Page 76 - 2022 Spring JSOM

Amputations of limbs < 8.5-cm diameter were successful with or in which the remoteness of the location precludes proper
the tools tested. All amputation attempts on limbs > 12 cm in surgical personnel and equipment from being present, limited
diameter were unsuccessful in < 2 minutes, regardless of the space to operate a Gigli or larger saw, or possible failure of
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tool used. ideal equipment. In these scenarios, the difference between
completing an amputation in 2 minutes versus 10 or 15 min-
The Leatherman, the Swiss Army Rescue Tool, and the Tree- utes could be lifesaving.
Hopper hunting knife consistently amputated the smaller-
circumference limbs regardless of amputator. The fixed-blade Another consideration about the 2-minute cycle was amputa-
SOG Pentagon knife did not achieve the same success because tor fatigue. The amputations took a sawing action that was
of the design of the SOG. The SOG Pentagon knife is designed physically demanding and required rest after the amputation
with a thicker middle where the bevels meet that taper to a was completed. The 2-minute cycle is the standard for phys-
narrow blade edge, causing the serrated edge to bind when ically demanding CPR, so this timeframe is generally well
cutting through bone. The other tools are designed with mul- known to medical personnel and first responders.
tiple unique folding tools, a nonserrated knife blade, and a
serrated saw blade with the same thickness through the saw Several amputation attempts were stopped at 2 minutes be-
blade, preventing the binding. cause that was the primary outcome defining success versus
failure from the outset, but these amputations were nearly
The subjective experience ranked the Leatherman multitool complete and likely would have been completed within 2.5 or
the highest. The Victorinox Swiss Army Rescue Tool has a 3 minutes, thus providing additional successful amputations.
good knife blade, cutting soft tissue quickly, but the disc saw,
designed to cut through windshield glass, was poor at cutting Finally, because our amputations were completed on cadav-
bone. The TreeHopper also has good knife blades, cutting ers, we did not account for the emotional/human aspect of
through soft tissue and bone, but it has a folding gut hook that completing an amputation. Under the scenarios that we are
protrudes from the handle and applied pressure into several discussing, an emergent field amputation is a life-changing
Operators’ hands when using the device. event. Sedation and pain control may not be available. The
emotional aspect of performing a field amputation on a living
Our amputators were emergency medicine resident physicians, human would be difficult to study, but there would likely be a
a nonsurgical specialty that is not typically trained in perform- significant difference in the amputator’s experience.
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ing amputations. Although nonphysicians were not among
the amputators in this study, based on our findings, we do not Limitations
think that this should prevent medical personnel or a search- We selected a convenient sample of knives at a North Ameri-
and-rescue worker from attempting a life-saving amputation can national outdoor supply store typical of the market sup-
in the austere field environment. We specifically chose to am- ply. We did not compare common hand tools to the Gigli saw
putate at locations with long bones because of the ease of the or a reciprocating bone saw; we wanted to study scenarios
anatomy and chose not to amputate joints because of their in which these ideal tools would be unavailable. We used a
complexity. Any amputation performed should be done at the brand-name Leatherman tool, not a “cheap knockoff” model,
4
lowest level possible to allow for future reconstruction and is such as the one described by Aron Ralston. We cannot com-
faster when done through the bone and not the joint. 13,14 ment on the success of cadaveric amputations using tools other
than the ones we tested.
Most emergency medical technician and first responder train-
ing provides sufficient anatomic knowledge to complete a This study used elderly cadavers that were lightly embalmed
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guillotine amputation. EMS technicians and first responders and approximately 1 month old. There was no blood flow, and
are trained in tourniquet use and bleeding control, which our the muscles and soft tissue had begun to degrade. Tourniquets
study did not investigate because we were using cadavers, but were also not applied. The application of a tourniquet could
which would be integral during a live amputation. Future re- potentially change the tension on the skin and provide other
search could include methods similar to those in our study but variables to the amputation. In an actual situation, the mus-
involve EMS and first responder personnel with knowledge of cle would be living and perfused, and considerations such as
proper tourniquet application. muscle retractions and bleeding would have to be considered.
A study of amputating living human tissue with multitools
Previous literature influenced how the amputations were con- would be challenging, so animal models or cadavers are used.
ducted, specifically in using a nonserrated blade to cut through
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soft tissue and a serrated saw blade to cut through bone. Our amputations took place in an ideal laboratory setting
An individual not familiar with human tissue may not achieve with ideal lighting. The extremities were secured, and the am-
the same success we did in this study. The assumptions that putators had easy access to the limbs. A field scenario would
amputators will amputate at long bone sites and will use a likely not produce the same settings. Therefore, the success
nonserrated edge to get through soft tissue and a serrated edge rates may not be the same as those found in this study.
to get through bone, excludes recommending that bystanders
attempt field amputations. The diameters and density of the bones were not independently
assessed; rather, the diameters of the limbs containing the
If the patient is not in a critical situation and proper equip- bones were. Because limb diameter, not bone diameter, is what
ment and medical personnel are available, there would be no rescuers see, the bones’ density and diameters were not eval-
need for an expedited amputation with a hand tool. This study uated. We also did not gauge the quality of the amputation,
considered austere or combat scenarios in which there is a lim- whether the bone cut straight or splintered, or the repair’s ul-
ited amount of time because of a patient’s clinical condition, timate difficulty.

74 | JSOM Volume 22, Edition 1 / Sping 2022