Clinical physiological parameters for the prediction of gram-negative bacterial infection in the emergency department

Abstract

Background Early detection and treatment of Gram-negative bacteria (GNB), major causative pathogens of sepsis, may benefit a patient’s outcome, since the mortality rate increases by 5–10% for each hour of delayed therapy. Unfortunately, GNB diagnosis is based on blood culture, which is time consuming. Therefore, an economic and effective GNB infection detection tool in the emergency department (ED) is warranted. Methods We conducted a retrospective case control-study in the ED of a university-affiliated medical center between January 01, 2014 and December 31, 2017. The inclusion criteria were as follows: (1) age ≥ 18; (2) clinical suspicion of bacterial infection; (3) positive bacterial culture of blood or sputum or urine. Descriptive statistics was performed on patient demographic characteristics, vital signs, laboratory data, infection sites, cultured microorganisms, and clinical outcomes. The accuracy of vital signs to predict GNB infection was identified via logistic regression and receiver operating characteristic (ROC) analysis. Results A total of 797 patients were included in this study; the mean age was 71.8 years and 51.3% were male. The results revealed that patients with body temperature ≥ 38.5°C, heart rate ≥ 110 beats per minute, respiratory rate ≥ 20 breaths per minute, and Glasgow coma scale (GCS) < 14, had a 2.3-, 1.4-, 1.9-, and 1.6-fold greater risk of GNB infection, respectively. The area under the curve values for ROC analysis of these measures were 0.70, 0.68, 0.69, and 0.67, respectively. Conclusion The four physiological parameters were rapid and reliable independent predictors for early detection of GNB infection.