war on the rocks

How Long Can the U.S. Military’s Golden Hour Last?

Confederate General Sidney Johnston’s physician once claimed that the Confederate Army might have won the Battle of Shiloh had his patient received better care and survived after being wounded by a minié ball. Military medicine can help win wars. Treating and then returning military personnel to duty — which has always been a primary mission of any military medical corps — maintains force strength. Moreover, knowing that they will be cared for and have a high chance of survival if injured boosts service members’ morale and will to fight. In a 2017 survey of West Point cadets conducted via the Modern War Institute, over 80 percent of respondents expressed confidence in the military’s ability to care for injured soldiers. This confidence also enables recruitment and maintenance of a robust all-volunteer force.

In the wars in Iraq and Afghanistan, the U.S. military medicine achieved the highest rate of survival from battlefield injuries in history. The wounded-to-killed ratio has more than doubled, from 4:1 during last century’s world wars, to 10:1 today. Substantial credit for this achievement goes to a tireless focus on getting wounded warfighters lifesaving care within 60 minutes of injury — a timespan that is referred to as the “golden hour.”

The military’s ability to deliver golden hour care was developed in the recent low-level counter-insurgencies and counter-terrorism wars of the early 21st century. With the shift away from global unipolarity, however, the United States may be more likely to fight conventional wars against peer or near-peer adversaries in the future. This shift requires the military to reassess existing approaches and innovate new ones for extending golden hour care in a different kind of war. Specifically, the military needs to recognize the new challenges to rapid evacuation and shift focus to bringing enhanced treatment capability to the patient on the battlefield, in order to accommodate the geographical and logistical constraints of future wars.

Origins of the Golden Hour

Coined by R. Adams Cowley of Maryland’s Shock Trauma Center, the golden hour concept presumes that some deaths are preventable if appropriate care is provided by appropriately trained individuals with the right lifesaving or life-sustaining equipment. It also requires a system of prehospital and hospital-based care to ensure the right patients get the right care at the right time. Cowley’s popularizing of the golden hour spurred the U.S. civilian health care sector in the 1980s and 90s to develop more capable emergency medical systems, regional trauma systems, and treatment technologies to improve survival during this 60-minute window. Today, Cowley’s original notion has been revised in some cases to the “platinum 10 or 15 minutes,” in the recognition that certain life-saving interventions must be applied within an even shorter period in order to be effective.

At the onset of the wars in Afghanistan and Iraq, the U.S. military did not have a joint service (i.e., Army, Navy, and Air Force) integrated trauma system that would allow it to get the wounded to the right facility for the right treatment within the golden hour. To make matters worse, the military also lacked the capability to collect and analyze data to determine how well it was doing. As a result, in the early days of the wars, military health professionals were unable to identify which changes needed to be made to improve a casualty’s odds of survival.

Between 2003 and 2005, the Army, Navy, and Air Force worked together to implement a “Joint Trauma System” and a clinical database known as the “Joint Theater Trauma Registry.” Using real-world data from the Joint Trauma System, military health experts were able to pinpoint the main causes of death within the golden hour (e.g. uncontrolled bleeding, loss of airway, pneumothorax) and target them with adjustments in training, improved theater evacuation policies, and research to develop new products, such as one-handed tourniquets. Soon, the military was using data collection and analytics to inform policy and improve care.

In June 2009, Joint Trauma System data revealed longer times to treatment and lower survival rates in Afghanistan compared to casualty transport times being achieved in Iraq. In testimony before Congress, Secretary of Defense Robert Gates stated: “In Iraq, our goal is to have a wounded soldier in a hospital in an hour. It’s closer to two hours in Afghanistan. And so what we’ve been working on is, how to get that MEDEVAC [medical evacuation] standard in Afghanistan down to the ‘golden hour’ we have in Iraq?” Following his testimony, Gates adjusted positioning of forward surgical teams and directed more helicopters to fly MEDEVAC missions in Afghanistan. Prior to the change, approximately 110 of every thousand injured military personnel died before receiving definitive care — i.e. the completion of the initial round of life-saving procedures or surgeries for any given pattern of injuries. Following implementation of Gates’ golden hour policy, the case fatality rate (which had been near 20 percent in early 2002) among U.S. troops decreased to below 10 percent.

