INTRODUCTION: The year-long mission of American astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko included the most complex biomedical experiments ever conducted on the International Space Station—and arguably in human spaceflight—to establish insight into human health risks of interplanetary exploration. Focusing on risk mitigation, NASA conducted investigations that addressed spaceflight health hazards to varying degrees. This pilot mission was initiated to gain further knowledge and monitor the physiological, psychological, and medical effects of long-duration exposure to spaceflight.METHODS: NASA’s Human Research Program and the Russian Academy of Sciences’ Institute of Biomedical Problems identified more than 20 biomedical risk-reduction research investigations to be conducted on the two crewmembers before, during, and after their yearlong expedition. A database of results, as well as observations on programmatic resources, was collected to understand essential elements for future spaceflight health studies.RESULTS: Statistical rigor requires additional testing at a length of 1 yr to demonstrate the presence or absence of unacceptable deleterious effects, and to permit extrapolation to longer durations in space. Review of experimental procedures from this mission suggests potential efficiencies for future investigations.DISCUSSION: The Kelly-Kornienko 1-yr mission demonstrated the importance of continuing joint investigations with the adoption of standard measures for rigorous comparisons across disparate populations. It identified improvements to collaborative processes across national and international scientific research programs. Additional studies will inform the development of an integrated applied research methodology for the space station and future interplanetary expeditions.Charles JB, Pietrzyk RA. A year on the International Space Station: implementing a long-duration biomedical research mission. Aerosp Med Hum Perform. 2019; 90(1):4–11.

BACKGROUND: Precooling (PC) before exercise may help prevent severe hyperthermia and exertional heatstroke (EHS). Before clinicians can advocate PC as an EHS prevention strategy, it must effectively mitigate factors associated with EHS development while not lessening the effectiveness of EHS treatment. Therefore, this study determined if PC affected rectal temperature (T_rec), body heat storage, heart rate (HR), ratings of perceived exertion (RPE), thermal sensation, sweat rate, and postexercise cold-water immersion (CWI) T_rec cooling rates.METHODS: In this randomized, crossover, counterbalanced study, 12 subjects (6 men, 6 women; age = 22 ± 2 yr; mass = 73.5 ± 7.9 kg; height = 171 ± 7 cm) underwent 15 min of CWI (10.0 ± 0.03°C) in an environmental chamber (38.6 ± 0.6°C; 36 ± 2% humidity). After a 10-min rest, they exercised to a T_rec of 39.5°C. Subsequently, they underwent CWI (9.99 ± 0.03°C) until T_rec reached 38°C. On control (CON) days, the same procedures occurred without the 15-min PC intervention. T_rec, HR, thermal sensation, and RPE were measured at various times before, during, and after exercise.RESULTS: PC lowered body heat storage and T_rec by 15.7 ± 15.0 W · m⁻² and 0.42 ± 0.40°C, respectively, before exercise. Subjects exercised significantly longer (PC = 66.7 ± 16.3 min, CON = 45.7 ± 9.5 min) and at lower T_rec (∼0.5 ± 0.5°C) and HR (∼10 ± 7 bpm) following PC. PC significantly lowered sweat rate (PC = 1.02 ± 0.31 L · h⁻¹, CON = 1.22 ± 0.39 L · h⁻¹), but did not affect RPE or CWI cooling rates (PC = 0.18 ± 0.14°C · min⁻¹; CON = 0.19 ± 0.05°C · min⁻¹). Thermal sensation significantly differed between conditions only at pre-exercise (PC = 3 ± 1, CON = 5 ± 0.5).DISCUSSION: PC delayed severe hyperthermia and mitigated dehydration without affecting thermal perception or cooling rates posthyperthermia. PC may help prevent dangerous hyperthermia in athletes.Wohlfert TM, Miller KC. Precooling, exertional heatstroke risk factors, and postexercise cooling rates. Aerosp Med Hum Perform. 2019; 90(1):12–17.

