he global war on terrorism has demonstrated the significant contributions of anesthesiologists on the battlefield. Since the beginning of combat operations in early 2003, more than half (~125) of the active duty Army, Navy and Air Force anesthesiologists have deployed overseas for an average of six months. These numbers are in addition to the many reserve anesthesiologists who have deployed once with many now being called up for a second deployment. These anesthesiologists have served with valor and distinction at military hospitals throughout Afghanistan, Iraq, Kuwait, the Persian Gulf and Europe. Some of the locations within these areas are familiar to any who have a television and include areas of current conflict such as Kabul in Afghanistan and Baghdad, Fallujah, Talil, Tikrit, Mosul and Abu Ghraib prison in Iraq. Others have been and are in places that have no names except a general location at sea in the Persian Gulf or in the deserts of Iraq supporting areas of intense conflict. These dedicated men and women continue to demonstrate the essential role of anesthesiologists in managing difficult polytrauma patients as well as developing improved battlefield care.

Not only have anesthesiologists been integral to the delivery of care, they have done what anesthesiologists always do — provide leadership and innovation in the implementation of care. In addition to serving leadership roles as chiefs of anesthesia, several anesthesiologists have been recognized for their executive leadership, filling roles such as Deputy Commander of Clinical Services for many combat support hospitals (CSH).

In the past few years, many anesthesiologists in the Navy and Air Force have been assigned to forward surgical units that provide care in close proximity to actual conflict. They have frequently been in front of the artillery and yet behind the forward combat units. Occasionally during the major conflicts in 2003, they have been close enough to be targeted with small weapons fire, necessitating the need to take cover in makeshift foxholes and behind available rubble.

Currently anesthesiologists are deployed primarily to CSH or at Air Force and Navy equivalents, the Emergency Medical Support System and the Fleet Surgical Hospital, respectively. These deployable hospitals provide the most comprehensive level of care for both injured coalition soldiers and Iraqi civilians. Typically two or more anesthesiologists are deployed with six to eight nurse anesthetists to provide both resuscitative and operative care for patients of all ages. However, with an ongoing shortage of nurse anesthetists and with 33 percent of that community in the Army rated as nondeployable, the number of deployments in 2005 for Army anesthesiologists has increased 100 percent as they fill vacant nurse anesthetist positions, which for 2005 accounts for approximately 25 percent of the active duty Army nurse anesthetist deployments.

While assigned to these units, the delivery of trauma care can be extremely busy. For example, from January 2004 to December 2004, the 31st CSH at Baghdad managed more than 3,500 trauma patients and performed more than 400 operative cases a month. Anesthesiologists typically function as medical directors of the operating room, but recent deployments have found anesthesiologists providing expanding roles in the management of all trauma patients, from development of a theater trauma system to intensive care management, delivery of regional anesthesia and pain management, combat casualty research, utilization of total intravenous anesthesia and air evacuation.

Trauma and Critical Care
Critically ill patients arriving at these hospitals require immediate life-saving therapies, including advanced airway management and massive resuscitation that are often directed or performed by anesthesiologists. During mass-casualty incidents, anesthesiologists frequently provide initial advanced trauma life support (ATLS) management of the most critically ill patients and expedite delivery of surgical care.

Anesthesiologists are pioneering innovative approaches to maximize patient outcomes in the CSH operating room by utilizing transthoracic echocardiography, balanced physiologic support, permissive hypotension and recombinant factor VIIa (rFVIIa). One CSH has successfully used rFVIIa in more than 90 patients who developed a coagulopathy during massive transfusions.

In the past year, more than 34 percent of patients were admitted to the intensive care unit (ICU) at the 31st CSH in Baghdad. A significant number of these patients underwent damage control surgery (DCS) with ongoing resuscitation needs in the ICU. Mortality was decreased by more than 35 percent when an anesthesiologist-intensivist who was assigned in a nurse anesthetist position directed team-managed ICU patient care. This decrease in mortality was likely due to care by the team, which also included cutting-edge and novel techniques such as advanced ventilator management, independent lung ventilation and the use of vasopressin to treat hemorrhagic shock.

Regional Anesthesia
The role of the anesthesiologist involves more than simply providing expert medical care in the operating room and ICU. With the onset of the Iraq war, advances in battlefield medicine and air evacuation have increased the survival rate among wounded soldiers. Postoperative pain and pain control within days of injury on the long transport to Landstuhl, Germany, and to the United States have been problematic. Unfortunately acute pain management on the modern battlefield has not kept pace with other advancements. The management of pain in war with opioids has remained essentially unchanged for more than 200 years.

In the current conflict, the anesthesiologist-driven Army Regional Anesthesia and Pain Management Initiative (ARAPMI) and Military Advanced Regional Anesthesia and Analgesia (MARAA) organizations have worked to advance the cause of improved pain management for our wounded soldiers. With the first successful application of continuous peripheral nerve blocks (CPNB) in a wounded soldier on October 7, 2003, many more soldiers have enjoyed the benefits of CPNB in their long-term pain management.¹ Central neuraxial and advanced regional anesthetics are now routinely performed for surgical anesthesia and postoperative analgesia. Through the tri-service efforts of MARAA, peripheral nerve infusion pumps have been approved for flight on military aircraft, allowing the benefits of CPNB to follow the patient onto the difficult medical environment of air evacuation.

