September 14, 2008
Mass Casualty in an Isolated Environment: Medical Response to a Submarine Collision
By Jankosky, Christopher John
ABSTRACT On January 8, 2005, the U.S.S. SAN FRANCISCO (SSN 711), a nuclear-powered submarine, collided with a seamount in a remote Pacific Ocean location. The high-speed impact resulted in injuries to 90% of the crew. Subsequent emergency medical response is described as well as the 3-month physical and psychological morbidity. Recommendations for medical training, equipment, and policy for workers in isolated environments are discussed. INTRODUCTION
Developing medical guidance for a possible catastrophic event requires extensive planning. Within the past decade, events in major metropolitan areas have seen the health care system strain under unexpected events. These include the severe acute respiratory syndrome outbreak in Toronto, the health effects following the collapse of the World Trade Center in New York, and access to health care immediately following Hurricane Katrina in New Orleans. These events reinforce the need to provide adequate training and equipment for potential crises precipitated by accidents, man-made and natural disasters, and infectious diseases. Thus, contingency planning for a mass casualty event has taken on increased importance in recent years.1 In 2006, disaster preparedness and emergency management was added as a core competency in occupational and environmental medicine.2
Disaster preparedness becomes more difficult when a crisis occurs far from metropolitan areas. Response to events in remote locations, such as those that occurred following the 2004 Indian Ocean Tsunami, may be delayed by distance, transportation, and other political and logistical factors. Perhaps the most isolated health care environment is aboard a deployed submarine. U.S. Navy nuclear- powered submarines are designed to deploy for months at a time throughout the world's oceans. Deployment duration is generally limited only by the amount of food that can be carried on board. It is recognized that during certain operational missions, such as traveling under the polar ice caps, patients are weeks or days away from additional medical care. To reduce the rate of seriously ill personnel, submariners are some of the most rigorously screened and monitored individuals in the military.3 The result is a young crew (average age mid-20s) with excellent baseline health.
While at sea, there is always a submarine-independent duty corpsman (IDC) on board. The IDC graduates from a 12-month course of clinical, laboratory, and radiological training at the Naval Undersea Medical Institute (Groton, Connecticut). Training includes 4 weeks of critical care at Yale-New Haven Medical Center (New Haven, Connecticut). On the submarine, an emergency medical assistance team (EMAT) assists the IDC in basic medical care, including activities such as patient transport and placing of intravenous lines. It is composed of crew members who are formally trained by the boat IDC. These skills are taught on a weekly basis, and proficiency is tested with periodic drills. Some EMAT members may have completed additional civilian training as emergency medical technicians (EMTs). Medical equipment carried on board includes basic laboratory equipment, an automatic defibrillator, over 200 different medications, and additional medical supplies. The IDC in most cases is able to communicate with a shore-based undersea medicine physician via satellite. Despite extensive planning to maintain a robust medical capability, unexpected events will continue to test the current system.
On January 8, 2005, the U.S.S. SAN FRANCISCO (SSN 711), a nuclear- powered submarine, collided with a seamount (a mountain rising from the ocean seafloor that does not reach to the water's surface) in a remote Pacific Ocean location. The submarine's homeport of Guam was the closest port, more than a 2-day sail. There were 138 individuals on board. There was no warning of a collision so the crew did not have an opportunity to brace themselves. The ensuing high-speed impact resulted in injuries to 90% of the crew. The intensity of the energy transfer can be visualized by the external damage to the bow of the submarine (Fig. 1).
On initial report, there were 2 severely injured personnel, 22 personnel requiring prompt medical attention, and 32 individuals with notable injuries not requiring prompt medical attention. Most of the remainder had only minor injuries. Approximately 10% of the crew was completely free of physical injury. Uninjured personnel were generally located in tightly enclosed spaces such as a bathroom stall or sleeping bunk.
The IDC was one of the uninjured. His attention was immediately drawn to the two most severely injured patients. Two crew members with some previous medical experience assisted him in caring for the other injured personnel. Injuries requiring the most urgent attention included head trauma, fractures, and lacerations (Table I). There were no initial reports of psychiatric casualties. All capable crew members manned their stations and ensured the continued operation of their boat.
One patient was thrown multiple feet at the time of the collision and suffered a fatal injury. He suffered immediate loss of consciousness from massive cerebral injury associated with a basilar skull fracture. He never regained consciousness. The IDC spent the majority of the next 24 hours tending to this patient as every effort was made to evacuate him for urgent neurosurgical care.