BACKGROUND: While participation of women in the military has increased, research on performance of female teams engaged in arduous physical activity in isolated, confined, and extreme (ICE) environments remains sparse.METHODS: A team of six British military women completed the Multidimensional Personality Questionnaire-Brief Form, Triarchic Psychopathy Measure, and Personal Values Questionnaire (PVQ) prior to embarking on an expedition that traversed the Antarctic continent. Questionnaires were completed weekly on the ice; repeat of the PVQ and individual semistructured debriefing interviews were carried out within 9 d post-expedition.RESULTS: Personality findings indicated a generally well-adjusted group with notable individual differences in personality and personal values. Positive affect and camaraderie among teammates was evident throughout, although pace vs. distance in the strategy of the daily trek was a continuing point of tension. Honesty in communication was viewed as key to team effectiveness. A significant post-expedition decline in the tradition value (Pre M = −0.55, SD = 0.99; Post M = −0.82, SD = 1.12) and an increase in the conformity value (Pre M = −0.26, SD = 0.46; Post M = 0.18, SD = 0.27) was found.DISCUSSION: Congruence in personal and team goals among group members engaged in highly challenging activities is crucial for optimal team performance. Presence of two highly dominant individuals has a negative effect on team dynamics. Application of study findings to space exploration is considered.Blackadder-Weinstein J, Leon GR, Norris RC, Venables NC, Smith M. Individual attributes, values, and goals of an all-military women Antarctic expedition. Aerosp Med Hum Perform. 2019; 90(1):18–25.

INTRODUCTION: Motion sickness is a feeling of unwellness and introduces a significant safety risk. If a specific questionnaire to screen for motion sickness susceptibility is available, it would have benefit for susceptible people. This aimed at examining test-retest reliability and internal consistency of the Thai, non-English version Motion Sickness Susceptibility Questionnaire Short-Form (MSSQ-Short).METHODS: The original English-version MSSQ-Short was translated into Thai and then had a backward translation into English. The process of forward and backward translation was repeated until fulfillment of content and language equivalence between the backward translation and the original questionnaire. The Thai-version MSSQ-Short then was applied to people with history of motion sickness for two occasions with a 2-wk interval. The two questionnaires were examined for test-retest reliability and the first occasion was examined for internal consistency. MSSQ total raw score and percentile score between the first and second occasions were tested for correlation.RESULTS: The questionnaires were completed by 30 subjects. The weighted kappa values between the two occasions for the 18 subitems of the MSSQ ranged from 0.38 to 0.86, with most being in the higher range. The Pearson’s correlation coefficient of the MSSQ raw score between the two occasions was 0.94. The internal consistency was 0.80.CONCLUSION: The Thai, non-English version MSSQ-Short had an acceptable value for reliability. Further studies should be conducted with a larger sample size and with other populations.Asawavichienjinda T, Patarapak S. Reliability of the Thai version of the Motion Sickness Susceptibility Questionnaire Short-Form. Aerosp Med Hum Perform. 2019; 90(1):26–31.

BACKGROUND: Studies support the use of new training models based on low volume and high intensity in athletes, especially in soldier populations, showing greater physical improvements than conventional and classic approaches. We conducted this study to analyze the psychophysiological response of soldiers in two different high intensity interval training protocols (HIIT), resisted (RHIIT) and endurance (EHIIT), in order to determine which HIIT elicits a psychophysiological response similar to that in actual theaters of operation.METHODS: We recruited 21 professional soldiers from the Spanish Army. HIIT protocols were conducted in accordance with actual military scenarios, performed at 36–38°C.RESULTS: Both protocols, RHIIT and EHIIT, produced a significant increase in blood lactate (1.6 ± 0.3 to 6.4 ± 4.8 and 1.7 ± 0.6 to 11.2 ± 5.0, respectively), rate of perceived exertion, heart rate, and lower limb explosive strength; skin temperature and bodyweight presented significant decreases. Only EHIIT presented a significant increase on cortical arousal (35.9 ± 2.1 to 37.3 ± 2.8) and isometric hand-grip strength, achieving similar psychophysiological response as in previous simulated combat studies.DISCUSSION: Both endurance and resisted high interval intensity training protocols produced a significant increase in the psychophysiological response of soldiers. EHIIT presented more similarities with actual combat situations.Tornero-Aguilera JG, Clemente-Suárez VJ. Resisted and endurance high intensity interval training for combat preparedness. Aerosp Med Hum Perform. 2019; 90(1):32–36.

