Objective To unveil the patterns of change in heart rate during long-haul simulated flights, summarize how flight fatigue varies, and analyze the persistent physiological changes throughout the experiment. Methods Eight healthy males were selected and assigned to four groups to perform tasks as a captain and a co-pilot respectively. Flights were simulated using a 4-hour work and 4-hour rest mode, and the experiment lasted 48 hours. Electrocardiogram signals were recorded throughout the process and individual physiological changes were evaluated using heart rate variability（HRV）indicators. Results Both the captains and co-pilots were affected by the circadian rhythm and workload accumulation to varying degrees. The circadian rhythm resulted in regular changes during seven independent flights within 48 hours, and reached the peak by midnight. The impact of workload accumulation resulted in differences in HRV indicators between the beginning and the end of the 4-hour simulated flight. Conclusion In the shift-simulating flight, the levels of fatigue of pilots are affected by the circadian rhythm and workload accumulation. The analysis of heart rate variability can intuitively capture the changes, and effectively distinguish the fatigue status from the non-fatigue status of pilots at the beginning and the end of the simulated flight in combination with related machine learning models.
Objective To explore the feasibility and effectiveness with which a new scenario simulation exercise model based on virtual simulation technology is used for organizing high-altitude physiological training in order to improve the quality and efficiency of high-altitude physiological training and update the training model. Methods Immersive high-altitude physiological training mission scripts were designed based on high-altitude emergencies, and corresponding evaluation criteria were established. Forty-four students of aviation medicine were divided into 3 groups randomly, with 14 or 15 students per group, to engage in training laid out in a scenario simulation exercise mode using virtual simulation technology alone or using traditional methods. After training, such indicators as changes in students' physiological parameters, mastery of skills and levels of satisfaction were analyzed. Results During the pressure breathing training, the differences in the total scores of physiological parameters, increases of systolic blood pressure, scores of subjective feelings and those of index recovery times between the three groups of trainees were statistically significant（F=4.139, 7.160, 5.770, P=0.023, 0.002, 0.006）. The trainees in the scenario simulation training group scored higher than those in the traditional mode group（P=0.019, 0.001, 0.005）. The differences in scores of indicators of training effect between the three groups were also of statistical significance（F=4.139~27.452, all P<0.05）. The trainees in the scenario simulation training group compared favorably with the traditional mode group and the virtual simulation platform group in terms of the total score of training, enthusiasm for training, subjective feelings, and mastery of knowledge and skills（all P<0.05）. Conclusion Scenario simulation exercises based on virtual simulation technology can effectively improve the quality and efficiency of high-altitude physiological training. This study is expected to provide a new line of thought for improving the ability of aviation health care givers to offer medical support and for updating high-altitude physiological training modes.
Objective To explore the effect of mindfulness-based stress reduction（MBSR）on nonpathological high blood pressure in students of teenager aviation schools of Air Force（TASAF）. Methods In November of 2022, TASAF students in grade 9 whose blood pressure increases were found to exceed the standard during the first-round test in the annual reexamination were randomly divided into the MBSR group（n=121）and self-relaxation group（n=120）before the effectiveness of the two approaches in reducing blood pressure was compared. A scale was designed to investigate the accumulation of physical fatigue-psychological tension among the subjects. Results There was statistically significant difference in the initial systolic blood pressure between students with different scores of physical fatigue-psychological tension（F=15.670, P=0.012）. After pairwise comparison, the results showed that the higher the score of physical fatigue-psychological tension, the higher the initial systolic blood pressure（all P<0.05）. There was no statistically significant difference（all P>0.05）in systolic blood pressure, diastolic blood pressure or heart rate between the two groups before relaxation. Students in both groups underwent relaxation adjustment using the prescribed method and had their blood pressure retested according to the prescribed procedure. There was more significant difference in systolic blood pressure, diastolic blood pressure, and heart rate before and after relaxation in MBSR group than in self-relaxation group（t=6.873, 5.144, 3.651, P=0.001, 0.002, 0.013）. Conclusion The MBSR method is more effective than the self-relaxation method in improving the excessive increase of blood pressure and heart rate among students in TASAF, which is why this method should be used more widely and MBSR training be incorporated into daily courses.
