Flight Surgeon Research Articles

James F. Thornton, MD.

I want to thank Dr. James F. Thornton for serving as our guest editor for this edition of Seminars in Plastic Surgery and additional authors for their contributions to this very important issue on “Biologic Agents in Plastic Surgery.” James F. Thornton, MD, is a professor in the Department of Plastic Surgery at the University of Texas Southwestern Medical Center in Dallas. Dr. Thornton attended UT Southwestern for his medical degree and did his surgery internship from Parkland Memorial Hospital in Dallas. Dr. Thornton served 3 years as a United States Navy Flight Surgeon in Kaneohe, Hawaii.

Migraine History and Outcomes in Military Pilots and Flight Surgeons.

BACKGROUND: Migraine is a common disorder with significant aeromedical implications. The variability and unpredictable nature of occurrences hampers accurate assessment of future risk. This uncertainty results in a necessarily conservative approach to aeromedical recommendations, which unfortunately may lead to over-restrictive dispositions. Limited long-term follow up information is available on migraine outcomes in pilots, particularly assessing for impact of potential modifiable aggravating factors.Methods: This retrospective study reviewed 159 U.S. Air Force pilots with migraine who had been granted aeromedical waivers. As a comparison group, 44 U.S. Air Force flight surgeons with migraine who had been granted aeromedical waivers were reviewed.Results: Migraine with aura and isolated migraine aura without headache accounted for the majority of migraine subtypes in both male and female subjects. Self-identified triggering factors were identified by 62% of subjects. The most commonly reported triggers were dietary factors, sleep disturbances, stress, caffeine intake, and hormonal factors. Sleep disturbances, stress, hormonal factors, and ethanol triggers were more frequently noted in female subjects. Self-reported positive response to trigger factor modification was noted in 54% of subjects. Subjects reported an average of only 3 migraine attacks in the previous year. Long-term follow up indicated continued aeromedical waiver in 91% of subjects.Discussion: The majority of subjects had migraine with aura or isolated migraine aura. Significant salutary response to modification of commonly-reported triggering factors was noted. These findings can be incorporated into individualized aeromedically-compatible management strategies to clarify symptom impact on aviation safety, improve symptom control, and increase the possibility of safe return to fly recommendations.Hesselbrock RR, Haynes JT. Migraine history and outcomes in military pilots and flight surgeons. Aerosp Med Hum Perform. 2022; 93(1):26-31.

In the Fleet as a Flight Surgeon: An Opportunity for Professional Growth.

In the Fleet as a Flight Surgeon: An Opportunity for Professional Growth.

Spaceflight validation of technology for point-of-care monitoring of peripheral blood WBC and differential in astronauts during space missions

During long duration orbital space missions, astronauts experience immune system dysregulation, the persistent reactivation of latent herpesviruses, and some degree of clinical incidence. During planned NASA ‘Artemis’ deep space missions the stressors that cause this phenomenon will increase, while clinical care capability will likely be reduced. There is currently minimal clinical laboratory capability aboard the International Space Station (ISS). The ability to monitor the white blood cell count (WBC) and differential during spaceflight has been an unmet NASA medical requirement, primarily due to a lack of capable hardware. We performed ground and flight validation of a device designed to monitor WBC and differential within minutes from a fingerstick blood sample. This device is miniaturized, robust, and generally compatible with microgravity operations. Ground testing for spaceflight consisted of vibration tolerance, power/battery and interface requirements, electromagnetic interference (EMI), and basic evaluation of sample preparation and operations in the context of spaceflight constraints. The in-flight validation performed aboard the ISS by two astronauts included assessment of three levels of control solution (blood) samples as well as a real time analysis of a fingerstick blood sample by one of the crewmembers. Flight and ground testing of the same lot of control solutions yielded similar total WBC values. There was some select discrepancy between flight and ground data for the differential analysis. However, the data suggest that this issue is due to compromise of the control solutions as a result of storage length before flight operations, and not due to a microgravity-associated issue with instrument performance. This evaluation also yielded lessons learned regarding crewmember training for technique-sensitive small-volume biosample collection and handling in microgravity. The fingerstick analysis was successful and was the first real-time hematology assessment performed during spaceflight. This device may provide an in-mission monitoring capability for astronauts thereby assisting Flight Surgeons and the crew medical officer during both orbital and deep space missions.

