Application of a zeolite hemostatic agent achieves 100% survival in a lethal model of complex groin injury in Swine.

BACKGROUND: Techniques for better hemorrhage control after injury could change outcome. We have previously shown that a zeolite mineral hemostatic agent (ZH) can control aggressive bleeding through adsorption of water, which is an exothermic process. Increasing the residual moisture content (RM) of ZH can theoretically decrease heat generation, but its effect on the hemostatic properties is unknown. We tested ZH with increasing RM against controls and other hemostatic agents in a swine model of battlefield injury. METHODS: A complex groin injury was created in 72 swine (37 +/- 0.8 kg). This included semitransection of the proximal thigh and complete division of the femoral artery and vein. After 3 minutes, the animals were randomized to 1 of 10 groups: group 1, no dressing (ND); group 2, standard dressing (SD); group 3, SD + 3.5 oz ZH with 1% RM (1% ZH); group 4, SD + 3.5 oz ZH with 4% RM (4% ZH); group 5, SD + 2 oz ZH with 1% RM (1% ZH 2oz); group 6, SD + 3.5 oz ZH with 8% RM (8% ZH); group 7, SD + chitosan-based hemostat, HemCon (HC); group 8, SD + 3.5 oz nonzeolite mineral hemostat, Quick Relief (NZH); group 9, SD + bovine clotting factors-based hemostat, Fast Act (FA); and group 10, SD + 30 g of starch-based hemostat, TraumaDex (TDex). Resuscitation (500 mL of Hespan over 30 minutes) was started 15 minutes after injury and hemodynamic monitoring was performed for 180 minutes. Primary endpoints were survival for 180 minutes and blood loss. In addition, maximum wound temperatures were recorded, and histologic damage to artery, vein, nerve, and muscle was documented. RESULTS: Use of 1% ZH decreased blood loss and reduced mortality to 0% (p < 0.05). Increasing the RM adversely affected efficacy without any significant decrease in wound temperatures. Minimal histologic tissue damage was seen with ZH independent of the percentage of RM. CONCLUSION: The use of zeolite hemostatic agent (1% residual moisture, 3.5 oz) can control hemorrhage and dramatically reduce mortality from a lethal groin wound.

A portable handpump is effective in the evacuation of hemothorax in a swine model of penetrating chest injury.

BACKGROUND: Standard pleural evacuation devices are not practical for use on the battlefield. A small, portable, easy-to-use handpump (HP) that does not require continuous suction for treating hemopneumothorax would offer a major logistical advantage. In addition, using endotracheal tubes instead of regular pleural tubes would help minimize supplies carried on the battlefield. A swine model of penetrating chest injury was designed to test this concept. Our hypothesis was that an HP would be as effective as the standard of care for the evacuation of a large hemopneumothorax. METHODS: A 2-cm lung laceration was created in 18 Yorkshire swine (35-51 kg) under inhaled anesthesia and 1.4 L of blood was infused into the pleural space (200 mL every 15 minutes). Fluid resuscitation (2,000 mL of 0.9% saline) was started 15 minutes after injury, and animals were randomized into one of three groups: group 1, 36-Fr Argyle pleural tube and Pleur-Evac chest drainage unit with 20-cm H2O suction (control); group 2, 36-Fr pleural tube attached to the HP; and group 3, a No. 8 endotracheal tube in the pleural space attached to the HP. After 120 minutes, a thoracotomy was performed to determine the amount of residual blood in the pleural space. RESULTS: Effectiveness of the three methods as a percentage of total blood (evacuated and retained) removed was measured over 2 hours. The handpump (group 2) performed better than the standard of care (group 1) at numerous time points and evacuated significantly (p < 0.05) more blood at the end of the experiment. CONCLUSION: Using the handpump with a pleural tube was more effective than the standard of care in treating traumatic hemothorax. The use of an endotracheal instead of a conventional pleural tube had no adverse impact on efficacy of the pump in evacuating blood from the chest cavity.