Effects of high-gravity acceleration forces and anti-gravity maneuver on the cardiac function of fighter pilots.

The fighter pilots exposed to high gravitational (G) acceleration must perform anti-G maneuvers similar to the Valsalva maneuver. However, the effects of high-G acceleration and anti-G maneuvers on cardiac function have rarely been studied. This study aimed to investigate the effects of high-G forces on cardiac function of fighter pilots. Fighter pilots who underwent regular health check-ups and echocardiography were included (n = 29; 100% men, 41 ± 10 years old; mean flight time, 1821 ± 1186 h). Trainees who had not experienced any flights were included in the control group (n = 16; 100% men, 36 ± 17 years old). Echocardiographic data included left ventricular chamber size, systolic and diastolic functions, right ventricular systolic pressure (RVSP), inferior vena cava (IVC) collapsibility, and tricuspid annular plane systolic excursion (TAPSE). No significant differences in left ventricular ejection fraction, RVSP, or IVC collapsibility were observed between two groups. In the multivariate linear regression analysis with total flight time as an independent continuous variable for fighter pilots, TAPSE was positively correlated with total flight time. The experience of fighter pilots who were exposed to high-G acceleration forces and anti-G maneuvers did not cause cardiac structural changes, but the exposure might be associated with right heart function changes.

Photorefractive Keratectomy in Student Naval Aviators: Outcomes of the U.S. Navy Accessioning Study.

PURPOSE: To present the outcomes of the U.S. Navy photorefractive keratectomy (PRK) accessioning study conducted between 2000 and 2005 that helped lead to the acceptance of laser vision correction within the U.S. aviation industry. METHODS: In this prospective masked study, a total of 301 students who had PRK and underwent naval flight training were compared to 4,368 untreated peers. Three training pipelines were compared: propeller/jet transport, jet fighters, and helicopters. The evaluated metrics were flight and academic performance (assessed for the primary and advanced stage of the training as normalized Navy Standard Score [NSS]), as well as the student attrition rate from training. RESULTS: The attrition rate was lower in the PRK group compared to controls (15.9% vs 23.2%; P = .004). In the primary stage of training, students who had PRK outperformed controls in flight training performance in the propeller/jet transport pipeline (average NSS after PRK: 52.4 ± 7.5 vs controls: 50.7 ± 6.4, P = .02), but the flight performance in the jet fighter and helicopter pipelines was comparable between the two groups. Academic performance in the primary stage of training was approximately 7% to 13% higher in students who had PRK for all training pipelines. During the advanced training stage, there was no difference in the flight performance between the groups in any of the presented pipelines. Academic performance was significantly better for students who had PRK in the helicopter pipeline (51.2 ± 11.0 vs 46.7 ± 11.7 P < .001) but comparable between the two groups in the remaining pipelines. CONCLUSIONS: Refractive surgery did not have adverse effects on flight performance metrics. Pilots who had PRK had comparable or better outcomes than their untreated peers. [J Refract Surg. 2024:40(3):e173-e181.].

Physiological Fitness of U.S. Army Aviators Compared to the U.S. General Population.

INTRODUCTION: U.S. Army aviators are required to maintain a level of physiological fitness as part of their qualifying process, which suggests that they are generally physically healthy. However, it has not been statistically proven that they are more "physiologically fit" than the general population.METHODS: This retrospective study compares physiological measurements of U.S. Army aviators from the Aeromedical Electronic Resource Office database to the U.S. general population using the Center for Disease Control's National Health and Nutrition Examination Survey data. To enable an accurate comparison of physiological metrics between U.S. Army aviators and the U.S. general population, aviators were categorized into the same age groups and biological genders used for segmentation of the national population data.RESULTS: On average, pulse rate was 4.85 bpm lower in male aviators and 6.84 bpm lower in female aviators. Fasting glucose levels were, on average, 10.6 mg · dL-1 lower in aviators compared to the general population. Key metrics like pulse rate and fasting glucose were lower in aviators, indicating cardiovascular and metabolic advantages. However, parameters like cholesterol showed less consistent differences.DISCUSSION: While aviation physical demands and administrative policies selecting for elite physiological metrics produce improvements on some dimensions, a nuanced view accounting for the multitude of factors influencing an aviator's physiological fitness is still warranted. Implementing targeted health monitoring and maintenance programs based on assessments conducted more frequently than the current annual flight physical may optimize aviator safety and performance over the course of a career.D'Alessandro M, Mackie R, Wolf S, McGhee JS, Curry I. Physiological fitness of U.S. Army aviators compared to the U.S. general population. Aerosp Med Hum Perform. 2024; 95(4):175-186.