Objective To investigate the prevalence of hyperuricemia（HUA）in military aircrews and analyze the contributing factors so as to provide a reference for the prevention and treatment of HUA. Methods The clinical data of 1 531 military aircrews admitted to the Aviation Medicine Department of Air Force Medical Center between December 2017 and December 2020 was retrospectively analyzed, including age, gender, aircraft types, flight time, height, weight, BMI, blood pressure, medical history, and related biochemical test results. These aircrews were divided into the HUA group（n=402）and non-HUA group（n=1 129）according to the national diagnostic criteria for HUA. The data was compared between the two groups and multivariate logistic regression analysis was used to analyze the related contributors to HUA. Results The incidence rate of HUA in military aircrews was 26.26%（402/1 531）. The HUA group had higher levels of BMI, SBP, DBP, serum creatinine（Scr）, fasting blood glucose（FBG）, TG, TC and LDL-C（Z=－6.920~－2.173, all P<0.05）, but lower HDL-C levels（Z=－3.300, P=0.001）than in the non-HUA group, with statistically significant differences. The HUA group also had a significantly higher incidence rate of combined glucose metabolism abnormalities, hypertension, and dyslipidemia（χ2=5.728, 12.562, 23.756, all P<0.05）. Multivariate logistic regression analysis revealed that higher BMI（OR=1.089, 95%CI: 1.022~1.161）, elevated DBP（OR=1.026, 95%CI: 1.009~1.044）, increased TG（OR=1.345, 95%CI: 1.064~1.700）, and elevated Scr（OR=1.029, 95%CI: 1.017~1.040）were risk factors for HUA while older age（OR=0.974, 95%CI: 0.959~0.990）served as a protective factor. Conclusion The prevalence of HUA in military aircrews reaches 26.26% in our aviation medicine department. Age, BMI, DBP, TG and Scr are closely related to the occurrence of the disease, which points to the need to develop personalized comprehensive prevention and treatment plans in order to reduce the occurrence and development of HUA in military aircrews.
Objective To analyze the incidence of pulmonary bullae detected by chance in pilots who underwent annual physical examinations at our center over the past three years in order to offer recommendations about related aeromedical assessments. Methods The results of chest CT examination of 5069 military pilots who received treatment at our center between July 2020 and November 2022 were retrospectively analyzed. The rates of detection, locations and sizes of pulmonary bullae were summarized. The detection rates of pulmonary bullae were compared between aircrews of different armed forces, aircraft types, flight times and jobs. The current number of confirmed cases of pulmonary bullae and the incidence of this disease accidentally found during aircrew physical examinations were analyzed. Considerations for aeromedical assessments were determined. Results The medical examination of aircrew found that the incidence of pulmonary bullae was about 4.46%（226/5 069）. The annual large-scale medical examination concluded that 6 cases were temporarily disqualified for flight, accounting for approximately 2.65%（6/226）of the total number of patients. Pulmonary bullae that ranged from over 1 to 2 cm in diameter accounted for 67.26%（152/226）. The detection rate of pulmonary bullae varied depending on the types of armed forces, with the army aircrews having a rate of 6.79%（55/810）, which was higher than that of aircrews from Air Force or Navy. The detection rate also varied according to types of aircraft（P=0.006, =0.001）, with the transport aircraft crews having a rate of 7.22%（76/1 052）, which was higher than among other crews（P=0.005, <0.001, <0.001）. The detection rate of pulmonary bullae in the group with flight time that ranged from over 3 000 to less than 5 000 hours was 8.70%（105/1213）, which was higher than in the group with flight time of ≤1 000 h and over 1 000 to 3 000 h（both P<0.001）. All these differences were statistically significant. However, no statistically significant difference was found in the detection rate of pulmonary bullae between aircrews doing different jobs（P=0.615）. Conclusion Aeromedical assessments should take into account such factors as the location and size of pulmonary bullae as well as the aircraft types and jobs of aircrews.
