ith the start of the global war on terrorism, United States military physicians have once again begun treating battlefield casualties on a regular basis. Although the wounds sustained in the current conflict are similar to those seen in past wars, recent technological advances in pain management allow anesthesiologists to intervene in ways that bestow significant short- and long-term benefits to these brave heroes. The vast majority of patients injured during Operation Iraqi Freedom (OIF) have been treated at Level III medical facilities such as Army Combat Support Hospitals (CSH), the Navy Fleet Surgical Hospital or the Air Force E-Med field hospital prior to being evacuated by air to Germany. The treatment policy of Level III facilities is to expeditiously save life, limb and eyesight while rapidly stabilizing patients in preparation for transport out of theater. In this brief stabilization phase, there exists a tremendous opportunity to assuage the many pains of the wounded.

During the build up and initial ground phase of OIF, leaders of U.S. medical units were required to critically assess their resources in order to include imperative supplies and eliminate unnecessary ones. Hundreds of these difficult decisions were made based on pre-existing inventories, doctrine and input from deploying military medical professionals. Many drugs and medical technologies were not included in the hospital’s initial inventory due to transportation limitations and doctrinal realities established in previous wars. Several anesthesia-specific examples of these omissions include long-acting opioid pain medicine (i.e., hydromorphone and methadone), long-acting local anesthetics (i.e., ropivacaine), patient-controlled analgesia (PCA) pumps and continuous peripheral nerve block (CPNB) supplies. The hospitals relied on the logistics system for resupply under the working hypothesis that other medical supplies and technologies as identified would be acquired for hospital use.

Dr. Croll, far right, poses with members of his team in Iraq. Photo by Scott M. Croll, M.D., and Sean M. Shockey, M.D.

The first Army CSH to reach Baghdad during the ground war was the 28th CSH, which set up a fully operational, surgically intensive tent hospital outside city limits just west of the Euphrates River on April 11, 2003. Other Level III hospital units, such as the Navy Fleet Hospital 3, set up operations south of Baghdad while the U.S. Navy Hospital Ship Comfort remained offshore to provide additional capacity.

During the first four weeks of the conflict, approximately 90 percent of the surgeries performed involved orthopedic injuries. Not surprisingly, postoperative acute pain management became a daily priority in the hospital and within the medical air evacuation chain. During this time, a majority of patients were Iraqi, and the language barrier made pain management quite challenging. Some regional anesthesia techniques such as subarachnoid and axillary blocks were employed, albeit sparingly, due to supply limitations. In spite of these challenges, however, most patients had their pain adequately controlled with standard analgesics such as fentanyl, morphine and ketamine.

In time, after moving to a fixed facility inside Baghdad, the 28th CSH was able to request and utilize other valuable medical supplies and state-of-the-art technologies to further expand treatment options at the hospital. Considerable challenges arise when introducing new medical innovations into any system. Examples highlighting how these challenges are amplified in the austerity of military medicine include developing reliable supply routes for new and often expensive technologies, obtaining official approval for use on aircraft (airworthiness certification) for safe use in a timely manner and simply introducing change into day-to-day operations within a battlefield environment. Quite often advancements in medicine take years to gain legitimacy and acceptance within a field hospital. In stark contrast to this reality, an amazing example of a rapid and timely safe-to-fly approval for use within the military medical system can be seen in the recent certification of a disposable infusion pump for CPNB.

The first reported battlefield CPNB was placed on October 7, 2003.¹ Without proper approval, however, an infusion pump to deliver continuous perineural local anesthesia would be prohibited from military aircraft. This would eliminate the benefits of acute pain control with CPNBs; namely, minimizing intravenous narcotics and their many undesirable side effects.² Authorization for use on military aircraft requires that new equipment be rigorously tested to demonstrate it will not cause adverse effects to the patient or aircraft. Testing includes an evaluation of electromagnetic fields, radiation emission and function under extreme conditions (such as explosive decompression). Based on initial data, a temporary waiver was issued for the pump in 2003 to expedite the use of CPNB throughout the air evacuation system, allowing the wounded to enjoy state-of-the-art pain control.

