BACKGROUND: This study explored the impact of a fatigue management health education intervention (FMI) on flight attendants fatigue management knowledge, attitudes, behavioral intention, self-efficacy, and fatigue intensity.METHODS: A quasi-experimental pretest-posttest design was used. The sample included 70 flight attendants of an international airline company in Taiwan. The experimental group (N 34) received an FMI, while the control group (N 36) had no intervention. Fatigue management knowledge, attitude, behavior intention, self-efficacy, and fatigue intensity were assessed at baseline and 1 wk later. Single-factor analysis of covariance and Jensen Neman methods were used to assess the differences in outcomes between the two groups.RESULTS: Attitude and self-efficacy in the experimental group were significantly improved after the FMI [standardized mean difference (SMD), 0.96; 1.98]. The intervention also reduced their fatigue intensity (SMD 6.05) and both knowledge and behavioral intention scores were increased in more than 80% of subjects in the experimental group.DISCUSSION: FMI can effectively improve fatigue management knowledge, attitudes, behavioral intention, and self-efficacy and reduce fatigue intensity in flight attendants.Hu CJ, Lee FP, Hong RM. Fatigue management health education intervention effects on flight attendants. Aerosp Med Hum Perform. 2020; 91(12):911917.

BACKGROUND: At sea level, performing chest compressions is a demanding physical exercise. On a commercial flight at cruise altitude, the barometric pressure in the cabin is approximately equal to an altitude of 2438 m. This results in a Po₂ equivalent to breathing an F_Io₂ of 15% at sea level, a condition under which both the duration and quality of cardiopulmonary resuscitation (CPR) may deteriorate. We hypothesized that rescuers will be able to perform fewer rounds of high-quality CPR at an F_Io₂ of 15%.METHODS: In this crossover simulation trial, 16 healthy volunteers participated in 2 separate sessions and performed up to 14 2-min rounds of chest compressions at an F_Io₂ of either 0.15 or 0.21 in randomized order. Subjects were stopped if their S_po₂ was below 80%, if chest compression rate or depth was not achieved for 2/3 of compressions, or if they felt fatigued or dyspneic.RESULTS: Fewer rounds of chest compressions were successfully completed in the hypoxic than in the normoxic condition, (median [IQR] 4.5 [3,8.5]) vs. 5 [4,14]). The decline in arterial S_po₂ while performing chest compressions was greater in the hypoxic condition than in the normoxic condition [mean (SD), 6.19% (4.1) vs. 2% (1.66)].DISCUSSION: Our findings suggest that the ability of rescuers to perform chest compressions in a commercial airline cabin at cruising altitude may be limited due to hypoxia. One possible solution is supplemental oxygen for rescuers who perform chest compressions for in-flight cardiac arrest.Clebone A, Reis K, Tung A, OConnor M, Ruskin KJ. Chest compression duration may be improved when rescuers breathe supplemental oxygen. Aerosp Med Hum Perform. 2020; 91(12):918922.

BACKGROUND: NASA has been making efforts to assess the carbon dioxide (CO₂) washout capability of spacesuits using a standard CO₂ sampling protocol. This study established the methodology for determining the partial pressure of inspired CO₂ (P_Ico₂) in a pressurized spacesuit. We applied the methodology to characterize P_Ico₂ for the extravehicular mobility unit (EMU).METHODS: We suggested an automated and mathematical algorithm to find the end-tidal CO₂ and the end of inspiration. We provided objective and standardized guidelines to identify acceptable breath traces, which are essential to accurate and reproducible calculation of the in-suit inhaled and exhaled partial pressure of CO₂ (Pco₂). The mouth guard-based method for measurement of inhaled and exhaled dry-gas Pco₂ was described. We calculated all individual concentrations of P_Ico₂ inhaled by 19 healthy subjects classified into 3 fitness groups. The transcutaneous Pco₂ was monitored as a secondary measure to validate washout performance.RESULTS: Mean and standard deviation values for the data collection performance and the CO₂ metrics were presented (e.g., minimum time weighted average Pco₂ at suited workloads of resting, 1000, 2000, and 3000 (BTU h¹) were 4.75 1.03, 8.09 1.39, 11.39 1.26, and 14.36 1.29 (mmHg s¹). All CO₂ metrics had a statistically significant association and all positive slopes with increasing metabolic rate. No significant differences in CO₂ metrics were found between the three fitness groups.DISCUSSION: A standardized and automated methodology to calculate P_Ico₂ exposure level is presented and applied to characterize CO₂ washout in the EMU. The EMU has been operated successfully in over 400 extravehicular activities (EVAs) and is considered to provide acceptable CO₂ washout performance. Results provide a basis for establishing verifiable Pco₂ requirements for current and future EVA spacesuits.Kim KJ, Bekdash OS, Norcross JR, Conkin J, Garbino A, Fricker J, Young M, Abercromby AFJ. The partial pressure of inspired carbon dioxide exposure levels in the extravehicular mobility unit. Aerosp Med Hum Perform. 2020; 91(12):923931.

