Thromboelastography on-the-go: Evaluation of the TEG 6s device during ground and high-altitude Aeromedical Evacuation with extracorporeal life support.

BACKGROUND: Coagulation monitoring capabilities during transport are limited. Thromboelastography (TEG) is a whole-blood clotting test measuring clot formation, stabilization, and fibrinolysis and is traditionally performed in a laboratory. We evaluated a new point-of-care TEG analyzer, TEG 6s (Haemonetics, Braintree, MA), in a large animal model of combat-relevant trauma managed with extracorporeal life support during ground and high-altitude aeromedical evacuation. The objective was to compare TEG 6s used during transport versus the predicate device, TEG 5000, used in the laboratory. We hypothesized that TEG 6s would be comparable with TEG 5000 during dynamically changing transport conditions. METHODS: Thromboelastography parameters (R, K, angle, MA, LY30) derived by TEG 6s and TEG 5000 were compared during transport of 8 swine. TEG 6s was transported with animals during ground transport and flight. TEG 5000 was stationary in an adjacent building. TEG 6s activated clotting time (ACT) was compared with a Hemochron Junior ACT analyzer (Accriva Diagnostics, San Diego, CA). Statistics were performed using SAS 9.4 with Deming regressions, Spearman correlations, and average differences compared. RESULTS: Correlation between devices was stronger at sea-level (R, r = 0.7413; K, r = 0.7115; angle, r = 0.7192; MA, r = 0.8386; LY30, r = 0.9099) than during high-altitude transport (R, r = 0.4787; K, r = 0.4007; angle, r = 0.3706; MA, r = 0.6573; LY30, r = 0.8481). Method agreement was comparable during stationary operation (R, r = 0.7978; K, r = 0.7974; angle, r = 0.7574; MA, r = 0.7841; LY30, r = 0.9140) versus ground transport (R, r = 0.7927; K, r = 0.6246; angle, r = 0.6967; MA, r = 0.9163; LY30, r = 0.8603). TEG 6s ACT trended higher than Hemochron ACT when subjects were heparinized (average difference, 1,442 ± 1,703 seconds) without a methodological difference by Deming regression. CONCLUSION: Mobile TEG 6s during ground and altitude transport is feasible and provides unprecedented information to guide coagulation management. Future studies should assess the precision and accuracy of TEG 6s during transport of critically ill.

Population trends in Vermivora warblers are linked to strong migratory connectivity.

Migratory species can experience limiting factors at different locations and during different periods of their annual cycle. In migratory birds, these factors may even occur in different hemispheres. Therefore, identifying the distribution of populations throughout their annual cycle (i.e., migratory connectivity) can reveal the complex ecological and evolutionary relationships that link species and ecosystems across the globe and illuminate where and how limiting factors influence population trends. A growing body of literature continues to identify species that exhibit weak connectivity wherein individuals from distinct breeding areas co-occur during the nonbreeding period. A detailed account of a broadly distributed species exhibiting strong migratory connectivity in which nonbreeding isolation of populations is associated with differential population trends remains undescribed. Here, we present a range-wide assessment of the nonbreeding distribution and migratory connectivity of two broadly dispersed Nearctic-Neotropical migratory songbirds. We used geolocators to track the movements of 70 Vermivora warblers from sites spanning their breeding distribution in eastern North America and identified links between breeding populations and nonbreeding areas. Unlike blue-winged warblers (Vermivora cyanoptera), breeding populations of golden-winged warblers (Vermivora chrysoptera) exhibited strong migratory connectivity, which was associated with historical trends in breeding populations: stable for populations that winter in Central America and declining for those that winter in northern South America.

Engineering Escherichia coli Co-Cultures for Production of Curcuminoids From Glucose.

Curcuminoids (cus) have attracted increasing attention because of the antioxidant, anticancer, and antitumor activities while their production is limited because of its main source, turmeric plant, demonstrates extensive seasonal variation. In this study, we constructed Escherichia coli co-culture system for the rapid production of curcuminoids from glucose. Firstly, the overexpression of curcuminoid synthase and four different strategies related to increasing the intracellular malonyl-CoA pool were conducted in engineered E. coli. We found that bisdemethoxycurcumin (BDMC) is the main product and that high level of malonyl-CoA pool is essential for BDMC production. We also obtained the maximum titer (13.8 mg L-1 ) of BDMC within 4 h by fast preparation directly from p-coumaric acid. Secondly, we developed a process for BDMC synthesis from glucose using a co-culture system where an E. coli strain is used to produce p-coumaric acid from glucose and another E. coli strain converted p-coumaric acid into the final product. Compared to the mono-culture system, the co-culture is more potent and resulted in 6.28 mg L-1 of BDMC from glucose within 22 h of fermentation in a 3-L bioreactor. This is the first time a co-culture method is employed for the production of curcuminoids from glucose in a lab scale bioreactor. This system provides a new method transforming inexpensive substrate into value-added products.

