David B. Hoyt

The coagulopathy of trauma: a review of mechanisms.

BACKGROUND Bleeding is the most frequent cause of preventable death after severe injury. Coagulopathy associated with severe injury complicates the control of bleeding and is associated with increased morbidity and mortality in trauma patients. The causes and mechanisms are multiple and yet to be clearly defined. METHODS Articles addressing the causes and consequences of trauma-associated coagulopathy were identified and reviewed. Clinical situations in which the various mechanistic causes are important were sought along with quantitative estimates of their importance. RESULTS Coagulopathy associated with traumatic injury is the result of multiple independent but interacting mechanisms. Early coagulopathy is driven by shock and requires thrombin generation from tissue injury as an initiator. Initiation of coagulation occurs with activation of anticoagulant and fibrinolytic pathways. This Acute Coagulopathy of Trauma-Shock is altered by subsequent events and medical therapies, in particular acidemia, hypothermia, and dilution. There is significant interplay between all mechanisms. CONCLUSIONS There is limited understanding of the mechanisms by which tissue trauma, shock, and inflammation initiate trauma coagulopathy. Acute Coagulopathy of Trauma-Shock should be considered distinct from disseminated intravascular coagulation as described in other conditions. Rapid diagnosis and directed interventions are important areas for future research.

Prospective Study of Blunt Aortic Injury: Multicenter Trial of the American Association for the Surgery of Trauma

BACKGROUND Blunt aortic injury is a major cause of death from blunt trauma. Evolution of diagnostic techniques and methods of operative repair have altered the management and posed new questions in recent years. METHODS This study was a prospectively conducted multi-center trial involving 50 trauma centers in North America under the direction of the Multi-institutional Trial Committee of the American Association for the Surgery of Trauma. RESULTS There were 274 blunt aortic injury cases studied over 2.5 years, of which 81% were caused by automobile crashes. Chest computed tomography and transesophageal echocardiography were applied in 88 and 30 cases, respectively, and were 75 and 80% diagnostic, respectively. Two hundred seven stable patients underwent planned thoracotomy and repair. Clamp and sew technique was used in 73 (35%) and bypass techniques in 134 (65%). Overall mortality was 31%, with 63% of deaths being attributable to aortic rupture; mortality was not affected by method of repair. Paraplegia occurred postoperatively in 8.7%. Logistic regression analysis demonstrated clamp and sew (p = 0.002) and aortic cross clamp time of > or = 30 minutes (p = 0.01) to be associated with development of postoperative paraplegia. CONCLUSIONS Rupture after hospital admission remains a major problem. Although newer diagnostic techniques are being applied, at this time aortography remains the diagnostic standard. Aortic cross clamp time beyond 30 minutes was associated with paraplegia; bypass techniques, which provide distal aortic perfusion, produced significantly lower paraplegia rates than the clamp and sew approach.

Transfusion of Plasma, Platelets, and Red Blood Cells in a 1:1:1 vs a 1:1:2 Ratio and Mortality in Patients With Severe Trauma: The PROPPR Randomized Clinical Trial