Objective To summarize the clinical and imaging features of pulmonary bullae in aviators and to offer data for aeromedical assessments. Methods We retrospectively analyzed the clinical data of aviators who were diagnosed with pulmonary bullae during routine physical examinations at Dalian Rehabilitation and Convalescence Center of the Joint Logistic Support Force between September 2020 and December 2023. Grouped by aircraft type, participants were categorized as fighter pilots（n=15）, helicopter pilots（n=15）, and bomber/transport pilots（n=21）. Baseline data, total flight hours, sizes and locations of bullae, and multiplicity were compared. Results Age and cumulative flight hours differed significantly between the three groups（F=11.568 and 8.563, P<0.001）. Fighter pilots were younger than both helicopter and bomber/transport pilots（P=0.029 and <0.001, respectively）, and had shorter accumulated flight hours （P=0.010 and <0.001, respectively）. There was no significant difference in height, body mass, BMI, or sizes of bullae between these groups（P>0.05）. Bullae were chiefly subpleural, and differences in locations of bullae were insignificant（P>0.05）. Conclusion The annual detection rate of pulmonary bullae in aviators is rising. More rigorous screening and cautious aeromedical assessments are needed. Prompt surgery is recommended when necessary.
Objective To study the curative effect of electric fire needle acupuncture combined with Shentong Zhuyu decoction against lumbar disc herniation（LDH）. Methods A total of 48 LDH patients treated at Dalian Rehabilitation and Convalescence Center between July 2023 and December 2023 were selected as the subjects and randomly divided into two groups. The observation group（n=24）was treated with electric fire needles combined with Shentong Zhuyu decoction while the control group（n=24）was given Shentong Zhuyu decoction alone. The time the symptoms disappeared, scores of quality of life（6 Item Short Form Survey Instrument, SF-36）, scores of the visual analogue scale（VAS）, and scores of lumbar spine function（Japanese Orthopaedic Association Scores, JOA）were compared between the two groups. Results After 5 weeks of treatment, the pain and discomfort in the waist and leg disappeared more quickly in the observation group than in the control group（t=7.530, 7.988, 11.735, 12.890, all P<0.001）. The scores of SF-36 were higher in the observation group than in the control group（t=12.493, 12.357, 12.531, 12.034, all P<0.001）. After 1 week, 3 weeks and 5 weeks of treatment, the scores of VAS were lower in the observation group than in the control group（P=0.001, <0.001, =0.001）while the JOA scores were higher（P=0.015, <0.001, <0.001）. Conclusion Electric fire needles combined with Shentong Zhuyu Decoction have obvious advantages over Shentong Zhuyu decoction alone in the treatment of lumbar disc herniation, which can significantly improve the quality of life of LDH patients, effectively restore the lumbar function, and reduce such symptoms as lumbar pain.
Objective To compare the therapeutic effects of two repair methods-the medial plantar island flap and free anterolateral thigh perforator flap-against soft tissue defects in the heel. Methods Ninety-five patients with soft tissue defects in the heel were selected as the subjects, who were divided into the control group（40 cases, repaired with the medial plantar island flap）and the study group（55 cases, repaired with the free anterolateral thigh perforator flap）. The survival of skin flaps, wound healing and complications, Maryland foot function scores before and after surgery, and levels of satisfaction with the appearance of the Thankappan skin flap one year after surgery were compared between the two groups. Results The postoperative survival rate of skin flaps in the control group was slightly lower than that of the study group, but the difference was of no statistical significance（χ2=2.160, P=0.142）. Two months after surgery, the healing of heel wounds reached stageⅠin both groups, while incisions at donor sites reached stageⅠlinear healing in the study group. There was a dent on the medial side of the foot in the control group, and some patients developed scar hyperplasia at the sites of skin graft. One year later, the color of skin flaps in the two groups was similar to that of the recipient skin, the thickness was moderate without swelling, and the patients resumed normal walking. The Maryland foot function scores in both groups showed a dramatic increase one year after surgery, but there was no significant difference between the two groups（t=1.808, P=0.074）. There was also no significant difference in patients' levels of satisfaction with the appearance of the Thankappan skin flap or in the rate of excellence between the two groups（t/χ2=1.450, 0.082, P=0.150, 0.775）. Conclusion Both the medial plantar island flap and the free anterolateral thigh perforator flap can effectively repair soft tissue defects in the heel, but there is no significant difference in the survival rate of skin flaps or in therapeutic effect between the two approaches. The free anterolateral thigh perforator flap repair is more conducive to postoperative recovery of foot function.