INTRODUCTION: Pilot workload assessment plays an important role on flight safety evaluation, interface design, and airworthiness certification. The design of an effective and reliable workload assessment method is a difficult problem in the human factors field.METHOD: This study proposed to assess pilot workload from four dimensions: cognitive activity, control activity, stress, and flight performance. A set of physiological, behavioral, and flight parameters were recorded and combined hierarchically to achieve overall workload assessment. A simulated flight experiment consisting of three flight phases (standard instrument departure, autopilot cruise, and nonprecision approach) was conducted to test the effectiveness of the proposed workload assessment method.RESULT: Experimental results determined the changes of each objective measure. The overall workload index could significantly distinguish the difference in workload caused by changing task difficulty and the result was consistent with the NASA-TLX. The four workload dimensions provided detailed differences about workload: during nonprecision approach there were more control activities and stress than in other flight phases; during autopilot cruise there were the least control activities and the highest flight performance. The correlation between workload dimensions provided extra diagnostic information: the cognitive and control activities in the approach phase were more stressful than in the takeoff phase; the correlation between control activity and performance was higher in the approach phase than in the takeoff phase.CONCLUSION: This study proposed an effective pilot workload assessment method which could also provide detailed and diagnostic information. It could be used as an auxiliary tool for the development and evaluation of pilot-cockpit interaction.Wang Z, Lu Y, Fu S. A multidimensional method for pilot workload assessment and diagnosis. Aerosp Med Hum Perform. 2020; 91(12):932939.

BACKGROUND: In their working life, airline pilots are exposed to particular risk factors that promote nonspecific low back pain (LBP). Because of the varying incidence internationally, we evaluated the point prevalences of acute, subacute, and chronic nonspecific LBP, as well as the current prevalences in German airline pilots. Furthermore, we compared the prevalence to the general German population and to European counterparts.METHODS: An anonymous online survey of 698 participating German airline pilots was evaluated. The impairment between groups was analyzed. Prevalences from our data were compared to existing data.RESULTS: The following point prevalences were found: 8.2% acute, 2.4% subacute, 82.7% chronic LBP; 74.1% of all individuals were suffering from current LBP when answered the questionnaire. A total time spent flying greater than 600 h within the last 12 mo was significantly related to acute nonspecific LBP. Individuals with any type of LBP were significantly impaired compared to those unaffected. It was found that German airline pilots suffer more often from current LBP than the general population and have a higher point prevalence of total LBP than their European counterparts.CONCLUSIONS: The evaluation showed a surprisingly high, previously unidentified, prevalence of nonspecific LBP in German airline pilots. Why German airline pilots suffer more often from LBP remains uncertain. The number of flying hours appears to have a negative effect on developing acute low back pain, but causation cannot be concluded. Other risk factors could not be confirmed.Albermann M, Lehmann M, Eiche C, Schmidt J, Prottengeier J. Low back pain in commercial airline pilots. Aerosp Med Hum Perform. 2020; 91(12):940947.

