Advanced hemostatic dressings are not superior to gauze for care under fire scenarios.

BACKGROUND: Advanced hemostatic dressings perform superior to standard gauze (SG) in animal hemorrhage models but require 2 minutes to 5 minutes application time, which is not feasible on the battlefield. METHODS: Twenty-four swine received a femoral artery injury, 30 seconds uncontrolled hemorrhage and randomization to packing with SG, Combat Gauze (CG), or Celox Gauze (XG) without external pressure. Animals were resuscitated to baseline mean arterial pressures with lactated Ringers and monitored for 120 minutes. Physiologic and coagulation parameters were collected throughout. Dressing failure was defined as overt bleeding outside the wound cavity. Tissues were collected for histologic and ultrastructural studies. RESULTS: All animals survived to study end. There were no differences in baseline physiologic or coagulation parameters or in dressing success rate (SG: 8/8, CG: 4/8, XG: 6/8) or blood loss between groups (SG: 260 mL, CG: 374 mL, XG: 204 mL; p > 0.3). SG (40 seconds ± 0.9 seconds) packed significantly faster than either the CG (52 ± 2.0) or XG (59 ± 1.9). At 120 minutes, all groups had a significantly shorter time to clot formation compared with baseline (p < 0.01). At 30 minutes, the XG animals had shorter time to clot compared with SG and CG animals (p < 0.05). All histology sections had mild intimal and medial edema. No inflammation, necrosis, or deposition of dressing particles in vessel walls was observed. No histologic or ultrastructural differences were found between the study dressings. CONCLUSIONS: Advanced hemostatic dressings do not perform better than conventional gauze in an injury and application model similar to a care under fire scenario.

Lyophilized plasma with ascorbic acid decreases inflammation in hemorrhagic shock.

BACKGROUND: Delivery of a high ratio of plasma to packed red blood cells to patients who require massive transfusion is associated with improved survival. Hemorrhagic shock causes increased production of pro-inflammatory cytokines. These are associated with late morbidity and mortality. The use of fresh frozen plasma makes high ratio resuscitation logistically difficult and does not address dysfunctional inflammation. Lyophilized plasma (LP) is a stable powdered form of plasma that is both safe and easily reconstituted. Previous work demonstrated that LP reconstituted with ascorbic acid (AA) decreased inflammation. Whether the reduction of inflammation was associated with LP or the AA is unknown. METHODS: Thirty female swine were anesthetized and subjected to a multisystem combat relevant model consisting of femur fracture, controlled hemorrhage, and hypothermia. A standardized grade V liver injury was made and the animals were randomly assigned to receive LP reconstituted with AA, citric acid (CA), or hydrochloric acid (HCl). Blood was drawn at baseline and at 2 hours and 4 hours for interleukin (IL)-6, IL-8, and tumor necrosis factor-α serum concentrations measured by enzyme-linked immunosorbent assay. Lung tissue was harvested and processed for gene expression before euthanizing the animals. RESULTS: No differences were observed in mortality, baseline cytokine serum concentration, or gene expression. Enzyme-linked immunosorbent assay demonstrated that IL-6 concentration increased over time for all groups (p < 0.05), but less so at 2 hours in the AA group compared with CA and HCl. CONCLUSION: In this animal model of trauma, hemorrhage and resuscitation, AA decreases IL-6 expression relative to CA and HCl. These findings confirm previous work from our laboratory and suggest that AA is responsible for suppression of dysfunctional inflammation in this model.

Lyophilized plasma reconstituted with ascorbic acid suppresses inflammation and oxidative DNA damage.

