaO₂/FiO₂ + PEEP, n = 108	1.26	1.08	1.64
Base model + PaO₂/FiO₂ + PEEP, n = 107	1.29	1.02	1.69
Base model + Vt, n = 108	1.32	1.05	1.70
Day 3
(Per 0.05 increment of dead space fraction)
Univariate analysis
VdVt	1.47	1.18	1.90
Multivariate analysis
Base Model (Shock + APACHE III predicted mortality), n = 108	1.43	1.13	1.87
Base model + PaO₂/FiO₂, n = 108	1.35	1.05	1.78
Base model + OI, n = 85	1.43	1.03	2.11
Base model + PaO₂/FiO₂ + PEEP, n = 108	1.35	1.05	1.79
Base model + PaO₂/FiO₂ + PEEP, n = 85	1.43	1.03	2.12
Base model + Vt, n = 108	1.47	1.14	1.96

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