BACKGROUND: Airsickness is a clinical syndrome manifesting in a variety of symptoms, particularly nausea and vomiting during flight. Studies of habituation to motion sickness in humans treated by scopolamine have produced conflicting results. The drug accelerated habituation, but a rebound effect on symptom severity was observed after its withdrawal. The purpose of the present study was to investigate whether scopolamine affects the adaptation process. We also evaluated the relationship between initial symptom severity and adaptation to airsickness.METHODS: Aviator cadets in the first two stages of their training were divided into two groups, treated and not treated by scopolamine. Airsickness severity was evaluated using both simulator sickness and motion sickness questionnaires, and drug administration was recorded.RESULTS: A statistically significant higher rate of adaptation was observed among the scopolamine-treated group compared with the nontreated group. On the simulator sickness questionnaire, rate of adaptation for the two groups was −0.21 ± 0.53 and −0.1 ± 0.17, respectively, and for the motion sickness questionnaire −2.34 ± 1.54 and −0.91 ± 1.41, respectively. Examination of a possible connection between initial symptom severity and adaptation rate failed to reveal a significant relationship.CONCLUSIONS: We recommend the use of oral scopolamine to accelerate habituation and find it a relatively safe short-term treatment for airsickness. Our results support the notion that scopolamine accelerates the natural adaptation process.Doron O, Samuel O, Karfunkel-Doron D, Tal D. Scopolamine treatment and adaptation to airsickness. Aerosp Med Hum Perform. 2020; 91(4):313–317.

BACKGROUND: General Aviation (GA) pilots who encounter hazardous weather inflight have a high probability of incurring fatal accidents. To mitigate this problem, previous research investigated pilot decision making and the effects of new technology. Limited investigations have examined usability and interpretability of observation and forecast weather products available to pilots. Therefore, this study examined the interpretability of weather observation and forecast reports that GA pilots use for preflight weather planning and the impact of pilot certification level on the interpretability of these displays.METHOD: There were 204 GA pilots (Mean age = 22.50 yr; Median flight hours = 131.0) who completed a 90-item multiple choice Aviation Weather Product Test. The questions portrayed static weather displays available on the NOAA/National Weather Service Aviation Weather Center website. The questions were designed to have high cognitive fidelity in comparison with preflight weather planning tasks.RESULTS: The results revealed overall low mean interpretability scores (Mean percent correct= 59.29%, SD = 16.01%). The scores for observation products and product attributes were lower for student pilots than experienced pilots. Forecast product scores for student and private pilots did not differ, however, student pilot scores were significantly lower than instrument rated private and commercial pilots.DISCUSSION: The low interpretability scores indicate that GA pilots misinterpret weather information provided by most weather observation and forecast products. Possible contributing factors to the low product interpretation scores include poor usability and a lack of training. Future research should measure the usability of weather displays designed for pilots.Blickensderfer BL, Guinn TA, Lanicci JM, Ortiz Y, King JM, Thomas RL, DeFilippis N. Interpretability of aviation weather information displays for general aviation. Aerosp Med Hum Perform. 2020; 91(4):318–325.

BACKGROUND: Aerobatic flight is a challenge for the vestibular system, which is likely to lead to adaptive changes in the vestibular responses of pilots. We investigated whether aerobatic pilots, as individuals who experience intense vestibular stimulation, present modifications of the vestibular-ocular reflex, motion sickness susceptibility and intensity, visual vertical estimation, and visual dependence as compared to normal volunteers.METHODS: To evaluate vestibulo-ocular reflexes, eye movements were recorded with videonystagmography while subjects were rotated on a rotatory chair with the axis of rotation being vertical (canal-ocular reflex) or inclined to 17° (otolith-ocular reflex). Motion sickness was evaluated after the rotatory test using the Graybiel diagnostic criteria. General motion sickness susceptibility and visual field dependence were also evaluated.RESULTS: Averaged data did not show significant difference in canal-ocular reflex and otolith ocular-reflex between groups. However, a significant asymmetry in otolith-driven ocular responses was found in pilots (CW 0.50 ± 1.21° · s⁻¹ vs. CCW 1.59 ± 1.12° · s⁻¹), though visual vertical estimation was not altered in pilots and both groups were found field independent. Pilots were generally less susceptible to motion sickness (MSSQ scores: 2.52 ± 5.59 vs. 13.5 ± 11.36) and less affected by the nauseogenic stimulation (Graybiel diagnostic criteria 3.36 ± 3.81 vs. 8.39 ± 7.01).DISCUSSION: We did not observe the expected habituation in the group of aerobatic pilots. However, there was a significant asymmetry in the otolith-driven ocular responses in pilots, but not in the controls, which may result from the asymmetry in piloting protocols.Kuldavletova O, Tanguy S, Denise P, Quarck G. Vestibulo-ocular responses, visual field dependence, and motion sickness in aerobatic pilots. Aerosp Med Hum Perform. 2020; 91(4):326–331.