Vitamin and Trace Element Loss from Negative-Pressure Wound Therapy.

OBJECTIVE: This study investigated select vitamin and trace element loss from wound exudates in burn and trauma patients treated with negative-pressure wound therapy (NPWT). DESIGN: A prospective observational study was performed using wound exudate samples. SETTING: A level I trauma center acute care hospital. PARTICIPANTS: The study was composed of 8 patients with open abdomens and 9 patients with 12 soft-tissue wounds. MAIN OUTCOME MEASURES: The goal was to collect wound exudate samples daily for 3 days, then every other day to day 9 or until NPWT was discontinued, and to analyze for vitamins A (retinol), C, and E and zinc (Zn), iron (Fe), and copper (Cu). Daily loss of each micronutrient was calculated from their concentration and 24-hour volumes of the exudates. MAIN RESULTS: Exudate loss in the open-abdomen group was significantly higher than in the patients with soft-tissue wounds (900 ± 547 vs 359 ± 246 mL/d). The mean 24-hour loss of vitamins A, C, and E were 0.3, 2.8, and 11 mg, respectively, in the open-abdomen group. Over the same period, the losses of Zn, Fe, and Cu were 0.5, 0.4, and 0.25 mg, respectively, in these patients. Micronutrient 24-hour loss was significantly lower in the soft-tissue wound patients than in the open-abdomen group. CONCLUSIONS: The data support the concept that significant amounts of micronutrients can be lost from NPWT wound exudates, particularly in open abdomens. These losses should be considered in the nutritional support of these patients who typically are in a hypermetabolic and catabolic state.

Hierarchical decomposition of burn body diagram based on cutaneous functional units and its utility.

A burn body diagram (BBD) is a common feature used in the delivery of burn care for estimating the TBSA burn as well as calculating fluid resuscitation and nutritional requirements, wound healing, and rehabilitation intervention. However, little change has occurred for over seven decades in the configuration of the BBD. The purpose of this project was to develop a computerized model using hierarchical decomposition (HD) to more precisely determine the percentage burn within a BBD based on cutaneous functional units (CFUs). HD is a process by which a system is degraded into smaller parts that are more precise in their use. CFUs were previously identified fields of the skin involved in the range of motion. A standard Lund/Browder (LB) BBD template was used as the starting point to apply the CFU segments. LB body divisions were parceled down into smaller body area divisions through a HD process based on the CFU concept. A numerical pattern schema was used to label the various segments in a cephalo/caudal, anterior/posterior, medial/lateral manner. Hand/fingers were divided based on anatomical landmarks and known cutaneokinematic function. The face was considered using aesthetic units. Computer code was written to apply the numeric hierarchical schema to CFUs and applied within the context of the surface area graphic evaluation BBD program. Each segmented CFU was coded to express 100% of itself. The CFU/HD method refined the standard LB diagram from 13 body segments and 33 subdivisions into 182 isolated CFUs. Associated CFUs were reconstituted into 219 various surface area combinations totaling 401 possible surface segments. The CFU/HD schema of the body surface mapping is applicable to measuring and calculating percent wound healing in a more precise manner. It eliminates subjective assessment of the percentage wound healing and the need for additional devices such as planimetry. The development of CFU/HD body mapping schema has rendered a technologically advanced system to depict body burns. The process has led to a more precise estimation of the segmented body areas while preserving the overall TBSA information. Clinical application to date has demonstrated its worthwhile utility.

Comparison of Decontamination Methods for Human Skin Grafts.