BACKGROUND: Lyophilized plasma (LP) has been shown to be as effective as fresh frozen plasma (FFP) for resuscitation in polytrauma and hemorrhagic shock. LP reconstituted with ascorbic acid is associated with suppression of cytokines when compared with fresh frozen plasma. We aimed to determine the effect of using alternate LP reconstitution acids on physiologic parameters, blood loss, coagulation, oxidative DNA damage, and proinflammatory cytokines in a polytrauma and hemorrhagic shock model. METHODS: Thirty swine were anesthetized, subjected to polytrauma, hemorrhagic shock, and randomized to resuscitation with LP-ascorbic acid (AA), LP-citric acid (CA), or LP-hydrochloric acid (HCL). Physiologic data were continuously monitored, blood loss measured, and serum collected at baseline, 2 hours, and 4 hours for enzyme-linked immunosorbent assays. Measured 8-OH-2'-deoxyguanosine (8-OHdG) was a biomarker of oxidative DNA damage. RESULTS: No differences were observed in physiologic measures, blood loss, or coagulation parameters. Interleukin-6 increased over time for all groups, but at 2 hours, the concentration in AA (median [minimum, maximum]: 113 ng/mL [0, 244]) was lower compared with CA (181 ng/mL [69, 314], p = 0.01) and HCL (192 ng/mL [41, 310], p = 0.03). Comparing 4 hours to baseline, a significant increase in oxidative DNA damage was observed in CA (22.9 ng/mL [16.3, 34.3] vs. 15.6 ng/mL [13.6, 26.7], p = 0.03) and HCL (19.6 ng/mL [15.7, 56.7] vs. 15.8 ng/mL [11.6, 21.4], p = 0.01) but not in AA (17.9 ng/mL [12.6, 26.9] vs. 17.1 ng/mL [11.8, 18.4], p = 0.24). CONCLUSIONS: Resuscitation with AA results in decreased interleukin-6 expression and oxidative DNA damage compared with CA and HCL.

High ratios of plasma and platelets to packed red blood cells do not affect mortality in nonmassively transfused patients.

BACKGROUND: Administration of high transfusion ratios in patients not requiring massive transfusion might be harmful. We aimed to determine the effect of high ratios of fresh frozen plasma (FFP) and platelets (PLT) to packed red blood cells (PRBC) in nonmassively transfused patients. METHODS: Records of 1,788 transfused trauma patients who received <10 units of PRBC in 24 hours at 23 United States Level I trauma centers were reviewed. The relationship between ratio category (low and high) and in-hospital mortality was assessed with propensity-adjusted multivariate proportional hazards models. RESULTS: At baseline, patients transfused with a high FFP:PRBC ratio were younger, had a lower Glasgow Coma Scale score, and a higher Injury Severity Score. Those receiving a high PLT:PRBC ratio were older. The risk of in-hospital mortality did not vary significantly with FFP:PRBC ratio category. Intensive care unit (ICU)-free days, hospital-free days, and ventilator-free days did not vary significantly with FFP:PRBC ratio category. ICU-free days and ventilator-free days were significantly decreased among patients in the high (≥1:1) PLT:PRBC category, and hospital-free days did not vary significantly with PLT:PRBC ratio category. The analysis was repeated using 1:2 as the cutoff for high and low ratios. Using this cutoff, there was still no difference in mortality with either FFP:PRBC ratios or platelet:PRBC ratios. However, patients receiving a >1:2 ratio of FFP:PRBCs or a >1:2 ratio PLT:PRBCs had significantly decreased ICU-free days and ventilator-free days. CONCLUSIONS: FFP:PRBC and PLT:PRBC ratios were not associated with in-hospital mortality. Depending on the threshold analyzed, a high ratio of FFP:PRBC and PLT:PRBC transfusion was associated with fewer ICU-free days and fewer ventilator-free days, suggesting that the damage control infusion of FFP and PLT may cause increased morbidity in nonmassively transfused patients and should be rapidly terminated when it becomes clear that a massive transfusion will not be required.

A predictive model for mortality in massively transfused trauma patients.

BACKGROUND: Improvements in trauma systems and resuscitation have increased survival in severely injured patients. Massive transfusion has been increasingly used in the civilian setting. Objective predictors of mortality have not been well described. This study examined data available in the early postinjury period to identify variables that are predictive of 24-hour- and 30-day mortality in massively transfused trauma patients. METHODS: Massively transfused trauma patients from 23 Level I centers were studied. Variables available on patient arrival that were predictive of mortality at 24 hours were entered into a logistic regression model. A second model was created adding data available 6 hours after injury. A third model evaluated mortality at 30 days. Receiver operating characteristic curves and the Hosmer-Lemeshow test were used to assess model quality. RESULTS: Seven hundred four massively transfused patients were analyzed. The model best able to predict 24-hour mortality included pH, Glasgow Coma Scale score, and heart rate, with an area under the receiver operating characteristic curve (AUROC) of 0.747. Addition of the 6-hour red blood cell requirement increased the AUROC to 0.769. The model best able to predict 30-day mortality included the above variables plus age and Injury Severity Score with an AUROC of 0.828. CONCLUSION: Glasgow Coma Scale score, pH, heart rate, age, Injury Severity Score, and 6-hour red blood cell transfusion requirement independently predict mortality in massively transfused trauma patients. Models incorporating these data have only a modest ability to predict mortality and should not be used to justify withholding massive transfusion in individual cases.