Incidental Diagnosis of Swyer-James-MacLeod Syndrome in a Military Pilot

BACKGROUND: Swyer-James-MacLeod syndrome (SJMS) is a specific form of bronchiolitis obliterans that occurs rarely, but represents recognized sequelae of common pediatric respiratory illness, and presents as unilateral hyperlucency on chest imaging. This case study describes such an incidental radiographic finding identified during the assessment of chest wall discomfort in a military pilot.CASE REPORT: A 35-yr-old military pilot presented to his flight surgeon with vague intermittent chest discomfort. Initial evaluation revealed an abnormal chest radiograph with unilateral hyperlucency and mild expiratory airflow limitation on pulmonary function testing. The evaluation also included computed tomography imaging with contrast infusion and echocardiography, though the presenting complaint had resolved. The airman was referred to our clinic for further evaluation and aeromedical recommendations regarding returning to flight duties. He was diagnosed with SJMS and recommended to be returned to flight duties.DISCUSSION: SJMS can be challenging to recognize to the untrained eye. An inflammatory response from viral or bacterial infection in childhood results in dysfunctional growth of the affected region of the lung, causing radiographic asymmetry. Although destruction of the alveoli and emphysema may occur, for most cases, there are minimal clinical sequelae. SJMS is not known to be progressive and is not associated with systemic conditions. The pilot likely had the abnormal chest radiograph at the time of commission and had not experienced any in-flight complications. His chest pain had resolved without intervention and SJMS was determined to be unlikely to impact his flight performance (such as response to supplemental oxygen) or life expectancy.Harrison MF, Cowl CT. Incidental diagnosis of Swyer-James-MacLeod syndrome in a military pilot. Aerosp Med Hum Perform. 2021; 92(4):281285.

A Novel Application of Head Tracking Data in the Analysis and Assessment of Operational Cervical Spine Range of Motion for Army Aviators.

Neck pain among rotary-wing aviators has been established as an important issue in the military community, yet no U.S. Army regulation defines exactly what cervical spine range of motion (CROM) is adequate for flight. This lack of regulation leaves flight surgeons to subjectively determine whether an aviator affected by limited CROM is fit to maintain flight status. The U.S. Army Aeromedical Research Laboratory is conducting a study among AH-64 and UH-60 pilots to define CROM requirements in simulated and actual flight using optical head tracking equipment. Presented here is a preliminary analysis of head position data from a pilot and co-pilot in two AH-64 missions. Maintenance data recorder (MDR) files from two AH-64 missions were provided by the Apache Attack Helicopter Project Management Office. Data were filtered down to three-dimensional pilot and co-pilot head position data and each data point was analyzed to determine neck posture. These neck postures were then categorized as neutral, mild, and severe for flexion/extension, lateral bending, and twist rotation postural categories. Twist rotation postures reached 90 degrees, particularly early in the flight; additionally, a few instances of 90-degree lateral bends were observed. Co-pilots spent more time than pilots in mild and severe twist rotation posture for both flights. Co-pilots also spend a high percentage of time in mild flexion and twist rotation. This investigation provides a proof of concept for analysis of head tracking data from MDR files as a surrogate measure of neck posture in order to estimate CROM requirements in rotary-wing military flight missions. Future studies will analyze differences in day and night flights, pilot versus co-pilot CROM, and neck movement frequency.

Rationale and Implementation of a Novel Special Operations Medical Officer Course.