Adverse weather and sea state precluded transfer of medical personnel from a surface vessel that arrived ~18 hours postcollision. At ~24 hours postcollision, a helicopter arrived on the scene and was able to transport a medical team on board. They treated the crew until return to port the following day. A psychiatric team (consisting of a psychiatrist, a psychiatric technician, and a chaplain) boarded the submarine as it was coming in to the harbor in Guam. Before docking, the team interviewed individuals thought to be in need of immediate support. Upon arrival, 29 patients were transported to the emergency room at U.S. Naval Hospital Guam for further evaluation of physical injuries. Three patients were admitted to the hospital. One was admitted for a pneumocephaly with zygomatic and rib fractures. The second was admitted for a lumbar spine fracture, and the third for a fracture of the thyroid cartilage.
Three months after the collision, >85% of the crew was healthy and had no significant residual problems. Medical conditions precluding return to full duty were predominantly associated with mental health (Table II). After the 3-month evaluation was performed, it became more difficult to track all personnel. The boat completed a successful surface transit to Puget Sound Naval Shipyard for repairs, and much of the crew was dispersed to other commands at different locations. Most of the submariners disqualified for mental health reasons were transferred to nonsubmarine assignments. In the 2 years since the collision, all patients with physical injuries returned to submarine duty, although two additional crew members were disqualified from submarine duty due to psychiatric conditions.
Immediately after the ship's return to Guam, a detailed evaluation of the medical response was initiated. Recommendations for improvements to submarine emergency preparedness and disaster response identified by the evaluation were implemented. New policies were directly applied to the entire U.S. submarine fleet, currently composed of 68 nuclearpowered submarines. Newly implemented policies have been tracked over the past 2 years to confirm completion and obtain feedback. The major policy changes can be placed in the following three categories: communications, training, and postcollision follow-on care.
Medical advice was provided to the U.S.S. SAN FRANCISCO from the Command Center at Submarine Force, U.S. Pacific Fleet (Pearl Harbor, Hawaii). The Command Center has decades of experience in responding to requests for medical advice from submarines. The force surgeon maintained a continuous physician rotating watch schedule for the 24- hour period before the physician team boarded the submarine. Often more than one physician was present, providing significant benefit since there were multiple simultaneous medical taskings. The most time-intensive tasking was to arrange care for the unconscious patient with the severe head injury. The situation was complicated by the fact that there was no neurosurgeon in the territory of Guam at the time of the collision. Plans were set in motion for a neurosurgeon to be flown to Guam (with equipment) from a base in Okinawa, Japan. Meanwhile, a general surgeon was identified to escort the patient via helicopter from the submarine to Guam Naval Hospital.
The demands of long duration medical communication via voice and naval message traffic are significant. Clear transfer of medical information, coupled witii confirmatory mechanisms, is required to avoid errors. Two approaches were taken to prepare for future incidents. First, a dedicated educational element was added to training at the Naval Undersea Medical Institute. All undersea medical officers, as well as all IDCs, are taught the basics of secure satellite communications, secure Internet chat groups, and other mechanisms that were used during this event. Second, a comprehensive Submarine Command Center Medical Guidebook was developed. The guidebook is updated annually to ensure contact information and communication procedures remain accurate. The medical response to this collision was outstanding, wim adequate medical supplies and appropriate care given to all casualties. Such success validated the annual update of required medical supplies currently in place, as well as the U.S. Navy's submarine training pipeline for medical providers. However, there were some fortuitous events in this case. The event could have ended much differently. Most noticeably, the IDC was one of the few uninjured personnel. Additionally, there were two crew members wim some previous medical training (one as an EMT, one as a junior corpsman before he became a submarine officer). Although neither had been assigned as a member of the EMAT, these two individuals were essential in providing care to the injured crew. Following the collision, a survey of Hawaii submarines confirmed that on each boat there was generally only one nonIDC crew member who had an EMT level of knowledge. There was no mechanism to improve the availability of a backup for an injured corpsman, or one overwhelmed by a mass casualty.