INTRODUCTION: The Integrated Medical Model (IMM) is a quantified, evidence-based decision support tool developed by National Aeronautics and Space Administration (NASA) to assist in the assessment of the medical risk of human spaceflight missions. The IMM utilizes a probabilistic risk assessment (PRA) approach to simulate potential in-flight medical events and resultant health and mission outcomes.METHODS: The IMM has been utilized to estimate the medical risk associated with International Space Station (ISS) missions. The IMM outputs that have been most informative to the ISS program are the probabilities of evacuation (pEVAC) and loss of crew life (pLOCL). These outputs are incorporated into a continuously maintained ISS PRA model so that its quantification of total ISS mission risk includes the medical risk.RESULTS: Results of this analysis revealed that the forecasted risk values of pEVAC and pLOCL due to medical events were improved by using the IMM with the ISS PRA model instead of using data from prior sources in which these values were underestimated.DISCUSSION: The IMM provides an evidence-based PRA approach to directly communicate and integrate medical risk with other ISS risks. A comparison of IMM outputs of pEVAC and pLOCL to empirical spaceflight data and analog population data revealed that IMM outputs were comparable with actual experience. With appropriate outcome context, these findings increase subject matter expert confidence in the accuracy of IMM risk estimates. IMM outputs provide quantifiable objective estimates of medical risk that can be used to inform mission risk assessments and to optimize crew health.Walton ME, Kerstman EL. Quantification of medical risk on the International Space Station using the Integrated Medical Model. Aerosp Med Hum Perform. 2020; 91(4):332–342.

INTRODUCTION: Studies have identified a great number of physiological conditions, including venous thromboembolism and hypoxia, that may give rise to medical disqualifications and in-flight incapacitations that can be costly to individuals and organizations. Over the past three decades, much attention has been focused on venous thromboembolism among passengers. However, studies on venous thromboembolism among commercial airline pilots are very scarce. With this consideration in mind, differently from the literature, this study set out to examine pilots' awareness of venous thromboembolism signs, symptoms, risk factors, and countermeasures.METHODS: For this purpose, a venous thromboembolism questionnaire was developed and applied to collect data. There were 427 airline pilots who participated in the questionnaire. The analysis of variance (ANOVA) technique was used to analyze the results of the questionnaire.RESULTS: According to the results of this study, approximately one-half (57.1%) of the participants had just heard of this particular health issue and 63.9% of the participants were unaware of flight-associated venous thromboembolism. Airline pilots between 20 and 40 yr of age were much less aware of venous thromboembolism in comparison to pilots 41 yr or older, and pilots flying more than 90 h/mo were at a greater risk.DISCUSSION: Airline pilots between 20 and 40 yr have less knowledge about venous thromboembolism and preventive measures against it in comparison to older pilots. Therefore they may be more vulnerable to possible risk factors. The findings of this study will contribute to increasing pilots’ awareness on flight-related venous thromboembolism and can improve the overall safety of civil aviation.Kilic B, Soran S. Awareness level of airline pilots on flight-associated venous thromboembolism. Aerosp Med Hum Perform. 2020; 91(4):343–347.