The Air Force Special Warfare Medical Officer Course was created to address the lack of operationally focused, job-specific clinical training for medical officers (MOs). This course addresses the gap in knowledge, skill, and application of operational medicine, as well as the behavioral health, human performance, education, and medical oversight of Operators. The course was designed around the senior author's decade of experience piecing together training for his own role as a pararescue flight surgeon and informed by 5 years of flight surgeon courses, lessons learned from case studies of ill-prepared deployed physicians, and input from prehospital medicine subject matter experts. Air Force pararescue and special tactics flight surgeons, physician assistants, and an independent duty medical technician (IDMT) attended. The course consisted of 10 full weekdays of didactics and skills sessions covering theory and application of operational medicine, human performance optimization, behavioral health for Operators, adult education theory, principles of prehospital clinical oversight, and other expeditionary concepts. The course culminated with combat casualty care scenario-based exercises, in which the providers performed operational medicine in full kit with weapons and simulation rounds. For many logistical and practical reasons, civilian medical experience, traditional military medical training, existing special operations medical courses, and "merit badge" card classes are not adequate preparation for this specialized role. Focused, job-specific training should be provided to Special Operations Forces Medical Officers (SOFMO) and, ultimately, to any MO deploying in support of medics or combatants. The goal is to maximize the success of military medical operations while reducing the morbidity and mortality of combat and training casualties. This operationally focused MO course can serve as a model for the future training of SOFMO and has stimulated discussion for consideration of a joint approach to prehospital medical training.

Orthopedic Surgery and Flight Surgery: Income Differences Between the Navy Health Professions Scholarship Program and Civilian Orthopedic Surgery.

The purpose of this study to analyze the financial impact of choosing a civilian or military orthopedic surgery career. It will examine the most common scenarios to become an orthopedic surgeon in the Navy Health Professions Scholarship Program to include becoming a flight surgeon. To the authors' knowledge, there is no peer-reviewed literature that financially analyzes the most common scenarios for a Navy Health Professions Scholarship Program scholarship recipient to become an orthopedic surgeon. Salaries for Navy orthopedic surgeons, residents, and flight surgeons were recorded using the 2020 Defense Finance and Accounting Service pay tables and Navy Fiscal Year 2019 Medical Corps Special Pay Guidance. The median income of civilian orthopedic surgeons was recorded using Salary.com. The present value (PV) and future value (FV) were calculated using the Consumer Price Index-U and average Department of Defense pay increases over the past 20years. Six common scenarios were utilized to calculate the PV and FV of civilian compared to Navy orthopedic surgeons. The two highest earning net FVs among all Navy scenarios were those surgeons who kept their Navy tour to 5 years or less (flight surgeon tour/separate or civilian deferment/separate). The civilian throughout scenario had the highest net FV of $19,974,673 after retiring at the age of 65. Flight surgeon tour/separate and civilian deferment/separate scenarios only made $843,751 and $1,401,630 less respectively than a pure civilian career due to the tax shelter afforded by the military pay. All Navy retirement scenarios to include Navy throughout, civilian deferment/Navy throughout, flight surgeon tour/Navy throughout resulted in a net FV less than $17,700,000. Civilian residency/deferment and retiring in the Navy had the worst net FV among all scenarios. It was found that the shorter tours in the Navy had a higher net FV than those who made the Navy a career in orthopedic surgery. Flight surgery is a rewarding operational experience with among the highest net FV among Navy scenarios and is only slightly less than the net FV of a pure civilian career. However, it can be more difficult to apply for civilian orthopedic surgery after serving a flight surgeon tour. Lastly, the net FV was very similar between a civilian orthopedic surgeon career and the shorter tours served in the Navy. Factors such as higher civilian income with associated loan repayment/signing bonuses makes the civilian orthopedic surgery route the best financial option. This study will help those medical students considering a military versus a civilian career in orthopedic surgery and aid in Department of Defense recruitment/retention.

Operational radiation protection for human space flight: the flight surgeon's perspective.

Yuri Gagarin was the first human in space in 1961 almost 60 years ago. Eight years later Neil Armstrong left his footprints on the Moon - the first human on the surface of a celestial body other than Earth. By now long-duration missions of up to 1 year have become a reality for humans in space. Nearly 19 years of continuous human presence at the International Space Station (ISS) have provided a unique insight into human life in space. Humans are reaching out for more - targeting missions to take us outside the protective hull of low earth orbit into deep space. The challenges to human health and well-being remain significant and increase with distance and time from Earth. The lack of gravity, the ubiquitous ionising radiation, remoteness, and confinement are just some examples of the hostile environment of space. More hurdles have to be overcome prior to the human endeavour of reaching out into deep space and radiation is one such primary and inevitable factor that is key to crew health, safety and overall mission success. This presentation will provide an introduction into operational space medicine and radiation protection for humans in space as executed on ISS, in low earth orbit and in preparation for the scenarios 'beyond'.

