Joseph F. Rappold

Impact of joint theater trauma system initiatives on battlefield injury outcomes

INTRODUCTION The US military forces developed and implemented the Joint Theater Trauma System (JTTS) and Joint Theater Trauma Registry (JTTR) using US civilian trauma system models with the intent of improving outcomes after battlefield injury. METHODS The purpose of this analysis was to elaborate the impact of the JTTS. To quantify these achievements, the JTTR captured mechanism, acute physiology, diagnostic, therapeutic, and outcome data on 23,250 injured patients admitted to deployed US military treatment facilities from July 2003 through July 2008 for analysis. Comparative analysis to civilian trauma systems was done using the National Trauma Data Bank (NTDB). RESULTS In contrast to civilian trauma systems with an 11.1% rate of penetrating injury, 68.3% of battlefield wounds were by penetrating mechanism. In the analyzed cohort, 23.3% of all patients had an Injury Severe Score (ISS) > or = 16, which is similar to the civilian rate of 22.4%. In the military injury population, 66% of injuries were combat-related. In addition, in the military injury group, 21.8% had metabolic evidence of shock with a base deficit > or = 5, 29.8% of patients required blood transfusion, and 6.4% of the total population of combat casualties required massive transfusion (>10 U red blood cells/24 hours). With this complex and severely injured population of battlefield injuries, the JTTS elements were used to recognize and remedy more than 60 trauma system issues requiring leadership and advocacy, education, research, and alterations in clinical care. Of particular importance to the trauma system was the implementation and tracking of performance improvement indicators and the dissemination of 27 evidence-based clinical practice guidelines (CPGs). In particular, the damage control resuscitation guideline was associated with a decrease in mortality in the massively transfused from 32% pre-CPG to 21% post-CPG. As evidence of the effectiveness of the JTTS, a mortality rate of 5.2% after battlefield hospital admission is comparable to a case fatality rate of 4.3% reported in an age-matched cohort from the NTDB. CONCLUSIONS JTTS initiatives contributed to improved survival after battlefield injury. The JTTS has set the standard of trauma care for the modern battlefield using contemporary systems-based methodologies.

Tranexamic Acid and Trauma: Current Status and Knowledge Gaps with Recommended Research Priorities

ABSTRACT A recent large civilian randomized controlled trial on the use of tranexamic acid (TXA) for trauma reported important survival benefits. Subsequently, successful use of TXA for combat casualties in Afghanistan was also reported. As a result of these promising studies, there has been growing interest in the use of TXA for trauma. Potential adverse effects of TXA have also been reported. A US Department of Defense committee conducted a review and assessment of knowledge gaps and research requirements regarding the use of TXA for the treatment of casualties that have experienced traumatic hemorrhage. We present identified knowledge gaps and associated research priorities. We believe that important knowledge gaps exist and that a targeted, prioritized research effort will contribute to the refinement of practice guidelines over time.

Trauma hemostasis and oxygenation research position paper on remote damage control resuscitation: definitions, current practice, and knowledge gaps.

ABSTRACT The Trauma Hemostasis and Oxygenation Research Network held its third annual Remote Damage Control Resuscitation Symposium in June 2013 in Bergen, Norway. The Trauma Hemostasis and Oxygenation Research Network is a multidisciplinary group of investigators with a common interest in improving outcomes and safety in patients with severe traumatic injury. The network’s mission is to reduce the risk of morbidity and mortality from traumatic hemorrhagic shock, in the prehospital phase of resuscitation through research, education, and training. The concept of remote damage control resuscitation is in its infancy, and there is a significant amount of work that needs to be done to improve outcomes for patients with life-threatening bleeding secondary to injury. The prehospital phase of resuscitation is critical in these patients. If shock and coagulopathy can be rapidly identified and minimized before hospital admission, this will very likely reduce morbidity and mortality. This position statement begins to standardize the terms used, provides an acceptable range of therapeutic options, and identifies the major knowledge gaps in the field.

Tranexamic acid in remote damage control resuscitation

With the advent of remote damage control resuscitation and far‐forward surgery, a renewed emphasis has been placed on examining a variety of pharmacologic adjuncts to controlling blood loss before definitive operative intervention. In this paper, the authors review the current state of the art for tranexamic acid (TXA) and its potential benefits to those patients who are in need of a massive transfusion. Specifically addressed are its biologic and pharmacologic properties, as well the results of a number of recent studies. The 2010 CRASH‐2 trial randomized in excess of 20,000 patients and demonstrated a reduction in all‐cause mortality from 16.0 to 14.5% and death due to bleeding from 5.7 to 4.9%. The 2012 Military Application of Tranexamic Acid in Trauma Emergency Resuscitation study provided a retrospective analysis of 896 wounded cared for at a military hospital in Afghanistan. This study demonstrated a 23.9%‐17.4% reduction in all‐cause mortality. Finally, they discuss the potential complications associated with TXA use as well as areas of future research, which are needed to solidify our knowledge of TXA and its potential beneficial effects on controlling bleeding.

