Mortality impact of empirical antimicrobial therapy in ESBL- and AmpC-producing Enterobacteriaceae bacteremia in an Australian tertiary hospital.

BACKGROUND: Treatment of ESBL- and AmpC-producing Enterobacteriaceae bacteremia is often complicated by lack of appropriate antibiotics. We aimed to determine the predictors of mortality and impact of empirical antibiotics. METHODS: A retrospective observational study was performed on consecutive adult cases of ESBL and AmpC bacteremia at the Alfred Hospital from 2014 through April 2018. RESULTS: Among 110 patients with ESBL (88.2%) and AmpC (14.5%) bacteremia episodes, 96.4% had comorbidities such as hematological malignancy (30%). Approximately 45% were on immunosuppressive drugs, while 69% had recent antibiotic exposure. Over 84% of bacteremias were hospital acquired or healthcare associated. Urinary tract was the main source of infection (40%) with E. coli being the commonest organism (66.4%). The isolates were least resistant to gentamicin (21.8%), which was often appropriately used in empirical therapy. About 34% of patients presented with severe sepsis or shock. The 30-day mortality rate was 20% with no correlation with inappropriate empirical antibiotics (52%). There was no significant mortality difference between carbapenem use in empirical and definitive therapy. Respiratory source [OR 11.77, 95% CI 1.30-106.85; p = 0.03], severe sepsis or shock [OR 5.17, 95% CI 1.37-19.55; p = 0.02] and inappropriate definitive therapy [OR 27.93, 95%CI 3.69-211.35; p = 0.001] were independent predictors for mortality. CONCLUSION: The choice and appropriateness of empirical therapy were not associated with mortality in ESBL and AmpC bacteremia. Prudent use of carbapenem is reasonable with gentamicin as alternative. Emphasis should be on prompt resuscitation in severe sepsis and early detection of ESBL and AmpC to facilitate appropriate switch to definitive therapy.

The Organisms and Factors Affecting Outcomes of External Ventricular Drainage Catheter-Related Ventriculitis: A Penang Experience.

INTRODUCTION: Ventriculostomy-related infection (VRI) from external ventricular drain (EVD) insertion is a common complication and carries a high mortality rate. Choice of empiric antibiotics depends on the institutions common causative organisms and their susceptibility. We determined risk factors for mortality in patients with VRI, the common organisms causing VRI, and the rate of EVD-related VRI at our institution. METHODS: Medical records and operative data of patients with cerebrospinal fluid positive cultures with an EVD inserted from 2012 to 2015 were traced. Forty-five patients with EVD-related VRI were included in the study. RESULTS: The overall rate of VRI was 6.3%, and the overall mortality rate due to VRI was 48.9%. Acinetobacter baumannii was the most common organism causing VRI (14 patients, 29.2%) with a mortality rate of 64.3%. Only 14.3% of A. baumannii are sensitive to meropenem and imipenem. We found that patients that had a decompressive craniectomy (DC) had a lower mortality rate (P = 0.042) and patients with a longer duration of the EVD being in place before the diagnosis of VRI had poor outcome (P = 0.040). Multivariate logistic regression was performed and we found that the use of steroid (P = 0.014), Pseudomonas aeruginosa infection (P = 0.010), multiple organism infection (P = 0.017), lower Glasgow Coma Scale (P = 0.043), and a longer duration the EVD was in place before the diagnosis of VRI (P = 0.008) were related with higher mortality. CONCLUSION: VRI mortality rate is high with an alarming resistance pattern seen in Acinetobacter VRI. EVDs should be removed as soon as feasible, and DC may be offered to patients with severe ventriculitis or meningitis.