Effects of ethanol intoxication and gender on blood coagulation.

BACKGROUND: Ethanol intoxication is a common contributor to traumatic injury. It is unknown whether ethanol consumption contributes to the coagulation differences seen between men and women after trauma. Our aim was to examine the combined effect of ethanol intoxication and gender on coagulation. METHODS: Fifty-eight healthy subjects participated and chose to enter into a control group (CG; n = 20; 10 men and 10 women) or drinking group (DG; n = 38; 20 men and 18 women). Venous blood samples for thrombelastography, plasminogen activator inhibitor, thrombin-antithrombin complex, and tissue plasminogen activator were drawn at the beginning of the study. Subjects then interacted in a social atmosphere for at least 2 hours, eating and consuming alcoholic (DG) or nonalcoholic (CG) beverages. After 2 hours, blood alcohol level was determined and blood was drawn for a second set of coagulation studies. RESULTS: Demographics were similar between groups except for age (36.7 years CG vs. 29.9 years DG; p = 0.009). All baseline thrombelastography measurements were similar between the CG and DG. Blood alcohol levels in the DG were similar between genders at the end of study. At the end of study, a decreased rate of fibrin formation, decreased clot strength, and a decreased rate of fibrin cross-linking was seen in men but not in women. Fibrinolysis was inhibited in drinkers compared with controls. CONCLUSIONS: Consumption of commonly ingested quantities of alcohol correlated with the development of a hypocoagulable state in men but had no effect on coagulation status in women. This phenomenon may contribute to differences in post-trauma coagulation status previously noted between genders.

High transfusion ratios are not associated with increased complication rates in patients with severe extremity injuries.

BACKGROUND: High transfusion ratios of plasma to packed red blood cells (>1:2) have been associated with increased survival and increased complications in patients receiving massive transfusion (MT). We hypothesized that high ratio transfusion would be associated with no survival benefit and increased complications in combat victims with compressible hemorrhage. METHODS: A retrospective analysis of soldiers injured in the current conflict during 5 years (n = 2,105) who received blood was performed on those with isolated extremity (abbreviated injury scale extremity score > or = 3 and abbreviated injury scale score 0-2 in all other regions) injury comparing those who received a MT with those who did not. Transfusion ratios in the first 24 hours were correlated with outcomes. RESULTS: Injury severity score (14.6 vs. 12.1; p < 0.05), international normalized ratio (1.65 vs. 1.28; p < 0.05), and base deficit (8.0 vs. 3.7; p < 0.05) were higher in the MT group. High transfusion ratios were associated with a trend toward decreased mortality (17.2% vs. 6.9%; p = 0.07) in MT patients and no increased complications (20.7% vs. 26.4%; p > 0.05). In those receiving a non-MT, high ratios were associated with similar mortality (4.8% vs. 3.9%; p > 0.05) and complications (12.4% vs. 9.2%; p > 0.05). CONCLUSIONS: Extremity injured patients receiving MT may benefit from high transfusion ratios and do not experience increased complications. No change in mortality or complications was observed in non-MT patients across transfusions ratios. High transfusion ratios are not associated with increased complications in patients with isolated extremity injury regardless of whether a MT is required.

Comparison of abdominal damage control surgery in combat versus civilian trauma.