Aeromedical disposition dilemma: Renal calculi

Renal colic is a condition which causes acute pain of variable intensity. At times, this makes the sufferer visibly powerless and prevents him from performing any skilled task satisfactorily. The most common cause of the symptom is related to a calculus, which is moving inside the ureter inducing ureteral spasm. A military aircrew is declared unfit to fly in case he/she is detected to have renal calculi. At present, with the newer and advanced investigation techniques, the detection of even small renal calculi is possible. This has led to an increase in clinical data. Since the clinical outcome of renal calculi is unpredictable, aeromedical disposition becomes a challenging task for such cases. The paper brings a review of existing disposition guidelines for cases of renal calculi both in the military and civil aviation in different parts of the globe. An attempt is also made to present an approach toward aeromedical certification and surveillance in the form of a proposed decision algorithm to be used by the flight surgeon.

FLIGHT RISK: BRONCHUS-ASSOCIATED LYMPHOID TISSUE IN A HEALTHY AVIATOR

SESSION TITLE: Fellows Lung Cancer Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Bronchus-associated lymphoid tissue (BALT) lymphoma is a rare marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). The incidence of MALT worldwide is estimated to be up to 1% of primary pulmonary lymphomas, most commonly endobronchial.(1) Infectious pathogens, amyloid deposition, rheumatological diseases and smoking have all been associated with pulmonary MALT to varying degrees.(2) Treatment is patient-specific, and ranges from observation to chemotherapy, radiation therapy or resection, usually with a favorable prognosis.(3) CASE PRESENTATION: We present a case of an asymptomatic United States Marine Corps F/A-18 fighter jet aviator who was incidentally found to have BALT, first identified as a 5mm lesion during a CT scan for an unrelated pericardial cyst four years earlier. The most recent imaging demonstrated the lesion to be similar in size to previous annual studies. To avoid further unnecessary exposure to radiation for a stable endobronchial lesion, we offered an inspection flexible bronchoscopy which confirmed the presence of a raised flesh-colored, polypoid lesion located in the medial right bronchus intermedius. PET/CT was non-avid. The lesion was easily biopsied and sent for pathological examination. After the diagnosis, the patient successfully underwent involved-site radiation therapy. He went on to receive a waiver from his flight surgeon to return to flight duty without limitations. DISCUSSION: Our case of BALT was diagnosed after it was noted incidentally on CT. Its radiographic appearance was consistent with other cases in the literature.(4, 5) This case underscores the importance of investigating such stable-appearing, non-resolving endobronchial lesions. In this instance, an efficient time course from diagnosis to treatment allowed this aviator to be cleared to fly again. CONCLUSIONS: Bronchus-associated lesions have a wide differential diagnosis.(5) This case highlighted how pursuit of such lesions may have clinical benefit, such as this case, which positively impacted this patient’s military flying career.(4) Reference #1: Takeshi K, Daisuke H, et. al. Endobronchial Mucosa-associated Lymphoid Tissue Lymphoma: A Report of Two Cases and a Review of the Literature. Intern Med. 2018; 57: 2233-2236. Reference #2: William J, Variakojis D, et. al. Lymphoproliferative Disorders. Archives of Pathology & Laboratory Medicine. 2013; 137: 382–391. Reference #3: Hiraishi Y, Iikura M, et. al. Two tracheal BALT lymphoma patients successfully treated with chemotherapy including rituximab. Respiratory Investigations. 2014; 52: 144- 146. DISCLOSURES: No relevant relationships by Neil Partain, source=Web Response

Crew-Friendly Countermeasures Against Musculoskeletal Injuries in Aviation and Spaceflight.

