Impact of High-Flow Nasal Cannula Use in Subjects With COVID-19 ARDS at High Altitudes: Clinical Presentation and Prognostic Factors.

BACKGROUND: High-flow nasal cannula (HFNC) reduces the need for intubation in adult subject with acute respiratory failure. Changes in hypobaric hypoxemia have not been studied for subject with an HFNC in ICUs at altitudes > 2,600 m above sea level. In this study, we investigated the efficacy of HFNC treatment in subjects with COVID-19 at high altitudes. We hypothesized that progressive hypoxemia and the increase in breathing frequency associated with COVID-19 in high altitudes affect the success of HFNC therapy and may also influence the performance of the traditionally used predictors of success and failure. METHODS: This was a prospective cohort study of subjects >18 y with a confirmed diagnosis of COVID-19-induced ARDS requiring HFNC who were admitted to the ICU. Subjects were followed up during the 28 d of HFNC treatment or until failure. RESULTS: One hundred and eight subjects were enrolled. At admission to the ICU, FIO2 delivery between 0.5-0.8 (odds ratio 0.38 [95% CI 0.17-0.84]) was associated with a better response to HFNC therapy than oxygen delivery on admission between 0.8-1.0 (odds ratio 3.58 [95% CI 1.56-8.22]). This relationship continued during follow-ups at 2, 6, 12, and 24 h, with a progressive increase in the risk of failure (odds ratio 24 h 13.99 [95% CI 4.32-45.26]). A new cutoff for the ratio of oxygen saturation (ROX) index (ROX ≥ 4.88) after 24 h of HFNC administration was demonstrated to be the best predictor of success (odds ratio 11.0 [95% CI 3.3-47.0]). CONCLUSIONS: High-altitude subjects treated with HFNC for COVID-19 showed a high risk of respiratory failure and progressive hypoxemia when FIO2 requirements were > 0.8 after 24 h of treatment. In these subjects, personalized management should include continuous monitoring of individual clinical conditions (such as oxygenation indices, with cutoffs adapted to those corresponding to high-altitude cities).

Clinical characteristics of pregnant women in labor with SARS-CoV-2 infection at high altitude: A case series / Características clínicas de gestantes en trabajo de parto con infección SARSCoV-2 en la altura: serie de casos

Resumen Introducción. A gran altitud, se ha observado menos casos y menos letalidad de COVID-19 en comparación con cifras reportadas a nivel del mar. Actualmente no hay publicaciones que informen el comportamiento clínico de COVID-19 en mujeres embarazadas adaptadas a la altura e hipoxia crónica en el Perú. Métodos. Estudio retrospectivo mediante revisión de historias clínicas del 6 de marzo de 2020 al 15 de junio de 2020. Se describe los primeros trece casos de gestantes con COVID-19 atendidos en el Hospital COVID-19 Simón Bolívar, ubicado a 2 750 msnm. Los casos procedían de altitudes entre 2 035 msnm y 3 502 msnm. El análisis estadístico se realizó con SPSS, versión 19.0. Resultados. Trece casos de gestantes con COVID-19 confirmado por IGM para SARS-CoV-2, fueron tratadas a 2 750 msnm (9 022,31 pies), en los Andes peruanos. El parto fue por cesárea en ocho casos (61,5%) y por vía vaginal en cinco (38,5%). Hubo dos casos (15,4%) de preeclampsia, uno de ellos diagnosticado como síndrome HELLP, prematuridad y muerte fetal. Tres casos (23,1%) desarrollaron hipotonía uterina posparto y requirieron sutura de Hayman o B-Lynch. Dos casos (15,4%) se complicaron con oligohidramnios y otros dos casos con infección urinaria. Los niveles de hemoglobina variaron entre 11,1 y 16 g/dL. Solo un caso (7,7%) presentó sintomatología, con dolor faríngeo leve. No se observó transmisión vertical detectada por IgM/IgG para SARS-CoV-2. La evolución clínica fue favorable en los trece casos y el alta fue a los 2 a 4 días, para continuar la cuarentena en domicilio. Conclusiones. En el presente estudio preliminar, las gestantes en trabajo de parto con COVID-19 por prueba rápida IgM para SARS-CoV-2 en la altura fueron generalmente asintomáticas; no hubo transmisión vertical. Se presentó alto porcentaje de otras complicaciones obstétricas.