Skin grafts intended for autologous transplant may be dropped on the operating room floor during handling. The authors examined optimal procedures for decontaminating tissue intended for burn surgery. Porcine skin (5 × 5 cm sections) harvested from expired animals using standard procedures was inoculated with either 10(6) CFU/ml Staphylococcus aureus or Klebsiella pneumoniae. Decontaminating strategies were compared: 10% povidone iodine, 0.04% chlorhexidine, or 50 U/ml bacitracin for injection, and mechanical agitation using normal saline or sterile water; each agent was applied for 60 seconds. Each skin section was blended and plated on agar for bacterial enumeration using the spread plate method. Tissue viability was evaluated in parallel using a cell viability reagent, along with a control (heat at 200 °C for 5 min). Bacterial counts were log transformed; one-way ANOVA with Tukey-Kramer HSD analysis were performed. Concentration of organisms <10(5) CFU/g was considered clinically insignificant colonization. Eight donors provided 21 S. aureus and six K. pneumoniae samples. After exposure, mean organism concentration (CFU/g) was <10(5) for povidone iodine (S. aureus 2.83 × 10(4); K. pneumoniae 1.85 × 10(4)), chlorhexidine (S. aureus 4.52 × 10(4); K. pneumoniae 1.77 × 10(4)), and normal saline (K. pneumoniae 8.76 × 10(4)) treated groups. After log transform, only povidone iodine and chlorhexidine were found to be different from control in both groups. Viability was decreased in the positive control group, but not in treatment groups. Agents routinely used for surgical skin prep (povidone iodine and chlorhexidine), reduced both Gram-positive and Gram-negative contamination in tissue intended for skin grafting procedures. Antiseptic treatments did not impair the cellular viability of porcine skin.

Derivation of candidates for the combat casualty critical care (C4) database.

OBJECTIVE: To describe the development of the Combat Casualty Critical Care Database, a comprehensive database of critically injured combat casualties to identify potentially modifiable risk factors for morbidity and mortality in this population. METHODS: The Department of Defense's Joint Theater Trauma Registry was queried for all combat casualties injured from February 1, 2002 through February 1, 2011. The search was limited to patients who required admission to the intensive care unit and survived to be evacuated to Landstuhl Regional Medical Center. RESULTS: The query yielded 6,011 patients. The mean age was 25.7 ± 6.2 years. The majority of patients were male (98.3%), injured in Iraq (80%) and were members of the U. S. Army (72.6%). Most patients (58.0%) had an injury severity score in the lowest severity category (0-15). The mortality rate was 1.8%. The median day of death after injury (interquartile range) was 6 (3-14). CONCLUSIONS: We identified a cohort of critically wounded combat casualties that encompasses the majority of such patients injured in the course of the wars in Iraq and Afghanistan. When this database is fully populated, rigorous epidemiologic analysis will seek to identify factors associated with morbidity and mortality to improve future care.

Citation classics in the burn literature during the past 55 years.

The objective of this study was to identify the 100 most cited, peer-reviewed burn-related articles over the past half century. Burn care presents ongoing challenges to both U.S. civilian and military healthcare personnel. Improvements in burn survival and quality of life are the result of advances in burn research. The Web of Science (including Science Citation Index) was searched for the most cited articles related to burn care, published from 1955 to the present. The most cited article was "Permanent coverage of large burn wounds with autologous cultured human epithelium," by G.G. Gallico et al, New England Journal of Medicine, 1984 (711 citations). Between the 1970s and the 1990s, there was a near doubling of the number of highly cited publications with each subsequent decade. A total of 85% of the articles were on the topics of pathophysiology (37%), wounds, tissue, or dressings (31%), or organ failure/sepsis (17%). B.A. Pruitt Jr. (2320 citations), D.N. Herndon (1972 citations), and A.D. Mason Jr. (1435 citations) were the most cited authors. This study identified some of the most important contributions to burn research and the areas of greatest scientific interest to the specialty during the past five decades, and highlights key research that has contributed to the evolution of modern burn care.

No slackers in tourniquet use to stop bleeding.

BACKGROUND: Tourniquets on casualties in war have been loose in 4%?9% of uses, and such slack risks death from uncontrolled bleeding. A tourniquet evidence gap persists if there is a mechanical slack?performance association. OBJECTIVE: The purpose of the present study was to determine the results of tourniquet use with slack in the strap versus no slack before windlass turning, in order to develop best practices. METHODS: The authors used a tourniquet manikin 254 times to measure tourniquet effectiveness, windlass turns, time to stop bleeding, and blood volume lost at 5 degrees of strap slack (0mm, 25mm, 50mm, 100mm, and 200mm maximum). RESULTS: When comparing no slack (0mm) to slack (any positive amount), there were increases with slack in windlass turns (p < .0001, 3-fold), time to stop bleeding (p < .0001, 2-fold), and blood volume lost (p < .0001, 2-fold). When comparing no slack to 200mm slack, the median results showed an increase in slack for windlass turns (p < .0001), time to stop bleeding (p < .0001), and blood volume lost (p < .0001). CONCLUSIONS: Any slack presence in the strap impaired tourniquet performance. More slack had worse results. Trainers can now instruct tourniquet users with concrete guidance.

