Page 58 - Journal of Special Operations Medicine - Fall 2014

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10
Studies by Floyd et al. (in 2012), Kheirabadi et al. They reported that the histological samples of the ves-
(in 2010), and Floyd et al. (in 2012) showed evidence sels from both groups demonstrated organized clot and
68
of local clot formation and occlusion in vessels treated that there was no evidence of kaolin or chitosan in the
with Combat Gauze with CTA of vessels. It is doubtful clot or inside the injured vessel.

that these findings by Floyd et al. (2012) and Kheirabadi
et al. (2010) convey a risk of thromboemboli events Rall et al.’s results support the low risk of chitosan-based
6
with the use of Combat Gauze because these studies did dressings concerns based on their safety evaluation. They
not report blood clot propagation intravascularly. 10,48 reported no significant histological damage to any of
Furthermore, in support of this low risk of complica- the tissues examined among all gauze groups. There was
tions, Combat Gauze has been the primary hemostatic some endothelial cell loss near the injury site and minor
dressing fielded from April 2008 to the present for all necrosis of the muscle in all gauze groups. They reported
US Operational Forces and NATO militaries. There has some foreign material in all tissues in the Celox Gauze
been no report of complications with Combat Gauze. group, which was reported most likely to be chitosan
69
Additionally, Ran et al. (in 2010) did not report any residues. There was no vessel thrombosis observed in
complications or side effects with 14 uses (of a total of any of the groups and no material from any hemostatic
56 hemostatic interventions in 35 cases) in Israeli De- gauze was found inside the vessels.
fense Force personnel. Combat Gauze was applied to
injuries to the head, neck, axilla, buttocks, abdomen,
back, and pelvis in 10 cases and to extremities in four Long-Term External and
cases. In 13 cases (93%), injuries were caused by blast Internal Hemostatic Dressing Application
or gunshot mechanisms. The success rate was reported
as 79% (11 of 14). No complications or thromboem- External Application
bolic events were reported. These authors report that The majority of animal studies evaluating efficacy of he-
the clinical field use of Combat Gauze by advanced pro- mostatic agents and dressings have assessed survival be-
viders suggests that it is an effective and safe product. tween 1 to 4 hours’ duration from the time of injury. This
has been sufficient duration for the majority of battlefield
In comparison, Celox Gauze, HemCon ChitoGauze, medical care focused on air or ground evacuation to sur-
and other chitosan-based dressings contain much larger gical teams within a goal of 60 minutes from the point
particles of a bioabsorbable chitosan that stick together of injury. This maximum 4-hour study duration is most
when they get wet. Chitosan gauze manual applica- likely not sufficient for examining hemostatic dressing ef-
tion methods are identical to Combat Gauze but very ficacy and animal survival for prolonged care and delayed
different from WoundStat clay granules. Chitosan pro- evacuation trauma scenarios between 24 and 72 hours.
duces a localized hemostatic effect only over the dam- To date, there are only a few clinical cases that have re-
aged blood vessels. As noted in Table 4, multiple combat ported hemostatic dressings (Celox Gauze) applied on 4
casualties had Celox Gauze successfully applied, and patients continuously between 12 and 48 hours. 26,28
it stopped bleeding to all wounds caused by IED blast
28
fragments and GSWs to the lower extremities, pelvic Tan et al. reported IED wounds and GSWs to seven
region, neck, ear, and nose without complications. Con- casualties. Two of seven battlefield casualties had
sequently, there is low risk of complication and embolic long-term Celox Gauze application. The first patient
vessel migration with chitosan-based dressings. (No. 5) had several GSWs to an arm, leg, and buttock.
Bleeding was most persistent from a large buttock
Other animal studies have also evaluated the safety of wound. Packing with sterile gauze had an insufficient
hemostatic dressings in short-term use (2–3 hours). 4,6,57,68 hemostatic effect. When Celox Gauze was packed into
57
Watters et al. reported that when standard gauze, the wound, the bleeding stopped. The wound was in-
Combat Gauze, and Celox Gauze dressings were used spected after 12 and 24 hours, and it was reported that
in their femoral wound model, all dressings had simi- there was no further bleeding; and after 24 hours, Ce-
lar findings of mild intimal and medial edema in the lox Gauze was easily removed. The next patient (No.
histological examinations. No inflammation, necrosis, 7) had a grade 3 open femur fracture with a piece of
or deposition of dressing particles in vessel walls was bone protruding through the skin and evidence of
observed. No histological or ultrastructural differences wound infection. Based on previous fracture history
were found among the study dressings. to the same leg, a guillotine above-knee amputation
was made. Postoperatively, a pressure bandage was ap-
4
Schwartz et al. conducted histological analysis as part plied, but after 6 hours, the wound was still bleeding.
of their safety evaluation of femoral artery samples fol- Celox Gauze was then placed on the open wound and
lowing euthanasia of seven swine—three from the Chi- pressure applied for 5 minutes, and again a pressure
toGauze group and four from the Combat Gauze group. bandage was applied. Over the next 12 and 24 hours,

50 Journal of Special Operations Medicine Volume 14, Edition 3/Fall 2014