Introduction and Background
Declaring War on Pain: Standardization and Optimization of Non-Opioid Pain Management Techniques in the Aeromedical Evacuation Milieu
The ultimate goal of the United States Air Force (USAF) Aeromedical Evacuation (AE) system is the safe and comfortable transport of ill and wounded warfighters, and beneficiaries of the Department of Defense (DoD), from primary areas of injury to definitive medical treatment facilities (MTFs). Emergency airlift of battle injured and wounded warfighters has evolved tremendously over the past century. “Speed saves lives” is the maxim in AE circles as rapid air evacuation of critically ill and battle wounded service members minimizes complications and reduces mortality. The changing nature of modern warfare increased the complexity and severity of the wounded casualties exposed to the inherent stressors of flight, and has added significant patient management challenges to AE crews striving to improve safe and effective en-route pain control. The recent introduction of multi-modal pain therapies necessitates up-to-date training and experience of all AE healthcare providers. Intravenous narcotic patient-controlled analgesia (PCA) infusion pumps entered the general AE system in 2004, and continuous epidural, and peripheral nerve catheter infusions were introduced in 2011 for pain management during extended evacuation missions.
Present day AE operations still rely primarily upon opioid-based interventions for pain control, thus exposing the injured or ill warfighters to significant inflight adverse side effects. Inadequate pain control is associated with long-term adverse sequelae, including chronic pain syndromes and post-traumatic stress disorder. Non-opioid based, multimodal pain management strategies, including continuous epidural and regional anesthesia techniques, have proven effective in safely controlling pain in the trauma victim. Battlefield acupuncture techniques are also being researched and introduced into the growing repertoire of effective pain intervention modalities. With the continued reliance on the “gold-standard” opioid-based therapies, the USAF AE lacks standardized multimodal pain management guidelines to improve the safety and comfort of our evacuated service men and women.
Short History of Aeromedical Evacuation
The USAF Aeromedical Evacuation system has been transporting ill and wounded patients for almost 80 years on multiple fixed-wing aircraft. From its infancy in World War I (WWI) through recent operations, AE has saved the lives of hundreds of thousands of soldiers. The modest early beginnings in WWI continued throughout the inter-war years and evolved into a proven AE system by the end of World War II (WWII). During WWII, the Army was using field ambulances to transport patients, even over long distances. “The Army Medical Department did not believe that the airplane was a substitute for field ambulances” (Green, et al., 2001, 14). However, with the massive number of casualties being evacuated by air from all fronts, by the end of WWII, the general idea that “air evacuation of the sick and wounded was dangerous, medically unsound, and militarily impossible” was put to an end. Brigadier General Bruce Green (2001) wrote:
“The sheer number of patients transported during World War II reflects the
great importance of AE. At its peak, the AAF evacuated the sick and wounded
at a rate of almost 100,000 per month. A one day record of 4,704 AE patients
evacuated was set in 1945. In his statement on 18 June 1945, Gen of the Army
Dwight D. Eisenhower said, “We evacuated almost every one of our forward
hospitals by air, and it has unquestionably saved hundreds of lives—thousands
of lives.” General Eisenhower placed AE in a class with sulfa drugs, penicillin,
blood plasma, and whole blood as a chief factor in cutting the fatality rate of
battle casualties” (Green, et al., 2001, 21).
The AE system continued to grow and prove its value throughout the many conflicts during the Cold War era and the recent operations in the Middle East. Specialized aircraft were devoted solely for AE missions; the most notable was the C-9A Nightingale airlift platform acquired in August 1968 and retired in August 2003 at Scott AFB. Today, dedicated “AE warriors,” nurses, technicians and physicians, continue to transport thousands of service members and DoD beneficiary casualties on multiple opportune aircraft from the farthest austere environments to more definitive MTFs (Pierce & Evers, 2003).
