INTRODUCTION: Cardiovascular (CV) diseases are a major public health issue, the prevention of which plays a key role in promoting flight safety. However, few studies have looked at the determinants of the overall risk of CV morbidity-mortality within the various aeronautical occupations.

METHODS: A monocentric, observational, cross-sectional study was based on the retrospective data collected during 6 mo at the Toulon Aeromedical Center. From October 2017 to April 2018, 2792 professional aircrew ages 18–74 were included. The overall CV risk was estimated using the European Society of Cardiology SCORE and the Framingham model, as well as a summation model.

RESULTS: More than two-thirds of this mainly male population (86.2%) had no more than one CV risk factor [69.9% (68.2–71.6)]. In 82.5% of cases, this was dyslipidemia according to current European criteria [55.8% (52.4–59.1)] or smoking [26.7% (23.8-29.8)]. An overall risk level of “moderate” to “very high” concerned only one subject in five according to the SCORE model [20.1% (18.6-21.6)], one in six according to Framingham [16.3% (14.9-17.7)] and almost one in three according to the summation model [30.1% (28.4-31.9)].

DISCUSSION: Multivariate analyses found no significant associations between socio-professional criteria and overall risk levels. The results have underlined the effect of dyslipidemia and smoking on early risk among applicants. Beyond the illustration of favorable cardiovascular status among aircrews related to the standards of selection and close monitoring process, areas for improvement were identified, inviting the development of prevention strategies around the “moderate” overall CV risk.

Huiban N, Gehant M, Brocq F-X, Collange F, Mayet A, Monteil M. Global cardiovascular risk and associated factors in 2792 French military and civilian aircrew. Aerosp Med Hum Perform. 2024; 95(5):233–244.

INTRODUCTION: The rapid development of the space industry requires a deeper understanding of spaceflight’s impact on the brain. MRI research reports brain volume changes following spaceflight in astronauts, potentially affecting cognition. Recently, we have demonstrated that this evidence of volumetric changes, as measured by typical T1-weighted sequences (e.g., magnetization-prepared rapid gradient echo sequence; MPRAGE), is error-prone due to the microgravity-related redistribution of cerebrospinal fluid in the brain. More modern neuroimaging methods, particularly dual-echo MPRAGE (DEMPRAGE) and magnetization-prepared rapid gradient echo sequence utilizing two inversion pulses (MP2RAGE), have been suggested to be resilient to this error. Here, we tested if these imaging modalities offered consistent segmentation performance improvements in some commonly employed neuroimaging software packages.

METHODS: We conducted manual gray matter tissue segmentation in traditional T1w MRI images to utilize for comparison. Automated tissue segmentation was performed for traditional T1w imaging, as well as on DEMPRAGE and MP2RAGE images from the same subjects. Statistical analysis involved a comparison of total gray matter volumes for each modality, and the extent of tissue segmentation agreement was assessed using a test of similarity (Dice coefficient).

RESULTS: Neither DEMPRAGE nor MP2RAGE exhibited consistent segmentation performance across all toolboxes tested.

DISCUSSION: This research indicates that customized data collection and processing methods are necessary for reliable and valid structural MRI segmentation in astronauts, as current methods provide erroneous classification and hence inaccurate claims of neuroplastic brain changes in the astronaut population.

Berger L, Burles F, Jaswal T, Williams R, Iaria G. Modern magnetic resonance imaging modalities to advance neuroimaging in astronauts. Aerosp Med Hum Perform. 2024; 95(5):245–253.

INTRODUCTION: Although an unintended aircraft landing on water (referred to as ditching) is a rare event, the potential for occupant injury/fatality increases immediately following the event due to adverse conditions. However, to date, few studies have addressed the subject. Herein, ditching events and post-ditching survival were investigated.

METHODS: Ditchings (1982–2022) in the United States were identified from the National Transportation Safety Board database. Occupant injury severity, aircraft type, pilot experience, flight conditions, and number of occupants were extracted. Poisson distribution, the Chi-squared test (2-tailed), Mann-Whitney U test, and Kruskal-Wallis one-way analysis of variance were employed.

RESULTS: A total of 96 ditchings were identified. A systematic survey was hampered by the lack of a standardized reporting matrix in the reports. In total, 77 reports were included in the analysis. Across all ditchings, 128 of 169 (76%) occupants survived ditching and were rescued. Importantly, the initial ditching event was survived by 95% of all occupants. However, 32 (19%) occupants died post-ditching by drowning (21/32 cases) or for undetermined reasons. Considering probability per ditching event, in 26 (34%) of all ditchings, one or more occupants was/were fatally injured.

DISCUSSION: Initial survival of the emergency ditching is high. Drowning was the leading cause of death after ditching and reduced the overall survival to 76%. Further investigation is needed to identify risk factors for fatal outcomes and/or improve probability of survival after ditching.

Schick VC, Boyd DD, Hippler C, Hinkelbein J. Survival after ditching in motorized aircraft, 1989–2022. Aerosp Med Hum Perform. 2024; 95(5):254–258.

INTRODUCTION: Travel by airline starts and ends at airports. Thousands of people consisting of passengers, relatives of passengers, and employees gather at airports every day. In this study, medical events (MEs) encountered at Istanbul Atatürk Airport (IAA) and health services provided were analyzed.

METHODS: The MEs encountered in IAA between January 1, 2016, and December 31, 2018, and health services provided by the private medical clinic in the airport terminal building were retrospectively analyzed.