IMPORTANCE Severely injured patients experiencing hemorrhagic shock often require massive transfusion. Earlier transfusion with higher blood product ratios (plasma, platelets, and red blood cells), defined as damage control resuscitation, has been associated with improved outcomes; however, there have been no large multicenter clinical trials. OBJECTIVE To determine the effectiveness and safety of transfusing patients with severe trauma and major bleeding using plasma, platelets, and red blood cells in a 1:1:1 ratio compared with a 1:1:2 ratio. DESIGN, SETTING, AND PARTICIPANTS Pragmatic, phase 3, multisite, randomized clinical trial of 680 severely injured patients who arrived at 1 of 12 level I trauma centers in North America directly from the scene and were predicted to require massive transfusion between August 2012 and December 2013. INTERVENTIONS Blood product ratios of 1:1:1 (338 patients) vs 1:1:2 (342 patients) during active resuscitation in addition to all local standard-of-care interventions (uncontrolled). MAIN OUTCOMES AND MEASURES Primary outcomes were 24-hour and 30-day all-cause mortality. Prespecified ancillary outcomes included time to hemostasis, blood product volumes transfused, complications, incidence of surgical procedures, and functional status. RESULTS No significant differences were detected in mortality at 24 hours (12.7% in 1:1:1 group vs 17.0% in 1:1:2 group; difference, -4.2% [95% CI, -9.6% to 1.1%]; P = .12) or at 30 days (22.4% vs 26.1%, respectively; difference, -3.7% [95% CI, -10.2% to 2.7%]; P = .26). Exsanguination, which was the predominant cause of death within the first 24 hours, was significantly decreased in the 1:1:1 group (9.2% vs 14.6% in 1:1:2 group; difference, -5.4% [95% CI, -10.4% to -0.5%]; P = .03). More patients in the 1:1:1 group achieved hemostasis than in the 1:1:2 group (86% vs 78%, respectively; P = .006). Despite the 1:1:1 group receiving more plasma (median of 7 U vs 5 U, P < .001) and platelets (12 U vs 6 U, P < .001) and similar amounts of red blood cells (9 U) over the first 24 hours, no differences between the 2 groups were found for the 23 prespecified complications, including acute respiratory distress syndrome, multiple organ failure, venous thromboembolism, sepsis, and transfusion-related complications. CONCLUSIONS AND RELEVANCE Among patients with severe trauma and major bleeding, early administration of plasma, platelets, and red blood cells in a 1:1:1 ratio compared with a 1:1:2 ratio did not result in significant differences in mortality at 24 hours or at 30 days. However, more patients in the 1:1:1 group achieved hemostasis and fewer experienced death due to exsanguination by 24 hours. Even though there was an increased use of plasma and platelets transfused in the 1:1:1 group, no other safety differences were identified between the 2 groups. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01545232.

Lethal injuries and time to death in a level I trauma center

BACKGROUND The purpose of this study was to identify the causes and time to death of all trauma victims who died at a level I trauma center during an 11-year period. STUDY DESIGN Autopsies were performed on all patients who died secondary to trauma. Retrospective review of these autopsies was carried out and appended to existing trauma registry data. Standard definitions were used to attribute the cause of death in each case. Preventable deaths were determined by a standardized peer review process. RESULTS Between January 1985 and December 1995, a total of 900 trauma patients died. This represented 7.3% of all major trauma admissions (12,320). Seventy percent of these patients died within the first 24 hours of admission. Thoracic vascular and central nervous system (CNS) injuries were the most common causes of death in the first hour after admission to the hospital. CNS injuries were the most common causes of death within the 72 deaths after admission. Acute inflammatory processes (multiple organ failure, acute respiratory distress syndrome, and pneumonia) and pulmonary emboli were the leading causes of death after the first 72 hours. Overall, 43.6% (393 of 900) of all trauma deaths were caused by CNS injuries, making this the most common cause of death in our study. The preventable death rate was 1%. CONCLUSIONS The first 24 hours after trauma are the deadliest for these patients. Primary and secondary CNS injuries are the leading causes of death. Prevention, early identification, and treatment of potentially lethal injuries should remain the focus of those who treat trauma patients.Background: The purpose of this study was to identify the causes and time to death of all trauma victims who died at a level I trauma center during an 11-year period. Study Design: Autopsies were performed on all patients who died secondary to trauma. Retrospective review of these autopsies was carried out and appended to existing trauma registry data. Standard definitions were used to attribute the cause of death in each case. Preventable deaths were determined by a standardized peer review process. Results: Between January 1985 and December 1995, a total of 900 trauma patients died. This represented 7.3% of all major trauma admissions (12,320). Seventy percent of these patients died within the first 24 hours of admission. Thoracic vascular and central nervous system (CNS) injuries were the most common causes of death in the first hour after admission to the hospital. CNS injuries were the most common causes of death within the 72 deaths after admission. Acute inflammatory processes (multiple organ failure, acute respiratory distress syndrome, and pneumonia) and pulmonary emboli were the leading causes of death after the first 72 hours. Overall, 43.6% (393 of 900) of all trauma deaths were caused by CNS injuries, making this the most common cause of death in our study. The preventable death rate was 1%. Conclusions: The first 24 hours after trauma are the deadliest for these patients. Primary and secondary CNS injuries are the leading causes of death. Prevention, early identification, and treatment of potentially lethal injuries should remain the focus of those who treat trauma patients.

