Efficacy of New Zeolite-Based Hemostatic Gauze in a Gunshot Model of Junctional Femoral Artery Hemorrhage in Swine

BACKGROUND

This work sought to (1) establish a reliable gunshot model of junctional femoral artery rupture in swine that accurately simulates field rescue conditions and (2) use the gunshot model to compare the efficacy and ease of application of zeolite nanometer hemostatic gauze with other hemostatic materials.

METHODS

Thirty-six healthy landrace swine (body weight 50 ± 5 kg) were randomly divided into three groups which were treated with Combat Gauze (CG), FeiChuang hemostatic gauze (FG), or standard medical gauze (SG). A gunshot model of femoral artery hemorrhage in landrace swine was used with portable ultrasound to accurately position the wound. After the shooting, when mean arterial pressure of swine decreased by at least 30% for 10 s, wounds were pressed with standard packing (39 g) of gauze materials for 3 min to stop bleeding, then bandaged with pressure. Blood samples were taken 15 min before injury, then 10 min, 30 min, and 60 min after injury to determine hemodynamic, coagulation, and arterial blood gas indexes. Wound temperatures were taken at 5 min, 10 min, 30 min, and 60 min after injury, and survival times were recorded. The volume of blood loss and survival time were used to evaluate hemostatic effect, whereas the fill time, wound temperature, and physiological indexes were used to evaluate the safety and operation of the product.

RESULTS

The CG (11.15 ± 3.09 mL/kg) and FG (12.19 ± 3.5 mL/kg) groups had significantly less blood loss than the SG group (16.8 ± 5.14 mL/kg) (P = 0.04; P = 0.039, respectively). After gauze packing, bleeding in CG (5.85 ± 1.17 mL/kg) and FG (5.37 ± 0.93 mL/kg) groups remained significantly lower than that of the SG group (6.93 ± 1.03 mL/kg) (P = 0.011; P = 0.003, respectively). Wound temperature rose with time for all groups (P < 0.001). The wound temperatures in the FG group and the CG group were significantly higher than that of the SG group (P = 004 and 0.009, respectively). Survival rates and times were not significantly different among the three groups, although the FG group had the longest average survival time (standard deviation [SD] 204.8 s), compared with the SG group (SD 177.8 s) and CG (SD 187.5 s) groups. No significant differences in hemodynamics, blood gas, and coagulation were observed among the three groups.

CONCLUSIONS

The gunshot model of junctional femoral arterial hemorrhage guided by ultrasound had high accuracy for femoral arterial rupture by bullet wound and provided consistent and reproducible field-simulation conditions for comparison of hemostatic materials. FeiChuang zeolite hemostatic gauze effectively controlled bleeding as well as combat gauze, without excessive heat as found in other zeolite-based products. However, improvements to application technique, such as a packing device, are needed to improve operating time.

Hydrophobically modified chitosan gauze: a novel topical hemostat

BACKGROUND

Currently, the standard of care for treating severe hemorrhage in a military setting is Combat Gauze (CG). Previous work has shown that hydrophobically modified chitosan (hm-C) has significant hemostatic capability relative to its native chitosan counterpart. This work aims to evaluate gauze coated in hm-C relative to CG as well as ChitoGauze (ChG) in a lethal in vivo hemorrhage model.

METHODS

Twelve Yorkshire swine were randomized to receive either hm-C gauze (n = 4), ChG (n = 4), or CG (n = 4). A standard hemorrhage model was used in which animals underwent a splenectomy before a 6-mm punch arterial puncture of the femoral artery. Thirty seconds of free bleeding was allowed before dressings were applied and compressed for 3 min. Baseline mean arterial pressure was preserved via fluid resuscitation. Experiments were conducted for 3 h after which any surviving animal was euthanized.

RESULTS

hm-C gauze was found to be at least equivalent to both CG and ChG in terms of overall survival (100% versus 75%), number of dressing used (6 versus 7), and duration of hemostasis (3 h versus 2.25 h). Total post-treatment blood loss was lower in the hm-C gauze treatment group (4.7 mL/kg) when compared to CG (13.4 mL/kg) and ChG (12.1 mL/kg) groups.

CONCLUSIONS

hm-C gauze outperformed both CG and ChG in a lethal hemorrhage model but without statistical significance for key endpoints. Future comparison of hm-C gauze to CG and ChG will be performed on a hypothermic, coagulopathic model that should allow for outcome significance to be differentiated under small treatment groups.