When I was a bedside nurse – and even before that, when I was a tech in the Emergency Department responsible for drawing blood – the issue of not being able to get two sets of blood cultures, or not getting enough blood in each bottle, would come up. Some patients are very hard to get blood from and blood cultures are a particularly onerous task. We require two separate sticks (often not drawing these from indwelling lines but requiring fresh sticks) and we require a very specific amount of blood in each bottle. This makes getting blood cultures difficult to obtain.
So, why do we need 2 bottles with 10mls each? As usual, Eddy Joe Gutierrez has the answers. He recently released an episode of his Saving Lives podcast where he discusses this. If you prefer to read, he had a blog post back in October of 2020 that covers the same material. As always, he provides links to the studies so you can check his facts. And let’s all be glad that we don’t routinely require three sets.