A novel means to classify response to resuscitation in the severely burned: Derivation of the KMAC value.

BACKGROUND: Resuscitation fluid rates following burn are currently guided by a weight and burn size formulae, then titrated to urine output. Traditionally, 24h resuscitation is reported as volume of resuscitation received without direct consideration for the physiologic response. We propose an input-to-output ratio to describe the course of burn resuscitation and predict eventual outcomes. METHODS: We reviewed admissions to a burn center from January 2003 through August 2006. Inclusion criteria were ≥20%TBSA, admission ≤8h after burn, and survived ≥24h. Demographics, input volume and urine output, and clinical outcomes were recorded. A ratio of input volume (cc/kg/%TBSA/h) to urine output (cc/kg/h) was calculated at 24h. The ratio of fluid intake to urine output reflecting an 'expected' response was developed: 4cc/kg/%TBSA/24h (0.166cc/kg/%TBSA/h) divided by 0.5-1.0cc urine/kg/h for an expected range 0.166-0.334. Subjects were classified based upon the ratio: over-responders (<0.166), expected (0.166-0.334), or under-responders (>0.334). Clinical outcomes were compared and concordance of classification to values was calculated at 12h. RESULTS: 102 subjects met inclusion criteria; 29 in the over-responders, 37 in the expected, and 36 in the under-responders. Resuscitation volume was directly proportional to the calculated ratio while urine output was inversely proportional. Group mortality was 21%, 11%, and 44%, respectively, with a significant difference between the expected and under-responders (p<0.002). We found decreased ventilator-free days in the under-responders, and when deaths were excluded, decreased ICU-free days as well (p<0.05). Concordance of paired data gathered at 12h and 24h was 67% for the under-responder group. CONCLUSIONS: We describe a novel ratio to classify acute resuscitation after severe burn including the patient's response. Such a classification is associated with eventual outcomes.

Incidence of primary blast injury in US military overseas contingency operations: a retrospective study.

OBJECTIVES: The present retrospective study was performed to determine the incidence and outcome of primary blast injury and to identify possible changes over the course of the conflicts between 2003 and 2006. SUMMARY BACKGROUND DATA: Combat physicians treating patients injured in overseas contingency operations observed an increase in the severity of explosion injuries occurring during this period. METHODS: This retrospective study included service members injured in explosions between March 2003 and October 2006. The Joint Theater Trauma Registry provided demographic information, injury severity score, and International Classification of Diseases 9 codes used to diagnose primary blast injury. Autopsy reports of the last 497 combat-related deaths of 2006 were also reviewed. RESULTS: Of 9693 admissions, of which 6687 were injured in combat, 4765 (49%) were injured by explosions: 2588 in 2003-2004 and 1935 in 2005-2006. Dates of injury were unavailable for 242 casualties. Injury severity score (9 +/- 10 vs. 11 +/- 10, P < 0.0001) and incidence of primary blast injury (12% vs. 15%, P < 0.01) increased. The return-to-duty rate decreased (40% vs. 18%, P < 0.001), but mortality remained low (1.4% vs. 1.5%, P = NS). There was no significant difference in incidence of primary blast injury between personnel who were killed in action and those who died of wounds at a medical facility. CONCLUSIONS: Injury severity and incidence of primary blast injury increased during the 4-year period, whereas return-to-duty rates decreased. Despite increasingly devastating injuries, the mortality rate due to explosion injuries remained low and unchanged.

Thromboembolic complications following trauma.

BACKGROUND: Some studies have reported an increased incidence of thromboembolic complications following trauma. STUDY DESIGN AND METHODS: We performed a literature review and queried the National Trauma Data Bank to more closely examine the incidence of a variety of thromboembolic complications following injury. RESULTS: Thromboembolic events are rare, but occur at a greater rate in more severely injured patients. It is unclear, however, whether the incidence of thromboembolic complications in trauma patients is on the rise overall. Differences in study populations, particularly injury severity scores, as well as different methods of screening, diagnosis, prophylaxis, and treatment have led to extreme differences in reported rates. CONCLUSION: While recent research has added to the body of knowledge, continued efforts focusing on risk stratification, diagnosis, screening, prophylaxis, and treatment are necessary to rationally understand the spectrum of thrombotic complications.

Increased mortality associated with the early coagulopathy of trauma in combat casualties.