A policy was initiated to require additional EMT-trained personnel on each submarine crew. At least one individual witii formal EMT training would then be available to assist the IDC. Volunteers for EMT training were drawn from that crew subset of young men with an interest in medicine, firefighting, or other emergency response fields. In 2006, 25 Hawaii submariners completed EMT training at Tripler Army Medical Center. Similar local EMT training programs were used at other submarine bases.
EMAT training requirements were increased, including a requirement for more frequent patient transport drills through the submarine and at all egress points out of the submarine. This was prompted by difficulties in maneuvering patients on stretchers following the collision. Because there are a variety of different submarine designs and modifications, the more inclusive annual drills have resulted in proactive solutions to solving difficult patient maneuvering problems specific to each individual submarine.
Detailed tracking of follow-on care was performed for all physical injuries sustained from the collision. This was of particular importance since patients with chronic intermittent musculoskeletal pain are often unable to tolerate submarine deployments. The submarine living spaces can cause strain to the human body. Sleeping areas are individual bunks stacked three high, with additional space limitations in working and living areas. Physical injuries were closely tracked so as to ensure appropriate and timely rehabilitation, allowing the return to work at 3 months by all but two patients with physical injuries.
Despite a robust proactive program to identify and treat mental health conditions associated with the collision, psychiatric disorders were the overwhelming reason for the departure of men at the 3-month point. Previously published reports have recognized the potential for the development of post-traumatic stress disorder and omer mental healtii conditions.4,5 Naval Hospital Guam dedicated all tiieir resources to the survivors, as well as arranging support for spouses and families with a school psychologist and licensed social workers from the U.S. Navy Fleet and Family Services Center.
After the collision, there were 17 submariners within the first 3 months who required follow-up psychiatric care for conditions that would possibly impact their ability to perform their submarine duties. There was no correlation between the degree of physical injury suffered during the collision and the development of a psychological condition. Despite efforts to retain all submariners in their current occupation, 3 months postcollision only 2 of 17 mental health patients had returned to full submarine duty.
The relatively large number of psychiatric casualties following the collision may be partially attributed to the strict psychiatric criteria for submariners. However, similar psychiatric morbidity was seen following an at-sea collision in 1975. The U.S.S. BELKNAP, a guided missile cruiser, suffered an at-sea collision resulting in the death of seven personnel.6 Eighteen of the surviving 329 men, none of whom had been hospitalized previously, required psychiatric hospitalization within the next 3 years. Thirteen of the men were hospitalized for neuroses, compared to only one man from a different guided missile cruiser used for comparison. Although each situation is unique, and the practice of psychiatry can vary over time and between geographic regions, it is likely that psychiatric diagnoses will continue to be common following future mass casualty events at sea.
This case offers insights into three areas that can be generalized to all disaster preparedness plans in isolated environments. First, update your plans according to advances in both verbal and Internet communication capabilities. There are now 3.3 billion worldwide mobile telephone subscriptions.7 Electrocardiogram strips, medical photographs, and patient videos can be sent via satellite from remote locations. Medical equipment previously thought too complex may now be reasonably deployed in an isolated environment if an expert can provide reliable long distance guidance. Second, ensure routine drills are performed for transport and evacuation of casualties. Medical personnel may not be informed when engineers or mechanics make alterations to the physical plant that affect passageways, ladders, and egress routes. Third, ensure that a written plan is in place to provide an early and robust medical response, including mental health resources for patients and their families. Physicians responsible for care of individuals in isolated environments are obligated to consider the potential for a worst case scenario, planning and drilling accordingly. These plans should be re-examined annually, so as to adjust to changes and maintain an effective emergency preparedness posture.
I am grateful to Dr. Dwayne DePry for his provision of outstanding psychiatric care to the submarine community in Guam and his assistance in collection of the mental health data.
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7. Global cell phone use at 50%. Washington Post, November 29, 2007. Available at http://www.waslungtonrx)st.com/wp-dyn/content/ article/2007/ 11/29/AR2007112901242.html?sub=AR; accessed December 3, 2007.
CDR Christopher John Jankosky, MC USN
Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Room A2056, 4301 Jones Bridge Road, Bethesda, MD 20814-4712.
The views expressed in this article are those of the author and do not necessarily reflect the official policy or position of the Department of the Navy, the Department of Defense, nor the U.S. government.
This manuscript was received for review in January 2008. The revised manuscript was accepted for publication in April 2008.
Copyright Association of Military Surgeons of the United States Aug 2008
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