Blood Far Forward: Time to Get Moving!

ABSTRACT In planning for future contingencies, current problems often crowd out historical perspective and planners often turn to technological solutions to bridge gaps between desired outcomes and the reality of recent experience. The US Military, North Atlantic Treaty Organization, and other allies are collectively taking stock of 10-plus years of medical discovery and rediscovery of combat casualty care after the wars in Iraq and Afghanistan. There has been undeniable progress in the treatment of combat wounded during the course of the conflicts in Southwest Asia, but continued efforts are required to improve hemorrhage control and provide effective prehospital resuscitation that treats both coagulopathy and shock. This article presents an appraisal of the recent evolution in medical practice in historical context and suggests how further gains in far forward resuscitation might be achieved using existing technology and methods based on whole-blood transfusion while research on new approaches continues.

Noncardiac surgery in patients on mechanical circulatory support.

This study examined outcomes in patients with left ventricular assist device (LVAD) and extracorporeal membrane oxygenation (ECMO) requiring noncardiac surgical procedures and identified factors that influence outcomes. All patients with mechanical circulatory support (MCS) devices at our institution from 2002 to 2013 undergoing noncardiac surgical procedures were reviewed. There were 148 patients requiring MCS during the study period, with 40 (27.0%) requiring 62 noncardiac surgical procedures. Of these, 29 (72.5%) had implantable LVAD and 11 (27.5%) were supported with ECMO. The two groups were evenly matched with regard to age (53.6 vs. 54.5 years, p = 0.87), male sex (71.4 vs. 45.5%, p = 0.16), and baseline creatinine (1.55 vs. 1.43 mg/dl, p = 0.76). Patients on ECMO had greater demand for postoperative blood products (0.8 vs. 2.8 units of packed red blood cells, p = 0.002) and greater postoperative increase in creatinine (0.07 vs. 0.44 mg/dl, p = 0.047). Median survival was markedly worse in ECMO patients. Factors associated with mortality included ECMO support, history of biventricular assist device, and postoperative blood transfusion. Preoperative aspirin was associated with survival. These findings demonstrate the importance of careful surgical hemostasis and minimizing perioperative blood transfusions in patients on MCS undergoing noncardiac surgical procedures. In addition, low-dose antiplatelet therapy should be continued perioperatively.

Examining prehospital intubation for penetrating trauma in a swine hemorrhagic shock model.

BACKGROUND: Prehospital intubation does not result in a survival advantage in patients experiencing penetrating trauma, yet resistance to immediate transportation to facilitate access to definitive care remains. An animal model was developed to determine whether intubation provides a survival advantage during severe hemorrhagic shock. We hypothesized that intubation would not provide a survival advantage in potentially lethal hemorrhage. METHODS: After starting a propofol drip, Yorkshire pigs were intubated (n = 6) or given bag‐valve mask ventilation (n = 7) using 100% oxygen. The carotid artery was cannulated with a 14‐gauge catheter, and a Swan‐Ganz catheter was placed under fluoroscopy using a central venous introducer. After obtaining baseline hemodynamic and laboratory data, the animals were exsanguinated through the carotid line until death. The primary end point was time until death, while secondary end points included volume of blood shed, temperature, cardiac index, mean arterial pressure, lactic acid, base excess, and creatinine levels measured in 10‐minute intervals. RESULTS: There was no difference in time until death between the two groups (51.1 [2.5] minutes vs. 48.5 [2.4] minutes, p = 0.52). Intubated animals had greater volume of blood shed at 30 minutes (33.6 [4.4] mL/kg vs. 28.5 [4.3] mL/kg, p = 0.03), 40 minutes (41.7 [4.7] mL/kg vs. 34.9 [3.8] mL/kg, p = 0.04), and 50 minutes (49.2 [8.6] mL/kg vs. 40.2 [1.0] mL/kg, p = 0.001). In addition, the intubated animals were more hypothermic at 40 minutes (35.5°C [0.4°C] vs. 36.7°C [0.2°C], p = 0.01) and had higher lactate levels (2.4 [0.1] mmol/L vs. 1.8 [0.4] mmol/L, p = 0.04) at 10 minutes. Cardiac index (p = 0.66), mean arterial pressure (p = 0.69), base excess (p = 0.14), and creatinine levels (p = 0.37) were not different throughout the shock phase. CONCLUSION: Intubation does not convey a survival advantage in this model of severe hemorrhagic shock. Furthermore, intubation in the setting of severe hemorrhagic shock may result in a more profuse hemorrhage, worse hypothermia, and higher lactate when compared with bag‐valve mask ventilation.

