As the administrative team likes to remind us: blood cultures before antibiotics.
Blood cultures before antibiotics.
Blood cultures? Before antibiotics.
What’s the point, we say – aren’t the antibiotics the actual life-saving intervention? And the answer, when relevant, ties into identifying the specific susceptibility of the infective agent, such that antibiotics may ultimately be narrowed to the minimum necessary for cure. It’s a noble premise, at least.
But, so, what does happen when you give antibiotics first?
At least one recent retrospective study has pulled data from their health system showing a clear decrease in blood culture positivity following administration of antibiotics, but these results may be limited by potential differences between groups. In contrast, this clever little study looks at it prospectively: the same 325 Emergency Department patients with “severe manifestation of” sepsis – hypotensive or lactate >4 mmol/L – received blood culture draws both prior to, and just following, antibiotic administration.
Before antibiotics: 31.4% positive blood cultures.
After antibiotics: 19.4% positive blood cultures.
It is not a perfect study by any means, but a long story short: if you’re going to go to the trouble of drawing and processing blood cultures, draw them before you start antimicrobial treatment. But, clearly, the antimicrobials are doing their job – do it expeditiously such that your patient does not suffer from unwanted delay.
“Blood Culture Results Before and After Antimicrobial Administration in
Patients With Severe Manifestations of Sepsis”
https://annals.org/aim/fullarticle/2751453/blood-culture-results-before-after-antimicrobial-administration-patients-severe-manifestations