Outcome after major trauma: 12-month and 18-month follow-up results from the Trauma Recovery Project

BACKGROUND The importance of outcome after major injury has continued to gain attention in light of the ongoing development of sophisticated trauma care systems in the United States. The Trauma Recovery Project (TRP) is a large prospective epidemiologic study designed to examine multiple outcomes after major trauma in adults aged 18 years and older, including quality of life, functional outcome, and psychologic sequelae such as depression and posttraumatic stress disorder (PTSD). Patient outcomes were assessed at discharge and at 6, 12, and 18 months after discharge. The specific objectives of the present report are to describe functional outcomes at the 12-month and 18-month follow-ups in the TRP population and to examine the association of putative risk factors with functional outcome. METHODS Between December 1, 1993, and September 1, 1996, 1,048 eligible trauma patients triaged to four participating trauma center hospitals in the San Diego Regionalized Trauma System were enrolled in the TRP study. The admission criteria for patients were as follows: (1) age 18 years or older; (2) Glasgow Coma Scale score on admission of 12 or greater; and (3) length of stay greater than 24 hours. Functional outcome after trauma was measured before and after injury using the Quality of Well-Being (QWB) Scale, an index sensitive to the well end of the functioning continuum (0 = death, 1.000 = optimum functioning). Follow-up at 12 months after discharge was completed for 806 patients (79%), and follow-up at 18 months was completed for 780 patients (74%). Follow-up contact at any of the study time points (6, 12, or 18 months) was achieved for 926 (88%) patients. RESULTS The mean age was 36 +/- 14.8 years, and 70% of the patients were male; 52% were white, 30% were Hispanic, and 18% were black or other. Less than 40% of study participants were married or living together. The mean Injury Severity Score was 13 +/- 8.5, with 85% blunt injuries and a mean length of stay of 7 +/- 9.2 days. QWB scores before injury reflected the norm for a healthy adult population (mean, 0.810 +/- 0.171). At the 12-month follow-up, there were very high levels of functional limitation (QWB mean score, 0.670 +/- 0.137). Only 18% of patients followed at 12 months had scores above 0.800, the norm for a healthy population. There was no improvement in functional limitation at the 18-month follow-up (QWB mean score, 0.678 +/- 0.130). The majority of patients (80%) at the 18-month follow-up continued to have QWB scores below the healthy norm of 0.800. Postinjury depression, PTSD, serious extremity injury, and intensive care unit days were significant independent predictors of 12-month and 18-month QWB outcome. CONCLUSION This study demonstrates a prolonged and profound level of functional limitation after major trauma at 12-month and 18-month follow-up. This is the first report of long-term outcome based on the QWB Scale, a standardized quality-of-life measure, and provides new and provocative evidence that the magnitude of dysfunction after major injury has been underestimated. Postinjury depression, PTSD, serious extremity injury, and intensive care unit days are significantly associated with 12-month and 18-month QWB outcome.

The etiology of missed cervical spine injuries.

Missed or delayed diagnosis of cervical spine (C-spine) injuries may lead to extension of those injuries and subsequent preventable mortality or morbidity. Previous reports examining the incidence of missed C-spine injuries have not determined the nature of the causal clinical errors made or the extent to which these errors are avoidable. This study was undertaken to (1) determine the incidence of delayed or missed diagnosis of C-spine injuries and the consequences of those missed injuries; (2) define the clinical errors leading to the delays; and (3) to determine if these errors are the result of fundamental problems or a lack of advanced diagnostic skills or equipment. Between August 1985 and February 1991, 32,117 trauma patients were admitted to one of the six trauma centers in San Diego county. Cervical spine injuries were identified in 740 patients and the diagnosis was delayed or missed in 34 patients (4.6%). Ten of the 34 patients (29%) developed permanent sequelae as a result of these delays. The single most common error was the failure to obtain an adequate series of C-spine roentgenograms. Delayed diagnosis could have been avoided in at least 31 of 34 injuries by the appropriate use of a standard three-view C-spine series and careful interpretation of those roentgenograms. Patients at risk for C-spine injuries require a technically adequate three-view C-spine series and skilled radiographic interpretation. Cervical spine precautions should be maintained, particularly in high risk patients, until appropriate and expert review of the cervical spine roentgenograms can be obtained.