Screening for Coronary Artery Disease in Asymptomatic Pilots with Diabetes Mellitus.

INTRODUCTION: Coronary artery disease (CAD) is a cause of death in 75% of patients with diabetes. Its often asymptomatic nature delays diagnosis. In aeronautics, it can cause in-flight incapacitation, beyond which it represents a major fear for the medical expert. Screening for CAD is still a topical subject with the advent of new cardiovascular (CV) risk biomarkers and more effective screening tests. We report the experience of the Aeromedical Expertise Center of Rabat in this screening of diabetic pilots, with a recommendations review.METHODS: A prospective study over 1 yr included diabetic pilots who benefited from systematic screening for CAD after a CV risk stratification. Coronary angiography is performed if a screening test is positive. Subsequent follow-up is carried out in consultation with the attending physician with regular evaluation in our center.RESULTS: There were 38 pilots included in our study. The average age was 55 ± 4.19 yr and about 73% had a high CV risk. CAD was detected in 4 cases (10.52%) who had abnormal resting electrocardiograms and required revascularization with the placement of active stents. Approximately 75% of pilots with CAD returned to fly through a waiver with restrictions.DISCUSSION: Screening for coronary disease in diabetics is controversial, and current recommendations are not unanimous. In our study, the screening did not identify coronary diabetic pilots who could benefit from bypass surgery. Nevertheless, coronary disease was diagnosed, justifying grounding to preserve flight safety, which is an absolute priority in aviation medicine.Zerrik M, Moumen A, El Ghazi M, Smiress FB, Iloughmane Z, El M'hadi C, Chemsi M. Screening for coronary artery disease in asymptomatic pilot with diabetes mellitus. Aerosp Med Hum Perform. 2024; 95(4):200-205.

Efficacy of Core Muscle Exercise Combined with Interferential Therapy in Alleviating Chronic Low Back Pain in High-Performance Fighter Pilots: A Randomized Controlled Trial.

BACKGROUND: Chronic low back pain (LBP) related to flight is a prevalent health issue in military aviation, impacting pilots. The objective of this investigation was to ascertain if the application of core muscle training in conjunction with interferential current (IFC) therapy results in a reduction in pain severity and associated disability, consequently enhancing core muscle functionality in Chinese Air Force high-performance fighter pilots experiencing chronic LBP. METHODS: Fifty-three fighter pilots with chronic LBP were randomized into 3 groups: a core muscle exercise combined with IFC group (CG, n = 19), a core muscle exercise group (EG, n = 19), and an IFC group (IG, n = 15). The three groups underwent therapeutic intervention 5 times a week for 12 weeks. The primary outcomes were pain intensity, Oswestry Disability Index (ODI) score and SF-12 health-related quality of life (PCS and MCS) score. Secondary outcomes included evaluations of trunk muscle strength, endurance, and range of motion (ROM) during medial/lateral rotation to assess muscle functionality. Measurements were obtained both before and after the implementation of the intervention therapy. RESULTS: After 12 weeks of intervention therapy, all the health condition parameters significantly improved among the three groups. However, the CG had a significant improvement in pain intensity compared to the EG (MD = - 0.84 scores; 95% CI = - 1.54 to - 0.15; p = 0.013) and the IG (MD = - 1.22 scores; 95% CI = - 1.96 to - 0.48; p = 0.000). Additionally, the CG led to greater conservation of ODI and improved SF-12 PCS scores than did the IG (p < 0.05). Finally, compared with those at baseline, the core muscle function parameters in the CG and EG improved significantly at the end of the study, but no statistically significant differences were observed between the two groups (p > 0.05). CONCLUSION: Among participants with chronic LBP, three intervention therapies appear effective in reducing pain, diminishing disability, and enhancing quality of life. Also, combined therapy significantly improved pain and disability compared to the other two monotherapies; moreover, combined therapy and core muscle exercise provided similar benefits in terms of core muscle function after 12 weeks of intervention therapy.

