Endotoxemia and mortality prediction in ICU and other settings: underlying risk and co-detection of gram negative bacteremia are confounders
Critical Care, 08/08/2012
Hurley JC et al. – The co–detection of gram negative (GN) bacteremia and endotoxemia is predictive of increased mortality risk versus the detection of neither but only in studies undertaken in a non–ICU setting. Variation in GN bacteremia species types and underlying risk are likely unrecognized confounders in the individual studies.Methods
- Published studies with [greater than or equal to]10 patients in either ICU or non-ICU settings, endotoxemia detection by limulus assay, reporting mortality proportions and [greater than or equal to]1 GN bacteremia were included.
- Summary odds ratios (OR) for mortality were derived across all studies by meta-analysis for the following contrasts; sub-groups with either endotoxemia (group 3), GN bacteremia (group 2) or both (group 1) each versus the group with neither detected (group 4; reference group).
- The mortality proportion for group 4 is the proxy measure of study level risk within L'Abbe plots.
- 35 studies were found.
- Among 9 studies in an ICU setting, OR for mortality was borderline (OR<2) or non-significantly increased for groups 2 (GN bacteremia alone) and 3 (endotoxemia alone) and patient group 1 (GN bacteremia and endotoxemia co-detected) each versus patient group 4 (neither endotoxemia nor GN bacteremia detected).
- The OR's were markedly higher for group 1 versus group 4 (OR 6.9; 95% CI, 4.4 - 11.0 when derived from non-ICU studies.
- The distributions of P aeruginosa and E coli bacteremias among groups 1 versus 2 are significantly unequal.