Status of nonoperative management of blunt hepatic injuries in 1995: a multicenter experience with 404 patients

INTRODUCTION Nonoperative management is presently considered the treatment modality of choice in over 50% of adult patients sustaining blunt hepatic trauma who meet inclusion criteria. A multicenter study was retrospectively undertaken to assess whether the combined experiences at level I trauma centers could validate the currently reported high success rate, low morbidity, and virtually nonexistent mortality associated with this approach. Thirteen level I trauma centers accrued 404 adult patients sustaining blunt hepatic injuries managed nonoperatively over the last 5 years. Seventy-two percent of the injuries resulted from motor vehicle crashes. The mean injury severity score for the entire group was 20.2 (range, 4-75), and the American Association for the Surgery of Trauma-computerized axial tomography scan grading was as follows: grade I, 19% (n = 76); grade II, 31% (n = 124); grade III, 36% (n = 146); grade IV, 10% (n = 42); and grade V, 4% (n = 16). There were 27 deaths (7%) in the series, with 59% directly related to head trauma. Only two deaths (0.4%) could be attributed to hepatic injury. Twenty-one (5%) complications were documented, with the most common being hemorrhage, occurring in 14 (3.5%). Only 3 (0.7%) of these 14 patients required surgical intervention, 6 were treated by transfusions alone (0.5 to 5 U), 4 underwent angio-embolization, and 1 was further observed. Other complications included 2 bilomas and 3 perihepatic abscesses (all drained percutaneously). Two small bowel injuries were initially missed (0.5%), and diagnosed 2 and 3 days after admission. Overall, 6 patients required operative intervention: 3 for hemorrhage, 2 for missed enteric injuries, and 1 for persistent sepsis after unsuccessful percutaneous drainage. Average length of stay was 13 days. Nonoperative management of blunt hepatic injuries is clearly the treatment modality of choice in hemodynamically stable patients, irrespective of grade of injury or degree of hemoperitoneum. Current data would suggest that 50 to 80% (47% in this series) of all adult patients with blunt hepatic injuries are candidates for this form of therapy. Exactly 98.5% of patients analyzed in this study successfully avoided operative intervention. Bleeding complications are infrequently encountered (3.5%) and can often be managed nonoperatively. Although grades IV and V injuries composed 14% of the series, they represented 66.6% of the patients requiring operative intervention and thus merit constant re-evaluation and close observation in critical care units. The optimal time for follow-up computerized axial tomography scanning seems to be within 7 to 10 days after injury.

The first randomized trial of human polymerized hemoglobin as a blood substitute in acute trauma and emergent surgery

BACKGROUND Human polymerized hemoglobin (PolyHeme) is a universally compatible, disease-free, oxygen-carrying resuscitative fluid. This is the first prospective, randomized trial to compare directly the therapeutic benefit of PolyHeme with that of allogeneic red blood cells (RBCs) in the treatment of acute blood loss. STUDY DESIGN Forty-four trauma patients (33 male, 11 female) aged 19-75 years with an average Injury Severity Score (ISS) score of 21+/-10 were randomized to receive red cells (n = 23) or up to 6 U (300 g) of PolyHeme (n = 21) as their initial blood replacement after trauma and during emergent operations. RESULTS There were no serious or unexpected adverse events related to PolyHeme. The PolyHeme infusion of 4.4+/-2.0 units (mean +/- SD) resulted in a plasma [Hb] of 3.9+/-1.3 g/dL, which accounted for 40% of the total circulating [Hb]. There was no difference in total [Hb] between the groups before infusion (10.4+/-2.3 g/dL control vs. 9.4+/-1.9 g/dL experimental). At end-infusion the experimental RBC [Hb] fell to 5.8+/-2.8 g/dL vs. 10.6+/-1.8 g/dL (p < 0.05) in the control, although the total [Hb] was not different between the groups or from pre-infusion. The total number of allogeneic red cell transfusions for the control and experimental groups was 10.4+/-4.2 units vs. 6.8+/-3.9 units (p < 0.05) through day 1, and 11.3+/-4.1 units vs. 7.8 +/-4.2 units (p = 0.06) through day 3. CONCLUSIONS PolyHeme is safe in acute blood loss, maintains total [Hb] in lieu of red cells despite the marked fall in RBC [Hb], and reduces the use of allogeneic blood. PolyHeme appears to be a clinically useful blood substitute.

