PEER REVIEWED

Mass Casualty Situations and Emergency Retinal Care

Lessons learned from the military and applications for retinal specialists

MARCUS H. COLYER, MD • YOSHIHIRO YONEKAWA, MD • ROBERT MAZZOLI, MD

On April 15, 2013, the Boston Marathon became the scene of a devastating mass-casualty incident (MASCAL), when two improvised explosive devices (IEDs) were detonated at the finish line, injuring 264 individuals and killing three young spectators.¹

The marathon was immediately stopped, and patients were transported to nearby trauma centers. Marathon medical tents were converted to triage stations, and many bystanders acted as first responders.

Despite the dire circumstances, Boston was fortunate to have six level 1 academic trauma centers and seven tertiary-level eye centers within a two-mile radius of the explosions, as well as EMS personnel who were predeployed for the event and city streets that were cleared for the marathon.² This led to patients reaching the operating rooms as early as 35 minutes after the IED detonations,³ resulting in survival of all critically injured patients.

Life-threatening injuries included amputations, severe abdominal injuries, and traumatic brain injury, which are similar to the polytrauma injuries encountered in current combat operations and in other terrorist events.

Emergent ophthalmology consultations were requested in 13% of patients transported to level 1 trauma centers: 100% of these eye injuries had significant coexistent systemic injuries (polytrauma). Two-thirds of consultations occurred after the patient was triaged in the emergency room. For the purposes of this article, outcomes of posterior-segment–specific injuries will be referenced and do not adhere specifically to Birmingham Eye Trauma Terminology.

Fifty-seven percent of injuries represented ocular polytrauma, including periocular burns in 86% of patients, ocular surface injuries, such as foreign bodies, abrasions, and partial-thickness lacerations in 59%, posterior-segment injuries in 14% (mutually inclusive percentages), and open globe injuries in 5%. Posterior-segment injuries consisted of cases of vitreous hemorrhage, complex retinal detachment, and/or intraocular foreign bodies (IOFBs).⁴

This article will highlight the current treatment protocols for the United States military, discuss some challenges faced by civilian counterparts, and suggest several preparatory steps that retinal specialists can undertake locally to prepare for a disaster.

ALL TOO COMMON

Blasts like the Boston attack are a regular occurrence in Iraq and Afghanistan and have become increasingly common in “noncombat” metropolitan areas worldwide over the last two decades (Table 1). Such intentional blasts share many features with accidental industrial explosions.⁴

Despite advanced body armor and armored vehicles, the eye remains very vulnerable to highly kinetic forces from explosions, even when military-grade ballistic eye protection is worn.

The Boston experience and others remind us that eye injuries similar to those seen in armed conflict are possible anywhere in the United States, at any time. As such, it is important to absorb lessons learned by military ophthalmology in the management of MASCAL/multitrauma cases to prepare for worst-case scenarios at home.

A TIERED SYSTEM OF ROLES

The US military has suffered nearly 59,000 deaths and injuries in the current conflicts.⁵ Treatment for these complex injuries frequently involves multiple subspecialists, such as trauma surgeons, orthopedists, neurosurgeons, ophthalmologists, and others to treat casualties most expeditiously and effectively.

The military deploys its medical forces in a tiered fashion (Table 2, page 22). Point of injury care, the equivalent of pre-hospital first-responder care, is provided by self- or buddy-aid (bystander aid) and combat medics (EMT), effectively providing basic life support.

Role 2 includes the forward surgical team (FST), by whom initial lifesaving resuscitation and surgery are performed (damage control resuscitation and surgery [DCR/DCS]).

Role 3 is the combat support hospital, a mobile tertiary medical center, where advanced surgical capabilities exist (including ophthalmology) and where initial “damage control” eye surgery is performed.

Role 4 is the regional medical hospital (currently Landstuhl Regional Medical Center in Germany), where close monitoring and revision of wounds occur, as necessary. Role 5 facilities are the traditional tertiary care centers in the United States — Walter Reed National Military Medical Center, Naval Medical Center San Diego, San Antonio Military Medical Center, and Madigan Army Medical Center in Tacoma, WA.

This role-based structure facilitates the orderly transfer and delivery of care to patients, with an emphasis on providing life-saving, globe-saving care early — especially in the case of MASCALs — and specialty restorative care at higher echelons. Relying heavily on a team of strong subspecialists, no single ophthalmologist has to “win the war” alone, regardless of location.

MILITARY PROCEDURES

As an example, because invasive retinal surgical care is only available at role 5 facilities in the United States, when patients have ocular injuries in concert with other trauma, evacuation is expedited to receive treatment in the United States as rapidly as possible (generally, as quickly as 48-72 hours postinjury).

Open globes are closed immediately in the theater, but military ophthalmologists routinely delay IOFB removal by seven to 14 days, while patients are stabilized and transferred in a precise and coordinated manner. Surgery on patients following this evacuation method have resulted in outcomes similar to those of civilian eye trauma.⁶ Notably, acute traumatic endophthalmitis is nearly nonexistent.

