Does inappropriate initial antibiotic therapy affect in-hospital mortality of patients in the emergency department with Escherichia coli and Klebsiella pneumoniae bloodstream infections?

Extended-spectrum ß-lactamase (ESBL)-positive bloodstream infection (BSI) is on the rise worldwide. The purpose of this study is to evaluate the impact of inappropriate initial antibiotic therapy (IIAT) on in-hospital mortality of patients in the emergency department (ED) with Escherichia coli and Klebsiella pneumoniae BSIs. This retrospective single-center cohort study included all adult patients with E. coli and K. pneumoniae BSIs between January 2007 and December 2013, who had undergone a blood culture test and initiation of antibiotics within 6 h of ED registration time. Multiple logistic regression was used to adjust for bacterial species, IIAT, time to antibiotics, age, sex, quick Sepsis Related Organ Failure Assessment (qSOFA) score ⩾ 2, and comorbidities. A total of 3533 patients were enrolled (2967 alive and 566 deceased, in-hospital mortality rate 16%). The patients with K. pneumoniae ESBL-positive BSI had the highest mortality rate. Non-survivors had qSOFA scores ⩾ 2 (33.6% vs 9.5%, P < 0.001), more IIAT (15.0% vs 10.7%, P = 0.004), but shorter mean time to antibiotics (1.70 vs 1.84 h, P < 0.001). A qSOFA score ⩾ 2 is the most significant predictor for in-hospital mortality; however, IIAT and time to antibiotics were not significant predictors in multiple logistic regression analysis. In subgroup analysis divided by qSOFA scores, IIAT was still not a significant predictor. Severity of the disease (qSOFA score ⩾ 2) is the key factor influencing in-hospital mortality of patients with E. coli and K. pneumoniae BSIs. The time to antibiotics and IIAT were not significant predictors because they in turn were affected by disease severity.

Difference between elderly and non-elderly patients in using serum lactate level to predict mortality caused by sepsis in the emergency department.

Elderly people are more susceptible to sepsis and experience more comorbidities and complications than young adults. Serum lactate is a useful biomarker to predict mortality in patients with sepsis. Lactate production is affected by the severity of sepsis, organ dysfunction, and adrenergic stimulation. Whether the predictive ability of serum lactate will be different between non-elderly and elderly patients is unknown.A retrospective cohort study was conducted to compare the prognostic value of hyperlactatemia in predicting the mortality between elderly (≥65 years) and non-elderly (<65 years) patients with sepsis.This is a single-center retrospective observational cohort study conducted from January 2007 to December 2013 in southern Taiwan. All patients with sepsis, who used antibiotics, with blood culture collected, and with available serum lactate levels in the emergency department, were included in the analysis. We evaluated the difference in serum lactate level between the elderly and non-elderly septic patients by using multiple regression models.A total of 7087 patients were enrolled in the study. Elderly and non-elderly patients accounted for 62.3% (4414) and 40.2% (2673) of all patients, respectively. Statistically significant difference of serum lactate levels was not observed between elderly and non-elderly survivors (2.9 vs 3.0 mmol/L; P = .57); however, elderly patients had lower lactate levels than those within the 28-day in-hospital mortality (5.5 vs 6.6 mmol/L, P < .01). Multiple logistic regression revealed higher adjusted mortality risk in elderly and non-elderly patients with lactate levels of ≥4.0 mmol/L (odds ratio [OR], 4.98 and 5.82; P < .01, respectively), and lactate level between 2 and 4 mmol/L (OR, 1.57 and 1.99; P < .01, respectively) compared to that in the reference group with lactate levels of <2.0 mmol/L in each group. In receiver operating characteristic curve analysis, sensitivity rates for predicting mortality were 0.80 and 0.77 for non-elderly and elderly patients, respectively, by using serum lactate levels higher than 2.0 mmol/L.Septic elderly non-survivors had 1 mmol/L lower serum lactate level than those of the non-elderly non-survivors. Lactate >2 mmol/L still could provide enough sensitivity in predicting sepsis mortality in elder patients.