Continuous perineural catheters placed in Iraq now allow for transport from the battlefield to the United States with excellent analgesia and allow surgical procedures to be performed en route by utilizing the catheters for delivery of anesthesia. Currently MARAA hopes to have patient-controlled analgesia (PCA) pumps approved for the battlefield and military aircraft within the year. While compassionate care is reason enough for these efforts at improved analgesia, evidence continues to mount that effective pain management on the battlefield facilitates recovery and possibly reduces the incidence of chronic pain states.

Combat Casualty Care Research
Lessons learned can be important tools for implementing changes in the delivery of care and in medical systems to maximize treatment of injured persons. Anesthesiologists have been instrumental in collecting and analyzing data for the Joint Theater Trauma Registry (JTTR), which has already led to changes in combat casualty care. Data have shown the benefit of intensivist-directed ICU teams and the need for improved tourniquets. Other areas of research include the role and use of whole blood on the battlefield. More than 500 units of fresh, whole blood to treat coagulopathy and anemia were given as part of a massive transfusion protocol developed by physicians at the 31st CSH in Baghdad. Previously the CSH was not supplied with platelets or large amounts of fresh, frozen plasma and cryoprecipitate. Platelet pheresis has been implemented recently, so further analysis will determine if there is a role for whole blood compared to component therapy in the CSH. The JTTR, with institutional review board approval, is currently being analyzed to answer many questions including the effects of hypothermia on mortality, the role of rFVIIa, predictors of mortality and the role of damage control surgery, to name a few. In the United States, research projects are being developed by anesthesiologists to improve battlefield pain control, evaluate hemostatic drugs and develop inflammatory mediator physiology and tools for emergency airway management.

Total Intravenous Anesthesia (TIVA)
Intravenous anesthesia is well-suited for use in the austere combat environment, although until recently it has never been used on a large scale in deployed hospitals. Some of the advantages of intravenous anesthesia include: 1) a decreased logistical footprint of the anesthesia provider by eliminating the need for an anesthesia machine; 2) reducing oxygen requirements; 3) eliminating waste gases from the environment; 4) reducing nursing interventions for postoperative nausea and pain control; 5) improving maintenance of hemodynamic stability and temperature conservation; and 6) improving patient outcomes. Anesthesiologists are charting the development, implementation and evaluation of TIVA at these hospitals. One recently deployed Army anesthesiologist serving in a nurse anesthetist position delivered TIVA to more than 100 patients who required either a craniotomy or craniectomy. One important finding is that his introduction of this technique decreased mortality by 50 percent when compared to similar neurotrauma patients receiving volatile-based anesthesia.

Critical Care Air Transport
Air Force and Navy anesthesiologists also have been leaders in the development of Critical Care Air Transport (CCAT) teams and the management of patients both in the forward resuscitation surgical system (FRSS) and on Navy hospital ships.² CCAT anesthesiologists manage air evacuation of the most critically ill soldiers, who often require ventilator and hemodynamic interventions. These providers also facilitate the seamless continuum of critical care and pain management that occurs from the point of injury to the deployed hospital to Landstuhl, Germany, and then to the United States. The phenomenal impact of these teams is that hundreds of critically ill ICU patients have moved safely from injury to a U.S.-based ICU in five to six days with no increase in morbidity or mortality.

The men and women of the U.S. Armed Forces deserve the highest level of medical care possible. The Army, Navy and Air Force are working diligently to provide cutting-edge and expert care to our soldiers. Anesthesiologists have proven their role for providing the most complete and safe perioperative care possible. As the Iraq conflict continues, anesthesiologists will continue to be the medical directors of anesthesia care teams throughout Iraq. The skills of the anesthesiologist, including perioperative medicine, advanced regional anesthesia, total intravenous anesthesia and critical care experience, have been shown to be important tools in delivery of the best care available to our soldiers.

References:

1. Buckenmaier CC, McKnight GM, Winkley JV, et al. Continuous peripheral nerve block for battlefield anesthesia and evacuation. Reg Anesth Pain Med. 2005; 30(2):202-205.

2. Stevens RA, Bohman HR, Baker BC, Chambers LW. The U.S. Navy’s forward resuscitative surgery system during operation Iraqi Freedom. Mil Med. 2005; 170(4):297-301.

Col. Paul D. Mongan, M.D., is Associate Professor and Chair, Department of Anesthesiology, Uniformed Services University, Bethesda, Maryland.

Lt. Col. Kurt W. Grathwohl, M.D., is Assistant Chief of Anesthesia and Operative Services, Brooke Army Medical Center, San Antonio, Texas.

Lt. Col. Chester C. “Trip” Buckenmaier, M.D., is Chief, Army Regional Anesthesia and Pain Management Initiative and Assistant Professor, Uniformed Services University, Washington, D.C.

Maj. Joel W. McMasters, M.D., is Staff Anesthesiologist; Assistant Program Director, San Antonio Uniformed Services Health Education Consortium Anesthesiology Residency; Director of Cardiac Anesthesia; and Vice-President of the Triservice Anesthesia Research Group Initiative on Total Intravenous Anesthesia, Brooke Army Medical Center, San Antonio, Texas.

Maj. Ian H. Black, M.D., is Chief of Anesthesia, U.S. Army Institute of Surgical Research, Brooke Army Medical Center, San Antonio, Texas.