J Korean Soc Emerg Med.  2023 Dec;34(6):622-630.

Visual estimation accuracy for external blood loss in diverse bleeding conditions: a comparative analysis between medical and non-medical personnel

• Lee HJ
• Choi Hs
• Hwang SY
• Park SS
• Lee JG
• Ryu HS
• Lee SJ
• Shin JE

Abstract

Objective
This study aimed to compare the accuracy of the visual estimation of blood loss between medical personnel (MP) and non-medical personnel (NP) and to evaluate how it varies with changes in the bleeding volume and environment.
Methods
A total of 78 MP and 132 NP were recruited for the study and asked to evaluate nine artificial blood stations and three different volumes of artificial blood (192 mL, 384 mL, 768 mL) in three different environments (floor, diaper, and commode). Statistical analysis and the two-way repeated measures analysis of variance test were used for data analysis.
Results
There were significant differences between MP and NP regardless of the actual bleeding loss in all the bleeding environments-floor (F=25.332, P<0.001), diaper (F=9.942, P=0.002), and commode (F=29.588, P<0.001). NP consistently had higher estimates of bleeding volume compared to MP. The interaction effect between group and volume was statistically significant for the floor and diaper-floor (F=9.708, P<0.001) and diaper (F=5.420, P=0.013), but there was no significant difference for the commode (P=0.087). Additionally, the standard deviation of bleeding volume estimates was higher for NP.
Conclusion
Visual estimation of blood loss differed significantly between MP and NP, with NP consistently overestimating and demonstrating lower accuracy and reliability compared to MP. These findings underscore the need for caution when relying on estimates by NP as a diagnostic tool for assessing blood loss.

Keyword

Hemorrhage; Emergency medical services; Health personnel