Pain Treatment Modalities Then and Now
For decades, morphine mono-therapy was the ‘gold-standard’ in pain treatment of transported injured soldiers. Massive narcotization and lack of adequate monitoring posed significant patient care safety issues. With the advent of more advanced pain relief techniques, such as Patient Controlled Analgesia (PCA), continuous epidural infusions and continuous peripheral nerve blocks (cPNBs), the quality of safe pain control and management improved significantly. Drs. Malchow and Black (2008), Brooke Army Medical Center anesthesiologists, argue a paradigm shift is occurring in early treatment of acute pain throughout the casualty evacuation process. They further contend inadequate treatment of acute pain may lead to debilitating chronic pain and even post-traumatic stress disorder (PTSD). The current rationale and movement toward multi-modal therapy pain control is based on synergistic interactions between pharmacologic agents and non-opioid regional/epidural techniques, which may reduce dependence on opioid only based therapies. This recent introduction of proven analgesia techniques and medications into the military aeromedical evacuation system has improved safe and effective pain control. The 2010 introductions into the AE system’s growing repertoire of pain relief techniques are the continuous epidural and PNB catheter infusions. These pain treatment modalities offer highly effective, localized pain relief without the need for continuous opioid medication administration. However, an occasional opioid bolus may be required for breakthrough pain as needed for patient comfort.
According to Major Gregory Malone, an anesthesiologist and flight surgeon, “The relatively austere medical environment of the Air Force evacuation aircraft makes the management of acute pain in … multitrauma patients particularly difficult” (Malone, 2008, 16). The recent contingencies have resulted in extreme poly-trauma injuries due to increasing lethality of improvised explosive devices (IEDs). Forward operating base stabilized battlefield wounded casualties with injuries ranging from multiple amputations, facial fractures, soft tissue damage, vascular injuries, multiple long bone fractures, pulmonary contusions and traumatic brain injuries are emergently airlifted on a daily basis (Malchow & Black, 2008).
Today`s modern Aeromedical Evacuation system is a critical, fast and highly refined system in which the injured casualties rely on dependable and comfortable care in any contingency operation or national emergency. According to current Congressional Research statistics, a total of 52,065 individuals were medically evacuated from OIF, and a total of 23,742 individuals were medically evacuated from OEF through December 3, 2012 with no in-flight deaths, a tribute to our medical and nursing professionals (Fischer, 2013).
Gaps and Concerns
Data collected by the Air Mobility Command (AMC), Aeromedical Evacuation (AE) En Route Care (ERC) division, Office of the Command Surgeon on aeromedically evacuated warfighters indicates an inconsistency in pain/sedation interventions, assessments and documentation by AE crewmembers. This deficiency poses a concern for safe and effective in-flight pain control, treatment and comfort management (AMC, 2012). Furthermore, Army Surgeon General, Lieutenant General Eric B. Schoomaker, offers recommendations for a comprehensive, holistic, interdisciplinary and multimodal pain management strategy across the military continuum of care, including the AE system. The Final Report of the Pain Management Task Force chartered in 2009 concluded that the military does meet the standards of care for pain management; however there is much variability in how each healthcare provider approaches and understands the concept of pain and its treatment. As a result, a new combined pain assessment scale was developed for use in the DoD and VHA known as the Defense and Veterans Pain Rating Scale. This new pain measurement tool is expected to promote improved objective consistency in pain assessment and become the standard for all DoD and VA health care settings.
Primary, experimental and randomized control trials specifically related to the aeromedical environment are lacking. Ethical and moral considerations of patients in pain must be always taken into consideration, thus making such studies more difficult. However, evidence based research in non-opioid pain interventions from other disciplines and settings should have applicability into the AE milieu. The military AE system is a long-range, highly specialized, and unique transport platform that has little or no comparison in the civilian sector. Thus, more non-randomized, quasi-experimental research needs to be done in this particular setting. The research opportunity definitely exists for military researchers.
