Michael R. Davis

A Comparison of the Hemoglobin-Based Oxygen Carrier HBOC-201 to Other Low-Volume Resuscitation Fluids in a Model of Controlled Hemorrhagic Shock

BACKGROUNDnThe ideal resuscitation fluid for military applications would be effective at low volumes, thereby reducing logistical constraints. We have previously shown that the bovine hemoglobin-based oxygen carrier HBOC-201 is an effective low-volume resuscitation fluid. The goal of this experiment was to evaluate the effectiveness of HBOC-201 in comparison with other low-volume resuscitation fluids in a swine model of controlled hemorrhagic shock.nnnMETHODSnForty-two immature female Yorkshire swine (55-70 kg) were divided into seven groups of six. Animals were hemorrhaged to a mean arterial pressure of 30 mm Hg. After 45 minutes, animals were resuscitated to a mean arterial pressure of 60 mm Hg with one of the following agents: hypertonic saline 7.5% (HTS), hypertonic saline 7.5%/Dextran-70 6% (HSD), pentastarch 6%, hetastarch 6%, or HBOC-201. Lactated Ringers (LR) solution was used as a standard resuscitation control. Another group of animals received no resuscitation. Resuscitation was continued for 4 hours. Hemodynamic variables and oxygen consumption were measured continuously. Arterial and mixed venous blood gases and serum lactate levels were measured at intervals throughout the experiment. Data were analyzed using analysis of variance with Tukeys post hoc test when appropriate. Significance was defined as p < 0.05.nnnRESULTSnFive of six animals in the no-resuscitation control group, six of six in the HTS group, and one animal in the HSD group died before completion of the study. All other animals survived to completion. Animals receiving resuscitation with HBOC-201 had significantly lower cardiac output, mixed venous oxygen saturation levels, and urinary output throughout the resuscitation period; however, there were no differences with regard to lactate, base excess, or oxygen consumption. Animals receiving HBOC-201 required significantly less fluid than any other group.nnnCONCLUSIONnIn this model, hypotensive resuscitation with HBOC-201 restores tissue oxygenation and reverses anaerobic metabolism at significantly lower volumes when compared with HTS, HSD, pentastarch, or hetastarch solutions. These data suggest that HBOC-201 would be an effective primary resuscitation fluid for far-forward military or rural trauma settings where logistic constraints and prolonged transport times are common. However, when HBOC-201 is administered as a primary resuscitation fluid in hypotensive protocols, common clinical markers for determining adequacy of resuscitation may not be useful.

Microvascular reconstructive surgery in Operations Iraqi and Enduring Freedom: the US military experience performing free flaps in a combat zone.

BACKGROUND Local nationals with complex wounds resulting from traumatic combat injuries during Operations Iraqi Freedom and Enduring Freedom usually must undergo reconstructive surgery in the combat zone. While the use of microvascular free-tissue transfer (free flaps) for traumatic reconstruction is well documented in the literature, various complicating factors exist when these intricate surgical procedures are performed in a theater of war. METHODS The microvascular experiences of six military surgeons deployed during a 30-month period between 2006 and 2011 in Iraq and Afghanistan were retrospectively reviewed. RESULTS Twenty-nine patients presented with complex traumatic wounds. Thirty-one free flaps were performed for the 29 patients. Location of tissue defects included the lower extremity (15), face/neck (8), upper extremity (6). Limb salvage was successful in all but one patient. Six of eight patients with head and neck wounds were tolerating oral intake at the time of discharge. There were three flap losses in 3 patients; two patients who experienced flap loss underwent a successful second free or regional flap. Minor complications occurred in six patients. CONCLUSION Microvascular free tissue transfer for complex tissue defects in a combat zone is a critically important task and can improve quality of life for host-nation patients. Major US combat hospitals deployed to a war zone should include personnel who are trained and capable of performing these complex reconstructive procedures and who understand the many nuances of optimizing outcomes in this challenging environment. LEVEL OF EVIDENCE Therapeutic study, level V.

Trends in endovascular surgery training.