BACKGROUND: Chronic Hepatitis B (CHB) remains a major cause of morbidity in several parts of the world. Aircrew with immune-active hepatitis are unfit for flying duties due to the risk of acute hepatic decompensation; those who have begun on treatment are generally also disqualified from flying duties due to the potential side effects of antiviral treatment. As treatment endpoints for nucleos(t)ide analogues (NUC) are typically achieved after prolonged therapy, aircrew treated for CHB may be subjected to an extended period of flying restriction.METHODS: We present a retrospective case series of seven aircrew who were returned to flying duties while on varying combinations of NUC for the treatment of CHB. All seven aircrew were comanaged by the flight surgeon and hepatologist, reviewed by a panel of flight surgeons, and had achieved normalized liver function tests prior to resumption of flying duties; two out of the seven aircrew had detectable serum Hepatitis B virus (HBV) DNA when reinstated back to flying duties. Only one aircrew member experienced side effects from the NUC treatment. This was promptly evaluated and managed prior to resumption of flying duties to ensure flight safety.DISCUSSION: Aircrew with CHB infection can be safely allowed back to flying duties, especially when their conditions have been well controlled via treatment with any of the NUC regimes. While there are limited studies evaluating the use of NUC in aircrew performing flight duties, our study has shown that NUC are generally well tolerated and have a good safety profile which is compatible with flying duties.Tan D, Kwan C, Tan BBC, Gan WH. Returning aircrew with chronic Hepatitis B back to flying while on nucleos(t)ide analogues. Aerosp Med Hum Perform. 2019; 90(1):37–42.

BACKGROUND: Microgravity induces redistribution of body fluids and reductions in muscle and bone mass. These effects correlate with changes in lab test results, including urea and bone minerals. Difficulties with collecting blood and urine during space missions limit the available data. This pilot study investigated metabolic changes during a space mission using untimed spot samples of urine and saliva. Untimed spot urine was used for urinalysis with data normalization per creatinine concentration. Saliva was proven useful as an index of serum urea and phosphorus.METHODS: Two astronauts collected urine and saliva samples 75 ± 5 d before launch (baseline) and 3–5 times during a 6-mo space mission. Samples were collected 3 h after morning breakfast. Urine was collected using a standard NASA device. Saliva was collected using a Salivette™ synthetic swab. Samples were kept frozen using automated biochemistry until lab work-up. Anthropometric data were collected at baseline and after the mission.RESULTS: For astronauts 1 and 2, respectively, total bone mineral density decreased (−1.4% and −0.9%). In-flight changes were as follows: transiently decreased urine urea/creatinine ratio (−32% and −24%), transiently decreased urine phosphorus/creatinine ratio (−52% and −30%), increased urine calcium/creatinine ratio (up to +116% and +27%), and transient increases in saliva urea (up to +48% and +195%) and phosphorus (up to +29% and +46%). The astronaut with greater changes in urine minerals had greater reduction in bone mineral density.DISCUSSION: The results support the hypothesis that untimed samples of urine and saliva are useful for investigation of metabolic changes during space missions. Changes in urine and saliva minerals suggested down-regulation of parathyroid gland activity during the space mission.Bilancio G, Cavallo P, Lombardi C, Guarino E, Cozza V, Giordano F, Cirillo M. Urea and minerals monitoring in space missions by spot samples of saliva and urine. Aerosp Med Hum Perform. 2019; 90(1):43–47.

INTRODUCTION: Fatigue continues to be a leading cause of military aviation mishaps. Several factors, including reversed shift missions, can negatively affect sleep patterns and increase the risk of fatigue due to sleep restriction. Currently, there is a lack of objective data regarding the current rest and activity patterns of military aviators across multiple operational conditions. The purpose of this descriptive study was to document the rest and activity patterns of U.S. Army aviators in operational training and garrison (routine) environments using wrist-worn actigraphy devices.METHODS: Actigraphy data were collected from U.S. Army aviators in training (N = 20) and garrison (N = 77) environments for a period of 1 wk.RESULTS: Results from this study indicate that 90% of subjects in the training environment, even after accounting for small sleep bouts during the day, averaged less than the recommended 8 h of sleep daily across the recording week. Approximately half of subjects in garrison averaged less than 8 h of sleep daily after accounting for smaller sleep bouts. Sleep efficiency was relatively high and similar in both groups (∼84%). Subjects in the training group averaged significantly more time awake and less time sleeping than those in the routine garrison group. Moreover, subjects in training were exposed to more light during sleep than those in garrison.DISCUSSION: Training environments that are representative of deployed conditions restrict aviator restorative sleep. These results highlight the importance of continued research on aviator sleep and fatigue mitigation in operational environments.Bernhardt KA, Kelley AM, Feltman KA, Curry IP. Rest and activity patterns of Army aviators in routine and operational training environments. Aerosp Med Hum Perform. 2019; 90(1):48–52.