AI co-pilot bronchoscope robot.

The unequal distribution of medical resources and scarcity of experienced practitioners confine access to bronchoscopy primarily to well-equipped hospitals in developed regions, contributing to the unavailability of bronchoscopic services in underdeveloped areas. Here, we present an artificial intelligence (AI) co-pilot bronchoscope robot that empowers novice doctors to conduct lung examinations as safely and adeptly as experienced colleagues. The system features a user-friendly, plug-and-play catheter, devised for robot-assisted steering, facilitating access to bronchi beyond the fifth generation in average adult patients. Drawing upon historical bronchoscopic videos and expert imitation, our AI-human shared control algorithm enables novice doctors to achieve safe steering in the lung, mitigating misoperations. Both in vitro and in vivo results underscore that our system equips novice doctors with the skills to perform lung examinations as expertly as seasoned practitioners. This study offers innovative strategies to address the pressing issue of medical resource disparities through AI assistance.

Association of Genotype, High-G Tolerance, and Body Composition in Jet Aircraft Aviators.

INTRODUCTION: Pilots of high-performance F15 and F16 jets must undergo periodic assessment of +8.5 Gz tolerance in a centrifuge, which is classified as a high-intensity exercise. Prior research has indicated that exercise performance may be correlated with alpha-actinin3 (ACTN3) and angiotensin-converting enzyme (ACE) genes, frequently termed the sports genes. This study aimed to investigate how ACTN3 and ACE genotypes correlate with high-g tolerance of Korean F15 and F16 pilots. MATERIALS AND METHODS: A total of 81 Korean F15 and F16 pilots (ages 25-39 years) volunteered to participate in human centrifuge testing at +8.5 Gz. Exercise tolerance was calculated as the mean breathing interval during high-g tests, the target gene genotypes (ACTN3 and ACE) were identified, and body composition measurements were measured. The relationship among the ACTN3 and ACE genotypes, high-g tolerance, and body compositions were evaluated. RESULTS: The ACTN3 genotypes identified included 23 RR (28.4%), 41 RX (50.6%), and 17 XX (21.0%). The ACE genotypes identified included 13 DD (16.0%), 39 DI (48.2%), and 29 II (35.8%). Both genes satisfied an equilibrium check. In multivariate analysis by Roy's max, the interaction of the target genes (ACTN3 and ACE) was significant (P < .05). The ACTN3 gene showed significance (P < .05), while ACE tended toward significance with a correlation of P = .057 with high-g tolerance(s). Body composition parameters including height, body weight, muscle mass, body mass index, body fat (%), and basal metabolic rate showed no significant correlation with either genotype. CONCLUSION: In a preliminary study, the RR ACTN3 genotype showed a significant correlation with +8.5 Gz tolerance. Pilots with the DI genotype showed the highest high-g tolerance in this test; however, the test pass rate was higher in pilots with the DD genotype in the preliminary study. This result shows the possibility of test passing and tolerance superiority consisting of two different factors in the relationship between high-g tolerance and ACE genotype. This study showed that pilots with the RR + DI genotype had the highest high-g tolerance, which correlated with the presence of the R and D alleles of the ACTN3 and ACE genes, respectively. However, body composition parameters were not significantly correlated with genotype. These results could suggest a plural gene effect on high-g tolerance; further follow-up is required to determine the practical usage and applications of these results.

Factors of significance for the ability of fighter pilots to visually indicate the magnitude of roll tilt during simulated turns in a centrifuge.