Objective To evaluate the preventive effect of the myofascial autonomic reciprocal therapy against training-induced knee pain in recruits. Methods During the training of freshmen from August to November 2023, 363 recruits from three teams of a university were selected and randomly divided into the observation group, control group A, and control group B, with 121 students in each group. The observation group adopted the myofascial autonomic reciprocal therapy, control group A played Baduanjin, also known as Eight Pieces of Brocade, and control group B served as the blank control. The incidence rate of knee joint injuries from training, scores of the Numerical Rating Scale（NRS）, the Lysholm knee score, the angle at which the affected limb hurt when squatting, and the ability of standing long jump were compared between the three groups at the end of the training. Results Except the angle at which the affected limb hurt when squatting（P<0.001）, there was insignificant difference in the incidence rate of training-caused knee joint injuries, scores of NRS, or in the Lysholm knee score between the observation group and control group A（all P>0.05）, but the above indicators were better in the observation group than in control group B（P<0.05, =0.031, <0.001, <0.001）, except the standing long jump ability（P>0.05）. Conclusion The myofascial autonomic reciprocal therapy can mitigate knee joint pain and reduce the incidence of training-induced knee joint injuries, which can be used for the prevention and management of such injuries during the training of first-year students.
Objective To explore the correlations between the risk of obstructive sleep apnea syndrome（OSAS）and heart rate variability（HRV）based on HRV, and to study the effect of sleep-disordered breathing on daytime autonomic nervous function in high-altitude military flying personnel. Methods A total of 47 military flying personnel stationed at high altitudes were selected as the subjects. A sleep questionnaire survey was conducted, data on short-term HRV was collected by a head-mounted HRV monitoring device and the risk of OSAS was assessed using the STOP-BANG scale and Epworth scale. Participants were divided into the risk group and normal group according to the results of evaluation of scales. The findings of the survey, the difference in HRV indexes and correlations between HRV and the scores of STOP-BANG scale and Epworth scale were analyzed across the 2 groups. Results Out of the 47 flying personnel, 20 were in the risk group and the rest were in the normal group. There were no significant differences in age, BMI, durations of flight, length of long-term stay on the plateau and total sleep time（all P>0.05） between the 2 groups. The incidence of attention/memory decline in the risk group was higher than that in the normal group（χ2=4.335, P=0.037）, so was the high frequency power（HF）（t=2.933, P=0.007）. There was no significant difference between other HRV indexes（all P>0.05）. The Epworth scale score had a moderate positive correlation with HF（rs=0.402, P=0.005）, while the STOP-BANG scale had a low positive correlation with HF and PNN50（%）（rs=0.394, 0.299, P=0.006, 0.041）. Conclusion Flying personnel at high risk of OSAS are more vulnerable to daytime symptoms related to sleep deficiency, especially decreased attention/memory. In addition, they are likely to develop autonomic nervous dysfunction, such as increased parasympathetic excitability. The more sleepy during the day, the higher the parasympathetic tension. It is recommended that autonomic nervous dysfunction be taken into consideration in case of sleep disorders among flying personnel at high altitudes.