BACKGROUND: The aim of this study was to evaluate the use of ground-based medical services (GBMS) by the cabin crew of a major South Korean airline for in-flight medical incidents involving passengers.METHODS: We conducted a survey of cabin crew to identify the anticipated use of GBMS in 2017. We compared the anticipated use to actual use as reported in cabin crew records submitted to the GBMS team and cabin crew logs from May 2013 to April 2016.RESULTS: Among 766 team leaders and assistant leaders, 211 individuals answered the questionnaire. A total of 915 instances of GBMS use were reported during the study period. There were no significant differences between anticipated and actual use in terms of the reasons for needing GBMS, with medication prescription being the most common reason. However, there were significant differences in the specific symptoms that triggered contact with GBMS. Pediatric and digestive symptoms were under-predicted, while neuropsychiatric and cardiac symptoms were over-predicted.DISCUSSION: Cabin crew tended to require GBMS to assist with pediatric and digestive conditions more often than anticipated. Furthermore, digestive and pediatric symptoms often require prescription medications.Kim JH, Choi-Kwon S. Ground-based medical services for in-flight emergencies. Aerosp Med Hum Perform. 2020; 91(4):348–351.

INTRODUCTION: Atrial fibrillation (AF) is one of the most common cardiac arrhythmias in the general population and is considered disqualifying aeromedically. This study is a unique examination of significant outcomes in aviators with previous history of both AF and stroke.METHODS: Pilots examined by the FAA between 2002 and 2012 who had had AF at some point during his or her medical history were reviewed, and those with an initial stroke or transient ischemic attack (TIA) during that time period were included in this study. All records were individually reviewed to determine stroke and AF history, medical certification history, and recurrent events. Variables collected included medical and behavior history, stroke type, gender, BMI, medication use, and any cardiovascular or neurological outcomes of interest. Major recurrent events included stroke, TIA, cerebrovascular accident, death, or other major events. These factors were used to calculate CHA₂DS₂-VASc scores.RESULTS: Of the 141 pilots selected for the study, 17.7% experienced a recurrent event. At 6 mo, the recurrent event rate was 5.0%; at 1 yr, 5.8%; at 3 yr 6.9%; and at 5 yr the recurrent event rate was 17.3%. No statistical difference between CHA₂DS₂-VASc scores was found as it pertained to number of recurrent events.DISCUSSION: We found no significant factors predicting risk of recurrent event and lower recurrence rates in pilots than the general population. This suggests CHA₂DS₂-VASc scores are not appropriate risk stratification tools in an aviation population and more research is necessary to determine risk of recurrent events in aviators with atrial fibrillation.Tedford J, Skaggs V, Norris A, Sahiar F, Mathers C. Recurrent stroke risk in pilots with atrial fibrillation. Aerosp Med Hum Perform. 2020; 91(4):352–357.

BACKGROUND: Aircrew-aircraft compatibility is important in military aviation for flight safety. Anthropometric aircrew selection standards in RAFO were embedded from the selection standards of western defense forces as the aircrafts were imported from there. Henceforth efforts were made to fit local native aviators into aircrafts not initially designed for them. In view of this, this study was carried out to obtain the anthropometric data of Oman aircrew recruits and compare these with published western and eastern data with a hope to understand and highlight the aircrew-aircraft mismatch issues, if any.METHODS: The anthropometric data of 2296 Omani recruits from 2003 to 2012 were collected and their statistical distribution of data was collated. Published data from the UK and Singapore were used to carry out the comparative distribution of five anthropometric dimensions.RESULTS: Minimal differences were noted between Oman and Singaporean recruits whereas differences were most pronounced between Oman and Western populations (UK). Aircrew cadets from Oman, Singapore, and UK differed significantly in standing height. The UK cadets (M = 177.4 cm) showed the highest standing height followed by Oman cadets (M = 171.9cm), and then Singapore cadets (M = 168.5 cm).DISCUSSION: This study has provided opportunities to recognize the discrepancies involved in selection of Middle Eastern aircrew for western cockpits. This adds impetus to the scope for application of military recruitment standards suitable to the native population in aiding the ideal man-machine interface. This approach shall consider national policy, the significant anthropometric trends of the general population, and the procured aircraft profile of the country.Al Wardi Y, Jeevarathinam S, Al Sabei S. A cross-cultural anthropometric analysis in military aviation. Aerosp Med Hum Perform. 2020; 91(4):358–362.