During coordinated flight and centrifugation, pilots show interindividual variability in perceived roll tilt. The study explored how this variability is related to perceptual and cognitive functions. Twelve pilots underwent three 6-min centrifugations on two occasions (G levels: 1.1G, 1.8G, and 2.5G; gondola tilts: 25°, 56°, and 66°). The subjective visual horizontal (SVH) was measured with an adjustable luminous line and the pilots gave estimates of experienced G level. Afterward, they were interrogated regarding the relationship between G level and roll tilt and adjusted the line to numerically mentioned angles. Generally, the roll tilt during centrifugation was underestimated, and there was a large interindividual variability. Both knowledge on the relationship between G level and bank angle, and ability to adjust the line according to given angles contributed to the prediction of SVH in a multiple regression model. However, in most cases, SVH was substantial smaller than predictions based on specific abilities.

Transcranial Direct Current Stimulation and Aviator Performance During Simulated Flight.

INTRODUCTION: Transcranial direct current stimulation (tDCS) is a promising method for maintaining cognitive performance. Anticipated changes in rotary-wing aircraft are expected to alter aviator performance.METHODS: A single-blind, randomized, sham-controlled study evaluated effects of 2-mA anodal tDCS to the right posterior parietal cortex on aviator performance within a Black Hawk simulator. A mixed design with one between-subjects factor was assessed: stimulation prior to flight (20 constant min) and during flight (two timepoints for 10 min each). The within-subjects factor included active vs. sham stimulation. Randomly assigned to each stimulation group were 22 aviators. Aircraft state metrics derived from the simulator were used to evaluate performance. Subjects completed two flights (active stimulation and sham stimulation) with an in-flight emergency introduced at the end to assess whether the timing of tDCS application (prior or during flight) affected the ability to maintain attention and respond to an unexpected event.RESULTS: Results found active stimulation during flight produced statistically significant improvements in performance during the approach following the in-flight emergency. Subjects maintained a more precise approach path with glideslope values closer to zero (M = 0.05) compared to the prior-to-flight group (M = 0.15). The same was found for localizer values (during flight, M = 0.07; prior to flight, M = 0.17). There were no statistically significant differences between groups on secondary outcome measures.DISCUSSION: These findings suggest stimulation during flight may assist in maintaining cognitive resources necessary to respond to an unexpected in-flight emergency. Moreover, blinding efficacy was supported with 32% of subjects correctly guessing when active stimulation was being delivered (52% correctly guessed the sham condition).Feltman KA, Kelley AM. Transcranial direct current stimulation and aviator performance during simulated flight. Aerosp Med Hum Perform. 2024; 95(1):5-15.

Helicopter Pilot Performance and Workload in a Following Task in a Degraded Visual Environment.

BACKGROUND: In this study, we investigated the impact of a loss of horizon due to atmospheric conditions on flight performance and workload of helicopter pilots during a low-altitude, dynamic flight task in windy conditions at sea. We also examined the potential benefits of a helmet-mounted display (HMD) for this specific task.METHODS: In a fixed-based helicopter simulator, 16 military helicopter pilots were asked to follow a maneuvering go-fast vessel in a good visual environment (GVE) and in a degraded visual environment (DVE). DVE was simulated by fog, obscuring the horizon and reducing contrast. Both visual conditions were performed once with and once without an HMD, which was simulated by projecting head-slaved symbology in the outside visuals. Objective measures included flight performance, control inputs, gaze direction, and relative positioning. Subjective measures included self-ratings on performance, situation awareness, and workload.RESULTS: The results showed that in DVE the pilots perceived higher workload and were flying closer to the go-fast vessel than in GVE. Consequently, they responded with larger control inputs to maneuvers of the vessel. The availability of an HMD hardly improved flight performance but did allow the pilots to focus their attention more outside, significantly improving their situation awareness and reducing workload. These benefits were found in DVE as well as GVE conditions.DISCUSSION: DVE negatively affects workload and flight performance of helicopter pilots in a dynamic, low-altitude following task. An HMD can help improve situation awareness and lower the workload during such a task, irrespective of the visual conditions.Ledegang WD, van der Burg E, Valk PJL, Houben MMJ, Groen EL. Helicopter pilot performance and workload in a following task in a degraded visual environment. Aerosp Med Hum Perform. 2024; 95(1):16-24.