This capstone research will be supported by current scholarly and substantive primary literature sources to help clarify how to best utilize and standardize non-opioid pain interventions during AE missions to deliver safe and effective in-flight pain control and management to our warfighters. The AMC, Command Surgeon Office (AMC/SGK) Aeromedical Evacuation/En Route Care Capabilities-Based Assessment Report (AE/ERC CBA) analyzes data collected on aeromedically evacuated warfighters. This report is the main source for identifying several AE mission research and knowledge capability gaps. A very high priority was given to the need for improvement of clinical knowledge and skills in providing effective pain control and pain management throughout the en route continuum of care. According to recent email communications with Lt Col Jennifer Hatzfeld, PhD, En Route Care Research Portfolio Manager, at this time, there is a significant “need for more standardized non-opioid pain management techniques in AE (nerve blocks, epidurals, acupuncture, etc.).” From her perspective, “it would be wonderful if you (I) were able to develop (or test/evaluate) an approach that would be appropriate for use in the transport environment.” (Hatzfeld, email).
Therefore, this project is intended to standardize and optimize multimodal, non-opioid pain management guidelines to improve the safety and comfort of injured and ill service men and women during aeromedical evacuation (AE) missions. The recent introduction of continuous peripheral nerve blocks (cPNBs), epidurals, and battlefield acupuncture (BAC) into the growing repertoire of AE pain control techniques necessitates advanced clinical knowledge and management skills from AE crewmembers. This project should provide the guidelines for flight nurses, aeromedical evacuation technicians (AETs), and civilian transport teams to reduce inflight patient complications and airway issues related to opioid-based dependent pain therapy.
My capstone focus is on facilitating safe and effective inflight pain control and comfort management to airlifted warfighters through the utilization and standardization of non-opioid continuous peripheral nerve blocks (cPNBs), epidural infusions and battlefield acupuncture adjuncts. The aeromedical evacuation system is beginning to shift away from opioid-based pain interventions because of the numerous potential in-flight side effects. Compounding the problem of opioid pain treatment in the airlift setting are provider concerns that opioids may lead to hypotension, respiratory depression, blurring of mental status, and changes in clinical status. The main side effect is airway and respiratory compromise, which can lead to emergency intubation and placement of a patient on a portable ventilator in-flight. Once that occurs, up to two crewmembers may be removed from the much needed care of others on board the aircraft.
According to Biddle (2013), the PICO acronym (population, intervention, comparison and outcome) is a useful model for asking and developing evidence based clinical questions. Some PICO descriptors have an additional time (T) element. I have slightly modified my initial PICO(T) focused research approach to a more detailed description of each of the elements:
P=Wounded and/or ill military members and DoD beneficiaries
I=Use of non-opioid pain techniques (epidural, peripheral nerve blocks and acupuncture)
C=Opioid pain techniques currently utilized (morphine, fentanyl, hydromorphone)
O=Improve patient safety, comfort, and minimize side effects from stressors of flight
T=Transportation event via the AE system
Thus, my EBP research question could be formulated in the following way:
For battle wounded and/or ill military members and DoD beneficiaries (P), how does the use of non-opioid regional pain management techniques (I), compared to the administration of standard opioid pain medications (C), improve the patient safety, comfort and reduction of side effects resulting from stressors of flight (O) during transportation via the AE system?