RESULTS: During the study period, 192,500,930 passengers traveled from the IAA and a total of 11,799 patients were seen at the clinic. There were 4898 (41.5%) male patients. The median age of the 9466 (80.2%) patients whose age was recorded was 34 (28–51) yr. Of 11,799 patients included in the present study, 9228 (78.21%) patients had medical complaints, 1122 (9.5%) patients had trauma complaints, 1180 patients (10%) were transferred to the hospital, and 269 (2.27%) patients required a certificate of preflight fitness. The most common medical complaint was gastrointestinal (1515 patients, 12.84%). The most common trauma was soft tissue injury (345 patients, 2.92%).

DISCUSSION: MEs in airports can be as various and also critical as health conditions seen in emergency departments. It is important to provide medical services with an experienced medical team trained in aviation medicine and adequate medical equipment at airports.

Ceyhan MA, Demir GG, Cömertpay E, Yıldırımer Y, Kurt NG. Medical events encountered at a major international airport and health services provided. Aerosp Med Hum Perform. 2024; 95(5):259–264.

INTRODUCTION: Employees from any type of aviation services industry were asked to give their opinions about the usefulness of consumer sleep technologies (CSTs) during operations and their willingness to share data from CSTs with their organizations for fatigue risk management purposes under a variety of circumstances.

METHODS: Respondents provided information about position in aviation and use of CST devices. Respondents ranked sleep issues and feedback metrics by perceived level of importance to operational performance. Respondents rated their likelihood to share data with their organization under a series of hypothetical situations.

RESULTS: Between January-July 2023, 149 (N = 149) aviation professionals responded. Pilots comprised 72% (N = 108) of respondents; 84% (N = 125) of all respondents worked short- or medium-haul operations. “Nighttime operations” and “inconsistent sleep routines” ranked as the most important issues affecting sleep. “Sleep quality history” and “projected alertness levels” ranked as most important feedback metrics for personal management of fatigue. Respondents were split between CST users (N = 64) and nonusers (N = 68). CST users did not indicate a strong preference for a specific device brand. The most-reported reason for not using a CST was due to not owning one or no perceived need. Respondents indicated greater likelihood of data sharing under conditions where the device was provided to them by their organization.

DISCUSSION: These results suggest that aviation professionals are more concerned about schedule-related disturbances to sleep than they are about endogenous sleep problems. Organizations may be able to increase compliance to data collection for fatigue risk management by providing employees with company-owned CSTs of any brand.

Devine JK, Choynowski J, Hursh SR. Fatigue risk management preferences for consumer sleep technologies and data sharing in aviation. Aerosp Med Hum Perform. 2024; 95(5):265–272.

INTRODUCTION: There is a current belief in aviation suggesting that aerobic training may reduce G-tolerance due to potential negative impacts on arterial pressure response. Studies indicate that increasing maximal aerobic capacity ( $\dot{\text{V}}$ o₂ max) through aerobic training does not hinder G-tolerance. Moreover, sustained centrifuge training programs revealed no instances where excessive aerobic exercise compromised a trainee’s ability to complete target profiles. The purpose of this review article is to examine the current research in the hope of establishing the need for routine $\dot{\text{V}}$ o₂-max testing in air force pilot protocols.

METHODS: A systematic search of electronic databases including Google Scholar, PubMed, the Aerospace Medical Association, and Military Medicine was conducted. Keywords related to “human performance,” “Air Force fighter pilots,” “aerobic function,” and “maximal aerobic capacity” were used in various combinations. Articles addressing exercise physiology, G-tolerance, physical training, and fighter pilot maneuvers related to human performance were considered. No primary data collection involving human subjects was conducted; therefore, ethical approval was not required.

RESULTS: The $\dot{\text{V}}$ o₂-max test provides essential information regarding a pilot’s ability to handle increased G_z-load. It assists in predicting G-induced loss of consciousness by assessing anti-G straining maneuver performance and heart rate variables during increased G-load.

DISCUSSION: $\dot{\text{V}}$ o₂-max testing guides tailored exercise plans, optimizes cardiovascular health, and disproves the notion that aerobic training hampers G-tolerance. Its inclusion in air force protocols could boost readiness, reduce health risks, and refine training for fighter pilots’ safety and performance. This evidence-backed approach supports integrating $\dot{\text{V}}$ o₂-max testing for insights into fitness, risks, and tailored exercise.

Zeigler Z, Acevedo AM. Re-evaluating the need for routine maximal aerobic capacity testing within fighter pilots. Aerosp Med Hum Perform. 2024; 95(5):273–277.

BACKGROUND: This article documents the stability of photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) in two astronauts during 6-mo missions to the International Space Station.

CASE REPORTS: Ocular examinations including visual acuity, cycloplegic refraction, slit lamp examination, corneal topography, central corneal thickness, optical biometry (axial length/keratometry), applanation tonometry, and dilated fundus examination were performed on each astronaut before and after their missions, and in-flight visual acuity testing was done on flight day 30, 90, and R-30 (30 d before return). They were also questioned regarding visual changes during flight.

DISCUSSION: We documented stable vision in both PRK and LASIK astronauts during liftoff, entry into microgravity, 6 mo on the International Space Station, descent, and landing. Our results suggest that both PRK and LASIK are stable and well tolerated during long-duration spaceflight.

Gibson CR, Mader TH, Lipsky W, Schallhorn SC, Tarver WJ, Suresh R, Hauge TN, Brunstetter TJ. Photorefractive keratectomy and laser-assisted in situ keratomileusis on 6-month space missions. Aerosp Med Hum Perform. 2024; 95(5):278–281.