A Biomechanical Investigation of Cervical Spine Range of Motion for UH-60 Aviators in Real and Simulated Flight Environments.

INTRODUCTION: Military flight surgeons evaluating aviators for flight fitness based on the cervical spine range of motion (CROM) have no operationally relevant reference with which to make a reliable determination. The published physiological limits for the general population do not necessarily apply to military aviators. CROM requirements for rotary-wing aviators would ideally be defined by measurements taken directly within their operational environment. MATERIALS AND METHODS: Nine subjects performed the same predetermined 1-hour flight mission in a UH-60 aircraft and then, at least 2 days later, in the U.S. Army Aeromedical Research Laboratory (USAARL) NUH-60 flight simulator. Head position was recorded using an optical-based inertial tracker attached to the night vision goggle mount of the subjects' flight helmets. Matched-pair t-tests were implemented to compare the maximum CROM between aircraft and simulated flights and the published general population. RESULTS: The percent of flight time in severe flexion and lateral bending was not statistically different (P > 0.05) between real and simulated flights but was statistically lower in the simulator for severe twist rotation (P < 0.05). The maximum CROM for the advanced maneuvers was significantly lower than the norms for the general population (P < 0.05). CONCLUSIONS: The flight simulator could be a useful platform for flight surgeons determining CROM-related flight fitness if methods to increase the frequency of neck twist rotation movements during flight were implemented. The published maximum CROM values for the general population are not an appropriate reference for flight surgeons making flight fitness determinations related to CROM.

Prevalence and risk factors of occupational neck pain in Chinese male fighter pilots: a cross-sectional study based on questionnaire and cervical sagittal alignment.

Background: Neck pain (NP) is a common musculoskeletal disorder among fighter pilots and has become a rising concern due to its detrimental impact on military combat effectiveness. The occurrence of NP is influenced by a variety of factors, but less attention has been paid to the association of NP with demographic, occupational, and cervical sagittal characteristics in this group. This study aimed to investigate the prevalence and risk factors of NP in Chinese male fighter pilots using a questionnaire and cervical sagittal measurements. Methods: Demographic and flight-related data, as well as musculoskeletal pain information, were gathered from Chinese male fighter pilots via a self-report questionnaire. Cervical sagittal parameters were measured and subtypes were classified using standardized lateral cervical radiographs. Differences in various factors between the case and control groups were analyzed using t-tests or chi-square tests. Binary logistic regressions were conducted to explore potential risk factors contributing to NP. Predictors were presented as crude odds ratios (CORs) and adjusted odds ratios (AORs), along with their respective 95% confidence intervals (CIs). Results: A total of 185 male fighter pilots were included in this cross-sectional study. Among them, 96 (51.9%) reported experiencing NP within the previous 12 months. The multivariate regression analysis revealed that continuous flight training (AOR: 4.695, 95% CI: 2.226-9.901, p < 0.001), shoulder pain (AOR: 11.891, 95% CI: 4.671-30.268, p < 0.001), and low back pain (AOR: 3.452, 95% CI: 1.600-7.446, p = 0.002) were significantly associated with NP. Conclusion: The high 12-month prevalence of NP among Chinese male fighter pilots confirms the existence of this growing problem. Continuous flight training, shoulder pain, and low back pain have significant negative effects on pilots' neck health. Effective strategies are necessary to establish appropriate training schedules to reduce NP, and a more holistic perspective on musculoskeletal protection is needed. Given that spinal integrated balance and compensatory mechanisms may maintain individuals in a subclinical state, predicting the incidence of NP in fighter pilots based solely on sagittal characteristics in the cervical region may be inadequate.

Do we need a co-pilot in the operating theatre? A cross-sectional study on surgeons' perceptions.