The population for this study would be all military members and Department of Defense beneficiaries sustaining traumatic accidental or battle injuries, and requiring routine, urgent or priority aeromedical evacuation from an austere environment. These members would be stabilized and/or treated surgically at a local Military Treatment Facility. Interventional pain control would range from non-opioid regional interventions, such as continuous epidural infusions, continuous peripheral nerve blocks (cPNBs) and/or battlefield acupuncture. As per AFI 41-307, only bupivacaine 0.125% and/or ropivicaine 0.2% would be infused. Regional catheters would be placed at Army or Air Force field hospitals and CASFs (combat aeromedical staging facilities) prior to patient movement. The battlefield would be too dangerous for catheter placement, whereas inflight turbulence and dirty nature of cargo planes would also be an issue. These patients would then be compared to a control group receiving PO opioids, NSAIDs or PCA opioid pumps for pain control. For practical reasons (all injured or ill will be transported from harms way), randomization would not be considered in this particular population; however, two groups would still be present. Group one would consist of patients whose pain is controlled with opioids, and group two would have non-opioid regional pain therapy. The best pain control intervention would be determined by the potential best patient outcome. “Nursing research often occurs in natural settings, where it is difficult to deliver an innovative treatment randomly to some people but not to others. Strong quasi-experimental designs introduce some research control when full experimental rigor is not possible” (Polit & Beck, 2014, 158-159). The control group would be the comparison group. There would be no control group with a placebo pain treatment, or no treatment at all, as this would not be ethical. Obviously, intravenous or per mouth opioids would not be withheld from research participants requiring an adjunct for breakthrough pain. I believe regional non-opioid pain interventions for long-term pain control are ideal in the AE environment. Pain levels can be easily measured via the recently validated Defense and Veterans Pain Rating Scale (DVPRS) tool. Many of the stressors of flight, such as aircraft vibrations, temperature fluctuations, gravitational forces, barometric pressure changes, and noise can contribute to a patient’s pain perception. A decrease in the partial pressure of oxygen and decreased humidity can affect a patient’s airway and respiratory status, particularly when being administered opioids and sedatives. The pulse oximeter would be used to measure the oxygenation status of patients en-route to definitive treatment facilities. Comparisons between pulse oximeter and pain levels would then be compared between the two groups. I hope that as an anesthesia provider and flight nurse, my input via this capstone project will have some impact on the AE leadership at the Air Mobility Command.
An online literature search was conducted using the RFUMS Boxer Library and Google Scholar. The Boxer search engine CINAHL, Medline and PubMed were probed for relevant evidence based research articles related to my capstone project. Keywords: pain, non-opioid, regional, AE, aeromedical evacuation of soldiers, acute pain in AE, and AE pain interventions with various Boolean ‘and/or’ alterations were used in Google, PubMed and Library Search. My search was not very successful in PubMed; I could not find any specific hits. I achieved the best and most relevant hits in Google Scholar, and ultimately the RFUMS ‘LibrarySearch’ engine by combining my keywords and selecting search filters. My final combined keyword phrase was: “acute pain interventions in aeromedical evacuation of soldiers.” This produced 990 hits in Google Scholar and 138 hits in Boxer LibrarySearch. I further added a ‘peer reviewed’ filter and narrowed the Boxer search to 123. I added the keyword ‘non-opioid’ to the phrase and got six Google hits of which two looked promising. Interestingly, in the school library search this reduced my hits from 123 to just one, so I removed the term ‘non-opioid’ and selected ten articles by examining the titles and skimming through the abstracts. I saved these ten articles into my library search folder and will review the articles in more detail. Overall, searching for relevant evidence based research related to my capstone project was not as simple as I thought it would be. My search in the Military Medicine Journal only produced one significant article out of 31. Most were related to traumatic head injuries. I will have to spend more time on improving my search engine skills and reviewing the Searching for Evidence lecture again. My next step is to ask for professional librarian help at RFUMS. I did not utilize this option because I trusted my literature search skills. As mentioned, the field of military patient AE transport is very small and unique. Opioid-based pain control still dominates, and has been used for decades. It is time, however, to enter the 21st century. There are only 400+ Air Force Flight Nurses trained to provide in-flight care. We follow the AE bible: AFI 41-307, Aeromedical Evacuation Patient Considerations and Standards of Care, which provides guidance related to numerous patient conditions, including pain interventions and management. Finally, my other option is to request permission from Air University to conduct online military searches through their school library. Perhaps signing up for Air War College will allow me access to the various military search engine databases.
In summary, this was an interesting exercise in conducting a thorough primary literature search, condensing the capstone project into the PICO(T) model, and developing a focused, evidence based clinical question of interest and relevance to further the nurse anesthesia knowledge base.