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

Abstract

Intraoperative blood loss estimation by members of the surgical and anesthesia teams is often inaccurate with potentially detrimental clinical consequences. Despite this, few trainees receive standardized visual blood loss estimation training. This study’s primary aim was to examine the impact of an educational intervention for visual blood loss estimation on surgery and anesthesia trainees’ interrater reliability. A quasi-experimental study was conducted with a convenience sample of Orthopaedic Surgery Residents and Student Registered Nurse Anesthetists. The study included a two- section pre-test, seven simulated blood loss stations, a brief PowerPoint lecture, a printed visual aid, and a two- section post-test. Low, moderate and high blood loss volumes were simulated with common operating room materials and theater blood. The two groups’ mean visual blood loss estimations at seven simulated blood loss stations were compared before and after an educational intervention. More than seventy percent of the participants reported no previous formal training in visual blood loss estimation as part of their training program. Consistent with previous literature, the Orthopaedic Surgery Resident group underestimated blood loss values at all seven stations while the Student Registered Nurse Anesthetist group overestimated at a majority of the stations prior to the intervention. There was a statistically significant difference in the groups’ estimations at four of the seven stations. Following the educational intervention, both groups had a significant reduction in estimation error and improved interrater reliability. There was no statistically significant difference between the two groups’ estimations at any of the seven post-intervention stations. The results of this study demonstrate that a multi-modal educational intervention can improve visual blood loss estimations by surgery and anesthesia trainees. While the clinical significance remains unknown, the results support implementation of an educational intervention for visual blood loss estimation during anesthesia and surgical training.