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Tools for the Real-Time Assessment of a Pseudomonas aeruginosa Infection Model
Published on: April 6, 2021
Time to positivity as prognostic tool in patients with Pseudomonas aeruginosa bloodstream infection
Matthias Willmann1, Ines Kuebart, Wichard Vogel
1Institute of Medical Microbiology and Hygiene, University of Tübingen, Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany.
Objectives:
The time to positivity (TTP), measured as the time span between the start of incubation and the alert signal from the blood culture device, has been described as useful tool of prognosis in patients suffering from blood stream infection with Staphylococcus aureus, Escherichia coli and Klebsiella pneumonia. The present study investigates the relationship between TTP and in-hospital mortality in patients with monomicrobial Pseudomonas aeruginosa blood stream infection (PA-BSI).
Methods:
From 2006 until 2012 a retrospective cohort study was undertaken in 3 hospitals in the region surrounding Tübingen, Germany. Seventy-four patients with monomicrobial PA-BSI were studied. TTP and clinical parameters were determined and analyzed by receiver operating characteristic (ROC) analysis and Cox regression.
Results:
The in-hospital mortality of our clinical cohort was 33.78%. In multivariate Cox regression, a TTP ≤ 18 h proved to be independently associated with mortality (HR 3.83, P = 0.012) along with SAPS II score (HR 1.04, P = 0.006), cardiac disease (HR 0.33, P = 0.008) and appropriate definitive antimicrobial treatment (HR 0.21, P = 0.013).
Conclusions:
TTP is an easy-to-measure laboratory tool for prognosis in patients with monomicrobial PA-BSI, providing useful information in addition to clinical parameters.
Insights
Time to positivity (TTP) in blood cultures is a valuable prognostic indicator for Pseudomonas aeruginosa bloodstream infections (PA-BSI). Shorter TTP, specifically 18 hours or less, is independently associated with increased in-hospital mortality in PA-BSI patients.
Area of Science:
- Medical Microbiology
- Clinical Infectious Diseases
- Prognostic Biomarkers
Background:
- Bloodstream infections (BSI) pose significant mortality risks.
- Time to positivity (TTP) in blood cultures is an established prognostic marker for BSIs caused by Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae.
- The prognostic value of TTP in Pseudomonas aeruginosa BSIs (PA-BSI) requires further investigation.
Purpose of the Study:
- To investigate the relationship between TTP and in-hospital mortality in patients with monomicrobial PA-BSI.
- To evaluate TTP as a prognostic tool for PA-BSI outcomes.
Main Methods:
- Retrospective cohort study conducted from 2006-2012 across three German hospitals.
- Analysis of 74 patients with monomicrobial PA-BSI.
- TTP and clinical parameters analyzed using receiver operating characteristic (ROC) analysis and Cox regression.
Main Results:
- In-hospital mortality for the cohort was 33.78%.
- A TTP of ≤ 18 hours was independently associated with mortality (HR 3.83, P = 0.012).
- Other independent predictors of mortality included SAPS II score, cardiac disease, and appropriate antimicrobial treatment.
Conclusions:
- Time to positivity (TTP) is a readily measurable laboratory parameter for prognosis in PA-BSI.
- TTP provides valuable prognostic information beyond traditional clinical parameters for PA-BSI patients.
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