It would be foolish to assume that it will be possible to achieve such a low case-fatality rate in future conflicts. Despite challenging geography and other operational constraints in Iraq and Afghanistan, the United States had reliable ground and air access, dependable communications, and was able to strategically position surgical teams and hospitals across both theaters of war. Additionally, the military was able to rapidly transport injured personnel to higher echelons of care — often using large military transport aircraft staffed by Critical Care Air Transport Teams, also known as flying ICUs — to Germany and from there to the United States within days of injury.

Future conditions may not be so favorable if, for example, the United States faces an adversary with advanced weapons and the capacity to disrupt communications and contest airspace over the battlefield. Under such challenging circumstances, can the golden hour of survival be maintained?

Challenges to the Golden Hour in More Symmetric Wars

Whether in a Pacific theater, Eastern Europe or other areas, war simulations we have participated in that pit the United States against sophisticated, near-peer adversaries suggest it will be far more difficult to assure golden hour care. Potential challenges include larger numbers of casualties, injuries from new types of weaponry (e.g. directed energy, thermobaric, nuclear), and degraded ability to promptly locate, treat, and evacuate patients.

The recent National Defense Strategy singling out China, Russia, and North Korea as key strategic rivals and a 2017 Army-Marine Corps White Paper describing the Multi-domain Battlefield both offer insight into the limitations of providing care in an anti-access/area denial environment, including the inability to establish typical medical evacuation and echelons of care. A war with North Korea, for example, would mean fighting a regime with an abundance of artillery sites and missiles capable of inflicting large numbers of casualties. Conflict in the vastness of the Pacific would require new approaches to the movement and critical care of injured service members, using land, air, and sea capabilities to mitigate the tyranny of distance. These realities have the military rethinking golden hour care, as well as how best to treat injured troops outside conventional U.S. facilities for days, weeks and even months after injury.

Overwhelming casualty numbers, including those unable to be located or triaged, create an additional challenge. During the Iraq and Afghanistan wars, the number of injured usually did not overwhelm the military system’s ability to triage and MEDEVAC. Each Army HH-60 helicopter was able to quickly transport one or two patients at a time to prepositioned echelons of care within the golden hour. The Air Force was then able to use its C-17 Globemaster inventory to execute transcontinental aeromedical evacuation back to the United States, usually within days of injury.

War with a near-peer foe would produce larger numbers of injured than the U.S. military has seen in decades. For example, conflict with China would likely mean attacks on U.S. surface ships such as aircraft carriers, each of which carries a crew of thousands. Similarly, a 2017 RAND report lays out sobering projections for NATO ground forces fighting a conventional war against a simulated Russian attack on the Baltic states. In either scenario, large numbers of casualties would severely stress existing air evacuation capabilities. With the exception of the CH-47 Chinook, most MEDEVAC helicopters can only accommodate a couple casualties at a time. To deliver the same capability within the golden hour, either larger aircraft would be needed (such as the V-22 Osprey), or the inventory of existing aircraft would need to be increased and deployed more frequently. But such changes in assets would pose significant challenges of their own. Larger aircraft may not be able to take off and land close to the injured; they may also be vulnerable to surface-to-air missiles, drone-directed fire, and even attack by fighter aircraft.

