iTClamp-Mediated Wound Closure Speeds Control of Arterial Hemorrhage With or Without Additional Hemostatic Agents.

BACKGROUND: Exsanguination is the leading cause of preventable posttraumatic death, especially in the prehospital arena. Traditional hemorrhage control methods involve packing the wound with hemostatic agents, providing manual pressure, and then applying a pressure dressing to stabilize the treatment. This is a lengthy process that frequently destabilizes upon patient transport. Conversely, the iTClamp, a compact wound closure device, is designed to rapidly seal wound edges mechanically, expediting clot formation at the site of injury. OBJECTIVES: To determine the efficacy of the iTClamp with and without wound packing in the control of a lethal junction hemorrhage. METHODS: Given the limited available information regarding the efficacy of the iTClamp in conjunction with traditional hemostatic agents, this study used a swine model of severe junctional hemorrhage. The goal was to compare a multiagent strategy using the iTClamp in conjunction with XSTAT to the traditional method of Combat Gauze packing with pressure dressing application. Readouts include application time, blood loss, and rebleed occurrence. RESULTS: Mean application times of the iTClamp treatment alone or in conjunction with other hemostatic agents were at least 75% faster than the application time of Combat Gauze with pressure dressing. Percent blood loss was not significantly different between groups but trended the highest for Combat Gauze treated swine, followed by iTClamp plus XSTAT, iTClamp alone and finally iTClamp plus Combat Gauze. CONCLUSION: The results from this study demonstrate that the iTClamp can be effectively utilized in conjunction with hemostatic packing to control junctional hemorrhages.

Red-Green Tactical Lighting Is Preferred for Suturing Wounds in a Simulated Night Environment.

BACKGROUND: Delivering medical care in nighttime conditions is challenging, as 25% of Special Operations medical Operators have reported that problems with lighting contributed to poor casualty outcomes. Red light is often used in nighttime operations but makes blood detection difficult and diminishes depth perception and visual acuity. Red-green combination lighting may be superior for differentiating blood from tissue and other fluids but had not been tested versus red-only or green-only lighting for combat-related medical procedures, such as wound suturing. METHODS: Dark-adapted medical resident physicians (N = 24) sutured 6cm long, 3cm deep, full-thickness lacerations in deceased swine under red-only, green-only, and red-green lighting provided by a tactical flashlight using a randomized within-subjects design. Time to suture completion, suture quality, user ratings, and user preference data were contrasted at p < .05. This study was approved by Naval Medical Center Portsmouth IRB. RESULTS: Suture completion time and suture quality were similar across all lighting conditions. Participants rated red-green lighting as significantly easier for identifying blood, identifying instruments, and performing suturing (p < .01). Red-green lighting was preferred by 83% of participants compared to 8% each for red-only and green-only (p < .001). CONCLUSIONS: Pending further study under tactical conditions, red-green lighting is tentatively recommended for treating battlefield wounds in low-light environments.

Impact of Marine Exposure on Hemostatic Gauzes Using Thromboelastography.

BACKGROUND: Military forces render emergency care in marine environments, where care for exsanguination is challenging. However, the effect of saltwater on the functionality of hemostatic agents is unknown. In this study, we used thromboelastography (TEG) to quantify the effect of saltwater on the efficacy of five gauze products. METHODS: Blood from 24 healthy adult men was diluted by 30% with hetastarch to mimic hemodilution. Dry and saltwater-soaked Kerlix™, ChitoGauze®, Combat Gauze®, NuStat™, and WoundClot™ were contrasted in terms of the TEG parameters of speed of clot initiation (R), clot amplification (K), α angle (i.e., clot formation rate), and maximum amplitude of clot (MA), using repeated-measures analysis of variance at the p < .05 statistical significance threshold. RESULTS: Compared with untreated dilute blood, R was significantly faster when any dry or wet gauze was added, with the fastest R values recorded for Combat Gauze. K and α angle findings were mixed. MA was greater than diluted blood for dry hemostatic gauze, but in the wet condition, only the MA for Combat Gauze was significantly greater than that of diluted blood. CONCLUSION: Gauze products, wet or dry, improved clotting compared to diluted blood without gauze. Saltwater exposure did not significantly detract from this benefit. Our findings suggest that Combat Gauze may be the choice hemostatic gauze for maritime environments.

Randomized Comparative Assessment of Three Surgical Cricothyrotomy Devices on Airway Mannequins.