Single versus Double Routing of the Band in the Combat Application Tourniquet.

BACKGROUND: Common first aid tourniquets, like the Combat Application Tourniquet (CAT) of a windlass and band design, can have the band routed through the buckle in three different ways, and recent evidence indicates users may be confused with complex doctrine. OBJECTIVE: The purpose of the present study is to measure the differential performance of the three possible routings in order to better understand good tourniquet practice. METHODS: A training manikin was used by two investigators to measure tourniquet effectiveness, time to stop bleeding, and blood loss. RESULTS: The effectiveness rate was 99.6% (239/240) overall. RESULTS were similar for both single-slit routings (inside vs. outside, p > 0.05). Effectiveness rates (yes-no results for hemorrhage control expressed as a proportion of iterations) were not statistically different between single and double routing. However, the time to stop bleeding and blood loss were statistically different (p < 0.05). CONCLUSIONS: CAT band routing, through the buckle either singly or doubly, affects two key performance criteria: time to stop bleeding and volume of blood lost. Single routing proved to be faster, thereby saving more blood. Learning curves required to optimize user performance varied over 30-fold depending on which variable was selected (e.g., effectiveness vs. blood loss).

Primary hemostatic capacity of whole blood: a comprehensive analysis of pathogen reduction and refrigeration effects over time.

BACKGROUND: Whole blood (WB) has been used in combat since World War I as it is readily available and replaces every element of shed blood. Component therapy has become standard; however, recent military successes with WB resuscitation have revived the debate regarding wider WB use. Characterization of optimal WB storage is needed. We hypothesized that refrigeration preserves WB function and that a pathogen reduction technology (PRT) based on riboflavin and ultraviolet light has no deleterious effect over 21 days of storage. STUDY DESIGN AND METHODS: WB units were stored for 21 days either at 4°C or 22°C. Half of each temperature group underwent PRT, yielding four final treatment groups (n = 8 each): CON 4 (WB at 4°C); CON 22 (WB at 22°C); PRT 4 (PRT WB at 4°C); and PRT 22 (PRT WB at 22°C). Testing was at baseline, Days 1-7, 10, 14, and 21. Assays included coagulation factors; platelet activation, aggregation, and adhesion; and thromboelastography (TEG). RESULTS: Prothrombin time (PT) and partial thromboplastin time increased over time; refrigeration attenuated the effects on PT (p ≤ 0.009). Aggregation decreased over time (p ≤ 0.001); losses were attenuated by refrigeration (p ≤ 0.001). Refrigeration preserved TEG parameters (p ≤ 0.001) and PRT 4 samples remained within normal limits throughout the study. Refrigeration in combination with PRT inhibited fibrinolysis (p ≤ 0.001) and microparticle formation (p ≤ 0.031). Cold storage increased shear-induced platelet aggregation and ristocetin-induced platelet agglutination (p ≥ 0.032), as well as GPIb-expressing platelets (p ≤ 0.009). CONCLUSION: The in vitro hemostatic function of WB is largely unaffected by PRT treatment and better preserved by cold storage over 21 days. Refrigerated PRT WB may be suitable for trauma resuscitation. Clinical studies are warranted.

Minor morbidity with emergency tourniquet use to stop bleeding in severe limb trauma: research, history, and reconciling advocates and abolitionists.

BACKGROUND: In prior reports of active data collection, we demonstrated that early use of emergency tourniquets is associated with improved survival and only minor morbidity. To check these new and important results, we continued critical evaluation of tourniquet use for 6 more months in the current study to see if results were consistent. METHODS: We continued a prospective survey of casualties and their records at a combat support hospital in Baghdad who had tourniquets used at a combat hospital in Baghdad (NCT00517166 at ClinicalTrials.gov). RESULTS: After comparable methods were verified for both the first and current studies, we report the results of 499 patients who had 862 tourniquets applied on 651 limbs. The clinical results were consistent. No limbs were lost from tourniquet use. CONCLUSION: We found that morbidity was minor in light of major survival benefits consistent with prior reports.

