Use of a novel abdominal aortic tourniquet to reduce or eliminate flow in the common femoral artery in human subjects.

BACKGROUND: Penetrating injuries of proximal femoral and iliac vessels are a common cause of death on the battlefield. Previous studies have shown that by applying 80 lb to 140 lb of pressure externally over the distal abdominal aorta, flow can be ceased in the common femoral artery (CFA). It has also been demonstrated that in a porcine model, an externally applied pneumatic abdominal aortic tourniquet (AAT) can occlude the aorta and inferior vena cava for 60 minutes without bowel injury or significant potassium elevations.The objectives of this study were (1) determine if AAT use in humans results in flow cessation in the CFA, (2) measure the pressure required to cease flow in the CFA, and (3) measure discomfort associated with application of the AAT. METHODS: Pulse wave Doppler measurements were taken in supine volunteers at the right CFA. The AAT was placed just above the iliac crests over the anterior abdomen. The AAT was inflated using a hand pump with an integrated manometer. Measurements were taken every 30 mm Hg. Discomfort was measured using a 10-point pain scale. RESULTS: In all subjects, flow was reduced in the CFA. Flow ceased in seven of nine subjects at a median pressure of 180 mm Hg (150-230 mm Hg). Median discomfort at ceasing of flow was 7 (3-10), returning to 0 after device removal. CONCLUSION: The AAT device was effective at reducing flow in the CFA and ceased flow in most of the subjects. Application of the device was associated with discomfort varying from moderate to severe and resolving with device removal.

Comparison of two packable hemostatic Gauze dressings in a porcine hemorrhage model.

BACKGROUND: Uncontrolled hemorrhage remains the primary cause of preventable battlefield mortality and a significant cause of domestic civilian mortality. Rapid hemorrhage control is crucial for survival. ChitoGauze and Combat Gauze are commercially available products marketed for rapid hemorrhage control. These products were selected because they are packable gauze that work via differing mechanisms of action (tissue adhesion versus procoagulant). OBJECTIVE: To compare the effectiveness of ChitoGauze and Combat Gauze in controlling arterial hemorrhage in a swine model. METHODS: Fourteen swine were studied. Following inguinal dissection and after achieving minimum hemodynamic parameters (mean arterial pressure [MAP] ≥ 70 mmHg), a femoral arterial injury was created using a 6-mm vascular punch. Free bleeding was allowed for 45 seconds, and then the wound was packed alternatively with ChitoGauze or Combat Gauze. Direct pressure was applied to the wound for 2 minutes, followed by a three-hour monitoring period. Resuscitation fluids were administered to maintain an MAP of ≥ 65 mmHg. Time to hemostasis, hemodynamic parameters, total blood loss, and amount of resuscitation fluid were recorded every 15 minutes. Data were analyzed using the Wilcoxon rank sum test. Histologic sections of the vessels were examined using regular and polarized light. RESULTS: No statistically significant differences were found between the groups regarding any measured end point. Data trends, however, favor ChitoGauze over Combat Gauze for time to hemostasis, fluid requirements, and blood loss. There was no evidence of retained foreign material on histologic analysis. CONCLUSION: ChitoGauze and Combat Gauze appear to be equally efficacious in their hemostatic properties, as demonstrated in a porcine hemorrhage model.