BACKGROUND: Circumstances in flight can adversely affect a pilots spatial abilities and lead to spatial disorientation (SD), increasing the potential for fatal accidents. To systematically understand the impact of SD, it is important to quantitatively and qualitatively analyze pilots flight performance and mental stress, and to verify the effectiveness of verbal reports (VR) in enabling pilots to deal with an SD situation. This study investigated the effects of VR execution and type of SD on flight performance and mental stress.METHODS: SD simulation experiments were conducted on 30 Air Force fighter pilots (15 in the VR group and 15 in the non-VR group) with electrocardiography (ECG) sensors attached. The pilots gave their VRs by immediately verbalizing their attention to instrument information and six potentially disorientating scenarios were implemented in each flight phase. Flight performance was analyzed using instructor evaluation and self-evaluation scores, and mental stress was measured using heart rate variability (HRV) and perceived distress score.RESULTS: In maintaining flight performance, the VR group, respectively, had 8% and 10% higher scores for altitude and speed than the non-VR group. The self-evaluation scores were lowest for Coriolis, while Graveyard Spin was scored lowest in the instructor evaluations. Regarding mental stress, the VR group tended to have higher HFs and lower LF/HF ratios among HRV measures than the non-VR group, and an 11% lower perceived distress score. The highest perceived distress score was for Coriolis.DISCUSSION: We suggest that pilots can be assisted to understand and overcome SD situations through VR.Kang Y, Yun MH, Kim S. Verbal reports influence on pilot flight performance and mental stress under spatial disorientation. Aerosp Med Hum Perform. 2020; 91(12):948955.

INTRODUCTION: Hypergolic propellants can be released in large amounts during space launch contingencies. Whether propellant-contaminated suit fabric poses a significant risk to rescue crews, due to off-gassing, has not been explored in detail. In this study, we addressed this issue experimentally, exposing space suit fabric to propellants (dinitrogen tetroxide [N₂O₄] and monomethyl hydrazine [MMH]).METHODS: The NASA Space Shuttle Program Advanced Crew Escape System II (ACES II) is similar to the NASA Orion Crew Survival System (OCSS) and was utilized here. Suit fabric was placed and sealed into permeation cells. Fabric exterior surface was exposed to constant concentrated hypergolics, simulating permeation and leakage. Fabric was rinsed, and permeation and off-gassing kinetics were measured. Experimental parameters were selected, simulating suited flight crewmembers during an evacuation transport without cabin air flow.RESULTS: The fabric allows for immediate permeation of liquid or vaporized MMH and N₂O₄. NO₂ off-gassing never exceeded the AEGL-1 8-h level (acute exposure guideline level). In contrast, MMH off-gassing levels culminated in peak levels, approaching AEGL-2 10-min levels, paralleling the drying process of the fabric layers. DISCUSSION: Our findings demonstrate that MMH off-gassing is promoted by the drying of suit material in a delayed fashion, resulting in MMH concentrations having the potential for adverse health effects for flight and rescue crews. This indicates that shorter decontamination times could be implemented, provided that suit material is either kept moist to prevent off-gassing or removed prior to medical evacuation. Additional studies using OCSS or commercial crew suits might be needed in the future.Schwertz H, Roth LA, Woodard D. Propellant off-gassing and implications for triage and rescue. Aerosp Med Hum Perform. 2020; 91(12):956961.

BACKGROUND: Emergency helicopter landing at sea is dangerous. Specialized training, known as helicopter underwater escape training (HUET), prepares occupants to quickly exit the helicopter, which often inverts and sinks. In most jurisdictions, helicopter occupants are equipped with a helicopter underwater egress breathing apparatus (HUEBA) to provide sufficient air for escape. HUET trainees report that the HUEBA is easy to use, but it is well known that learners are often overconfident in their judgement of learning. To better understand how the HUEBA affects HUET sequence performance, we investigated whether using the HUEBA influences the sequence movement time and number of errors.METHODS: Twelve participants (7 men and 5 women, mean age 25.33 9.57 SD) with no prior experience with HUET performed consecutive trials of the HUET sequence, 5 with the HUEBA and 5 without the HUEBA. Video of each trial recorded the total movement time and enabled movement time analyses of each component of the sequence: crossing arms, tucking the head, pushing the window, inserting the regulator, and releasing the seatbelt. These recordings were also used to score performance errors according to a checklist.RESULTS: Analyses revealed that using a HUEBA increased the total movement time and time to release the seatbelt by 0.36 and 0.39 s, respectively, in comparison to without the HUEBA.DISCUSSION: Our study illustrates that using the HUEBA during the HUET sequence increases total movement time and time to release the seatbelt. However, this difference is marginal and unlikely to have practical significance during underwater escape.King M, Sanli E, Mugford K, Martina S, Brown R, Carnahan H. Evaluation of the helicopter emergency breathing apparatus on egress performance. Aerosp Med Hum Perform. 2020; 91(12):962965.