Severe controlled hemorrhage resuscitation with small volume poloxamer 188 in sedated miniature swine.

BACKGROUND: The surfactant poloxamer 188 (P188) has been shown to improve survival following hemorrhage. This study used P188 as a small volume resuscitation product in a sedated, sexually mature, male miniature swine severe hemorrhage model for potential improvement in rate and time of survival. METHODS: Fourteen swine were anesthetized, catheterized for hemorrhage and resuscitation and allowed to recover from anesthesia. The animals were sedated and hemorrhaged 60% of estimated blood volume (∼39 mlkg(-1)) exponentially over 1h. Following hemorrhage the animals were treated with either 1.33 mlkg(-1) of P188 (150 mgml(-1); 7 swine) or the P188 citrate vehicle (7 swine) given as an i.v. infusion over 2 min without additional resuscitation fluids. The data were compared with control data from sedated swine similarly hemorrhaged, but with no resuscitation (untreated; n=16). RESULTS: Median (95% CI) survival time for the untreated control swine was 55.8 (36.5-86) min with a 6% survival at 180 min. Median survival time of 161 (80-180) min for the P188 swine was significantly greater than control (p=0.0186), whereas the citrate vehicle median survival time of 91 (32-180) min was not significantly different from control or P188. At the survival target time of 180 min, survival rates were not significantly different among the three groups. TEG data from swine demonstrated anti-coagulant properties of P188. This was confirmed with human blood ex vivo. CONCLUSION: In the presence of severe controlled hemorrhage, P188 improved median survival time. However, retardation of blood clotting raises concerns as to its use in the presence of uncontrolled hemorrhage.

Fasciotomy rates in operations enduring freedom and iraqi freedom: association with injury severity and tourniquet use.

OBJECTIVE: To compare fasciotomy rates and Injury Severity Scores (ISSs) before and after tourniquets were fielded for combat casualties in March 2005. METHODS: A military trauma registry was used to identify 4332 casualties with limb injury between 2003 and 2006. Descriptive statistics and regression analysis were used to compare changes in ISSs, limb Abbreviated Injury Scale (AIS) scores, and fasciotomy rates. An item of specific interest was whether changes in fasciotomy rates occurred before and after March 2005, when tourniquets were fielded. Therefore, this time point served as a specific comparator in the statistical analyses. RESULTS: Among the 4332 limb casualties, 669 (15%) underwent fasciotomy. The ISS doubled (100% increase) during the study. Limb AIS increased 35%. The increase in limb AIS constituted most of the increase in ISS. Monthly fasciotomy rates increased 500% (5% to 30%) during the study. When controlling injury severity (both AIS and ISS), fasciotomy rates tripled (200% increase); but when comparing fasciotomy before and after tourniquet fielding by AIS and ISS, rates only doubled (100% increase). On logistic regression for predicting fasciotomy, the model was unable to determine a good fit for the data because the variables were not significant except weakly for injury severity. CONCLUSIONS: During the period of the study, fasciotomy rates increased as a result of a combination of factors: increasing injury severity, increasing use of tourniquets, and increased awareness of the need to perform prophylactic fasciotomy. Further research should be aimed at determining what the optimum rate of fasciotomy is in such an environment.

Computer decision support software safely improves glycemic control in the burn intensive care unit: a randomized controlled clinical study.

The optimal method for glycemic control in the critically burned patient is unknown. The purpose of this randomized controlled study was to determine the safety and efficacy of computer decision support software (CDSS) to control serum glucose concentration in a burn intensive care unit. Eighteen adult burn/trauma patients receiving continuous insulin infusion were initially randomized to receive glucose management by a traditional paper protocol or a computer protocol (CP) for 72 hours and then crossed over to the alternate method for an additional 72 hours. Time in target glucose range (range: 80-110 mg/dl) was higher in the CP group (47 ± 17% vs 41 ± 16.6%; P ≤ .05); time over target range was not significantly reduced in the CP group (49 ± 17.8% vs 54 ± 17.1%; P = .08); and no difference was noted in time under target range of 80 mg/dl (CP: 4.5 ± 2.8%, paper protocol: 4.8 ± 3.3%; P = .8), less than 60 mg/dl (P = .7), and less than 40 mg/dl (P = 1.0). Severe hypoglycemic events (<40 mg/dl) did not differ from the CP group compared with historical controls for patients receiving no insulin (P = .6). More glucose measurements were performed in the CP group (P = .0003), and nursing staff compliance with CP recommendations was greater (P < .0001). Glycemic control using CDSS is safe and effective for the critically burned patient. Time in target range improved without increase in hypoglycemic events. CDSS enhanced consistency in practice, providing standardization among nursing staff.