Original Scientific ArticlesLethal Injuries and Time to Death in a Level I Trauma Center 1

BACKGROUND The purpose of this study was to identify the causes and time to death of all trauma victims who died at a level I trauma center during an 11-year period. STUDY DESIGN Autopsies were performed on all patients who died secondary to trauma. Retrospective review of these autopsies was carried out and appended to existing trauma registry data. Standard definitions were used to attribute the cause of death in each case. Preventable deaths were determined by a standardized peer review process. RESULTS Between January 1985 and December 1995, a total of 900 trauma patients died. This represented 7.3% of all major trauma admissions (12,320). Seventy percent of these patients died within the first 24 hours of admission. Thoracic vascular and central nervous system (CNS) injuries were the most common causes of death in the first hour after admission to the hospital. CNS injuries were the most common causes of death within the 72 deaths after admission. Acute inflammatory processes (multiple organ failure, acute respiratory distress syndrome, and pneumonia) and pulmonary emboli were the leading causes of death after the first 72 hours. Overall, 43.6% (393 of 900) of all trauma deaths were caused by CNS injuries, making this the most common cause of death in our study. The preventable death rate was 1%. CONCLUSIONS The first 24 hours after trauma are the deadliest for these patients. Primary and secondary CNS injuries are the leading causes of death. Prevention, early identification, and treatment of potentially lethal injuries should remain the focus of those who treat trauma patients.Background: The purpose of this study was to identify the causes and time to death of all trauma victims who died at a level I trauma center during an 11-year period. Study Design: Autopsies were performed on all patients who died secondary to trauma. Retrospective review of these autopsies was carried out and appended to existing trauma registry data. Standard definitions were used to attribute the cause of death in each case. Preventable deaths were determined by a standardized peer review process. Results: Between January 1985 and December 1995, a total of 900 trauma patients died. This represented 7.3% of all major trauma admissions (12,320). Seventy percent of these patients died within the first 24 hours of admission. Thoracic vascular and central nervous system (CNS) injuries were the most common causes of death in the first hour after admission to the hospital. CNS injuries were the most common causes of death within the 72 deaths after admission. Acute inflammatory processes (multiple organ failure, acute respiratory distress syndrome, and pneumonia) and pulmonary emboli were the leading causes of death after the first 72 hours. Overall, 43.6% (393 of 900) of all trauma deaths were caused by CNS injuries, making this the most common cause of death in our study. The preventable death rate was 1%. Conclusions: The first 24 hours after trauma are the deadliest for these patients. Primary and secondary CNS injuries are the leading causes of death. Prevention, early identification, and treatment of potentially lethal injuries should remain the focus of those who treat trauma patients.

Blunt carotid artery dissection : incidence, associated injuries, screening, and treatment

Blunt carotid dissection (BCD) is a rare injury occurring in less than one in 1,000 victims of blunt injuries. Using a 4-year experience in a trauma system with 14 cases of BCD, we performed a matched blunt trauma patient case-control analysis to determine if there were patterns of injuries that were associated with increased risk of BCD. Patients with combinations of head, facial, and cervical spine injuries with or without extremity fractures proved to be at significantly increased risk for BCD. Duplex scanning appears to be a useful screening tool for these patients. Anticoagulation was the preferred treatment once neurologic deficits were present.