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Published on: June 20, 2025
Early blood-based microbiological testing is ineffective in severe stroke patients
Christoph Gumbinger1, Andreas Hug, Bettina Mürle
1Department of Neurology, University Hospital of Heidelberg, Germany.
Background And Purpose:
Patients with severe acute stroke are at high risk for systemic infections which are associated with an increase in morbidity and mortality; nevertheless current guidelines do not recommend prophylactic antibiotic therapy. Sensitive detection of pathogens in the blood is desirable to guide early antibiotic therapy. We studied the yield of blood culture testing and microbiological PCR-based methods for early detection of post-stroke bacteremia.
Methods:
Serial blood culture tests either during the first fever episode (>38.5°C) or 24h after admission were performed every 12h for up to 96h after admission. Additionally, microbiological PCR-based techniques for the detection of microbiological pathogens were performed once during the first fever episode prior to initiating antibiotic treatment.
Results:
21 severely affected acute stroke patients deemed at high risk for systemic infections (median (interquartile range (IQR)) at admission NIHSSS 19 (15-30) were enrolled; 20 patients were intubated within 5h after ICU admission. All patients developed clinical signs and laboratory constellations compatible with systemic infections within 36h after admission. However, no patient had pathogenic bacteria either in serial blood culture analyses during the first 96h after admission or by PCR-based techniques.
Conclusions:
Very early bacteremia seems not to be a feature of severe stroke in patients despite signs of early immune system depression and frequent subsequent evidence of infection including pneumonia. Consequently our data suggests, that routine early blood-based standard or molecular microbiological assays do not reveal bacteremia, this finding questions the usefulness of their routine performance in this context.
Insights
Severe stroke patients often show infection signs but rarely have early bacteremia. Routine blood cultures and PCR tests for bacteria are unlikely to be beneficial in this patient group.
Area of Science:
- Neurology
- Infectious Diseases
- Critical Care Medicine
Background:
- Severe acute stroke patients face high risks of systemic infections, increasing morbidity and mortality.
- Current guidelines do not recommend prophylactic antibiotic therapy for stroke patients.
- Early and sensitive pathogen detection in blood is crucial for guiding antibiotic therapy.
Purpose of the Study:
- To investigate the diagnostic yield of blood culture testing and microbiological PCR-based methods for detecting early bacteremia in severe acute stroke patients.
- To assess the utility of routine microbiological assays in identifying pathogens in this high-risk population.
Main Methods:
- Serial blood cultures were performed every 12 hours for up to 96 hours in 21 severe acute stroke patients.
- Microbiological PCR-based techniques were employed once before antibiotic treatment during the first fever episode.
- Patients were characterized by high NIH Stroke Scale scores and frequent intubation post-ICU admission.
Main Results:
- All 21 enrolled patients exhibited signs and laboratory findings consistent with systemic infections within 36 hours of admission.
- Despite signs of infection, no pathogenic bacteria were detected in any patient via serial blood cultures or PCR-based methods.
- This indicates a lack of early bacteremia in this severe stroke cohort.
Conclusions:
- Early bacteremia is not a typical feature in severe acute stroke patients, even with signs of immune depression and subsequent infections like pneumonia.
- Routine early blood-based microbiological assays, including standard and molecular methods, do not appear to detect bacteremia in this context.
- The findings question the routine use and clinical utility of early blood microbiological testing in severe acute stroke patients.
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