BACKGROUND: Recent civilian studies have documented a relationship between increased mortality and the presence of an early coagulopathy of trauma diagnosed in the emergency department (ED). We hypothesized that acute coagulopathy (international normalized ratio >/=1.5) in combat casualties was associated with increased injury severity and mortality as is seen in civilian trauma patients. METHODS: A retrospective study of combat casualties who received a blood transfusion at a single combat support hospital between September 2003 and December 2004 was performed. Coagulation status, pH, base deficit, and temperature were recorded at arrival to the ED. These were analyzed by Injury Severity Score (ISS), associated injury patterns, and mortality. RESULTS: A total of 3,287 patients were treated at the combat support hospital during the study period. Of these, 391 patients were transfused and primarily admitted, thus meeting the study criteria, 347 had coagulation data, and 92% had a penetrating mechanism. The prevalence of acute coagulopathy in transfused casualties measured with point-of-care devices at arrival in the ED was 38%. Mortality in those who were coagulopathic at arrival to the ED was 24% (32/133) versus 4% (8/214) in those not presenting with coagulopathy (p < 0.001). The prevalence of mortality by coagulopathy increased as ISS increased. Coagulopathy and acidosis were associated with mortality, odds ratio (OR), 5.38 [95% confidence interval (CI), 1.55-11.37] and 6.9 (95% CI, 2.1-19.5), respectively. Temperature did not affect outcomes (OR, 1.1; 95% CI, 0.4-2.6). CONCLUSIONS: The early coagulopathy of trauma was rapidly diagnosed in the ED and present in more than one-third of combat casualties who received a transfusion, similar to the incidence found in civilian trauma patients. Coagulopathy, independent of hypothermia but strongly correlated with acidosis and ISS, was associated with mortality in combat casualties, similar to that found in civilian trauma patients. Early diagnosis and treatment of acute traumatic coagulopathy with new resuscitation paradigms may improve outcomes.

Injury severity and causes of death from Operation Iraqi Freedom and Operation Enduring Freedom: 2003-2004 versus 2006.

BACKGROUND: The opinion that injuries sustained in Iraq and Afghanistan have increased in severity is widely held by clinicians who have deployed multiple times. To continuously improve combat casualty care, the Department of Defense has enacted numerous evidence-based policies and clinical practice guidelines. We hypothesized that the severity of wounds has increased over time. Furthermore, we examined cause of death looking for opportunities of improvement for research and training. METHODS: Autopsies of the earliest combat deaths from Iraq and Afghanistan and the latest deaths of 2006 were analyzed to assess changes in injury severity and causes of death. Fatalities were classified as nonsurvivable (NS) or potentially survivable (PS). PS deaths were then reviewed in depth to analyze mechanism and cause. RESULTS: There were 486 cases from March 2003 to April 2004 (group 1) and 496 from June 2006 to December 2006 (group 2) that met inclusion criteria. Of the PS fatalities (group 1: 93 and group 2: 139), the injury severity score was lower in the first group (27 +/- 14 vs. 37 +/- 16, p < 0.001), and had a lower number of abbreviated injury scores >or=4 (1.1 +/- 0.79 vs. 1.5 +/- 0.83 per person, p < 0.001). The main cause of death in the PS fatalities was truncal hemorrhage (51% vs. 49%, p = NS). Deaths per month between groups doubled (35 vs. 71), whereas the case fatality rates between the two time periods were equivalent (11.0 vs. 9.8, p = NS). DISCUSSION: In the time periods of the war studied, deaths per month has doubled, with increases in both injury severity and number of wounds per casualty. Truncal hemorrhage is the leading cause of potentially survivable deaths. Arguably, the success of the medical improvements during this war has served to maintain the lowest case fatality rate on record.

A predictive model for massive transfusion in combat casualty patients.

BACKGROUND: Massive transfusion (MT) is associated with increased morbidity and mortality in severely injured patients. Early and aggressive use of blood products in these patients may correct coagulopathy, control bleeding, and improve outcomes. However, rapid identification of patients at risk for MT has been difficult. We postulated that evaluation of clinical variables routinely assessed upon admission would allow identification of these patients for earlier, more effective intervention. METHODS: A retrospective cohort study was conducted at a single combat support hospital to identify risk factors for MT in patients with traumatic injuries. Demographic, diagnostic, and laboratory variables obtained upon admission were evaluated. Univariate and multivariate analyses were performed. An algorithm was formulated, validated with an independent dataset and a simple scoring system was devised. RESULTS: Three thousand four hundred forty-two patient records were reviewed. At least one unit of blood was transfused to 680 patients at the combat support hospital. Exclusion criteria included age less than 18 years, transfer from another medical facility, designation as a security internee, or incomplete data fields. The final number of patients was 302, of whom 26.5% (80 of 302) received a MT. Patients with MT had higher mortality (29 vs. 7% [p < 0.001]), and an increased Injury Severity Score (25 +/- 11.1 vs. 18 +/- 16.2 [p < 0.001]). Four independent risk factors for MT were identified: heart rate >105 bpm, systolic blood pressure <110 mm Hg, pH <7.25, and hematocrit <32.0%. An algorithm was created to analyze the risk of MT (area under the curve [AUC] = 0.839). In an independent data set of 396 patients the ability to accurately identify those requiring MT was 66% (AUC = 0.747). CONCLUSIONS: Independent predictors for MT were identified in a cohort of severely injured patients requiring transfusions. Patients requiring a MT can be identified with variables commonly obtained upon hospital admission.

