Estimation of Surgical Blood Loss by Anesthesia and Surgical Trainees: Impact of an Educational Intervention on Interrater Reliability

Intraoperative blood loss estimation by members of the anesthesia and surgical teams is often inaccurate, with potentially detrimental clinical consequences. Despite this, few trainees receive standardized training in blood loss estimation. This study examined the impact of an educational intervention for visual blood loss estimation on anesthesia and surgical trainees' accuracy and interrater reliability. A quasi-experimental study was conducted with student registered nurse anesthetists (SRNAs) and orthopedic surgery residents. The groups' mean visual blood loss estimations at 7 simulated stations were compared before and after an educational intervention. Low, moderate, and high blood loss volumes were simulated with common operating room materials and theater blood. Of the 42 participants, 29 (70%) reported no previous formal training in blood loss estimation. Before the educational intervention, orthopedic surgery residents underestimated blood loss values at all stations, whereas the SRNAs tended toward overestimation. Following the educational intervention, there was no significant difference between the groups' mean estimations. Both groups had a significant reduction in estimation error and improved interrater reliability (P<.001). The results of this study demonstrate that a multimodal educational intervention can improve visual blood loss estimations by surgical and anesthesia trainees, supporting implementation of such programs during anesthesia and surgical training.