BACKGROUND: Human fatigue is an important factor within aviation, leading organizations to develop strategies to assess and mitigate associated risks. The U.S. Air Force’s Air Mobility Command (AMC) conducted the current pilot study to assess fatigue-related risks and issues in mobility operations. Specifically, we examined the relationship among fatigue perceptions, fatigue mitigation strategies, performance effectiveness graph reference, and circadian typology.METHODS: There were 21 volunteers from the Joint Base Charleston C-17 pilot community (M_age = 28.67; SD_age = 2.11; Proportion_male = 85.71%) who completed a survey. Items referred to fatigue perceptions, fatigue mitigation strategies, performance effectiveness graph reference, and circadian typology. We examined descriptive statistics, correlations among the variables of interest, and possible moderation effects of circadian typology.RESULTS: Overall, aircrew perceived fatigue to be a serious safety of flight concern. Personal fatigue concerns and perceptions of pressure to continue missions despite fatigue were associated with increased use of the strategy of limiting light exposure during sleep episodes (r = 0.49 and 0.47). Fatigue perceptions were not directly associated with performance effectiveness graph usage. Results suggested that morning type participants might be more likely to utilize specific fatigue mitigation strategies when there are concerns of fatigue compared to evening types.DISCUSSION: Despite organizational efforts, fatigue continues to be a serious concern for the mobility community. This pilot study suggests that circadian typology might affect the relationship between fatigue perceptions and fatigue mitigation strategies and resource use. Future research should further examine these relationships and their impact within fatigue risk management (FRM) programs.Morris MB, Howland JP, Amaddio KM, Gunzelmann G. Aircrew fatigue perceptions, fatigue mitigation strategies, and circadian typology. Aerosp Med Hum Perform. 2020; 91(4):363–368.

BACKGROUND: Chronic flight-related neck pain is a common, well-recognized problem in military aircrew. The reasons for flight-related neck pain are multifactorial; however, there are currently no evidence-based guidelines for its prevention or clinical management. This case study describes the novel use of a synthetic training device in the rehabilitation of a Chinook crewman with chronic neck pain.CASE REPORT: The patient is a 34-yr-old rear crewman with 10 yr flying experience in the Chinook helicopter. He has a history of intermittent neck and shoulder pain since 2009 following a rugby injury. Over the years he has self-managed recurrent episodes of neck pain. However, in November 2017 his pain was so severe that he could no longer continue flying. This pain made him unfit for flying duties for 18 mo and he received intensive rehabilitation and injection therapy. RAF Odiham’s new flying simulator was used in his return to flying program, so enabling him to become fully fit and return to all flying duties.DISCUSSION: Management and treatment of chronic flight-related neck pain is challenging. This case study highlights the importance of a multifactorial management approach and how a synthetic training device can be used in the rehabilitation of rotary rear crew.Jobges S, Leaming F. Novel use of a synthetic training device in the rehabilitation of chronic neck pain of rotary rear crew. Aerosp Med Hum Perform. 2020; 91(4):369–372.

INTRODUCTION: Airplane headache (AH) is unique to plane travel and looks like a short duration migraine attack or paroxysmal hemicrania (PH) attack without any autonomic symptoms. Until now, there has been no documented association between AH and PH.CASE REPORT: We report a 50-yr-old healthy woman with a very severe and sudden pulsating headache located in the left frontal region with radiation into the left eye during takeoff which diminished within 10-15 min during her airplane journeys.DISCUSSION: The patient was diagnosed with AH and she had good response to indomethacin. The pain was unique to plane travel but looked like PH. We discuss the association between AH and PH attack in the light of diagnostic criteria and therapeutic approach in the report.Koçer A. Headache attack similar to paroxysmal hemicrania seen during flight. Aerosp Med Hum Perform. 2020; 91(4):373–375.

Warneke J, Pavelites J. You’re the flight surgeon: tularemia. Aerosp Med Hum Perform. 2020; 91(5):379–381.