Safe surgery: how accurate are we at predicting intra‐operative blood loss?

Abstract

Predicted intra-operative blood loss was within 500 mL of measured blood loss in 89% of operations. In 30% of patients who ultimately receive a blood transfusion, both the surgeon and anaesthetist significantly underestimate the risk of blood loss by greater than 500 mL. Theatre staff must be aware that 1 in 14 patients undergoing intermediate or major surgery will have an unexpected blood loss exceeding 500 mL and so robust policies to identify and manage such circumstances should be in place to improve patient safety.