Infections in the Emergency Department: improving diagnosis and prognosis

Early warning scores (EWS) were designed to predict chance of deterioration in hospitalised patients. In 2016 qSOFA was introduct as part of the new sepsis criteria.1 In chapter 3 we started a prospective multicentre study to compare the performance of qSOFA, NEWS, MEWS and SIRS in the ED in patients with suspected infection. All patients 18 years and older and with suspected infection were included. We compared the scores of NEWS ≥5, MEWS ≥3 , qSOFA≥ 2 and SIRS≥2 to predict 30 days mortality and ICU admission. NEWS ≥5 showed to have the best balance between sensitvity (75.8% (95%CI 63.3-85.8), specificity (65.9% (95%CI 63.2-68.5) and NPV (98.2% (95% CI 97.3-98.9) for early identification of high risk patients with suspected infection in the ED. In chapter 4 we conducted an observational, retrospective multicenter cohort study. All patients aged 18 and over with suspicion of COVID-19 who visited the ED were enrolled. Multipele variables were collected and analysed as potential risk factors for poor outcome. Ten predictors of poor outcome were identifed, The AUC was 0.86 (95%CI 0.83-0.89), with a Brier score of 0.32 and, and R2 of 0.41. The AUC in the external validation in 500 patients was 0.70 (95%CI 0.65-0.75). The COVERED risk score showed an excellent discriminatory ability also in an external validation. In chapter 5 we aimed to prospectively validate the COVID-19 Reporting and Data System (CO-RADS) at the ED and we analyzed whether the CT- severity Score (CTSS) was associated with hospital admission, ICU and mortality. Diagnostic accuracy measures were calculated for CO-RADS using PCR as reference. The area under the curve (AUC) of 0.91 (95%CI 0.89-0.94) was found for CO-RADS using PCR as reference. The optimal CO-RADS cutoff was 4 with a sensitivity of 89.4% (CI 84.7-93.0) and specificity of 87.2% ICI 83.9-89.9). A significant association between CTSS and admission , ICU and 30 day mortality was found, adjusted ORs per point increase in CTSS were 1.19 (CI 1.09-1.28), 1.23 (1.15-132), 1.14 (1.07-1.22) respectively. This findings support the use of CO-RADS and CTSS in triage and diagnosis for patients presenting with possible COVID-19 at the ED. In chapter 6 we compared the diagnostic accuracy of lung ultrasound (LUS) with chest CT in suspected COVID-19 patients at the ED. Area under the receiver operating characteristic (AUROC) was 0.81 (95% CI 0.75-0.88) for LUS and 0.89 (95% CI 0.84-0.94) for CT. Sensitivity and specificity for LUS were 91.9% (95%CI 84.0-96.7) and 71.0% (95%CI61.1-79.6) respectively versus 88.4% (95% CI79.7-94.3) and 82.0% (95% CI 73.1-89.0) for CT. Agreement between LUS and CT was 0.65 and inter-observer agreement for LUS was good 0.89 (95% CI 0.83-0.93). LUS can safely exclude clinically relevant COVID-19 pneumonia and may aid in COVID-19 diagnosis in high prevalence situations. In chapter 7 we investigated whether the optimal use of procalcitonin (PCT) is different in patients with and without proven viral infections for the purpose of excluding bacteremia. The study was a prospective observational study where all patients 18 year and older for whom a blood culture and viral test were ordered in the ED were included. PCT had an area under the curve of 0.85% (95%CI 0.80-0.91) for prediction of bacteremia. In patients with proven viral infection PCT < 0.5ug/L had a sensitivity of 100% (95%CI 63.1-100) and specificity of 81.2% (95% CI75.1-86.3) to exclude bacteremia. This study suggest that a PCT concentration of < 0.5ug/L makes bacteremia unlikely in patients with a viral infection.