Description: Bacteremia is the presence of bacteria in the bloodstream, which can cause systemic inflammatory response syndrome (SIRS), sepsis, or septic shock1. Bacteremia with enteral microflora refers to the translocation of bacteria from the gastrointestinal tract to the blood, which can occur in critically ill patients due to impaired intestinal barrier function, altered intestinal motility, and changes in the gut microbiome2.
Feasibility/Equipment: Bacteremia with enteral microflora can be diagnosed by blood cultures, which require sterile collection techniques, laboratory processing, and microbiological identification1. Blood cultures should be obtained before starting antibiotic therapy and repeated as clinically indicated1. The identification of enteral microflora in blood cultures may indicate the source of bacteremia and guide the choice of antibiotic therapy2.
Scoring information: Bacteremia with enteral microflora is scored based on the number and type of bacteria isolated from blood cultures, as well as the clinical signs and symptoms of infection1. The most common enteral microflora that cause bacteremia are gram-negative bacilli, such as Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., and Pseudomonas aeruginosa2. The severity of bacteremia can be assessed by using scoring systems such as the Sequential Organ Failure Assessment (SOFA)1.
Cost: Cost of blood cultures maybe significant and depending on the clinical scenario the yield may be low.
Evidence: There is limited evidence on how to prevent or treat bacteremia with enteral microflora in critically ill patients. Some possible strategies include maintaining adequate nutrition, avoiding overuse of antibiotics, using probiotics or prebiotics, and modulating the immune system2. Early administration of appropriate antibiotics has been shown to improve survival in patients with bacteremia, but the optimal timing and duration of therapy are unclear4.
Accuracy/Measurement properties: Blood cultures have variable accuracy and measurement properties depending on the quality of specimen collection, transport, and processing1. Blood cultures may be contaminated by skin flora or environmental bacteria, which can lead to false-positive results and unnecessary antibiotic use1. Blood cultures may also be negative due to prior antibiotic use, low bacterial load, or fastidious organisms, which can lead to false-negative results and delayed diagnosis1.
References:
- 1: Best Practices in the Diagnosis and Treatment of Bacteremia. AHRQ. https://www.ahrq.gov/antibiotic-use/acute-care/diagnosis/bacteremia.html
- 2: Tatsumi, H. Enteral tolerance in critically ill patients. j intensive care 7, 30 (2019). https://doi.org/10.1186/s40560-019-0378-0
- 3: Daneman, Nick MD1; Rishu, Asgar H. MBBS2; Xiong, Wei MSc2; Bagshaw, Sean M. MD3; Dodek, Peter MD4; Hall, Richard MD5; Kumar, Anand MD6; Lamontagne, Francois MD7; Lauzier, Francois MD8; Marshall, John MD9; Martin, Claudio M. MD10; McIntyre, Lauralyn MD11; Muscedere, John MD12; Reynolds, Steve MD13; Stelfox, Henry T. MD14; Cook, Deborah J. MD15; Fowler, Robert A. MD16 on behalf of the Canadian Critical Care Trials Group. Duration of Antimicrobial Treatment for Bacteremia in Canadian Critically Ill Patients*. Critical Care Medicine 44(2):p 256-264, February 2016. | DOI: 10.1097/CCM.0000000000001393
- 4: Lee, CC., Lee, CH., Hong, MY. et al. Timing of appropriate empirical antimicrobial administration and outcome of adults with community-onset bacteremia. Crit Care 21, 119 (2017). https://doi.org/10.1186/s13054-017-1696-z
- 5: Havey, T.C., Fowler, R.A. & Daneman, N. Duration of antibiotic therapy for bacteremia: a systematic review and meta-analysis. Crit Care 15, R267 (2011). https://doi.org/10.1186/cc10545