Body computed tomography in sepsis: predictors of CT findings and patient outcomes in a retrospective medical ICU cohort study

Abstract

Background Sepsis is a life-threatening condition that requires immediate focus identification and control. However, international sepsis guidelines do not provide information on imaging choice. Purpose To identify predictors of CT findings and patient outcomes in a population of septic patients from a medical ICU. Material and methods A full-text search in the radiological information system (RIS) retrieved 227 body CT examinations conducted to identify infectious sources in 2018. CT reports were categorized according to identified foci and their diagnostic certainty. Diagnostic accuracy of CT was compared to microbiological results. Clinical and laboratory information was gathered. Statistical analysis was performed using nonparametric tests and logistic regression analysis. Results CT revealed more positive infectious foci 52.4% (n = 191/227) than microbiological tests 39.3% (n = 79/201). There were no significant differences between focus-positive CT scans with regard to positive microbiological testing (p = 0.32). Sequential organ failure assessment (SOFA) scores were slightly but nonsignificantly higher in patients with a focus-positive CT, odds ratio (OR) = 0.999 (95% CI 0.997-1.001) with p = 0.52. Among C-reactive protein (CRP), procalcitonin (PCT), and leukocytes, in focus-positive versus focus-negative CT scans, CRP showed a minor but statistically significant elevation in the group with focus-positive CT scans (OR = 1.004, 95% CI = 1.000-1.007, p = 0.04). No significant association was found for PCT (OR = 1.007, 95% CI = 0.991-1.023; p = 0.40) or leukocytes (OR = 1.003, 95% CI = 0.970-1.038; p = 0.85). In 33.5% (n = 76/227) of cases, the CT findings had at least one therapeutic consequence. In 81.6% (n = 62/76), the CT findings resulted in one consequence, in 14.5% (n = 11/ 76) in two consequences, and in 3.9% (n = 3/76) in three consequences. There was no significant association between focus-positive CT scans and mortality (p = 0.81). Conclusion In this population of septic patients in medical intensive care, microbiological analysis complemented CT findings. Both clinical and laboratory parameters were not predictive of CT findings. While therapeutic consequences of CT findings in this study population underline the role of CT for decision making in septic patients, CT findings do not predict patient outcomes in this retrospective analysis.