Lessons of War

The experiences of wartime ophthalmologists in managing multitrauma patients have highlighted several challenges not otherwise apparent.^7,8 First, ophthalmologists must be prepared to operate at the location of the patient, without the benefit of adequate or familiar equipment and trained ophthalmic surgical personnel, as it may be too risky to transport the patient to another hospital (or even another OR).⁷

Many retinal specialists operate at a surgery center exclusively or in an OR that is separate from other rooms. It is imperative that retinal and trauma specialists have a “break the glass” set of equipment to perform emergency “damage control” surgery elsewhere. On deployment, ophthalmologists routinely deploy with the equipment they are comfortable using, because the equipment available may be unfamiliar or broken.

Important equipment includes microsurgical tying forceps, needle drivers, surgical loupes, suture, indirect ophthalmoscope and lens, and a portable table-mounted microscope if no portable microscope is available.

Time Is of the Essence

Second, during the initial repair of eye injuries during a MASCAL, all surgeons have only a brief time during which they can operate. Multiple surgeons may be operating simultaneously, and their procedures usually require the use of a traditional OR table.

As such, ophthalmologists must work closely with their colleagues to carefully but expeditiously repair globe injuries without the comforts of a standard “eye bed” or a ceiling-mounted scope. In such cases, consider “damage control” surgery, aiming simply to close the eye expeditiously and putting off more complex surgeries.

Moreover, it may be necessary to perform ophthalmic-specific triage by choosing surgical cases in sequence, based on: 1) likely postoperative visual potential; 2) shortest surgical times; and 3) the greatest benefit to the most patients. It should be assumed that not every patient can be treated, and referrals to other institutions may be necessary to facilitate the greatest benefit for the most patients.

Some techniques to optimize the ergonomics of ophthalmic surgery on traditional tables would be to position the patient as superior as possible or to reverse the patient to have the head at the bottom of the table, where there is more room underneath for legs and to operate the microscope.

The surgical technicians and nurses will also be unfamiliar with ophthalmic instruments and will need to be guided accordingly. Other factors to consider include: reminding anesthesia providers not to manipulate the eyes (tape, ointment) during intubation; avoiding the use of povidone-iodine scrub soap and chlorhexidine around the eyes; prepping the eyes yourself; and protecting the eyes from inadvertent pressure when turning a coronal flap for neurosurgery.

Worst-case Scenarios

Third, when performing retinal surgeries for victims of bombings, we must consider the systemic status of the patient — if using gas, we can expect the patient to undergo future surgery, and communication with anesthesiologists and other surgeons is essential to avoid the use of nitrous oxide gas.

Further, patients with nonocular injuries may require muscle flaps to treat wounds or otherwise undergo extensive laparotomy procedures. Both of these situations create challenges for postoperative positioning and must be considered carefully preoperatively.

As such, it is essential that retinal specialists consider a “worst case scenario” if a mass casualty situation occurs in their communities. They should be prepared with the requisite equipment to do the job in the challenging circumstances that a MASCAL presents.

Further, it is important to survey the operating environment where MASCAL care might be rendered to ensure it has the necessary equipment and personnel to ensure effective and efficient delivery of care (Table 3).

What Boston Taught Us

As a result of the Boston terrorist attacks, recommendations for future planning efforts, based on our experiences during this mass-casualty incident, were published. More thorough discussions are available in a recently published report.²

(1) Manpower and Coordination of Care. There is no shortage of ophthalmology house staff coverage in Boston, but the simultaneous consultation requests across multiple hospitals required reallocation of several residents. In smaller medical communities, deeper layers in the on-call algorithm may be necessary to meet the needs of a mass-casualty incident.

(2) Communication Methods. Cellular networks were down during the initial hours of the bombing, so land lines and paging systems were crucial for reliable communication.

(3) Access to Subspecialty Services. Similar to the polytraumatic nature of the systemic injuries of blast patients, the eye also sustains polytrauma. While most anterior-segment injuries can be managed under general ophthalmology credentials, access to vitreoretinal services was critical in the management of retinal detachment and IOFBs.

(4) Rigid Eye Shields. No patients received rigid eye shields in the field. We are in communication with local EMS leadership to increase awareness of rigid eye shields in suspected ocular injuries to prevent iatrogenic ocular trauma. The military has instituted a Clinical Practice Guideline with improved usage.⁹

(5) Working With Trauma Teams. Most (64%) of the ophthalmology consultation requests were called intraoperatively or postoperatively in the surgical intensive care units. Ocular injuries are a part of the blast polytrauma complex but often escape immediate detection due to distracting injuries.

Life support is obviously the primary goal of trauma surgery, but ophthalmic injuries should be detected early to facilitate overall surgical planning, such as mobilizing portable microscopes, obtaining orbital CT scans, starting appropriate broad spectrum antibiotics, and placement of rigid eye shields.

CONCLUSION

Whether intentional or unintentional, man-made or natural disasters, civilian mass-casualty incidents will continue to occur, and we must remain engaged with and integrated into regional trauma teams to provide high-quality care for patients with ocular trauma. RP

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