A clinical decision rule to rule out bloodstream infection in the emergency department: retrospective multicentric observational cohort study.

BACKGROUND: We aimed to identify patients at low risk of bloodstream infection (BSI) in the ED. METHODS: We derived and validated a prediction model to rule out BSI in the ED without the need for laboratory testing by determining variables associated with a positive blood culture (BC) and assigned points according to regression coefficients. This retrospective study included adult patients suspected of having BSI (defined by at least one BC collection) from two European ED between 1 January 2017 and 31 December 2019. The primary end point was the BSI rate in the validation cohort for patients with a negative Bacteremia Rule Out Criteria (BAROC) score. The effect of adding laboratory variables to the model was evaluated as a second step in a two-step diagnostic strategy. RESULTS: We analysed 2580 patients with a mean age of 64 years±21, of whom 46.1% were women. The derived BAROC score comprises 12 categorical clinical variables. In the validation cohort, it safely ruled out BSI without BCs in 9% (58/648) of patients with a sensitivity of 100% (95% CI 95% to 100%), a specificity of 10% (95% CI 8% to 13%) and a negative predictive value of 100% (95% CI 94% to 100%). Adding laboratory variables (creatinine ≥177 µmol/L (2.0 mg/dL), platelet count ≤150 000/mm3 and neutrophil count ≥12 000/mm3) to the model, ruled out BSI in 10.2% (58/570) of remaining patients who had been positive on the BAROC score. The BAROC score with laboratory results had a sensitivity of 100% (95% CI 94% to 100%), specificity of 11% (95% CI 9% to 14%) and negative predictive value of 100% (95% CI 94 to 100%). In the validation cohort, there was no evidence of a difference in discrimination between the area under the receiver operating characteristic for BAROC score with versus without laboratory testing (p=0.6). CONCLUSION: The BAROC score safely identified patients at low risk of BSI and may reduce BC collection in the ED without the need for laboratory testing.

Point-of-care ultrasonography for risk stratification of non-critical suspected COVID-19 patients on admission (POCUSCO): a prospective binational study

BackgroundLung point-of-care ultrasonography (L-POCUS) is highly effective in detecting pulmonary peripheral patterns and may allow early identification of patients who are likely to develop an acute respiratory distress syndrome (ARDS). We hypothesized that L-POCUS performed during the initial examination would identify non-severe COVID-19 patients with a high risk of getting worse. MethodsPOCUSCO was a prospective, multicenter study. Non-critical adult patients who were admitted to the emergency department (ED) for suspected or confirmed COVID-19 were included and had L-POCUS performed within 48 hours following admission. The severity of lung damage was assessed using the L-POCUS score based on 36 points for ARDS. The primary outcome was the rate of patients requiring intubation or who died within 14 days following inclusion. ResultsAmong 296 participating patients, 8 (2.7%) had primary outcome. The area under the curve (AUC) of the receiver operating characteristic of L-POCUS was 0.80 [95%CI:0.60-0.94]. The score values which achieved a sensibility > 95% in defining low-risk patients and a specificity > 95% in defining high-risk patients were <1 and [≥]16, respectively. The rate of patients with an unfavorable outcome was 0/95 (0%[95%CI:0-3.9]) for low-risk patients (score=0) versus 4/184 (2.17%[95%CI:0.8-5.5]) for intermediate-risk patients (score 1-15) and 4/17 (23.5%[95%CI:11.4-42.4]) for high-risk patients (score [≥]16). In patients with confirmed COVID-19 (n=58), the AUC of L-POCUS was 0.97 [95%CI:0.92-1.00]. ConclusionsL-POCUS allows risk-stratification of patients with suspected or confirmed COVID-19. These results should be confirmed in a population with a higher risk of an unfavorable outcome. Trial registration numberNCT04338100