BACKGROUND: Spontaneous aneurysm of the superficial temporal artery in a helicopter pilot while operating in the extreme cold climatic conditions of a very high altitude area led to a thorough search for etiological possibilities related to this case.CASE REPORT: A 38-yr-old military helicopter pilot, while flying at altitudes ranging from 4500 m to 6000 m (15,000 to 20,000 ft) reported with an acute onset of a subcutaneous swelling on his left temple. History and clinical profile did not suggest any traumatic, hematologic, or vasculitic etiology. His inflammatory markers, anti-nuclear antibody, anti-neutrophil cytoplasmic antibodies, complement levels, and whole-body PET scan did not suggest any evidence of vasculitis. Presence of any other intracranial aneurysms was also ruled out. He underwent curative excision biopsy, which showed perivascular inflammation. He was diagnosed as a case of left superficial temporal artery aneurysm. The recovery period was uneventful and the follow-up color Doppler flow imaging of the temporal artery and acute phase reactants was normal.DISCUSSION: Spontaneous aneurysms involving the superficial temporal artery is a very rare diagnosis. Occurrence of such an aneurysm in a young pilot without any identifiable predisposing factors led the authors to hypothesize a possible etiological combination of environmental and mechanical factors along with aviation stresses with the likely compounding role of the helmet. Management and aeromedical aspects of this unique case are discussed in this paper.Sekhar BM, Sheoran S, Routh D, Sharma S. Superficial temporal artery aneurysm in a helicopter pilot operating at high altitude. Aerosp Med Hum Perform. 2019; 90(1):53–57.

INTRODUCTION: Changes of visual function/neuro-opthalmic structures during spaceflight have been described as visual impairment and intracranial pressure syndrome (VIIP)/spaceflight-associated neuro-ocular syndrome (SANS). Although theories are suggested, the mechanism is unknown. Only indirect measurements of intracranial pressure (ICP) have been performed in spaceflight. Direct determination of in-flight ICP is crucial to understanding VIIP. Current “gold standard” is lumbar puncture (LP). The only direct evaluation has occurred with postflight LP. In-flight measurements would allow correlation of opening pressures/possible contributing factors. The only imaging modality on the International Space Station (ISS) is ultrasound. With appropriate methodology, remotely guided ultrasound-guided lumbar puncture (USGLP) may allow safe performance in flight. Therefore, we sought to develop a novel ultrasound approach for definitive placement of an LP needle, and to show this can be achieved with remote guidance by those without training.METHODS: Literature review and round-table discussions with multiple medical fields was performed. Volunteers were scanned with ultrasound for optimizing technique. A cadaver was used to perform this technique by a radiologist, then taught to volunteers not experienced in image guided procedures, and finally was repeated multiple times by volunteers with simulated remote guidance.RESULTS: Optimal visualization was in the fetal and seated lordotic positions. Technical success was achieved by the radiologist in all attempts and achieved in 9 of 11 attempts by the trainees.DISCUSSION: Given ultrasound experience at NASA and the ability to educate non-image-guided trained personnel, these could make this technique feasible and aid in direct in-flight measurements to further research VIIP.Lerner DJ, Chima RS, Patel K, Parmet AJ. Ultrasound guided lumbar puncture and remote guidance for potential in-flight evaluation of VIIP. Aerosp Med Hum Perform. 2019; 90(1):58–62.

Dillard S. You’re the flight surgeon: splenic infarct following altitude exposure with sickle cell trait. Aerosp Med Hum Perform. 2019; 90(1):63–64.