Cortisol levels and adrenal response in severe community-acquired pneumonia: a systematic review of the literature

Abstract

Objectives: Our aim was to review the literature on the prevalence and impact of critical-illness related corticosteroid insufficiency (CIRCI) on the outcomes of patients with severe community-acquired pneumonia (CAP).

Methods: We reviewed Cochrane, Medline, and CINAHL databases (through July 2008) to identify studies evaluating the adrenal function in severe CAP. Main data collected were prevalence of CIRCI and its mortality.

Results: We screened 152 articles and identified 7 valid studies. Evaluation of adrenal function varied, and most studies used baseline total cortisol levels. The prevalence of CIRCI in severe CAP ranged from 0% to 48%. Among 533 patients, 56 (10.7%) had cortisol levels of 10 μg/dL or less and 121 patients (21.2%) had cortisol levels of 15 μg/dL or less. In a raw analysis, there was no significant difference in mortality when patients with cortisol levels less than 10 μg/dL (8.6 vs 15.5%; P = .55) or less than 15 μg/dL (12.4 vs 16%; P = .38) were compared with those with cortisol above these levels. In the meta-analysis, relative risk for mortality were 0.81 (confidence interval, 0.39-1.7; P = .59; χ(2) = 1.04) for cortisol levels less than 10 μg/dL and relative risk was 0.67 (confidence interval, 0.4-1.14; P = .84; χ(2) = 1.4) for cortisol levels less than 15 μg/dL.

Conclusions: A significant proportion of patients with severe CAP fulfilled criteria for CIRCI. However, CIRCI does not seem to affect the outcomes. Noteworthy, the presence of elevated cortisol levels is associated with increased mortality and may be useful as a prognostic marker in patients with severe CAP.