Objective To explore the therapeutic effect of warm moxibustion and skin scraping (gua sha) against primary dysmenorrhea in high-altitude and extremely cold areas, and to recommend a better treatment for primary dysmenorrhea in young women in these areas. Methods Sixty cases of primary dysmenorrhea collected from high-altitude and extremely cold areas were divided into the observation group and control group by random number table method, with 30 cases in each. The observation group received the warm moxibustion and skin scraping therapy while the control group was treated with ibuprofen extended-release capsules. The patients in both groups were treated for three menstrual cycles and followed up for another 3 months. The clinical efficacy, the Cox Menstrual Symptom Scale（CMSS）scores, Numerical Rating Scale（NRS）scores, and pressure pain thresholds at different sites were compared between the two groups before treatment and at months 1, 2, 3 and 6 after treatment. Results At the 6th month, the total effective rate of the observation and control groups was 63.33% and 20.00%, respectively, and the differences were statistically significant（χ2=11.589, P=0.001）. The dynamics were compared between the 2 groups at different time points. The CMSS scores were statistically significant at months 3 and 6（P<0.001, =0.025）while the NRS scores were of statistical significance at months 1 and 6（P=0.008, <0.001）. The pressure pain threshold scores for the left lumbar vertebrae, right lumbar vertebrae, left rectus abdominis muscle and right rectus abdominis muscle were statistically significant at month 6 in the 2 groups（P<0.001, <0.001, <0.001, =0.001）. After treatment, the differences in CMSS scores, NRS scores, and pressure pain threshold scores of the left side of the lumbar spine, the right side of the lumbar spine, the left side of the rectus abdominis muscle, and the right side of the rectus abdominis muscle were statistically significant in the observation group at months 1, 2, 3 and 6（all P<0.05）, but at months 1, 2 and 3 in the control group（all P<0.05）. Conclusion The efficacy of the warm moxibustion and skin scraping therapy against primary dysmenorrhea in young women in high-altitude and extremely cold areas is definite. This therapy is environmentally-friendly, safe, user-friendly, and better than ibuprofen interventions in terms of the sustainability of the effect.
Objective To explore the characteristics and patterns of medical evacuations out of high-altitude areas in order to provide a reference for military training at high altitudes. Methods Cases of medical evacuation in an Air Force unit during high-altitude training between May 2020 and May 2024 were retrospectively analyzed. Results From May 2020 to May 2024, a total of 61 cases of medical evacuation were recorded. The top three causes were injuries and poisoning（19 cases, 31.15%）, digestive system diseases（13 cases, 21.31%）, and diseases of the ear, nose, throat, and eyes as well as acute high-altitude reactions（8 cases each, 13.11%）. Medical evacuations accounted for 47.54% of the total（29/61）in 2020 and 26.23%（16/61）in 2021. Cases that occurred in December 2020, January 2021, and September 2020 accounted for 22.95%（14/61）, 11.48%（7/61）, and 9.84%（6/61）respectively. Conclusion The diseases that led to medical evacuations in high-altitude areas were mostly injuries and poisoning, digestive system diseases, diseases of the ear, nose, throat and eyes, and acute high-altitude reactions. They were more prevalent in December 2020, January 2021, and September 2022. There is an urgent need to plan for medical support in winter, enhance the high-altitude adaptability of soldiers in order to reduce the incidence of training injuries and improve the combat effectiveness of the troops.
Plateau frostbite is one of the common injuries and illnesses among officers and soldiers in high-altitude areas of China. It not only affects the physical health of officers and soldiers, but also affects their combat and survival abilities, posing a serious threat to the combat effectiveness of the military. Hyperbaric oxygen, as an adjuvant therapy, can effectively treat and prevent high-altitude frostbite by reducing cell damage and promoting wound healing. The author reviews the research progress of hyperbaric oxygen therapy in the treatment of high-altitude frostbite, aiming to lay a more solid foundation for subsequent clinical applications.