Battle casualty survival with emergency tourniquet use to stop limb bleeding.

BACKGROUND: In a previous study conducted at a combat support hospital in Iraq, we reported the major lifesaving benefits of emergency tourniquets to stop bleeding in major limb trauma. Morbidity associated with tourniquet use was minor. STUDY OBJECTIVES: The objective of this study is to further analyze emergency tourniquet use in combat casualty care. DESIGN AND SETTING: This report is a continuation of our previous study of tourniquet use in casualties admitted to a combat support hospital (NCT00517166 at www.ClinicalTrials.gov). METHODS: After verifying comparable methodologies for the first study and the current study, we compared patient results for these two time periods and then pooled data to analyze outcomes with a larger sample size. RESULTS: The total study population was 499 (232 in the previous study and 267 in the current study). In all, 862 tourniquets were applied on 651 limbs. Survival was 87% for both study periods. Morbidity rates for palsies at the level of the tourniquet were 1.7% for study 1 and 1.5% for study 2; major limb shortening was 0.4% for both. Survival was associated with prehospital application (89% vs. 78% hospital, p < 0.01) and application before the onset of shock (96% vs. 4% after). CONCLUSIONS: This study shows consistent lifesaving benefits and low risk of emergency tourniquets to stop bleeding in major limb trauma.

Development and resuscitation of a sedated, mature male miniature swine severe hemorrhage model.

BACKGROUND: A sedated, mature male miniature swine hemorrhage model has been specifically developed to evaluate resuscitation products for the Defense Advanced Research Projects Agency Surviving Blood Loss program. METHODS: Animals were placed in a sling, sedated with midazolam, and hemorrhaged 60% of estimated blood volume (∼39 mL/kg) exponentially for 1 hour with no resuscitation (control; n = 16). An additional 26 swine were treated similarly, then resuscitated with 1 mL/kg/min of Hextend to a systolic blood pressure of either 65 mm Hg ± 2 mm Hg (n = 7) or 80 mm Hg ± 5 mm Hg (n = 7) and with 17ß-estradiol (E2) at 1 mg/kg (n = 6) or 10 mg/kg (n = 6). Animals were observed for 3 hours with periodic blood sampling. Survival times for the two E2 groups were not significantly different (p = 0.59); therefore, the groups were combined for comparison with control. RESULTS: Hemorrhage resulted in a characteristic hypotension and metabolic acidosis. Survival time for the control swine was 64 minutes ± 11.5 minutes with a 6% survival at 180 minutes. The 180 minutes Hextend survival was 86% for 65 mm Hg and 100% for 80 mm Hg. E2 survival was 125 minutes ± 15.3 minutes, significantly different from control (p = 0.01), but E2 survival of 25% at 180 minutes was not different from control. CONCLUSION: A sedated, sexually mature male miniature swine severe hemorrhage model has been successfully developed, resuscitated with Hextend and used to evaluate E2 as a small volume resuscitation product.

Loss of protein, immunoglobulins, and electrolytes in exudates from negative pressure wound therapy.

BACKGROUND: A relatively new technology in wound care, negative pressure wound therapy (NPWT), has become widely used for the management of open abdomens and soft tissue wounds and provides a means to collect wound exudate to quantify protein loss. METHODS: A prospective observational study was conducted in surgical, trauma, or burn patients (8 patients with open abdomens and 9 patients with acute soft tissue wounds on NPWT). NPWT exudate was collected and assayed to characterize loss of protein, electrolyte, and immunoglobulins over multiple days of NPWT. RESULTS: Total protein was present in open abdomen NPWT exudate, 2.9 ± 0.9 g/dL. In the soft tissue wound exudate, a similar mean concentration was found, 2.59 ± 0.6 g/dL (P = .34). Exudate concentrations of albumin, urea nitrogen, immunoglobulins, and electrolytes between wound types were also not significantly different. There were significant (P = .03) differences in the median volume of exudate, 1031 mL/d for open abdomens in contrast to 245 mL/d soft tissue wounds. Therefore, 24-hour losses of proteins and electrolytes were greater in patients with open abdomens than soft tissue wounds. Mean total protein loss was 25 ± 17 g/d for open abdomens and 8 ± 5 g/d for soft tissue wounds. CONCLUSION: There are significant losses of proteins in wound exudate. As there is no significant difference in the concentration of total protein between wound type, the rate of loss may be calculated as 2.9 g/dL times the volume of wound exudate. The rate of protein loss from wounds is similar to the presently assumed insensible loss rate of 12-25 g/d.