BACKGROUND: The majority of individuals who perform damage control surgery in the military arena are trained in civilian venues. Therefore, it is important to compare and contrast damage control performed in civilian and military settings. In contrast to civilian trauma, which is primarily caused by blunt injury and addressed at one or two surgical facilities, combat casualties primarily sustain explosion-related injuries and undergo treatment at multiple levels of care across continents. We aimed to compare patients undergoing abdominal damage control surgery across these two very different settings. METHODS: Parallel retrospective reviews were conducted over 2 years (2005-2006) in a combat setting and at a US Level I trauma center. Patients were examined during the first 7 days after injury. RESULTS: The civilian population (CP) was older (40 vs. 23; p < 0.01) with a higher injury severity score (35 vs. 27; p < 0.02). The CP experienced greater blunt injury than the military population (MP) (83 vs. 4%; p < 0.01). Explosion-related injury was only present in the MP (64%). At baseline, the CP presented with lower systolic blood pressure (108 vs. 126) and larger base deficit (9.8 vs. 6.5; p < 0.05). The MP underwent more surgeries (3.5 vs. 2.9; p = 0.02) with similar rates of fascial closure (48.7% vs. 70.0%; p = 0.11). Complication rates were similar between the CP and the MP (43% vs. 58%, respectively; p = 0.14). CONCLUSIONS: Military and civilian trauma patients who undergo damage control surgery experience similar fascial closure rates despite differing demographics and widely disparate mechanisms of injury. The MP undergoes a greater number of procedures than the CP, but complication rates do not differ between the groups.

Emerging therapies in traumatic hemorrhage control.

PURPOSE OF REVIEW: Care of the injured patient is a dynamic process. Hemorrhage remains the primary cause of preventable death after trauma. Rapid and effective early care can improve survival and outcomes. Emerging therapies to address traumatic hemorrhage will be discussed. RECENT FINDINGS: Current concepts in trauma care include damage control resuscitation with rapid surgical correction of bleeding; prevention of the development of the lethal triad; limitation of crystalloid administration and application of high ratios of plasma and platelets to packed red blood cells. Prehospital resuscitation strategies can effect care of the hemorrhaging trauma patient, as well. The goal should be to preserve vital functions without increasing the risk for further bleeding. The concept of hypotensive resuscitation has been formulated to address this issue. The type of resuscitation fluid also plays an important role, with novel fluids currently being studied for routine use. Compressible hemorrhage constitutes an important component of potentially survivable injury. Hemostatic dressings and tourniquets can prove essential to the management of combat and civilian wounds. SUMMARY: Given the potential to preserve life with appropriate attention applied to the bleeding trauma victim, it is vitally important to explore the options currently available and continue to make improvements in care.

Management and outcomes of traumatic colon injury in civilian and military patients.

Divergent injury patterns may indicate the need for differing strategies in combat and civilian trauma patients. This study aims to compare outcomes of colon injury management in these two populations. Parallel retrospective reviews were conducted comparing warfighters (n = 59) injured downrange and subsequently transferred to the United States with civilians (n = 30) treated at a United States Level I trauma center. Patient characteristics, mechanisms of injury, treatment course, and complications were compared. The civilian (CP) and military (MP) populations did not differ in Injury Severity Score (MP 20 vs CP 26; P = 0.41). The MP experienced primarily blast injuries (51%) as opposed to blunt trauma (70%; P < 0.01) in the CP. The site of colon injury did not differ between groups (P = 0.15). Initial management was via primary repair (53%) and resection and anastomosis (27%) in the CP versus colostomy creation (47%) and stapled ends (32%) in the MP (P < 0.001). Ultimately, the CP and MP experienced equivalent continuity rates (90%). Overall complications (MP 68% vs CP 53%; P = 0.18) and mortality (MP 3% vs CP 3%; P = 0.99) did not differ between the two groups. The CP and MP experience different mechanisms and initial management of colon injury. Ultimately, continuity is restored in the majority of both populations.

Oncologic outcomes after resection of rectal cancer: Laparoscopic versus open approach.

BACKGROUND: This study examined outcomes of laparoscopic and open rectal cancer surgery in a community hospital setting. METHODS: A community health care system cancer registry was reviewed retrospectively (2004-2007) for rectal cancer patients undergoing surgical treatment. Primary end points were rates of recurrence and survival. RESULTS: Both open and laparoscopic resection groups had similar demographic, treatment, and tumor characteristics. Most patients in the open resection and laparoscopic resection populations experienced no recurrence (79% vs 83%, respectively; P = .5). Overall, the groups had similar mean (88% vs 96%, respectively; P = .4) and disease-free (21 and 23 months, respectively; P = .5) survival. CONCLUSIONS: In a community hospital setting, laparoscopic resection of rectal cancer was found to be as safe and effective as open resection in selected patients.

