Page 37 - Journal of Special Operations Medicine - Winter 2016

Table 2 Pressure-Loss Curve Information
Time to Time to
<5mmHg <1mmHg
Tourniquet Application: Slow from from
Target Completion-Pressure, Plateau Fast Half- Half-Life Goodness- Plateau Plateau
Gel or Limb, Tourniquet (mmHg) Life (sec) (sec) % Fast of-Fit R 2 (min:sec) (min:sec)
262mmHg
10% ballistic gel
C-A-T −48 26.6 315.9 23.8 0.92 15:09 27:22
RMT −43 13.2 376.1 20.8 1.0 * 17:22 31:55
Blood pressure cuff −47 14.4 193.3 38.1 0.98 8:09 15:38
SWATT −22 14.6 296.4 20.7 0.90 9:00 20:28
20% ballistic gel
C-A-T −37 14.6 224.9 31.5 0.97 8:47 17:29
RMT −32 20.2 287.4 17.6 0.85 11:34 22:41
Blood pressure cuff −38 14.6 213.1 41.1 0.70 7:45 16:00
SWATT — † 44.2 — † — † 0.89 — ‡ — ‡
Human thigh
C-A-T −32 7.3 106.1 55.4 0.49 2:40 6:46
RMT −38 8.4 78.9 42.3 0.87 2:48 5:51
Blood pressure cuff −30 8.9 104.8 37.6 0.99 3:19 7:22
SWATT −11 0.4 281.7 5.1 0.87 5:09 16:07
Human arm
C-A-T −39 4.2 84.5 31.6 0.48 3:24 6:40
RMT −66 4.7 78.7 19.6 0.86 4:29 7:32
SWATT −11 — † 169.0 — † 0.68 3:15 5:06
362mmHg
10% ballistic gel
C-A-T −64 44.7 308.8 25.2 0.87 16:45 28:42
Blood pressure cuff −55 24.8 218.0 32.7 0.96 10:28 18:54
SWATT −42 36.9 491.9 17.9 0.92 22:45 41:47
20% ballistic gel
C-A-T −50 19.1 309.1 21.5 0.98 15:16 27:14
RMT −41 20.9 395.2 14.7 0.82 18:32 33:50
Blood pressure cuff −49 12.3 190.0 36.3 0.97 8:21 15:42
SWATT −34 42.3 608.8 11.5 0.99 26:10 49:45
Human thigh
C-A-T −68 4.9 91.1 38.4 0.71 4:40 8:11
RMT −62 10.3 116.3 31.6 0.98 6:00 10:31
Blood pressure cuff −34 7.1 131.2 28.3 0.90 4:59 10:04
SWATT −13 0.7 291.4 4.0 0.78 6:24 17:41
Human arm
C-A-T −50 5.0 96.2 41.4 0.84 4:07 7:50
RMT −87 7.9 124.2 30.8 0.77 7:26 12:14
—, no single value or no value (see footnotes † and ‡); C-A-T, Combat Application Tourniquet; RMT, Ratcheting Medical Tourniquet;
SWATT, Stretch Wrap And Tuck-Tourniquet.
*RMT on 10% ballistic gel only had one trial.
†No single value because many combinations of parameter values led to equally good curve fits.
‡No value because there was no single plateau value.

the ballistic gels and thigh rebounded to some extent indenting strap bunches created by advancing the ratchet-
immediately and completely by 30 minutes. ing buckle (see Table 1 for numbers of teeth advanced).

Tourniquet Application Consequences Ballistic gel tearing with the C-A-T was also worse on
after 300 and 600 Seconds the 10% gel and at the higher completion-pressure than
No ballistic gel tearing occurred with the blood pressure on the 20% gel or at the lower completion-pressure.
cuff. One SWATT application on the 10% gel had tearing. The C-A-T-associated gel tearing occurred at the base
Gel tearing occurred with the C-A-T and RMT. The worst plate and friction buckle edges.
tearing occurred with the RMT on the 10% gel at the
higher completion-pressure and was sufficient to preclude No skin tearing occurred, and at no point was sufficient
repeating that application combination. The RMT- discomfort induced for the recipient to stop an applica-
associated gel tearing occurred at the edges of the deeply tion or have a tourniquet removed early. On the thigh,

Tourniquet Pressure Loss 21