Page 53 - Journal of Special Operations Medicine - Winter 2014

Figure 3 Dilated right femoral artery prior to injury. of the femoral artery was made followed by insertion of
a 5.5mm vascular punch into the incision to create an
ateriotomy wound in the vessel. Once the wound was
inflicted, the subject was allowed to bleed, unimpeded,
for 45 seconds before treatment was applied. All blood
was collected for the first 30 seconds of free bleeding and
recorded to calculate a blood loss per minute rate to en-
sure no statistical difference between injuries and groups.
The remaining 15 seconds of free bleeding was used to
fill the wound cavity. Any excess blood not remaining in
the wound cavity was collected and used to calculated
additional blood loss after the 30-second bleed.

After creation of the injury and 45 seconds of hemor-
rhage, the randomized predetermined dressing was
with a 20-gauge catheter for infusion of resuscitative handed to and applied by the applicator (Figures 4 and
fluid. Continuous temperature monitoring was achieved 5). Application time and blood loss during application
via placement of an indwelling rectal probe, and an elec- was recorded. After application, direct pressure was
tric table warmer and blankets maintained a core body applied for 3 minutes. On release of compression, a
temperature of 36°C to 38°C. 500mL bolus of Hextend (Hospira Inc.; http://www
®
.hospira.com/) was infused via rapid-infuser pressure
After preparation of the animal, baseline vital signs bag and maintenance fluids were given at a rate of 2mL/
were recorded every 10 minutes before proceeding with kg/hr. Vital signs (MAP, HR, temperature, and oxygen
the creation of the groin injury. During this period, anes- saturation level) were recorded prior to injury, at time
thesia was titrated to adequate surgical pain threshold, of dressing application, after the 3-minute compressive
as determined by a motor response to hoof and jaw tone
stimulation. Figure 4 Combat Gauze application.

Subjects were placed in dorsal recumbency. A complex
injury to the right femoral artery was then created to
produce uncontrolled hemorrhage, as previously de-
scribed by Keirabati et al. (Figure 3). A No. 10 blade
16
scalpel was used to create an oblique superficial skin
incision perpendicular to the right inguinal crease, 10cm
long, at a inferiolateral angle from the inferiormost right
nipple. Subsequently, gentle, blunt dissection exposed
the adductor fascial layers. This plane was then followed
cranially toward the inguinal canal, until faint direct vi-
sualization of the femoral vascular bundle was achieved.
On visualization, the belly of the adductor muscle was
removed and a minimum of 3cm of femoral artery was
exposed. A fasciotomy was performed on the right fem- Figure 5 NuStat application.
oral artery prior to a 2% lidocaine bath for a minimum
of 2 minutes to achieve a diameter of 5mm or greater.
Atraumatic vessel loops were applied proximal and dis-
tal to the exposed section of femoral artery to ensure
vascular control during creation of injury. Skin incision
length, vessel exposure length, vessel predilation and
postdilation diameter, mean arterial pressure (MAP),
temperature, heart rate (HR), and oxygen saturation lev-
els were recorded prior to injury to ensure all metrics
were within study parameters. Cavity volume was mea-
sured using displacement weight of saline (1mL equals
1g of saline). When subjects met the appropriate criteria,
a hemorrhagic injury was created in the following man-
ner: Using a No. 11 blade, a direct 3mm to 4mm incision

Evaluation of NuStat Compared With Combat Gauze in Porcine Model 43