Aviation and space medicine face many common musculoskeletal challenges that manifest in crew of rotary-wing aircraft (RWA), high-performance jet aircraft (HPJA), and spacecraft. Furthermore, many astronauts are former pilots of RWA or HPJA. Flight crew are exposed to recurrent musculoskeletal risk relating to the extreme environments in which they operate, including high-gravitational force equivalents (g-forces), altered gravitational vectors, vibratory loading, and interaction with equipment. Several countermeasures have been implemented or are currently under development to reduce the magnitude and frequency of these injuries. Cervical and lumbar spine, as well as extremity injuries, are common to aviators and astronauts, and occur in training and operational environments. Stress on the spinal column secondary to gravitational loading and unloading, ± vibration are implicated in the development of pain syndromes and intervertebral disk pathology. While necessary for operation in extreme environments, crew-support equipment can contribute to musculoskeletal strain or trauma. Crew-focused injury prevention measures such as stretching, exercise, and conditioning programs have demonstrated the potential to prevent pre-flight, in-flight, and post-flight injuries. Equipment countermeasures, especially those addressing helmet mass and center of gravity and spacesuit ergonomics, are also key in injury prevention. Furthermore, behavioral and training interventions are required to ensure that crew are prepared to safely operate when faced with these exposures. The common operational exposures and risk factors between RWA and HPJA pilots and astronauts lend themselves to collaborative studies to develop and improve countermeasures. Countermeasures require time and resources, and careful consideration is warranted to ensure that crew have access to equipment and expertise necessary to implement them. Further investigation is required to demonstrate long-term success of these interventions and inform flight surgeon decision-making about individualized treatment. Lessons learned from each population must be applied to the others to mitigate adverse effects on crew health and well-being and mission readiness.

You're the Flight Surgeon.

Warneke JA, Pavelites JJ. You're the flight surgeon: Raynaud's phenomenon/hand arm vibration syndrome. Aerosp Med Hum Perform. 2020; 91(5):459-461.

Systemic Corticosteroids for Upper Respiratory Tract Infections in the Flyer.

INTRODUCTION: The use of systemic corticosteroids for upper respiratory tract infections has become increasingly common, but remains controversial. Given their purported ability to decrease duration of illness and hasten recovery, systemic corticosteroids offer an attractive treatment modality for flight surgeons desiring to minimize DNIF (Duty Not Including Flying) time. This commentary presents an evidence-based approach to the use of systemic corticosteroids for upper respiratory tract infections in flyers, concluding that the current body of evidence and missional concerns justify their routine use in sore throat and acute rhinosinusitis.Tanael M. Systemic corticosteroids for upper respiratory tract infections in the flyer. Aerosp Med Hum Perform. 2020; 91(5):453-454.

Making sense of political violence: an interview with Marc Sageman

Marc Sageman is an independent scholar on terrorism. After graduating from Harvard, he obtained an MD. and a PhD. (sociology) from New York University. He was a flight surgeon in the US. Navy and a...

A methodology for investigating the impact of medical countermeasures on the risk of exposure induced death

The space radiation environment is composed of ionizing particles that may pose health risks to crew members during Low Earth Orbit (LEO) and deep space missions. NASA has established astronaut career radiation limits for cancer of 3% Risk of Exposure Induced Death (REID) at the 95% confidence level. The REID is the increased lifetime risk of death from cancer due to radiation exposure in comparison to an unexposed background population and has been traditionally mitigated by passive shielding design concepts and limiting safe days in space. Additional reduction in radiation exposure risk may be achieved with Medical Countermeasures (MCM). Recent meta-analyses have demonstrated the efficacy of aspirin in the reduction of the background colorectal cancer incidence and mortality rates for specific cohorts. Additional studies of warfarin in patients greater than 50 years of age have indicated statistically significant decreases in stomach, bladder, brain, prostate, and lung cancer incidence as compared to control groups. While ultimate selection of suitable countermeasures will be the responsibility of flight surgeons, this paper presents a general methodology for incorporating MCM into the NASA Space Radiation Cancer Risk model and includes modifications of the background mortality rates (hazard rates) and the radiation risk coefficients to numerically quantify the benefits of MCM. As examples of the method, aspirin and warfarin will be employed as MCM in a sensitivity analysis to compute the REID for astronauts embarking on a one-year deep space mission scenario.

