Proper estimation of blood loss on scene of trauma: tool or tale?
BACKGROUND
Visually estimated amount of blood loss may influence decision making in the prehospital setting. The purpose of this study was to determine the ability and accuracy of paramedics and emergency physicians to visually estimate a volume of external blood loss and the influence of different vital signs.


METHODS
In a prospective, blinded, observational design, participants were asked to visually estimate the amount of blood in six simulated trauma scenarios. Casualties were provided with a simulated injury, and a certain amount of artificial blood that was poured on the casualties' clothing and on the floor. In addition, vital signs (i.e., blood pressure and heart rate) were given. Each two moulage patients were provided with the same injury pattern and the same simulated blood loss. Although one patient seemed to be normovolemic, the other seemed to be hypovolemeic by the given vital signs.


RESULTS
With regard to all given amounts of blood loss, providing vital parameters suggesting instability (i.e., low blood pressure, high heart rate) led to a higher estimation of the lost blood volume in both paramedics and emergency physicians. However, estimations were influenced impressively by the given parameters. For both stable and unstable patients, small actual volumes were overestimated, whereas higher volumes tended to be underestimated. Neither occupational status (emergency physician or paramedic) nor gender or level of experience influenced accuracy of estimated blood loss significantly.
Frank
Matthias
M
Department of Trauma and Orthopedic Surgery, Ernst-Moritz-Arndt-University, Greifswald, Germany. matthias.frank@uni-greifswald.de
Schmucker
Uli
U
Stengel
Dirk
D
Fischer
Lutz
L
Lange
Joern
J
Grossjohann
Rico
R
Ekkernkamp
Axel
A
Matthes
Gerrit
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure; D001810:Blood Volume; D004632:Emergency Medical Services; D004634:Emergency Medical Technicians / Q000592:standards*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006470:Hemorrhage / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010808:Physical Examination / Q000379:methods*; D011336:Probability; D011361:Professional Competence; D011446:Prospective Studies; D016037:Single-Blind Method; D000078329:Workforce; D014947:Wounds and Injuries / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D055815:Young Adult