Page 90 - JSOM Winter 2022

-Combat-Gauze.htm) and XSTAT (RevMedx, https://www. (0.025mg/kg intramuscularly [IM]) for analgesia. Then, injec-
revmedx.com/xstat/). We hypothesized that in a swine model tion of tiletaminezolazepam (Telazol 4mg/kg IM) was used
of severe junctional hemorrhage, a multiagent strategy using for induction and 5% isoflurane in oxygen via facemask used
the iTClamp in conjunction with XSTAT or Combat Gauze for initial anesthesia. The swine were intubated and ventilated
would be faster to apply and as effective in hemorrhage con- with 100% oxygen. The tidal volume and ventilation rate were
trol as compared to the traditional method of Combat Gauze adjusted to maintain an end-tidal partial pressure of carbon
packing with pressure dressing application. dioxide (Etco ) of 40 ± 2mmHg. Anesthesia was maintained
2
with 2% isoflurane added to 100% oxygen gas via respirator.
Lactated Ringer’s (LR) was administered at 5mL/kg/h through
Materials and Methods
an ear vein. Blood pressure (systolic and diastolic), mean arte-
rial pressure (MAP), heart rate (HR), and respiratory rate (RR)
Materials
iTClamp is a 6 cm × 4.5 cm × 3.5 cm hinged, plastic self- were monitored. Baseline vitals were assessed every 5 minutes
locking wound closure device with two rows of stainless-steel for 15 minutes, then averaged for statistical analysis.
teeth of suture needle construction designed to grab and pull
together then lock into place opposing tissue edges of a wound Surgical Procedure
(Figure 1). After anesthetizing subjects, a 4-cm incision was made through
the skin of the medial thigh. The femoral artery was then sur-
gically isolated. Hemorrhage was induced with a 6-mm vas-
FIGURE 1 iTClamp. cular punch to create an arteriotomy. Following unrestricted
bleeding for 45 seconds, the site was treated with a randomly
assigned hemostatic treatment regimen, described in Table 1.
All treatments were applied by a single physician trained in the
use of all study materials.

TABLE 1 Treatment Groups and Descriptions
Abbreviation n Treatment Description
CG 7 Combat Gauze (CG) packed into the wound
and manual pressure applied for 3 min,
following by application of a pressure dressing
XSTAT 30 (US Patent 8,828,050 B2) is a syringe containing IT 9 The wound was sealed with the iTClamp (IT)
ninety-three 1-mm tablet-size chitosan-coated sponges designed alone, per manufacturer’s recommendations
to rapidly expand to create a tamponade effect when injected IT+CG 8 Combat Gauze packed into the wound, then
deep into a wound. the wound was immediately closed with an
iTClamp
Combat Gauze is a 7.6 cm × 3.7 m z-folded nonwoven gauze IT+XS 8 XSTAT injected into the wound, then the wound
coated in kaolin, a naturally occurring inorganic mineral that was immediately closed with an iTClamp
promotes clotting by activating factor XII of the coagulation
cascade. 10 Animal Monitoring and Assessment
After treatment application, the injury was observed for 30
The Emergency Trauma Dressing (North American Rescue, seconds and assessed for initial hemostasis. If continued bleed-
https://www.narescue.com/emergency-trauma-dressing-etd. ing was noted, indicating a failure to seal, the investigator
html) is a 6-in elastic wrap equipped with a sterile nonadher- removed and reapplied the iTClamp. This was followed by
ent pad intended to absorb blood and apply direct pressure to another 30 seconds assessment for hemostasis, repeating if
a wound. necessary. A bolus of Hextend (500mL) was administered 5
minutes after injury to simulate standard battlefield treatment
Swine Model of Extremity Arterial Hemorrhage practices. Heart rate, blood pressure, and respiratory rate were
To evaluate the efficacy of the hemostatic agents, we used a recorded every 5 minutes beginning after the completion of
swine arterial injury model (6-mm arteriotomy), modified to femoral artery isolation. External blood loss during the free
accommodate the different anatomic sites and devices. 6,11 This bleed and treatment application process was collected via a
study was approved by the Institutional Animal Care and Use suction device and preweighted gauze and recorded.
Committee and was conducted in compliance with the Ani-
mal Welfare Act and Regulations and per the principles of the Subjects were monitored up to 1 hour postinjury or until early
“Guide for the Care and Use of Laboratory Animals” (Institute endpoint criteria were met, defined as by the loss of the normal
of Laboratory Animals Resources, National Research Council, sinus electrocardiographic waveform and/or Etco of 0mmHg
2
National Academies Press, 1996). Animals were maintained for longer than 10 minutes. No additional resuscitative mea-
in a facility accredited by the Association for Assessment and sures were taken. After 1 hour, the injured leg of the surviving
Accreditation of Laboratory Animal Care (AAALAC). Inter- subjects was flexed and stretched five times, mimicking patient
national. Subjects were 32 female Yorkshire cross-bred swine movement to test the stability of the hemostasis. At necropsy,
weighing a mean (SD) of 41.2 kg (4.9), purchased from Smith- any hemostatic agents, free blood or clot within the wounds
field Farms (Turlock, VA). were evacuated and measured.

Presurgical Preparation Design and Data Analysis
Swine were fasted for 12 hours with water provided ad libi- In this between-subjects design, continuous variables (baseline
tum before surgery. Animals were premedicated with ketamine values and time to application) were assessed using analysis

88 | JSOM Volume 22, Edition 4 / Winter 2022