BACKGROUND: Olfactory meningiomas are typically benign, slow-growing intracranial tumors with subtle presentations that result in delayed diagnosis. To date, only a few published reports describe meningiomas in airmen. None specifically mention olfactory meningiomas or detail the associated presence of cognitive impairment.CASE REPORT: This was a 55-yr-old commercial pilot with over 20 yr of flight experience who presented for a fitness-for-duty evaluation due to alarming performance at work and neurocognitive concerns. On examination, the patient had an odd affect and anosmia. Imaging showed a large, frontal, midline intracranial mass consistent with an olfactory meningioma.DISCUSSION: Fitness-for-duty cases are often challenging and even more so when neurocognition is called into question. Symptoms may be subtle and gradual in onset, making recognition and diagnosis difficult. Dementia, alcohol or substance misuse/abuse, and psychiatric diagnoses are often the first conditions considered when evaluating new cognitive impairment in a pilot. This case highlights the importance of keeping a broad differential, including intracranial masses, conducting a thorough neurological examination, and the judicious use of brain imaging.Hong M, Kreykes AJ. Cognitive changes in a commercial pilot secondary to an olfactory meningioma. Aerosp Med Hum Perform. 2020; 91(12):966969.

BACKGROUND: Increased frequencies of physiological episodes have been a significant concern for Naval Aviation for the last several years. These include several aircraft platforms, but no previously documented E-2D Hawkeye events. This report documents an episode in an E-2D, with multiple aircrew affected at the same time.CASE REPORT: While deployed aboard a U.S. aircraft carrier, five E-2D Hawkeyes aircrew were simultaneously exposed to the same over-pressurization during a routine sortie. Out of the five aircrew, four immediately reported hypoxic-like neurocognitive symptoms of mental slowing, difficulty concentrating, and headache. They were evaluated and treated using standard protocol according to the Physiologic Event Clinical Practice Guidelines set by the Naval Safety Center. All aircrew were treated with 100% ground level oxygen with resolution of symptoms.DISCUSSION: Although rare, physiological events may occur in multipassenger platforms such as the E-2D Hawkeye. Utilizing and strictly adhering to standard clinical practice guidelines provided an efficient process of evaluation by different flight surgeons concurrently that avoided a possible delay in treatment. After, eliminating other potential etiology for the crews symptoms, a pressure-related mechanism of injury appears to be the most probable cause.Ko SY, Rice GM. Multiple E-2D Hawkeye aircrew with neurocognitive symptoms during a single over-pressurization episode. Aerosp Med Hum Perform. 2020; 91(12):970974.

INTRODUCTION: A significant proportion of the astronauts who spend extended periods in microgravity develop ophthalmic abnormalities, including optic disc edema, optic nerve sheath distention, globe flattening, chorioretinal folds, hyperopic refractive error shifts, and nerve fiber layer infarcts. A constellation of these neuro-ophthalmic findings has been termed spaceflight-associated neuro-ocular syndrome. An increased understanding of factors contributing to this syndrome is one of the top priorities for ESA and NASA because the length of missions is expected to increase substantially in the future. As discussed in the present article, the very recent discovery of an ocular glymphatic clearance system can potentially help to unlock mechanisms underlying microgravity-induced optic disc edema. Observations pertaining to the ocular glymphatic pathway provide supporting evidence for the hypothesis, originally proposed by our group, suggesting that the glymphatic outflow from the eye into the optic nerve may be impeded under prolonged microgravity conditions, leading to optic disc edema.Wostyn P, De Winne F, Stern C, Mader TH, Gibson CR, De Deyn PP. Potential involvement of the ocular glymphatic system in optic disc edema in astronauts. Aerosp Med Hum Perform. 2020; 91(12):975977.