Effect of plasma and red blood cell transfusions on survival in patients with combat related traumatic injuries.

BACKGROUND: The amount and age of stored red blood cells (RBCs) are independent predictors of multiorgan failure and death in transfused critically ill patients. The independent effect of plasma transfusion on survival has not been evaluated. Our objective was to determine the independent effects of plasma and RBC transfusion on survival for patients with combat-related traumatic injuries receiving any blood products. METHODS: We performed a retrospective review of 708 patients transfused at least one unit of a blood product at one combat support hospital between November 2003 and December 2004. Admission vital signs, laboratory values, amount of blood products transfused in a 24-hour period, and Injury Severity Score (ISS) were analyzed by multivariate logistic regression to determine independent associations with in-hospital mortality. RESULTS: Seven hundred and eight of 3,287 (22%) patients admitted for traumatic injuries were transfused a blood product. Median ISS was 14 (range, 9-25). In-hospital mortality was 12%. Survival was associated with admission Glasgow Coma Scale score, SBP, temperature, hematocrit, base deficit, INR, amount of RBCs transfused, and massive transfusion. Each transfused FFP unit was independently associated with increased survival (OR: 1.17; 95% CI: [1.06-1.29]; p = 0.002); each transfused RBC unit was independently associated with decreased survival (OR: 0.86; [0.8-0.92]; p = 0.001). A subset analysis of patients (n = 567) without massive transfusion (1-9 RBC/FWB units) also revealed an independent association between each FFP unit and improved survival (OR: 1.22; 95% CI: [1.0-1.48]; p = 0.05) and between each RBC unit and decreased survival (OR: 0.77; [0.64-0.92]; p = 0.004). CONCLUSION: For trauma patients transfused at least one unit of a blood product, FFP and RBC amounts were independently associated with increased survival and decreased survival, respectively. Prospective studies are needed to determine whether the early and increased use of plasma and decreased use of RBCs affect mortality for patients with traumatic injuries requiring transfusion.

The effect of recombinant activated factor VII on mortality in combat-related casualties with severe trauma and massive transfusion.

BACKGROUND: The majority of patients with potentially survivable combat-related injuries die from hemorrhage. Our objective was to determine whether the use of recombinant activated factor VII (rFVIIa) decreased mortality in combat casualties with severe trauma who received massive transfusions and if its use was associated with increased severe thrombotic events. METHODS: We retrospectively reviewed a database of combat casualty patients with severe trauma (Injury Severity Score [ISS] >15) and massive transfusion (red blood cell [RBCs] >/=10 units/24 hours) admitted to one combat support hospital in Baghdad, Iraq, between December 2003 and October 2005. Admission vital signs and laboratory data, blood products, ISS, 24-hour and 30-day mortality, and severe thrombotic events were compared between patients who received rFVIIa (rFVIIa) and did not receive rFVIIa (rFVIIa). RESULTS: Of 124 patients in this study, 49 patients received rFVIIa and 75 did not. ISS, laboratory values, and admission vitals did not differ between rFVIIa and rFVIIa groups, except for systolic blood pressure (mm Hg) 105 +/- 33 and 92 +/- 28, p = 0.02 and temperature ( degrees F) 96.3 +/- 2.1 and 95.2 +/- 2.4, p = 0.03, respectively. Interactions between all vital signs and laboratory values measured upon admission, to include systolic blood pressure and temperature, were not significant when measured between rFVIIa use and 30-day mortality. Twenty-four-hour mortality was 7 of 49 (14%) in rFVIIa and 26 of 75 (35%) in rFVIIa, (p = 0.01); 30-day mortality was 15 of 49 (31%) and 38 of 75 (51%), (p = 0.03). Death from hemorrhage was 8 of 14 (57%) for rFVIIa patients compared with 29 of 37 (78%) for rFVIIa patients, (p = 0.12). The incidence of severe thrombotic events was similar in both groups. CONCLUSIONS: The early use of rFVIIa was associated with decreased 30-day mortality in severely injured combat casualties requiring massive transfusion, but was not associated with increased risk of severe thrombotic events.