Abstract
Background
An element lacking in medical education is training to estimate blood volumes. Therefore,
health care workers currently use visual estimation as their only means of determining
blood volumes, which has shown to be highly inaccurate. This study proposes and tests
a new method using one's fist to determine external blood loss.
Methods
Increments of human whole blood were measured and used to compare fist size to surface
area of blood present. A formula was created averaging blood per fist, hereafter known
as the MAR Method. Two scenarios were staged using set quantities of blood (75 and
750 mL). Participants estimated blood volumes before and after being taught the MAR
Method in a 1-minute session. Errors in estimation before and after using the MAR
Method were compared.
Results
The MAR Method was created using a fist to cover a surface area of blood that equals
20 mL. A total of 74 participants had errors of 120% and 73% for visualization of
the small and large pools, respectively. For the smaller volume, the average error
from the mean decreased by 76% (
P < .0001), and the interquartile range of errors decreased by 60%. For the larger
volume, the average error from the mean reduced by 40% (
P < .0001), and the interquartile range of errors reduced by 45%.
Conclusion
Use of the MAR Method improves blood volume estimations. After less than 1 minute
of instruction, participants were able to determine blood volumes with improved accuracy
and precision.
To read this article in full you will need to make a payment
Subscribe to The American Journal of Emergency Medicine
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- The accuracy of external blood loss estimation by ambulance and hospital personnel.Emerg Med (Fremantle). 2003; 15: 318-321
- Accuracy of estimation of external blood loss by EMS personnel.J Trauma. 2001; 50: 914-916
- An educational presentation does not improve visual estimation of blood loss by paramedics.Prehosp Emerg Care. 2007; 11 ([Abstract]): 113
- Blood loss estimation by out-of-hospital emergency care providers.Prehosp Emerg Care. 1999; 3: 239-242
- Fluid resuscitation and blood replacement in patients with polytrauma.Clin Orthop Relat Res. 2004; 422: 37-42
- Advanced Trauma Life Support for Doctors.7th ed. American College of Surgeons, Chicago2004
- How big is a hand?.Burns. 1996; 22: 230-231
- Burns area estimation—an error perpetuated.Burns. 2004; 30: 481-482
Article Info
Publication History
Accepted:
July 29,
2008
Received in revised form:
July 28,
2008
Received:
July 9,
2008
Identification
Copyright
© 2009 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
