How long can a unit of blood remain on the unit before it must be started?

A unit of blood must be started within 30 minutes of being taken out of the blood bank to maintain its viability and safety for transfusion. If blood is left out for longer than this timeframe, it can become unsafe due to temperature changes and the potential for bacterial growth. The shorter timeframe helps ensure that the blood maintains its properties and effectiveness, which is critical for patient safety during transfusion procedures. Ensuring that the blood is infused promptly after retrieval is a priority in transfusion practices to minimize risks associated with blood storage and potential complications for the recipient.