OBJECTIVE: The aim of this original study was to investigate general surgeons' perceptions on the role of dual surgeon operating for high-risk, elective complex surgical procedures. MATERIAL AND METHODS: A 21-part cross-sectional online survey was self-completed by 85 general surgeons across hospitals in the UK. The survey assessed the perception of dual surgeon operating on patient morbidity and mortality, surgeons' burnout rates, complaints, patient waiting times and overall trainee experience. Statistical analysis was performed using R version 3.6.1. RESULTS: Overall 78.8% believed that dual surgeon operating could help to overcome these human factors. Sub-analysis includes improve surgeon fatigue (89.4%), improve confidence (83.5%), improve decision-making (76.5%), minimise technical error (69.4%), improve communication, team work and leadership skills (65.9%). 65.9% believed it would reduce surgeons' burnout. There was a statistically significant relationship between the participants believing it would reduce surgeons' burnout and those who felt it would reduce complaints, Chi-squared(4) = [30.8], p = [0.00000342]. A statistically significant relationship was noted between participants believing it would reduce surgeons' burnout and those who felt it would reduce patient mortality/morbidity, Chi-squared(4) = [19.9], p = [0.000517]. CONCLUSION: The survey has highlighted positive surgeons' perceptions regarding dual surgeon operating.

Wire Strikes and In-Air Obstacle Collisions During Agricultural Aviation Operations.

INTRODUCTION: Wire strikes and in-air collisions with obstacles are a leading cause of accidents in the aerial application industry. While some of these collisions occur due to unseen obstacles, some pilots report being previously aware of the obstacles that they collide with. Whether or not pilots are aware of obstacles pre-collision is an important factor to inform methods of accident prevention.METHODS: Final reports from the National Transportation Safety Board were analyzed for Part 137 Agricultural Operation accidents that took place between January 2020 and December 2022. A deeper analysis of cases that involved an in-air collision with an obstacle was performed, excluding cases that were attributable to an external cause (e.g., aerodynamic stall). The pilot's awareness of the obstacle pre-accident was inferred from accident narratives if available.RESULTS: Nearly half of all accidents (N = 45 of 107) involved an in-air collision with an obstacle (e.g., wire, tree, pole) as the defining event. In cases where pilot awareness of the obstacle was determinable through the accident report, over half of pilots (N = 21 of 39) had previously seen this obstacle yet still made contact with it.DISCUSSION: In-air obstacle collisions make up a substantial portion of accidents within Part 137 Agricultural Operations. Nearly half of pilots were already aware of the obstacle before collision, indicating that inadequate preparation in scoping the field is not a predominant driver of these events. Instead, these findings suggest that other factors including distractions, high task difficulty, and errors in decision-making may contribute.Baumgartner HM. Wire strikes and in-air obstacle collisions during agricultural aviation operations. Aerosp Med Hum Perform. 2023; 94(11):852-856.

Deficient Aeronautical Decision-Making Contributions to Fatal General Aviation Accidents.

INTRODUCTION: General aviation (GA), mainly comprised of light (≤12,500 lb) aircraft, maintains an inferior safety record compared with air carriers. To improve safety, aeronautical decision-making (ADM) practices have been advocated to GA pilots since 1991. Herein, we determined the extent to which GA pilots disregard such practices.METHODS: Fatal accidents (1991-2019) involving private pilots (PPLs) in single-engine airplanes were identified (N = 1481) from the National Transportation Safety Board AccessR database. Of these, deficient go/no-go and in-flight ADM-related mishaps were scored using the PAVE (pilot, aircraft, environment, external pressure)/IMSAFE (illness, medicine, stress, alcohol, fatigue, eating) and PPP (perceive, process, perform) models, respectively. Statistical testing used Poisson distributions, Fisher exact tests, and Mann-Whitney U-tests.RESULTS: Of the 1481 accidents, 846 were identified as deficient ADM-related. Electing to depart into a hazardous environment (PAVE), disregarding wellness (IMSAFE), and poor aircraft familiarity (PAVE) represented the most common categories (54%, 21%, and 20%, respectively) of errant go/no-go ADM. A 64% decline in fatal accidents related to errant go/no-go decisions for the environment category was evident over the 30-yr period, with little decrements in the other domains. Within the errant environment-related category accidents, the decision to depart into forecasted adverse weather (e.g., degraded visibility, icing, thunderstorms) constituted the most prevalent subcategory (56%, N = 195). Surprisingly, of this subcategory, accidents were overrepresented by over nine- and threefold for instrument-rated PPLs disregarding icing and thunderstorm forecasts, respectively.CONCLUSION: With little decrement in ADM-related accidents in the pilot, aircraft, and external pressure domains, new strategies to address such deficiencies for PPLs are warranted.Boyd DD, Scharf MT. Deficient aeronautical decision-making contributions to fatal general aviation accidents. Aerosp Med Hum Perform. 2023; 94(11):807-814.