Use of recombinant factor VIIa in US military casualties for a five-year period.

BACKGROUND: Two prospective randomized trauma trials have shown recombinant factor VIIa (rFVIIa) to be safe and to decrease transfusion requirements. rFVIIa is presently used in 22% of massively transfused civilian trauma patients. The US Military has used rFVIIa in combat trauma patients for five years, and two small studies of massively transfused patients described an association with improved outcomes. This study was undertaken to assess how deployed physicians are using rFVIIa and its impact on casualty outcomes. METHODS: US combat casualties (n = 2,050) receiving any blood transfusion from 2003 to 2009 were reviewed to compare patients receiving rFVIIa (n = 506) with those who did not (n = 1,544). Propensity-score matching (primary analysis) and multivariable logistic regression were used to compare outcomes. Differences were determined at p < 0.05. RESULTS: Twenty-five percent of patients received rFVIIa. Significant differences were noted between groups in indices of injury severity (Injury Severity Score, Abbreviated Injury Scale score, and Glasgow Coma Scale score), admission physiology (systolic blood pressure, diastolic blood pressure, heart rate, temperature, base deficit, hemoglobin, and international normalization ratio), and use of blood products, indicating that patients treated with rFVIIa were more severely injured, in shock, and coagulopathic. For propensity-score matching, factors associated with death were used: Injury Severity Score, Glasgow Coma Scale score, heart rate, systolic blood pressure, diastolic blood pressure, Hgb, and total packed red blood cell. A total of 266 patients per group were matched; 52% of the rFVIIa group. After pairing, there were no significant differences in any of the demographics, including incidence of massive transfusion (53% vs. 51%). There was no difference in the rate of complications (21% vs. 21%) or mortality (14% vs. 20%) for patients not treated or receiving rFVIIa, respectively. CONCLUSION: In military casualties, rFVIIa is used in the most severely injured patients based on physician selection rather than on guideline criteria. Use of rFVIIa is not associated with an improvement in survival or an increase in complications. The undetected bias of physician selection of patients for treatment with rFVIIa, likely, has an impact on case matching to achieve equivalence similar to that of randomized control studies. This inability to match populations, thus, prevents definitive interpretation of this study and others studies of similar design. This problem emphasizes the need to develop entry criteria to identify patients who could potentially benefit from use of rFVIIa and the need to subsequently perform efficacy studies.

Association of shock, coagulopathy, and initial vital signs with massive transfusion in combat casualties.

BACKGROUND: Timely initiation of a massive transfusion (MT) protocol is associated with improved survival and reduced transfusion for patients requiring MT; however, a priori identification of this population is difficult. The objective of this study was to compare the results of an MT prediction model and actual MT incidence in combat casualties. METHODS: We performed a retrospective review of the Joint Theater Trauma Registry transfusion database for all US service personnel injured in combat during overseas contingency operations who received at least 1 unit of blood. Systolic blood pressure at the time of admission, heart rate, hemoglobin, international normalized ratio, and base deficit were used in a previously developed prediction model for MT. RESULTS: Casualties (n = 1124) were identified who had received at least 1 unit of blood and had all data points. Of these patients, 420 patients (37%) received an MT. Subjects presenting with any two of four possible variables (heart rate >110, systolic blood pressure <110 mm Hg, base deficit < or = -6, and hemoglobin <11) had a 54% incidence of MT with a model sensitivity of 69%. Patients predicted but not observed to receive an MT had earlier time of death and an increased incidence of head injuries compared with those predicted and observed to receive an MT. Patients not predicted but observed to receive an MT had increased chest, abdominal, and extremity injuries than those neither predicted nor observed to receive an MT. CONCLUSION: The decision to implement an MT seems to rely heavily on clinical evaluation of severity of abdominal and extremity injury rather than physiologic derangement. Using a model based on the physiologic parameters--a more objective measure--may decrease mortality in combat casualties.