Dose Tracker Application for Collecting Medication Use Data from International Space Station Crew.

INTRODUCTION: There are knowledge gaps in spaceflight pharmacology with insufficient in-flight data to inform future planning. This effort directly addressed in-mission medication use and also informed open questions regarding spaceflight-associated changes in pharmacokinetics (PK) and/or pharmacodynamics (PD).METHODS: An iOS application was designed to collect medication use information relevant for research from volunteer astronaut crewmembers: medication name, dose, dosing frequency, indication, perceived efficacy, and side effects. Leveraging the limited medication choices aboard allowed a streamlined questionnaire. There were 24 subjects approved for participation.RESULTS: Six crewmembers completed flight data collection and five completed ground data collection before NASA's early study discontinuation. There were 5766 medication use entries, averaging 20.6 ± 8.4 entries per subject per flight week. Types of medications and their indications were similar to previous reports, with sleep disturbances and muscle/joint pain as primary drivers. Two subjects treated prolonged skin problems. Subjects also used the application in unanticipated ways: to note drug tolerance testing or medication holiday per research protocols, and to share data with flight surgeons. Subjects also provided usability feedback on application design and implementation.DISCUSSION: The volume of data collected (20.6 ± 8.4 entries per subject per flight week) is much greater than was collected previously (<12 per person per entire mission), despite user criticisms regarding app usability. It seems likely that improvements in a software-based questionnaire application could result in a robust data collection tool that astronauts find more acceptable, while simultaneously providing researchers and clinicians with useful data.Wotring VE, Smith LK. Dose tracker application for collecting medication use data from International Space Station crew. Aerosp Med Hum Perform. 2020; 91(1):41-45.

Dr. Yusuf Balkan; Yurtsever Bir Tıbbiyeliden Ülkemizin İlk Uçuş Tabipliğine Uzanan Hayatı

Dr. Yusuf Balkan; Yurtsever Bir Tıbbiyeliden Ülkemizin İlk Uçuş Tabipliğine Uzanan Hayatı

You're the Flight Surgeon: Renal Cell Carcinoma.

Searson-Norris L. You're the flight surgeon: renal cell carcinoma. Aerosp Med Hum Perform. 2019; 90(12):1064-1068.

Squamous Cell Papilloma in a Student Aviator

BACKGROUND: Although oropharyngeal squamous cell papilloma (OSCP) is not uncommon in the general population, reports of OSCP in aviators are rare. This case report serves as a call for flight surgeons to consider all oropharyngeal pathology as a potential source of airway compromise during flight, and highlights regional risk factors for developing malignancies of the oropharynx.CASE REPORT: A 24-yr-old male foreign national student aviator from a central Asian country was at Fort Rucker for flight training. He presented to the clinic with a chief complaint of sore throat and cough for 2 d. He was afebrile but reported a history of a "throat" mass which was previously evaluated by a U.S. military otolaryngologist. Said mass was approximately 0.5 cm × 0.5 cm, irregular appearing, inflamed, and protruding from the inferior aspect of the right tonsil. Previous biopsy report revealed a squamous cell papilloma and, after consideration of the pilot's training program, active surveillance of the lesion was mutually agreed upon until the student's training had concluded and definitive excision was performed.DISCUSSION: A robust history and physical exam including an occupational, social, and environmental exposure history is crucial to diagnosis. Foreign national patients often have unique backgrounds that merit consideration when developing a differential diagnosis, assessment, and plan. In the field of Flight Medicine, a patient's occupational demands are essential to his or her care. In particular, any potential obstruction of the airway during flight must be considered, even if a pathology does not represent an immediate threat to the pilot's health.Swinson K, Burlile J, Pavelites J. Squamous cell papilloma in a student aviator. Aerosp Med Hum Perform. 2019; 90(11):978-981.