The diagnostic ability of NEWS2 in adult patients with positive blood cultures to detect sepsis according to SOFA-score

Abstract

Abstract Background Blood stream infection (BSI), and especially sepsis and septic shock, is associated with high mortality and significant morbidity. The visible, clinical signs can vary from patient to patient depending on several factors. NEWS2 is quick, easy and non-invasive and includes bedside measurable vital signs. Although NEWS2 is recommended as a risk-stratifying and identification tool in patients with suspected sepsis, it is not a sepsis-specific score. Correlations between vital signs and bacterial species found in blood cultures have not been sufficiently investigated. An early and clear signal through the NEWS2 score could be useful especially in those patients with infections caused by common bacteria rendering high mortality and morbidity. The primary aim was to evaluate the diagnostic accuracy of NEWS2 to detect sepsis in adult patients with positive blood cultures caused by community-acquired infections. A secondary aim was to study a possible association between NEWS2 score and different bacterial species. Method This is a retrospective observational study. All patients with positive blood cultures were evaluated for participation (n = 1318). After retrospective medical chart review, 555 patients were eligible for inclusion. Positive NEWS2-score indicating sepsis was defined as NEWS2 ≥ 5. Results The presence of sepsis according to SOFA-score was 425 of 555, 76.6% and 28 days mortality was 67 of 555, 12.1%. The sensitivity of NEWS2 to detect sepsis was 87% (95% CI 0.83–0.90). Most common pathogens were Escherichia coli 35.1%, followed by Staphylococcus aureus 15.7% and Streptococcus pneumoniae 13.0%. The ability of NEWS2 to predict sepsis was not statistically associated with the etiology of the infection. The specificity of NEWS2 detection of sepsis was low, 52% (95% CI 0.43–0.59) with no statistically significant differences observed between pathogens. Conclusions Patients attending the Emergency Department (ED) with positive blood cultures and NEWS2 score ≥ 5 presented an overall sensitivity of 87% and PPV of 85% to detect patients with sepsis defined by Sepsis-3 criteria. NEWS2 score ≥ 5 could be considered as a quick, first screening tool to highlight a high likelihood of sepsis in the ED. However, NEWS2 score could not discriminate different bacterial species causing the sepsis episode.