Page 38 - JSOM Fall 2019

mechanisms of action are different and complementary. When that plain gauze is NOT a recommended treatment option per
considering the clinical endpoints of mortality and total blood TCCC guidelines.
loss, the iTClamp is an effective device. Table 1 compares the
weight, volume, and cost of different hemorrhage control de- The iTClamp has also demonstrated effectiveness in cases
vices and adjuncts. where patients were known to be coagulopathic prior to
trauma. 9,43 Given the shorter application time, the ability to
TABLE 1 Product Comparisons Across Different Classes of combine with existing hemostatic agents, and comparable
Hemorrhage Control Devices survival to hemostatic dressings, the iTClamp can be seen as
Cost, Volume (packaged), Weight, an alternative to prolonged manual compression for wounds
Product US$ in 3 oz where the skin edges can be approximated.
C-A-T 32 23 2.7
Kerlix 2 36 2.2 3. What is the evidence for the effectiveness of the iTClamp?
Combat Gauze 40 15 0.8 Animal and Cadaver Studies
XStat 30 235 92 3.5 The first published controlled trial of iTClamp use involv-
iTClamp 35 6 1.3 ing 20 animals with a lethal femoral junctional injury model
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was published in 2013. Although the authors did not use
To compare topical hemostatic dressings, a DoD consensus the standard USAISR model, it was a 100% lethal model in
group accepted a standardized lethal swine model for evalua- which 5 cm of femoral artery and vein were excised just be-
tion, referred to as the USAISR hemorrhage model. 53,54 This al- low the inguinal ligament and overlying muscles were excised.
lows appropriate comparisons between gauze-based dressings, There were five animals in each of the four study arms: con-
such as Combat Gauze, Celox Gauze, and ChitoGauze, which trol (no treatment); iTClamp placement after 10 seconds of
12
have similar application procedures. The iTClamp has con- bleeding (high pressure bleed); delayed iTClamp placement
sistently been shown to be effective in controlling hemorrhage, after 3 minutes of bleeding (low pressure, animal in shock);
either alone or in combination with packed gauze and hemo- and standard gauze packing after 3 minutes of bleeding (an
static agents in multiple independent studies, 6,7,41,42,44–47,49,50,55,56 additional 3 minutes of direct pressure were also added to this
using the standard USAIR hemorrhage control model. arm). There was no hemostatic dressing arm in this study. The
study period was 180 minutes. Early and late applications
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St. John et al. evaluated the iTClamp versus hemostatic of the iTClamp resulted in significantly higher survival rates
dressing, plain gauze, and direct pressure in various combina- (p = .003) (Table 2). Blood loss was decreased in the early
tions. In comparison with Combat Gauze and direct pressure, iTClamp (120mL) and late iTClamp (480mL) groups compared
the application of the iTClamp was significantly faster and did to standard gauze packing (680mL) and control (1060mL)
not require 3 minutes of direct pressure as mandated in TCCC (p < .002). Researchers did not observe breakthrough bleeding
guidelines for hemostatic dressings {hemostatic dressing + seal in the iTClamp groups after initial application.
(125.8 [56.2] seconds), hemostatic dressing + compression
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(223.0 [6.8] seconds)}. The iTClamp significantly improved A 2014 study involved three fresh thawed cadavers that
both survival and blood loss in both packed and unpacked were declotted and reperfused with water using a peristaltic
wounds versus controls. Survival was similar between gauze pump to replicate human blood flow. A complex elliptical
+ compression (87.5%), hemostatic dressing + compression wound was excised over compressible bleeding areas in the
(62.5%), and gauze + seal (100%) (p > .05). Combining the neck, arm, groin, and leg of two cadavers. A 6mm arteriotomy
iTClamp and wound packing demonstrated improved survival was made in the common carotid, common femoral, and su-
and considerably reduced treatment times. perficial femoral arteries. The brachial artery was completely
transected. In the third cadaver, simple 4.4cm scalp incisions
The authors did not evaluate the iTClamp with a hemostatic were made through all tissue layers to the bone over the left
dressing because the dressing manufacturer’s instructions state frontal, left temporal, right frontal, and midline frontal areas.
that the hemostatic dressing is to be compressed for at least Ten measurements of fluid loss from each compressible region
three minutes after application and the iTClamp does not re- were made in both static (cadaver not moving) and dynamic
quire compression. The authors did not want to add “off-la- conditions (body regions were flexed and extended over the
bel” use of the hemostatic dressing. It is important to note area of injury to replicate patient movement). There were

TABLE 2 Comparison of Survival for Different Methods of Hemorrhage Control
Negative Packing + Packing + HS-Packing +
Control Seal Packing Seal Compression Compression Compression
Mean (SD) (n = 5) (n = 8) (n = 8) (n = 8) (n = 5) (n = 8) (n = 8)
Weight, kg 29.6 (2.3) 30.2 (2.8) 28.8 (2.3) 28.6 (2.0) 27.6 (1.2) 29.3 (4.6) 29.8 (1.3)
Baseline MAP, mmHg 73.0 (7.9) 79.6 (5.8) 76.6 (5.7) 78.6 (11.2) 74.7 (5.0) 78.3 (8.5) 74.1 (5.2)
MAP at 1 min of free 41.0 (7.5) 52.7 (12.5) 48.5 (14.1) 54.3 (16.1) 58.0 (4.3) 56.5 (8.5) 56.3 (10.6)
bleeding, mmHg
36 180 152 180 42 180 180
†
Survival time, min
(30–53) (171–180) (92.5–169.5) (180–180) (37–43) (180–180) (61–180)
Survival, % * 0 62.5 12.5 100 0 87.5 62.5
*Significantly heterogeneous variable across intervention groups by Pearson χ test (p < .05).
2
† Survival time reported as median (interquartile range).
Adapted from St John AE, et al. Effects of rapid wound sealing on survival and blood loss in a swine model of lethal junctional arterial hemor-
rhage. J Trauma Acute Care Surg. 2015;79(2):256–262.
36 | JSOM Volume 19, Edition 3 / Fall 2019