Transcontinental aeromedical evacuation of large numbers of U.S. service members would also be challenging. The United States had great success evacuating tens of thousands of injured from Iraq and Afghanistan, including more than 5,000 by Critical Care Air Transport Teams, with very low in-flight mortality. However, the simulation exercises we have observed suggest that a war on the Korean Peninsula would require evacuating a number of casualties equivalent to the whole of the past 17 years in a period of months, if not weeks. Indeed, according to one estimate, war with North Korea could see 20,000 fatalities per day. Rising to this challenge would require a large increase in the number of aeromedical evacuation platforms as well as personnel. It would also require integrating the existing land-based evacuation system with an expanded sea-based evacuation capability, a scenario that has not been tested.

An attack using chemical, biological, or nuclear weapons would further test the military’s ability to deliver care within the golden hour. In some scenarios the system would have to administer life-saving antidotes within minutes to save lives. Because decontamination would be required, such an attack would make it harder to quickly triage and evacuate wounded troops. Crews sent to evacuate casualties might be just as vulnerable as the personnel on the ground. In such an event, delivery of care would be compromised and an unprecedented number of fatalities would likely result.

Redefining the Golden Hour

To overcome these challenges, the U.S. military will have to extend the golden hour, focusing less on quickly evacuating the injured and more on bringing life-saving capabilities directly to the patient. This means focusing on prolonged field care, advanced resuscitative care, and long-distance en-route care. Redefining the golden hour in this way will require that the military adapt its medical technologies, training, and expectations.

Technologies

A variety of developing technologies will improve resuscitative care at the front lines. New tools may allow medics working near the point of injury to autonomously establish entry inside the large arteries and veins of the torso. Linked to small catheters that can work inside the vessels, these tools could allow medics to stop bleeding, restore blood volume, and control the circulatory system. New endovascular devices (that is, devices operating inside vessels) could also be coupled with automated drug and fluid delivery tools to provide pain control, anesthesia, and organ support. While this network of technologies is complex, all the elements exist in some form today. The remaining challenges are to miniaturize and integrate them, make them battery-powered, and test them in the lab and in field conditions.

Wearable biosensors and advanced vital signs monitors, which could serve the dual purpose of remotely locating and triaging injured troops, are also on the horizon. Collecting and analyzing large amounts of real-time patient data (a.k.a. predictive analytics) from these monitors could help inform and build automated devices such as ventilators, organ support machines, and infusion pumps. Decision support and automated devices would expand the medic or corpsman’s ability to provide golden hour care to a greater number of injured at any one time.

In situations where MEDEVAC and other life-saving measures are not available, telemedicine will also expand the capability of point-of-injury providers to perform some types of surgeries such as wound debridement, extremity fasciotomy, or amputation. Subsequent prolonged field care delivered by medics and corpsmen could then include treatment of large wounds, intra-abdominal injuries, and mangled extremities — injuries managed inside of a hospital operating room today. Although the science is less advanced in these areas, the military is investing in research on antimicrobial dressing systems and self-expanding foams able to be injected into the abdomen to stabilize bleeding and contamination until definitive surgery can occur.

Managing traumatic brain injury during the new golden hour will be challenging. In addition to more comprehensive study of new and wearable blast gauge technologies and improved protection measures to avoid blast exposure, research is focusing on devices to diagnose concussive traumatic brain injury and limit severe brain injury. Brain-wave and eye-tracking devices and rapid blood tests may soon be available to diagnose concussions on the battlefield. Innovations such as small devices that use light sources and software algorithms to look inside the skull to diagnose bleeding and then drill a hole to evacuate blood and relieve pressure could help treat more severe forms of traumatic brain injury.

Unmanned technology could also enable a new golden hour paradigm. Drones or unmanned ground vehicles could preposition — or deliver in real time — supplies for different tactical situations, a strategy already employed for humanitarian aid in Africa. Additionally, the military is researching whether and how unmanned MEDEVAC might augment patient evacuation. By creating teams of combat developers, medics, scientists and engineers to work on these initiatives, the military is trying to make sure that new technologies are not merely “cool,” but that they are actually necessary and will be effective in the golden hour of future wars.

