Evaluation of a Novel Fibrin Sealant Patch in Hemorrhage Control After Vascular or Hepatic Injury.

INTRODUCTION: Acute hemorrhage remains the leading cause of death in potentially survivable injuries. The use of topical hemostatic agents has increased over the last two decades with the evolution of damage control surgery. By 2008, the military widely adopted Combat Gauze as the hemostatic dressing of choice for compressible hemorrhage. The goal of this study was to compare the performance of a novel fibrin sealant patch to Combat Gauze in two clinically relevant models of hemorrhage. MATERIALS AND METHODS: Yorkshire swine underwent unilateral femoral artery puncture or a grade V liver laceration with timed free bleeding then received either the fibrin patch or Combat Gauze packing with 3 minutes of standardized pressure. Animals were then resuscitated to maintain a mean arterial pressure of 60 mmHg for 4 hours. Hemostasis, blood loss, resuscitation volume, survival, vessel patency, and hematologic parameters were evaluated. RESULTS: Hemostasis was equivalent in both groups after hepatic and vascular injury. Survival was 80% in the fibrin patch vascular injury group and 100% in all other groups. Hematologic parameters were not significantly different between treatment groups. Femoral artery patency was 80% in both groups after vascular injury. With simulated ambulation after vessel injury, 60% of the Combat Gauze group and 80% of the fibrin patch group remained hemostatic (p > 0.05). In simulated re-exploration with packing removal, all animals rebled after hemostatic product removal. CONCLUSION: There was no significant difference in hemostasis between a novel fibrin patch and Combat Gauze after extremity arterial or hepatic injury. This novel fibrin patch may have a clinical advantage over the Combat Gauze, as it can be left in the body, thereby limiting the potential need for reoperation.

What If I Don't Have Blood? Hextend is Superior to 3% Saline in an Experimental Model of Far Forward Resuscitation After Hemorrhage.

INTRODUCTION: Hypertonic crystalloid solutions, colloids, and fresh whole blood (FWB) have all been proposed for prehospital resuscitation after hemorrhage. However, there are no direct comparisons of the efficacy of these different fluids. We compared Hextend, 3% hypertonic saline (HS), and FWB in a porcine model of hemorrhagic shock. MATERIALS AND METHODS: Female swine (n = 5/group) underwent splenectomy and pressure-controlled hemorrhage followed by resuscitation with Hextend, 3% HS, or FWB. They were maintained at a target mean arterial pressure (MAP) for 4 h, holding or infusing fluid as necessary. Sham animals for comparison underwent splenectomy alone. RESULTS: The mean volume required to maintain target MAP was significantly higher for 3% HS (1,016 ±â€Š386 mL) than for Hextend (346 ±â€Š299 mL, P < 0.05). After 4 h of resuscitation, the MAP in the 3% HS group (44 ±â€Š3 mmHg) was significantly lower than shams (56 ±â€Š7 mmHg, P < 0.05). Three percent HS recipients had a significantly worse metabolic acidosis and anemia than shams or FWB recipients, as well as significant increases in serum sodium and chloride. Serum interleukin-6 was significantly elevated in 3% HS and FWB recipients relative to Hextend recipients (105.3 ±â€Š58.6 and 97.2 ±â€Š21 vs. 38.6 ±â€Š27.1 pcg/mL, P < 0.05). CONCLUSIONS: HS performed inferiorly to Hextend as a volume expanding resuscitative fluid after hemorrhage. On the basis of our data, we would recommend the use of Hextend over 3% saline in far forward resuscitation after hemorrhage.

Portable mechanical ventilation with closed-loop control of inspired fraction of oxygen maintains oxygenation in the setting of hemorrhage and lung injury.

BACKGROUND: Closed-loop controllers (CLCs) embedded within portable mechanical ventilators may allow for autonomous weaning. The ability of CLCs to maintain adequate oxygenation in the setting of hemorrhage and lung injury is unknown. We hypothesized that a portable ventilator with a CLC for inspired fraction of oxygen (FIO2) could provide oxygenation in a porcine model of hemorrhage and lung injury. METHODS: Female pigs randomized to the study group (n = 6) underwent a pressure-controlled bleed (mean arterial pressure = 40 mm Hg for 30 minutes). Acute lung injury was induced by saline lung lavage followed by intentional infliction of barotrauma. Sham pigs (n = 6) underwent placement of monitoring devices without hemorrhage or lung injury. All pigs were then placed on a portable ventilator modified with a CLC algorithm, which uses feedback from pulse oximetry (SpO2) and FIO2 trends to adjust FIO2 and maintain a target SpO2 of 94% (2%). The initial FIO2 was set at 0.60. Tidal volume, positive end-expiratory pressure, rate, and inspiratory-to-expiratory ratio were constant unless changes were required clinically. RESULTS: Study pigs had lower mean arterial pressures than shams at all time points except baseline. PaO2/FIO2 ratios were less than 300 and significantly lower than both baseline values and corresponding sham values at all time points. The CLC weaned the FIO2 at a reduced rate in study pigs relative to shams with a final mean FIO2 of 0.54 and 0.29 in study and sham pigs, respectively (p < 0.05). There was a significant divergence in the study and sham FIO2 curves but no significant difference in oxygen saturation or hypoxemia. CONCLUSION: Adequate oxygenation can be maintained in the setting of hemorrhage and lung injury using a portable ventilator embedded with a CLC of FIO2 based on pulse oximetry. These devices may be valuable for providing advanced medical care in resource-limited environments.