Variation in size of blood puddles on different surfaces.
OBJECTIVE
It is known that visual estimation of blood loss is inaccurate independently from experience and qualification of rescuers or members of hospital staff. There is no information available about the size of a puddle of blood for a given amount of blood depending on the surface. This pilot study evaluated the size of blood puddles on various surfaces.


METHODS
Human blood was portioned in standardized amounts of fluid and poured on different surfaces: wooden and polyvinyl chloride (PVC) floors, flagging, carpet, asphalt, concrete, forest soil, mattress and towel. The resulting puddles of blood were documented by digital photos and their surface areas measured using a computer.


RESULTS
The largest blood puddles were found on even surfaces such as PVC floors and concrete, and the smallest blood puddles were found on forest soil and carpet. When blood volume was 100 ml, the difference between the smallest and the largest blood puddle added up to a factor of 13.8 (77 cm forest soil, 1061 cm PVC). This factor was comparable in all other blood amounts on these two surfaces (13.7 with 250 ml, 13.0 with 500 ml, 13.5 with 1000 ml). A table with objects of daily life of comparable size (CD, letter, newspaper, etc.) was added for teaching purposes.


CONCLUSIONS
The size of puddles of blood depended strongly on the type of surface. Up to 13 times larger blood puddles were found on hard and nonabsorbant surfaces (PVC, concrete) than on absorbant surfaces such as carpet or forest soil.
Departments of aAnaesthesiology and Critical Care Medicine bTransfusion Medicine, Medical University of Innsbruck cRed Cross Tyrolia, Innsbruck dPublic Hospital of Hall in Tirol, Austria.
Janett
J
Kreutziger
Andreas
A
Haim
Kim
K
Jonsson
Volker
V
Wenzel
Matthias
M
Stark
Walter
W
Nussbaumer
D001769:Blood; D005430:Floors and Floorcoverings; D006470:Hemorrhage / Q000097:blood / Q000175:diagnosis; D006801:Humans; D013499:Surface Properties