Heart Rate Variability Indices of Student Pilots Undergo Modifications During Flight Training.

INTRODUCTION: Heart rate variability (HRV) indicates the temporal fluctuation of the intervals between adjacent beats. HRV expresses neuro-cardiac activity and is generated by heart-brain interactions and dynamics related to the function of the autonomous nervous system and other components. To investigate this issue, we started a series of experiments by coupling the flight tasks of student pilots and their HRV.METHODS: Before each experimental session, the participating student was fitted with a five-electrode, three-channel Holter electrocardiogram monitor. We defined three time-phases for each training mission: before flight operations on the ground, during flight operations, and after flight operations on the ground. The HRV analysis was performed by quantifying some indices of the time domain and the frequency domain.RESULTS: The analysis of RR-wave intervals revealed two types of trends: 1) students whose RR intervals decreased during flight operations compared to before flight ground operations; and 2) students whose RR intervals increased during flight operations compared to before flight ground operations. These differences found in the RR intervals produced changes in the indices of both the time and frequency domains of the two students' samples.DISCUSSION: Flight training involves regular and advanced tasks and/or emergency situations. When this happens, the total power of the heart decreases because the RR intervals are forced toward low values. Flight activity involves continuous demanding tasks that can be potentially read by an analysis of the HRV; a high HRV ensures better management of tasks that require a greater commitment of cardiovascular function.Li Volsi G, Monte IP, Aruta A, Gulizzi A, Libra A, Mirulla S, Panebianco G, Patti G, Quattrocchi F, Bellantone V, Castorina W, Arcifa S, Papale F. Heart rate variability indices of student pilots undergo modifications during flight training. Aerosp Med Hum Perform. 2023; 94(11):835-842.

Neuro-Cardiovascular Responses to Sympathetic Stimulation in Fighter Pilots.

INTRODUCTION: The chronic effects of regular exposure to high acceleration levels (G-force) on the neuro-cardiovascular system are unclear. We compared the mean arterial pressure (MAP) and cardiac autonomic modulation between nonpilots (NP) vs. military fighter (FP) and transport (TP) pilots. Additionally, we correlated the cardiac autonomic indices with the cardiorespiratory fitness and flight experience of FP.METHODS: A total of 21 FP, 8 TP, and 20 NP performed a tilt test (TT), during which beat-to-beat blood pressure and heart rate were recorded.RESULTS: No difference was detected between groups for changes in MAP and heart rate variability indices during the TT. However, the analysis of areas under the curves showed a greater increase in MAP in FP vs. TP and NP. Conversely, there was a greater decrease in indices reflecting vagal modulation in TP vs. FP and NP (rMSSD, pNN50, and SDNN), and a greater increase in heart rate and sympathovagal balance in TP vs. other groups (LF/HF). The maximal oxygen uptake was strongly correlated with the vagal reserve in FP (r = -0.74). Moreover, the total flying hours of FP were positively correlated with resting HFnu (r = 0.47) and inversely correlated with resting LFnu (r = -0.55) and LF/HF (r = -0.46).CONCLUSION: FP had a higher pressor response to TT than TP and NP. Vagal withdrawal and sympathovagal increase induced by TT in FP were similar vs. NP and attenuated vs. TP. Greater cardiorespiratory fitness and accumulated flying hours in FP seemed to favor lower sympathetic and greater vagal modulation at rest.dos Santos Rangel MV, de Sá GB, Farinatti P, Borges JP. Neuro-cardiovascular responses to sympathetic stimulation in fighter pilots. Aerosp Med Hum Perform. 2023; 94(10):761-769.