Current conflicts have presented many opportunities for anesthetic interventions never before utilized in a combat environment. While many of the injured sustained multiple traumatic injuries requiring general anesthesia with prolonged mechanical ventilation and intensive care unit courses, there were a significant number that were amenable to regional anesthesia, including central neuraxial and peripheral nerve blocks. Standard spinal and epidural kits have been used since the Vietnam War; nerve stimulators, stimulating needles and peripheral nerve catheters, however, were utilized for the first time during this conflict.

Patients with isolated extremity injuries were offered CPNB whenever possible. Single injections and CPNBs of the paravertebral space and the brachial, lumbar and sacral plexuses were performed. Since a majority of these patients did not have immediately life-threatening injuries, the placement of a CPNB allowed effective pain control with subsequent redosing for surgery and continuous infusion of local anesthetic to manage their pain for days. Not only was CPNB helpful for acute pain control, it was advantageous for bedside dressing changes and additional surgeries done at several different hospitals along the evacuation chain. This accomplishment has given some of our wounded soldiers the previously unavailable advantage of superior anesthesia and dependable analgesia from the battlefield all the way home.

One advance that made a huge difference during this conflict was the utilization of different pain management drugs. In the not-so-distant past, the only narcotic available for pain control was morphine sulfate. Although an outstanding and time-honored drug, as the only available battlefield pain management tool, morphine’s significant side-effect profile has limited its effectiveness in the current air evacuation environment. After discussion with 86th CSH pharmacist Capt. John Mbue and supply personnel, the 86th CSH was able to obtain other medications, including hydromorphone, methadone, gabapentin, carbamazepine and clonidine for long-term pain management. These drugs significantly improved the acute and chronic pain management of these severely injured soldiers.

Another advance introduced during this war was the assignment of physical therapists to the CSH. These medical professionals helped with the management of personnel in theater who had chronic pain problems and provided a continuity of care that had previously been unavailable. The physical therapy clinic at the 86th CSH in Baghdad was often busier than any other clinic. The single physical therapist, Capt. Charles Blake, would disregard his “clinic hours” in order to accommodate patients unable to work a normal 9-to-5 job in Baghdad. His efforts certainly benefited these patients, and his willingness to treat the ward patients helped to make a difference in the management of pain in the combat theater of operations.

Other technological advances in the treatment of soldiers’ pain include PCA; the creation of Military Advanced Regional Anesthesia and Analgesia (MARAA), a triservice consultant committee on pain management; and the Regional Anesthesia Tracking System (RATS). As surprising as it may seem, existing CSH doctrine does not include the use of PCA for acute pain control. An interim PCA infusion pump was given a certificate of airworthiness in 2005 that allowed injured soldiers to effectively manage their pain from the field hospital all the way back to U.S. military hospitals. Since its inception, MARAA (a committee of the ASA Uniformed Services Society of Anesthesiologists) has offered evidence-based recommendations in multiple areas of pain control to include the field utility of fentanyl lollipops³ and guidelines for the management of epidural catheters on air evacuation flights.

RATS is another success story in 21st century battlefield pain management that originated from the MARAA committee. RATS is a secure, Web-based, password-protected data-entry pain management tracking system that allows providers from anywhere along the military evacuation chain to enroll and track a soldier’s pain control.

In summary, significant advancements have been made in the acute pain management of wounded soldiers. Military anesthesiologists have established themselves as indispensable members of the combat casualty team and the soldier’s primary advocate in the treatment of pain.

References:
1. Buckenmaier CC III, McKnight GM, Winkley JV, et al. Continuous peripheral nerve block for battlefield anesthesia and evacuation. Reg Anesth Pain Med. 2005; 30:202-205.
2. Klein SM, Buckenmaier CC III. Ambulatory surgery with long-acting regional anesthesia. Minerva Anestesiol. 2002; 68:833-841.
3. Stanley TH, Hague B, Mock DL, et al. Oral transmucosal fentanyl citrate (lollipop) premedication in human volunteers. Anesth Analg. 1989; 69(1):21-27.

Scott M. Croll, M.D., Maj., Medical Corps, U.S. Army, is Assistant Professor of Anesthesiology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, and Anesthesiology Residency Director, Walter Reed Army Medical Center, Washington, D.C.

Sean M. Shockey, M.D., Maj., Medical Corps, U.S. Army, is Staff Anesthesiologist, Walter Reed Army Medical Center, Washington, D.C.