PURPOSEnTo gather vascular surgery fellows opinions on various issues related to endovascular surgery (EVS) over a 2-year period and analyze the responses to identify trends in EVS training.nnnMETHODSnVascular surgery fellows in 2 consecutive years were given a 2-page questionnaire inquiring about training protocols and local practice habits. Respondents included 64 vascular fellows from the academic year 1998-1999 (F98) and 52 vascular fellows from the academic year 1999-2000 (F99) (78% men in the entire population; mean age 34 years), representing a significant fraction of trainees in North America. Data from F98 and F99 were compared and analyzed.nnnRESULTSnThe majority (66%) of vascular surgery fellows were trained at university hospitals and performed EVS at the time of the survey: 83% in the F98 class and 92% in the F99 group (p=0.17). Utilization rates among the 9 interventions surveyed ranged from angiography (83%) and angioplasty (77%) to intravascular ultrasound (33%) and atherectomy (15%). Performance of endovascular grafting significantly increased among trainees (50% versus 81%, p<0.005), while atherectomy and angioscopy decreased. EVS performed in the operating room with portable imaging equipment decreased (67% versus 42%, p=0.02) as access to the radiology and cardiology suites increased. In most communities (63%), radiology specialists performed most of the EVS procedures, but the portion of communities where vascular surgery performed the majority of EVS procedures increased from 20% to 35% (p=0.10) from F98 to F99. Responders (90%) believed that EVS would become a major component of vascular surgery and comprise 30% of their future practice. The proportion of fellows who believed they were sufficiently trained in endovascular techniques increased from 30% to 50% (p=0.04), with the remainder willing to devote a short period (<3 months) for further training.nnnCONCLUSIONSnThe vast majority of vascular trainees perform EVS and believe that it will have an increasing role in their practice. Trends include increased endovascular grafting and performance of EVS by vascular surgeons in interventional suites.

Launch of the National Trauma Research Repository coincides with new data sharing requirements

Previous analyses of research data have shown that many trauma studies cannot be replicated or validated due to a variety of factors, including lack of access to study data, lack of access to protocol information, and inability to replicate procedures used in the study. New data sharing rules for federally funded studies have been put in place to address factors associated with this issue.nnTo address these new data sharing requirements, beginning this month, investigators conducting research on trauma and critical care will be able to maximize the utility of the data they produce with the launch of the National Trauma Research Repository (NTRR). The system was developed as a resource to support new and emerging data sharing needs within the trauma research community and is envisioned to be a key piece of the national trauma research infrastructure. It is funded by the Department of Defense (DoD) and developed by the National Trauma Institute (NTI) to promote collaboration, accelerate research, and advance knowledge on the treatment of trauma. When it becomes fully functional, the NTRR will be a comprehensive repository offering thousands of data points from hundreds of studies, enabling investigators to query across studies for their own research objectives.nnThe NTRR was developed by trauma researchers for trauma researchers. A national committee was convened of civilian and military trauma researchers and stakeholder organizations to define the functional requirements of the repository that would best serve investigators.1 The NTRR allows users to peruse available data elements, study dataxa0sets, and supporting documentation (eg, protocols, consent forms, data dictionaries). Investigators contributing data to the NTRR can upload completed dataxa0sets and supporting documents at the completion of a study or as the study is being conducted. All studies will submit core data elements and study metadata (information about the study). Use of …

Letter to the editor regarding the joint statement from the American College of Surgeons' Committee on Trauma (ACS-COT) and the American College of Emergency Physicians (ACEP) regarding the clinical use of resuscitative endovascular balloon occlusion of the aorta (REBOA)

At a time when the value of military-civilian coordination in trauma care practice, research and development is being emphasized,1 we are concerned byxa0the recentlyxa0published statement of the American College of Surgeons’ Committee on Trauma and the American College of Emergency Physicians (ACS-COT/ACEP) on the use of resuscitative endovascular balloon occlusion of the aorta (REBOA).2 We are disconcerted that the work group did not include any representatives from the US military’s Joint Trauma System (JTS) and failed to cite the JTS’ REBOA clinical practice guideline (CPG).3 We are concerned that after overlooking the military perspective on thexa0use of REBOA, the work group crafted language is too prescriptive and that could limit the military health system’s use of this life-saving technique in deployed settings.nnThe data that defined the disproportionate mortality from torso hemorrhage that led to the development of REBOA werexa0generated by the US military.4 JTS-led studies of combat injured indicate that as many as one in five service members killed in action during the recent wars bled to death while being transported to, or waiting for, a surgeon and an equipped operating room.4 …