Daily Caffeine Intake and the Effect of Caffeine on Pilots' Performance After Extended Wakefulness.

INTRODUCTION: Fatigue is a major contributor to aviation accidents. Sufficient sleep may be difficult to achieve under operational conditions in military aviation. Countermeasures include caffeine, however, studies evaluating its effects often do not represent daily practice with regular caffeine consumption. This study aims to establish the effect of caffeine on psychomotor performance in a realistic scenario (i.e., after a limited period of extended wakefulness).METHODS: This randomized, double-blind, crossover, placebo-controlled trial included 30 aeromedically fit subjects. On trial days, subjects followed their normal routine till 17:00, after which caffeine intake was stopped. At midnight, subjects were given 300 mg of caffeine or placebo and performed the Psychomotor Vigilance Test, Vigilance and Tracking Test, and the Stanford Sleepiness Scale hourly up to 04:00 and again at 06:00 and 08:00. Four blood samples were collected. Statistical analyses included repeated-measures ANOVA or Friedman tests, marginal models, and Wilcoxon Signed Rank tests.RESULTS: Median time awake at midnight was 17 h (IQR 16.5-17.5 h). Performance decreased significantly less during the night in the caffeine condition versus placebo. Neither habitual intake nor daytime caffeine consumption affected this. No statistically significant correlation was identified between blood concentrations of caffeine and performance.DISCUSSION: A single dose of 300 mg of caffeine has beneficial effects on performance during the night in a realistic scenario for military aviation. Daytime caffeine consumption does not affect the effects of caffeine at night. These findings could be relevant for all industries in which optimal performance is required during nighttime after a limited period of extended wakefulness.Wingelaar-Jagt YQ, Wingelaar TT, de Vrijer L, Riedel WJ, Ramaekers JG. Daily caffeine intake and the effect of caffeine on pilots' performance after extended wakefulness. Aerosp Med Hum Perform. 2023; 94(10):750-760.

Consensus on the pharmacological treatment of acute stress disorder in Chinese pilots: a Delphi study.

BACKGROUND: Appropriate medication is very important for pilots with acute stress disorder. Improper medication can not only affect the physical and mental health of the pilots but can also endanger flight safety. Hence, we aimed to quickly and effectively relieve symptoms and restore cognitive function by forming a consensus of Chinese experts on the pharmacological treatment of acute stress disorder in pilots using the Delphi method. METHODS: Relevant literature was searched to enumerate the current status of pharmacological treatment of acute stress disorder in pilots, followed by two rounds of expert consultation and discussion according to the listed status of the survey using the Delphi method. A descriptive statistical method was used to analyze the basic information, authority coefficients, concentration of opinions, and survey items of the experts to develop a consensus on the pharmacological treatment of acute stress disorder in pilots. RESULTS: A total of 16 experts in psychiatry, pharmacology, and aerospace medicine from different provinces and cities across China were invited for consultation. The recovery rate of the two rounds of consultation was 100%, and the expert authority coefficients were 0.897 and 0.906, respectively. Kendall's coefficient of concordance of indicators at all levels was 0.564-0.594 (p < 0.01). Based on the number of votes received, alprazolam tablets (16), eszopiclone tablets (15), and lorazepam tablets (14) were recommended for the treatment of excitatory psychomotor symptoms of acute stress disorder; paroxetine tablets (15) and sertraline tablets (15) were available for psychomotor depressive symptoms; olanzapine tablets (15), olanzapine orally disintegrating tablets (14), and quetiapine fumarate tablets (14) were selected for psychotic symptoms. CONCLUSIONS: This study formed a consensus on rapid and effective pharmacological treatment for different symptoms of acute stress disorder pilots, which provides a reference for clinical treatment.