Page 35 - Journal of Special Operations Medicine - Winter 2014

Figure 3 RMT pressures and CAT pressures for all Table 3 Tourniquet Pressure Losses Over 1 Minute
tourniquets that reached Occlusion. (A) RMT and CAT
pressures at each time point. (B) RMT Occlusion pressures, Pressure 1 Minute 1 Minute
Values
Values
Loss
CAT Occlusion pressures, and the line showing Predicted Tourniquet Location (mmHg) >300mmHg >500mmHg
Occlusion pressures graphed versus limb circumference/
tourniquet width for all tourniquets that reached occlusion. RMT Thighs 40 ± 12 62 5
Unlike the previously obtained CAT Occlusion pressures, the Ladders (n = 64)
RMT Occlusion pressures do appear to have a direct linear RMT Thighs 36 ± 12 40 2
relationship with limb circumference. Straps (n = 48)
RMT Arms
(A) Ladders (n = 64) 29 ± 11 29 0
RMT Arms 24 ± 11 14 0
Straps (n = 48)
Thighs
CAT 49 ± 39 19 2
(n = 32)
Arms
CAT 40 ± 27 17 4
(n = 32)
Notes: p < .0001 for RMT Ladders versus Straps on thighs. p < .0001
for RMT Ladders versus Straps on arms. Values are mean ± SD.
Sources: CAT data from reference 5 is used with permission from
Military Medicine: International Journal of AMSUS; Tourniquets and
Occlusion: The Pressure of Design. Authors: Wall, P; Duevel, D; Has-
san, M; Welander, J; Sahr, S; Buising, C; Mil Med. 2013 May; 178
(B) (5): 578–587.
the 1 Minute following Completion (Table 4). This was
different from the CAT; many CAT applications had a
loss of arterial occlusion within 1 Minute of Completion
(Table 4).

Ease of Application and Release
The Tactical and Mass Casualty RMTs received equiva-
lent ease of application ratings. Both RMT designs and
the CAT were rated Easy to apply (Table 5). Despite
ratcheting buckle size differences, all RMT designs were
Sources: CAT data from reference 5 is used with permission from also generally rated Easy to release: Tactical RMT 56
Military Medicine: International Journal of AMSUS; Tourniquets and of 64 releases, Mass Casualty RMT 56 of 64 releases,
Occlusion: The Pressure of Design. Authors: Wall, P; Duevel, D; Has-
san, M; Welander, J; Sahr, S; Buising, C; Mil Med. 2013 May; 178 and Flexible Mass Casualty RMT 29 of 32 releases.
(5): 578–587. Eighteen of the release ratings were Challenging. The
only Difficult release rating was with a Mass Casualty
Pressure Losses Over Time RMT. Most of the non-Easy release ratings occurred
For all designs, tourniquet pressures decreased a clinically with thigh locations (15 thigh versus 4 arm, p = .0077),
significant amount over the 1 Minute following Comple- and all came from female appliers.
tion. These decreases in pressure between Completion
and 1 Minute are shown in Table 3. Despite these sig- Discomfort
nificant pressure decreases, the majority of RMT thigh The Tactical and Mass Casualty RMTs received equiva-
pressures remained above 300mmHg at 1 Minute. Pres- lent recipient discomfort ratings (Table 6). The discom-
sure decreases on the arm were less than on the thigh, and fort ratings of the RMTs suggested less discomfort than
fewer RMT arm pressures were ever above 300mmHg. previously found with the CAT (Table 6).
RMT pressure decreases were not statistically compared
with CAT pressure decreases because the pressure mea- RMT Tooth Skipping
surement techniques were slightly different. Tooth skipping sometimes occurred when the RMTs
were being tightened via rotation of the pawl of the
Arterial Occlusion at 1 Minute ratcheting buckle. In no instance did tooth skipping
All the tourniquet designs had high rates of reaching prevent reaching Occlusion with any of the RMTs.
arterial occlusion (Table 4). Despite the pressure de- Tooth skipping occurred more frequently with the Old
creases over time, both RMT designs maintained arterial Mass Casualty RMT than with the Old Tactical RMT
occlusion very well on the thigh and the arm throughout (p < .0001). Table 7 shows the results of prospectively

Tourniquet Pressures: Strap Width and Tensioning System Widths 25