Examining Noncardiac Surgical Procedures in Patients on Extracorporeal Membrane Oxygenation.

As extracorporeal membrane oxygenation (ECMO) is increasingly used for patients with cardiac and/or pulmonary failure, the need for noncardiac surgical procedures (NCSPs) in these patients will continue to increase. This study examined the NCSP required in patients supported with ECMO and determined which variables affect outcomes. The National Inpatient Sample Database was examined for patients supported with ECMO from 2007 to 2010. There were 563 patients requiring ECMO during the study period. Of these, 269 (47.8%) required 380 NCSPs. There were 149 (39.2%) general surgical procedures, with abdominal exploration/bowel resection (18.2%) being most common. Vascular (29.5%) and thoracic procedures (23.4%) were also common. Patients requiring NCSP had longer median length of stay (15.5 vs. 9.2 days, p = 0.001), more wound infections (7.4% vs. 3.7%, p = 0.02), and more bleeding complications (27.9% vs. 17.3%, p = 0.01). The incidences of other complications and inpatient mortality (54.3% vs. 58.2%, p = 0.54) were similar. On logistic regression, the requirement of NCSPs was not associated with mortality (odds ratio [OR]: 0.91, 95% confidence interval [CI]: 0.68–1.23, p = 0.17). However, requirement of blood transfusion was associated with mortality (OR: 1.70, 95% CI: 1.06–2.74, p = 0.03). Although NCSPs in patients supported with ECMO does not increase mortality, it results in increased morbidity and longer hospital stay.

THOR Position Paper on Remote Damage Control Resuscitation: Definitions, Current Practice and Knowledge Gaps

ABSTRACT The Trauma Hemostasis and Oxygenation Research Network held its third annual Remote Damage Control Resuscitation Symposium in June 2013 in Bergen, Norway. The Trauma Hemostasis and Oxygenation Research Network is a multidisciplinary group of investigators with a common interest in improving outcomes and safety in patients with severe traumatic injury. The network’s mission is to reduce the risk of morbidity and mortality from traumatic hemorrhagic shock, in the prehospital phase of resuscitation through research, education, and training. The concept of remote damage control resuscitation is in its infancy, and there is a significant amount of work that needs to be done to improve outcomes for patients with life-threatening bleeding secondary to injury. The prehospital phase of resuscitation is critical in these patients. If shock and coagulopathy can be rapidly identified and minimized before hospital admission, this will very likely reduce morbidity and mortality. This position statement begins to standardize the terms used, provides an acceptable range of therapeutic options, and identifies the major knowledge gaps in the field.

Permissive hypoventilation in a swine model of hemorrhagic shock.

BACKGROUND Many penetrating trauma patients in severe hemorrhagic shock receive positive pressure ventilation (PPV) upon transport to definitive care, either by intubation (INT) or bag-valve mask (BVM). Using a swine hemorrhagic shock model that simulates penetrating trauma, we proposed that severely injured patients may have better outcomes with “permissive hypoventilation,” where manual breaths are not given and oxygen is administrated passively via face mask (FM). We hypothesized that PPV has harmful physiologic effects in severe low-flow states and that permissive hypoventilation would result in better outcomes. METHODS The carotid arteries of Yorkshire pigs were cannulated with a 14-gauge catheter. One group of animals (n = 6) was intubated and manually ventilated, a second received PPV via BVM (n = 7), and a third group received 100% oxygen via FM (n = 6). After placement of a Swan-Ganz catheter, the carotid catheters were opened, and the animals were exsanguinated. The primary end point was time until death. Secondary end points included central venous pressure, cardiac output, lactate levels, serum creatinine, CO2 levels, and pH measured in 10-minute intervals. RESULTS Average survival time in the FM group (50.0 minutes) was not different from the INT (51.1 minutes) and BVM groups (48.5 minutes) (p = 0.84). Central venous pressure was higher in the FM group as compared with the INT 10 minutes into the shock phase (8.3 mm Hg vs. 5.2 mm Hg, p = 0.04). Drop in cardiac output (p < 0.001) and increase in lactate (p < 0.05) was worse in both PPV groups throughout the shock phase. Creatinine levels were higher in both PPV groups (p = 0.04). The FM group was more hypercarbic and acidotic than the two PPV groups during the shock phase (p < 0.001). CONCLUSION Although permissive hypoventilation leads to respiratory acidosis, it results in less hemodynamic suppression and better perfusion of vital organs. In severely injured penetrating trauma patients, consideration should be given to immediate transportation without PPV.