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an improved risktobenefit ratio for tourniquet use dur overtightening the first tourniquet to stop both bleed
ing the 21st century wars. ing and the distal pulse. 35
Potential complications of tourniquet use are many, Clinical evidence indicates that field tourniquet place
and have been reported in great detail in the orthopedic ment may be effective, but at the hospital or after resus
surgery literature. 40,41 However, the complications from citation is begun, the tourniquet may become ineffective
emergency tourniquet use are much more difficult to due to an increase in the blood pressure ; this loss of
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quantify in comparison to elective surgery, due to the ef effectiveness during resuscitation underscores the need
fects of the injury itself, which may contribute to similar for reassessment of tourniquet use so that the tourni
outcomes. Kragh et al. selected the following complica quet may be retightened or adjusted. New evidence also
tions to report in their prospective observational study indicates that initial tourniquet placement may be effec
of tourniquet use: amputation, fasciotomy, clot, palsy, tive, but within a minute muscle tension under the tour
myonecrosis, acute renal failure, significant pain, and niquet may lessen and cause the tourniquet to become
rigor. 1,19 In general, complications of tourniquet use re ineffective ; this early loss of effectiveness underscores
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sult from direct pressure at the site of the tourniquet, the need for early reassessment of tourniquet use so that
venous congestion, rebleeding from a partially occlusive the tourniquet may be retightened or adjusted.
tourniquet, or ischemia induced by arterial occlusion.
Training must emphasize that tourniquets need to stop
Direct pressure injuries are risked with narrower tourni both bleeding and the distal pulse and that frequent re
quets and higher tourniquet pressures, resulting in nerve assessment is essential to maintain effectiveness of the
palsy, vascular injury, or direct tissue injury. Such iat tourniquet. It is recognized that partial amputation and
rogenic injuries may be minimized through the use of isolated arterial injury may result in no palpable distal
wider tourniquets at lower compression pressures. 42,43 pulse. In many combat situations, obtaining full expo
Device selection has been instrumental in reducing sure and removing footwear to check pulses may be de
direct pressure injuries. TCCC guidelines and training layed; in such cases, visibly confirming control of wound
have also recommended placement of a second tourni hemorrhage suffices. In darkness, palpation for pulses
quet side by side with the first if the initial application is may be more useful than observing for hemorrhage.
ineffective, thereby effectively widening the tourniquet,
an innovation from users in the field that led Dr. John Ischemic complications increase as tourniquet time in
Kragh to clarify its usefulness and to propose its imple creases. There is no consensus on an absolutely safe du
mentation formally. Conversion to wider pneumatic ration for tourniquet use; however, a range of 1–3 hours
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tourniquets, as is frequently done on arrival to a surgical has been suggested, with 2 hours accepted as a useful
facility, may further reduce the risk of pressure injuries. guideline for safe use during elective surgery. 1,45–49 Serum
creatine phosphokinase (CPK) level has been used as a
The “venous tourniquet” occurs when the tourniquet marker for limb muscle damage at and distal to the tour
is tight enough to occlude venous outflow from the niquet. In dogs, the CPK level does not increase after
limb while failing to occlude arterial inflow. Continued 1 hour of ischemia, but does rise after 2–3 hours of isch
inflow of blood with impaired outflow leads to loss emia. In addition, Olivecrona et al. demonstrated that
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of blood in the body’s core and swelling of the distal tourniquet times longer than 100 minutes were associ
limb with higher risk of compartment syndrome, but ated with an increase in complications after knee arthro
may also increase the amount of wound bleeding, par plasty (independent of comorbidities or primary/revision
ticularly from venous injuries. Kragh et al., in 2008, indication), with the odds of a complication increasing
1
reported that 44 of 232 casualties with prehospital by 20% for each 10 minutes of longer tourniquet time
applied tourniquets had persistent bleeding on arrival throughout a range of 39–156 minutes. Other authors
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to a CSH and 43 of the 232 had persistent distal pulses; have postulated that the effects of traumatic injury and
these casualties experienced an increased morbidity blood loss may reduce the ischemic tolerance of the limb
and mortality rate. The authors described the clinical in comparison to elective surgery, suggesting that safe
progression associated with ineffective tourniquets: tourniquet times may be shorter than expected for pa
persistent pulse, venous congestion, venous distension, tients in shock. 52,53
rebleeding after a period of hemorrhage control, ex
panding hematomas, compartment syndrome, fasci In general, minimizing tourniquet time is the most effec
otomy, and death. 1,19 These observations resulted in tive strategy to minimize the risks of tourniquetrelated
two refinements of the TCCC guidelines in 2008: (1) injury. Minimizing harm is particularly important for
the elimination of the distal pulse on the extremity was those casualties who may have had a tourniquet placed
added as a goal of tourniquet application, and (2) the for hemorrhage that is not life threatening, which may
recommendation to use a second tourniquet rather than frequently occur in realworld scenarios during CUF.
22 Journal of Special Operations Medicine Volume 15, Edition 1/Spring 2015
