Page 56 - Journal of Special Operations Medicine - Winter 2014

Table 3 Secondary End Points*
NuStat (n = 8) Combat Gauze (n = 7)
Secondary Metrics Mean SD Median Mean SD Median p Values
Additional blood loss during 189.7 107.3 166.3 225.6 171.2 244.3 0.4348**
application, mL
Additional blood loss during 60-min 0 0 0 1218.3 807.7 0 0.0385** ,†
observation, mL
Application time, sec 31 7 32 38 2 40 0.0093** ,†
Blood absorbed by dressing, mL 137.6 29.2 137 89.7 31.6 90.2 0.1276**
Resuscitation fluids used to maintain 174 214 100 842 1291 425 0.0042** ,†
MAP, mL
Hemostatic with ROM testing, Y/N Y=5 N=3 — Y=1 N=6 — 0.1189 §
Notes: MAP, mean arterial pressure; N, no; ROM, range of motion; SD, standard deviation; Y, yes.
*Secondary end points were chosen to reflect stability of the patient as well as resources needed to stabilize the patient for a 60-min observation
window.
**Two-tailed paired t test.
†Statistically significant (p < .05).
§Fisher exact test.

equivalence between NS and CG, statistical superiority the applicator. Although the surgeon was blinded to
of NS at T0 was proven. This study provides data to the dressing for which they were making the injury, the
demonstrate NS’s superiority at achieving immediate he- applicator was not blinded, due to textural and size
mostasis in traumatic hemorrhage. Likely due to initial differences between products. The applicator was not
hemostasis, additional blood loss and fluids needed to informed which dressing they would apply and had no
maintain MAP during the 60-minute observation were knowledge of the product until they removed it from
also significantly less. The investigators feel this is also, the dressing tray after the bleed was complete. However,
in part, due to the ability to rapidly apply the NS versus once the applicator picked up the dressing they were
CG. There was a 7-second average differential between able to discern a difference. A blinded study would be
the two groups in application time. At the rate these preferable, but there are practical limitations that make
animals were bleeding, that could equate to between this very difficult due to dissimilarity of dressings.
60mL to 100mL of blood. Given what we know about
CG’s mechanism of action, that relatively small volume
of blood is sufficient to begin washing away the impreg- Conclusions
nated kaolin. It is interesting to note the performance of NS is efficacious for immediate control of life-threat-
the two dressings during ROM testing: NS (yes = 5/no = 3) ening hemorrhage in a well-described and validated,
compared with CG (yes = 1/no = 6). Although the p traumatic, 5.5mm punch arteriotomy porcine model.
value was not significant (p = .1189), it is possible that NS required less resuscitation fluid and allowed less
with a larger sample size, NS might show superiority. blood loss after dressing application over the course
Given the environments these dressings are applied in of the 60-minute observation window. NS had trends
and the need to move and transport many of the recipi- toward superiority over CG in all additional primary
ents, this is a significant end point to analyze. and secondary metrics outcomes; however, these trends
failed to reach statistical significance. In this study, NS
showed superiority or equivalence to CG for all metrics
Limitations and Future Research
evaluated.
This study was limited by the small sample size. Using
published data of CG and anecdotally obtained data on
NS, a power analysis was performed (G-Power; www.g Disclosures
power.hhu.de/). The power analysis revealed a need for The authors have nothing to disclose.
83 subjects in each group to show superiority for all
three primary metrics. This is both logistically and fi-
nancially unfeasible. Due to these limitations, our study References
was powered to show equivalence between groups. In 1. Kelly JF, Ritenour AE, McLaughlin DF, et al. Injury sever-
the future, it would be beneficial to conduct a study with ity and causes of death from Operation Iraqi Freedom and
a larger sample size to achieve significance for all pri- Operation Enduring Freedom: 2003–2004 versus 2006. J
mary outcomes. A second major limitation was blinding Trauma. 2008;64:S21–S26; discussion S26–27.

46 Journal of Special Operations Medicine Volume 14, Edition 4/Winter 2014