Association between admission biomarkers and clinical outcome in older adults diagnosed with an infection in the emergency department.

INTRODUCTION: In older adults, prognostic performances of admission biomarkers have been poorly investigated. This study aims to compare the prognostic abilities of usual admission biomarkers, especially PCT and CRP, for major clinical outcomes, comparing older to younger adults diagnosed with an infection in the ED, and to investigate the prognostic abilities of PCT and CRP depending on the glomerular filtration rate (GFR). METHODS: It was an observational, single-center, retrospective study, conducted in the Reims University Hospital, France. Endpoints were bacteremia, septic shock, and in-hospital mortality, related to the same ED visit. RESULTS: Over 1 year, 852 patients were included with 291 (34.2%) ≥75 years, and 127 (15.3%) patients had a GFR <30 mL.min-1.1.73 m2. Overall, 74 bacteremia, 56 septic shock and 82 in-hospital deaths have been observed. Prognostic abilities of admission biomarkers tended to be systematically lower in older compared to younger adults (PCT and CRP AUROC for bacteremia were, respectively, 0.71 and 0.62 in older adults vs 0.75 and 0.70 in younger adults; PCT and CRP AUROC for septic shock were, respectively, 0.71 and 0.66 in older adults vs 0.82 and 0.68 in younger adults). PCT showed a significant discriminating power for septic shock and in-hospital mortality only for GFR ≥ 30, and CRP showed a significant discriminating power for bacteremia and septic shock only for GFR ≥60. CONCLUSION: Caution must be taken when interpreting admission biomarkers, as their prognostic abilities are lower in older adults or in patients with renal insufficiency diagnosed with an infection.

Clinical Outcome Predictive Value of Procalcitonin in Patients Suspected with Infection in the Emergency Department.

Procalcitonin (PCT) may be useful for early risk stratification in the emergency department (ED), but the transposition of published data to routine emergency practice is sometimes limited. An observational retrospective study was conducted in the adult ED of the Reims University Hospital (France). Over one year, 852 patients suspected of infection were included, of mean age 61.7 years (SD: 22.6), and 624 (73.2%) were hospitalized following ED visit. Overall, 82 (9.6%) patients died during their hospitalization with an odds ratio (OR) of 5.10 (95% CI: 2.19-11.87) for PCT ≥ 0.5, in multivariate logistic regression analyses. Moreover, 78 (9.2%) patients were admitted to an ICU, 74 (8.7%) had attributable bacteremia, and 56 (6.6%) evolved toward septic shock with an OR of 4.37 (2.08-9.16), 6.38 (2.67-15.24), and 6.38 (2.41-16.86), respectively, for PCT ≥ 0.5. The highest discriminatory values were found for patients with age <65 years, but PCT lost its discrimination power for in-hospital mortality in patients with a bronchopulmonary infection site or a temperature ≥37.8°C and for ICU admission in patients with severe clinical presentations. PCT could be helpful in risk stratification, but several limitations must be considered, including being sometimes outperformed by a simple clinical examination.

Lack of admission biomarkers' clinical utility in outcomes prediction in patients suspected with infection in the emergency department.

INTRODUCTION: Initial procalcitonin (PCT) levels may fail in mortality and septic shock prediction and raise cost-effectiveness issues. Since measurement of lactate, C-reactive protein (CRP), white blood cells and neutrophils is common in the emergency department (ED), we compared prediction abilities of these biomarkers to PCT. METHODS: From January 1st to December 31st, 2018, an observational, single center, retrospective study was conducted in the adult ED of the Reims University Hospital (France). Endpoints were bacteremia, septic shock, and in-hospital mortality, related to the same ED visit. RESULTS: Over one year, 459 patients suspected with infection were included, of mean age 60.4 years (SD: 22.0), with 50.8% male, and 364 (79.3%) were hospitalized following ED visit. Overall, 45 (9.8%) patients had a bacteremia, 39 (8.5%) a septic shock and 54 (11.8%) died during their hospitalization. PCT and CRP showed the best discrimination for bacteremia, with an area under curve (AUC) of 0.68 for PCT and 0.65 for CRP. PCT and lactate showed similar good discriminative power for septic shock, with an AUC of 0.78 for both, and poor discrimination for in-hospital mortality, with an AUC of 0.62 for PCT and 0.69 for lactate. Systolic blood pressure and pulse oximetry showed similar discrimination for septic shock as PCT or lactate, while they showed higher discrimination for in-hospital mortality than PCT. CONCLUSION: Usual admission biomarkers lack clinical utility in predicting septic shock or in-hospital mortality. CRP and PCT are poorly efficient in predicting bacteremia.