Page 48 - Journal of Special Operations Medicine - Summer 2016

3.8cm-wide Single Tactical RMT. As expected, however, significant under-tourniquet pressure decreases occur
Occlusion Pressures under each of the two 3.8cm-wide in minutes even without muscle tension changes, and
side-by-side Paired Tactical RMTs were lower than un- increases in recipient blood pressure at some point fol-
der either the Single Tactical RMT or the Wide RMT. lowing tourniquet application are possible.

The pressure measuring system is a possible factor in the No failures of the pawl to properly advance along the
finding of a lack of differences in Occlusion Pressures ladder (tooth skipping) occurred during any of the
between the Wide and the Single RMT. Each 3.8cm RMT applications in this study. We specifically picked
Tactical RMT provided the same amount of strap cover- experienced RMT appliers who used a ratcheting buckle
age of each inflated bladder of the pressure measurement advancing technique that included applying pressure to-
system (bladder was 2.2cm-wide when not inflated). ward the ladder at the forward portion of the buckle,
With the Wide RMT, strap coverage extended farther which pushes the rotating pawl toward the teeth of the
beyond the side edges of the bladder than was the case ladder. We have noticed that not all appliers will use this
for the Tactical RMTs. This may have created greater technique without specific instruction to do so.
constraint against bladder expansion, which could re-
sult in higher bladder pressures for the same strap cir- Besides the influence of any measurement system on the
cumferential tension. An alternate pressure measuring values obtained, an important limitation of this study
system would be useful for examining this idea. was the method of application of the paired tourniquets.
Because a single properly applied Tactical RMT would
The confirmation of lower pressures to reach occlusion achieve occlusion on each of the recipients’ arms and
with two side-by-side 3.8cm-wide RMTs than with a thighs, we used an alternating tightening approach with
single 3.8cm-wide RMT should be applicable to other the paired tourniquets. Field use of a pair of tourniquets
nonelastic strap-based tourniquets of this width. Specifi- would be expected to occur when a single tourniquet
cally, it should be true for the windlass tightened Com- was ineffective and, therefore, would involve the ad-
4
bat Application Tourniquet (Composite Resources, Inc., dition and tightening of a proximal tourniquet after a
combattourniquet.com) and Special Operations Forces distal tourniquet had already been tightened.
®
Tactical Tourniquet-Wide (Tactical Medical Solutions
Inc., www.tacmedsolutions.com). However, the trans- Additional important study differences from field condi-
lation of occluding at lower pressures to finishing the tions are that each limb was supported and relaxed dur-
tourniquet applications with lower pressures (Comple- ing tourniquet application with no reason for movement,
tion Pressures) is likely to be more variable with either muscle tension changes, or blood pressure changes.
windlass tightened tourniquet. This is because neither Combined with the short application duration, these
windlass tourniquet allows the same consistency and factors should optimize the maintenance of occlusion as
resolution of discrete tightening increments as are pres- compared to what might be encountered in field use.
ent with the RMTs (2 or 2.5 teeth/cm).
A strength of this study is the use of human subjects
With the self-securing RMTs, the user can choose how rather than tourniquet mannequins. An additional
many teeth beyond occlusion the pawl is advanced be- strength is the use of each tourniquet on each recipient,
fore stopping. The pressures applied to limbs by non- which factors out inter-recipient variations in systolic
elastic strap-based tourniquets decrease significantly in blood pressure and limb circumferences.
just minutes (M.R.P. Rometti et al., unpublished data,
August 2015) ; therefore, the RMT pawl should be Conclusions
5,8
advanced at least one-tooth beyond reaching occlusion.
The more teeth the pawl is advanced, the greater the pres- Side-by-side tourniquets achieve occlusion at lower pres-
sure gain. The possible occlusion maintaining aspects of sures than single tourniquets. This supports the use rec-
greater pressure gain are attractive, but increasing the ommendation to add a second tourniquet immediately
Completion Pressure increases the risk of pressure re- adjacent to the first should the first fail to achieve occlu-
lated neurologic consequences and increases the rate of sion. Additionally, pressure decreases under tourniquets
4
pressure declines under the tourniquet (M.R.P. Rometti over time; so both single and paired tourniquet applica-
et al., unpublished data, August 2015). Just as a user tions require reassessments for continued effectiveness.
must decide which secure point past occlusion should be
used with a windlass tourniquet, the user will need to de- Disclosures
cide how many teeth past occlusion to advance the pawl.
The field use of any nonelastic strap-based tourniquet None of the authors have any financial relationships rel-
needs to include occlusion reassessments because tour- evant to this article to disclose, and there was no outside
niquet occlusion to completion pressure gain is variable; funding.

34 Journal of Special Operations Medicine Volume 16, Edition 2/Summer 2016