Taking Blood Cultures

  • Blood cultures remain a cornerstone of the diagnosis if infective endocarditis and should be taken PRIOR to treatment in all cases
  • In patients with a chronic or sub-chronic presentation, three sets of optimally filled blood cultures should be taken within 24hr from peripheral sites with few hours between them prior to commencing antibiotics.
  • In patients with suspected infective endocarditis and sepsis +/- septic shock at the time of presentation, two sets of optimally filled blood cultures should be taken at different times within 1hour prior to the commencement of therapy, to avoid undue delay in starting therapy.
  • If a stable patient has suspected IE but is already on antibiotic treatment, consideration should be given to stopping treatment and performing 3 sets of blood cultures while off antibiotics. It may take 7-10 days off antibiotics for cultures to become positive.

All clinically confirmed cases to be discussed with microbiology.

For synergistic dosing of gentamicin -> aim for peak 3-5mg/l and trough <1mg/l

If renal function is poor or deteriorating, discuss dosing and frequency with pharmacist