Case Report of Extracorporeal Membrane Oxygenation and Aeromedical Evacuation at a Deployed Military Hospital

Indications and Outcomes for Adult Extracorporeal Membrane Oxygenation at a Military Referral Facility

INTRODUCTION

Extracorporeal life support, including extracorporeal membrane oxygenation (ECMO), is a potentially life-saving adjunct to therapy in patients experiencing pulmonary and/or cardiac failure. The U.S. DoD has only one ECMO center, in San Antonio, Texas. In this study, we aimed to analyze outcomes at this center in order to determine whether they are on par with those reported elsewhere in the literature.

MATERIALS AND METHODS

In this observational study, we analyzed data from patients treated with ECMO at the only DoD ECMO center between September 2012 and April 2020. The primary outcome was survival to discharge, and secondary outcomes were discharge disposition and incidence of complications.

RESULTS

One hundred and forty-three patients were studied, with a 70.6% rate of survival to discharge. Of the patients who survived, 32.7% were discharged home; 32.7% were discharged to a rehabilitation facility; and 33.7% were transferred to another hospital, 29.4% of whom were transferred to lung transplant centers. One patient left against medical advice. Incidence of ECMO-related complications were as follows: 64 patients (44.7%) experienced hemorrhagic complications, 80 (55.9%) had renal complications, 61 (42.6%) experienced cardiac complications, 39 (27.3%) had pulmonary complications, and 5 patients (3.5%) experienced limb ischemia. We found that these outcomes were comparable to those reported in the literature.

CONCLUSIONS

Extracorporeal membrane oxygenation can be an efficacious adjunct in management of critically ill patients who require pulmonary and/or cardiac support. This single-center observational study demonstrated that the DoD's only ECMO center has outcomes comparable with the reported data in Extracorporeal Life Support Organization's registry.

Hemorrhagic Resuscitation Guided by Viscoelastography in Far-Forward Combat and Austere Civilian Environments: Goal-Directed Whole-Blood and Blood-Component Therapy Far from the Trauma Center

Modern approaches to resuscitation seek to bring patient interventions as close as possible to the initial trauma. In recent decades, fresh or cold-stored whole blood has gained widespread support in multiple settings as the best first agent in resuscitation after massive blood loss. However, whole blood is not a panacea, and while current guidelines promote continued resuscitation with fixed ratios of blood products, the debate about the optimal resuscitation strategy-especially in austere or challenging environments-is by no means settled. In this narrative review, we give a brief history of military resuscitation and how whole blood became the mainstay of initial resuscitation. We then outline the principles of viscoelastic hemostatic assays as well as their adoption for providing goal-directed blood-component therapy in trauma centers. After summarizing the nascent research on the strengths and limitations of viscoelastic platforms in challenging environmental conditions, we conclude with our vision of how these platforms can be deployed in far-forward combat and austere civilian environments to maximize survival.

A Case Report of Combat Blast Injury Requiring Combat Casualty Care, Far-Forward ECMO, Air Transport, and All Levels of Military Critical Care

We describe a 34-year-old soldier who sustained a blast injury in Syria resulting in tracheal 5 cm tracheal loss, cervical spine and cord injury with tetraplegia, multiple bilateral rib fractures, esophageal injury, traumatic brain injury, globe evisceration, and multiple extremity soft tissue and musculoskeletal injuries including a left tibia fracture with compartment syndrome. An emergent intubation of the transected trachea was performed in the field, and the patient was resuscitated with whole blood prehospital. During transport to the Role 2, the patient required cardiopulmonary resuscitation for cardiac arrest. On arrival, he underwent a resuscitative thoracotomy and received a massive transfusion exclusively with whole blood. A specialized critical care team transported the patient to the Role 3 hospital in Baghdad, and the DoD extracorporeal membrane oxygenation (ECMO) team was activated secondary to his unstable airway and severe hypoxia secondary to pulmonary blast injury. The casualty was cannulated in Baghdad approximately 40 hours after injury with bifemoral cannulae in a venovenous configuration. He was transported from Iraq to the U.S. Army Institute of Surgical Research Burn Center in San Antonio without issue. Extracorporeal membrane oxygenation support was successfully weaned, and he was decannulated on ECMO day 4. The early and en route use of venovenous ECMO allowed for maintenance of respiratory support during transport and bridge to operative management and demonstrates the feasibility of prolonged ECMO transport in critically ill combat casualties.

Aeromedical Transport of Critically Ill Patients: A Literature Review

The aeromedical transport of critically ill patients has become an integral part of practicing medicine on a global scale. The development of reliable portable medical equipment allows physicians, emergency medical technicians, and nurses to transport wounded and diseased patients under constant critical care attention. Air transportation involves utilizing a fixed-wing (airplane) or rotor-wing (helicopter) aircraft to accomplish different types of transports ranging from scene responses to international transfers. The proper preparation and management of patients undergoing aeromedical transport require a basic understanding of the physiological changes and unique challenges encountered within the aircraft environment at 8,000 ft above sea level. The purpose of this paper is to review the literature and provide guidelines for approaching the aeromedical transportation of critically ill patients.

Evolution of the United States Military Extracorporeal Membrane Oxygenation Transport Team

INTRODUCTION

The use of extracorporeal membrane oxygenation (ECMO) for the care of critically ill adult patients has increased over the past decade. It has been utilized in more austere locations, to include combat wounded. The U.S. military established the Acute Lung Rescue Team in 2005 to transport and care for patients unable to be managed by standard medical evacuation resources. In 2012, the U.S. military expanded upon this capacity, establishing an ECMO program at Brooke Army Medical Center. To maintain currency, the program treats both military and civilian patients.

MATERIALS AND METHODS

We conducted a single-center retrospective review of all patients transported by the sole U.S. military ECMO program from September 2012 to December 2019. We analyzed basic demographic data, ECMO indication, transport distance range, survival to decannulation and discharge, and programmatic growth.

RESULTS

The U.S. military ECMO team conducted 110 ECMO transports. Of these, 88 patients (80%) were transported to our facility and 81 (73.6%) were cannulated for ECMO by our team prior to transport. The primary indication for ECMO was respiratory failure (76%). The range of transport distance was 6.5 to 8,451 miles (median air transport distance = 1,328 miles, median ground transport distance = 16 miles). In patients who were cannulated remotely, survival to decannulation was 76% and survival to discharge was 73.3%.

CONCLUSIONS

Utilization of the U.S. military ECMO team has increased exponentially since January 2017. With an increased tempo of transport operations and distance of critical care transport, survival to decannulation and discharge rates exceed national benchmarks as described in ELSO published data. The ability to cannulate patients in remote locations and provide critical care transport to a military medical treatment facility has allowed the U.S. military to maintain readiness of a critical medical asset.