BACKGROUND: Airway obstruction is the second leading cause of preventable battlefield death, at least in part because surgical cricothyrotomy (SC) failure rates remain unacceptably high. Ideally, SC should be a rapid, simple, easily-learned, and reliably-performed procedure. Currently, 3 SC devices meet Tactical Combat Casualty Care (TCCC) standards: The Tactical CricKit® (TCK), Control-CricTM(CC), and Bougie-assisted Technique (BAT). However, no previous studies have compared these devices in application time, application success, user ratings, and user preference. METHODS: United States Navy Corpsmen (N = 25) were provided 15 minutes of standardized instruction, followed by hands-on practice with each device on airway mannequins. Participants then performed SC with each of the 3 devices in a randomly assigned sequence. In this within-subjects design, application time, application success, participant ratings, and participant preference data were analyzed using repeated-measures ANOVA, regression, and non-parametric statistics at p < 0.05. RESULTS: Application time for CC (M = 184 sec, 95% CI 144-225 sec) was significantly slower than for BAT (M = 135 sec, 95% CI 113-158 sec, p < 0.03) and TCK (M = 117 sec, 95% CI 93-142 sec, p < 0.005). Success was significantly greater for BAT (76%) than for TCK (40%, p < 0.02) and trended greater than CC (48%, p = 0.07). CC was rated significantly lower than TCK and BAT in ease of application, effectiveness, and reliability (each p < 0.01). User preference was significantly (p < 0.01) higher for TCK (58%) and BAT (42%) than for CC (0%). Improved CC blade design was the most common user suggestion. CONCLUSION: While this study was limited by the use of mannequins in a laboratory environment, present results indicate that none of these devices was ideal for performing SC. Based on slow application times, low success rates, and user feedback, the Control-CricTM cannot be recommended until improvements are made to the blade design.

Comparison of Three Junctional Tourniquets Using a Randomized Trial Design.

BACKGROUND: Hemorrhage remains a leading cause of death in both civilian and military settings. Of preventable deaths from hemorrhage, a significant portion occurs from junctional wounds that are not amenable to traditional extremity tourniquets. Junctional tourniquets (JTQs) can potentially provide hemorrhage control by compressing the arteries at the junction of the trunk and extremities. The FDA has cleared 3 JTQ products: The Combat Ready Clamp (CRoC®), the Junctional Emergency Treatment Tool (JETT™), and the SAM® Junctional Tourniquet (SJT). However, little is known regarding which of these JTQs is superior in application time, effectiveness in pulse elimination, effectiveness during transport, and user preference. METHODS: Active duty corpsmen (N = 49) were given standardized instruction and hands-on training with the CRoC®, JETT™, and SJT, then sequentially applied each JTQ unilaterally to a fellow study participant in a randomized order. Pulse elimination was determined by Doppler ultrasound at the dorsalis pedis immediately then reevaluated after a short transport. User preference data were collected following testing. Data were analyzed using repeated measures ANOVA and non-parametric statistics at p < 0.05. RESULTS: The CRoC® was significantly slower in application time than the JETT™ and SJT. Effectiveness was similar for CRoC®, JETT™, and SJT. Effectiveness during transport was significantly higher for SJT than for the JETT™, but no JTQ performed well during transport (24-48% effectiveness). SJT ranked first in perceived ease of use, stability, and reliability, and in user trust and overall preference. Participants provided cogent suggestions for product improvement. CONCLUSIONS: All JTQ devices performed poorly during transport. Combined, present findings highlight the potential of JTQ products for saving lives threatened by junctional wounds, but also highlight the need for specific product improvements towards fostering JTQ performance in patient transport.

A Pilot Study of Four Intraosseous Blood Transfusion Strategies.

BACKGROUND: Intraosseous (IO) access is used by military first responders administering fluids, blood, and medications. Current IO transfusion strategies include gravity, pressure bags, rapid transfusion devices, and manual push-pull through a three-way stopcock. In a swine model of hemorrhagic shock, we compared flow rates among four different IO blood transfusion strategies. METHODS: Nine Yorkshire swine were placed under general anesthesia. We removed 20 to 25mL/kg of each animal's estimated blood volume using flow of gravity. IO access was obtained in the proximal humerus. We then autologously infused 10 to 15mL/kg of the animal's estimated blood volume through one of four randomly assigned treatment arms. RESULTS: The average weight of the swine was 77.3kg (interquartile range, 72.7kg-88.8kg). Infusion rates were as follows: gravity, 5mL/min; Belmont rapid infuser, 31mL/min; single-site pressure bag, 78mL/min; double-site pressure bag, 103mL/min; and push-pull technique, 109mL/min. No pulmonary arterial fat emboli were noted. CONCLUSION: The optimal IO transfusion strategy for injured Servicemembers appears to be single-site transfusion with a 10mL to 20mL flush of normal saline, followed immediately by transfusion under a pressure bag. Further study, powered to detect differences in flow rate and clinical complications. is required.