Training

New technologies require changes in training. Revamping the golden hour will require evolving military medical training both at the level of professional certification and as it relates to proficiency for specific procedures. In addition to the Committee on Tactical Combat Casualty Care and the Joint Trauma System, the Defense Health Agency and the Uniformed Services University could play a larger role in changes in training related to future golden hour capabilities.

Expectations

Americans have become accustomed to low numbers of military fatalities. But based on projections of war against sophisticated adversaries, not all of the injured will be able to be triaged or even located within the golden hour. The military should work tirelessly to mitigate battlefield mortality, but in some settings, attempting to save the lives of all may not be possible or practical. Expectations regarding triage categories — that is, the prioritization of which injuries are most treatable — may need to change. In some scenarios, the military may need to be willing to categorize the severely injured or incapacitated as delayed or expectant, essentially accepting that these patients will die in the absence of life-saving care. This ungratifying reality would allow medics to focus on the most salvageable patients with the goal of quickly stabilizing them to be returned to duty. In extreme circumstances, a golden hour paradigm might be less focused on saving lives and more attentive to stabilizing less severely injured troops in order to maintain force strength. Such an approach would represent a radical departure from procedures used in Iraq and Afghanistan, but might be necessary in conditions of mass casualties, limited evacuation capabilities, and/or the use of chemical, biological, radioactive, or nuclear weapons — all of which are more likely in the event that the United States fights a peer or near-peer adversary.

Expectations about resources for golden hour care may also need to be modified. During recent wars, the United States enjoyed virtually unconstrained logistics operations that allowed it to transport from home all medical facilities, equipment, and personnel necessary to provide care. Care in a large war against a sophisticated adversary would require different medical resources than those the United States normally brings to the battlefield. This could be as simple as using local shelters or medical equipment, or as extensive as relying on host nation hospitals or medical systems to supplement or provide golden hour care.

One of the great success stories in today’s golden hour care is the reintroduction and revamping of the tourniquet, after decades of disuse because of antiquated designs and a poor understanding of how it was to be optimally used. But this story also serves as a cautionary tale. Had tourniquets been used more effectively in the Korean and Vietnam wars, thousands of lives could have been saved with this simple intervention. The history of the tourniquet is a reminder that, just as military strategy and tactics need to change as new wars are fought against new adversaries, so too do technologies, procedures, and beliefs surrounding medical care. If the golden hour of survival is to last — and maybe even lengthen — the U.S. military medical community must recalibrate technologies, training, and expectations to extend golden hour care in more complex combat scenarios. Just as the military medical corps revolutionized golden hour care in the face of a new type of war ten years ago, it can do the same thing now as it prepares to engage a different type of adversary and conflict.

 

Tanisha M. Fazal is Associate Professor of Political Science at the University of Minnesota. She is the author, most recently, of Wars of Law: Unintended Consequences in the Regulation of Armed Conflict.

Col. Todd Rasmussen is Professor of Surgery and Associate Dean for Research at the Uniformed Services University in Bethesda Maryland. He is a career military vascular surgeon and physician-scientist with extensive deployed experience in Iraq and Afghanistan and in leading the military’s trauma and injury research programs.

Col. Paul Nelson, MD, MPH, is the Air Force Surgeon General’s Chair to Air University. He is a graduate of the Uniformed Services University School of Medicine, and is a career military physician, boarded in Aerospace Medicine and Family Medicine, and whose research interests include operational medicine, military reintegration and organizational change management.

Lt. Gen. P.K. Carlton, MD (Ret., USAF) was the Surgeon General of the Air Force from 1999 to 2002 and is an emeritus professor of Surgery at Texas A&M Health Science Center. His current work is focused on bringing the lessons learned in the last 17 years of conflict to the U.S. civilian health sector. The viewpoints expressed in this essay are those of the authors and do not reflect official positions or policies of the Department of Defense, the United States Air Force, or the Uniformed Services University.

Image: Todd Rasmussen