Splenectomy leads to a persistent hypercoagulable state after trauma.

BACKGROUND: It was hypothesized that splenectomy following trauma results in hypercoagulability. METHODS: A prospective, nonrandomized, single-center study was performed to evaluate coagulation parameters in trauma patients with splenic injury. RESULTS: Patients with splenectomy (n = 30) and nonoperative management (n = 50) were enrolled. Splenectomy patients were older, had higher Injury Severity Scores, and had longer intensive care unit and hospital stays (P < .05). Splenectomy patients had significantly increased white blood cell counts and platelet counts at baseline and follow-up (P < .01). Fibrinogen was initially elevated in both groups and remained elevated in the splenectomy group (P < .05). Tissue plasminogen activator, plasminogen activator inhibitor-1, and activated partial thromboplastin time were higher in splenectomy patients only at baseline (P < .05). Baseline thromboelastography showed faster fibrin cross-linking and enhanced fibrinolysis following splenectomy (P < .05). Only clot strength was greater at follow-up in the splenectomy group (P < .01). Deep venous thrombosis developed in 7% of splenectomy patients and no control patients (P = .03). CONCLUSIONS: A significant difference in deep venous thrombosis formation was noted, and coagulation assays indicated persistent hypercoagulability following splenectomy for trauma.

A high ratio of plasma and platelets to packed red blood cells in the first 6 hours of massive transfusion improves outcomes in a large multicenter study.

BACKGROUND: In trauma, most hemorrhagic deaths occur within the first 6 hours. This study examined the effect on survival of high ratios of fresh frozen plasma (FFP) and platelets (PLTs) to packed red blood cells (PRBCs) in the first 6 hours. METHODS: Records of 466 massive transfusion trauma patients (>or=10 U of PRBCs in 24 hours) at 16 level 1 trauma centers were reviewed. Transfusion ratios in the first 6 hours were correlated with outcome. RESULTS: All groups had similar baseline characteristics. Higher 6-hour ratios of FFP:PRBCs and PLTs:PRBCs lead to improved 6-hour mortality (from 37.3 [in the lowest ratio group] to 15.7 [in the middle ratio group] to 2.0% [in the highest ratio group] and 22.8% to 19.0% to 3.2%, respectively) and in-hospital mortality (from 54.9 to 41.1 to 25.5% and 43.7% to 46.8% to 27.4%, respectively). Initial higher ratios of FFP:PRBCs and PLTs:PRBCs decreased overall PRBC transfusion. CONCLUSIONS: The early administration of high ratios of FFP and platelets improves survival and decreases overall PRBC need in massively transfused patients. The largest difference in mortality occurs during the first 6 hours after admission, suggesting that the early administration of FFP and platelets is critical.

A highly porous silica and chitosan-based hemostatic dressing is superior in controlling hemorrhage in a severe groin injury model in swine.

BACKGROUND: This study compared the efficacy of 3 hemostatic dressings in a severe groin injury model in swine. METHODS: Twenty-three swine received TraumaStat (OreMedix, Lebanon, OR), Chitoflex (HemCon, Inc., Portland, OR), or standard gauze for hemostasis. Complete femoral vessel transections were followed by 30 seconds of uncontrolled hemorrhage. The groin was packed with the randomized dressing followed by 30 seconds of compression. Resuscitation with lactated Ringer's solution commenced immediately postcompression to the preinjury mean arterial blood pressure. Hemostasis failure was defined as blood pooling outside the wound. Animals were monitored and maintained at the preinjury mean arterial pressure for 120 minutes, culminating with euthanization. RESULTS: There were no differences in baseline values between groups. TraumaStat resulted in less hemostasis failure (P < .05), decreased postcompression blood loss (P < .05), and decreased fluid requirement (P < .05). No significant difference in mortality was seen between groups. There were no differences between standard gauze and Chitoflex with respect to dressing failure, posttreatment blood loss, or fluid resuscitation. CONCLUSIONS: TraumaStat performed significantly better than Chitoflex and standard gauze in controlling hemorrhage from a severe groin injury in swine.