Abstract Introduction: Fewer COVID-19 cases and less lethality have been observed at high altitude compared to cases reported at sea level. There are currently no publications reporting clinical behavior of pregnant women with COVID-19 at high altitude. Methods: This is a retrospective study with review of medical records between March 6, 2020 and June 15, 2020. The first thirteen cases of pregnant women with COVID-19 who were attended at Simón Bolívar COVID-19 Hospital, located at 2 750 meters above sea level, are described. The cases came from altitudes between 2 035 and 3 502 meters above sea level (masl). Statistical analysis used SPSS, version 19.0. Results: Thirteen cases of pregnant women with COVID-19 confirmed by IgM for SARS-CoV-2 were attended at 2 750 masl (9 022.31 feet) in the Peruvian Andes. Delivery by cesarean section occurred in eight cases (61.5%) and five (38.5%) delivered vaginally. There were two cases (15.4%) of preeclampsia, one with diagnosis of HELLP syndrome, prematurity and fetal death. Three cases (23.1%) developed uterine hypotonia that required Hayman or B-Lynch suture. Two cases (15.38%) were complicated with oligohydramnios and two with urinary infection. Hemoglobin levels were between 11.1 and 16 g/dL. Only one case (7.7%) was symptomatic, with mild pharyngeal pain. No vertical transmission was detected by IgM/IgG for SARS-CoV-2. Clinical evolution was favorable in the thirteen cases and they were discharged after 2 to 4 days hospitalization to continue home quarantine. Conclusions: Results in this short study show pregnant women in labor with COVID-19 by rapid IgM test for SARS-CoV-2 at high altitude were mostly asymptomatic; there was no vertical transmission, but high presence of other obstetrical complications.

Relationship between Lightning, Lightning Fire and Human Activities

Lightning is the main source of natural fire, and lightning fire and other types of forest fires together constitute the global forest fire system. It is generally believed that lightning fire, as a natural fire source, has nothing to do with human beings and is different from man-made fire sources, but in fact, human activities have inextricable links with the occurrence of lightning fire. Since 2019, due to the severe impact of COVID-19 lockdowns, non-essential activities and mobility have decreased, which has led to a significant decrease in pollutant concentrations and lightning. In this paper, we linked the lightning fire with modernization process of human beings, the expansion of habitation, the change of underlying surface, the development of prediction technology and firefighting technology, and the laws and regulations of the country, to explore the impact of human activities on the occurrences of lightning and the forest lightning fire. Lightning is the fire source of the three elements in lightning fire occurrence, the lightning that can cause lightning fire is mainly cloud-to-ground lightning. The human activities in recent decades have profoundly affected the content of aerosols in environment. Aerosols are the main factors affecting lightning, and the large amount of pollution aerosols emitted from urban areas, soot aerosols emitted from biomass combustion and urban heat island effect have all increased the probability of lightning occurrence. The average annual ground lightning density of different land cover types is obviously different, and the construction land has the highest average annual ground lightning density. Intense lightning in forest areas has a higher density and slope. Most of the forests are located in high altitude areas, which is consistent with previous studies showing high lightning frequency in high altitude areas. The lightning in forests is intenser, steeper and more destructive, so forest areas are prone to lightning strikes. Lightning has the characteristic of selective discharge, that is, it will discharge into some special areas, which are also known as lightning selection areas, such as the place groundwater is exposed to the ground, where different conductive soils are connected, and where there are underground metal mines, such as copper and iron mines, and underground lake and water reservoir areas. Lightning strikes are caused by changes in soil conductivity caused by human activities such as mining waste rock sites, reservoir construction on mountain tops, and power transmission lines in mountainous areas. At the same time, due to the abundant trees in the mountainous area, it is also important to avoid the resulting lightning fire. With the development of lightning monitoring technology, a lightning location monitoring system has been established in some areas of China. Especially in 2021, the National Forestry and Grassland Administration launched the "Enlisting and Leading" emergency science and technology project of forest lightning fire prevention and control, and the project team has constructed a lightning fire sensing system in the Daxing'anling region with three-dimensional lightning full-wave detection network as the main body, covering the forest area of the Daxing'anling forest region, which can accurately locate the location of cloud-to-ground lightning in real time, improve the monitoring and warning ability of lightning fires, and improve the efficiency of lightning fire discovery. National laws and regulations indirectly affect lightning fires by affecting forest cover and climate change. This paper is expected to provide reference for the occurrence, prevention and control of forest lightning fire in the future, and provide a basis for the formulation of corresponding policies.

Factors Associated with COVID-19 Death in a High-Altitude Peruvian Setting during the First 14 Months of the Pandemic: A Retrospective Multicenter Cohort Study in Hospitalized Patients.

Risk factors for COVID-19 death in high-altitude populations have been scarcely described. This study aimed to describe risk factors for COVID-19 death in three referral hospitals located at 3399 m in Cusco, Peru, during the first 14 months of the pandemic. A retrospective multicenter cohort study was conducted. A random sample of ~50% (1225/2674) of adult hospitalized patients who died between 1 March 2020 and 30 June 2021 was identified. Of those, 977 individuals met the definition of death by COVID-19. Demographic characteristics, intensive care unit (ICU) admission, invasive respiratory support (IRS), disease severity, comorbidities, and clinical manifestation at hospital admission were assessed as risk factors using Cox proportional-hazard models. In multivariable models adjusted by age, sex, and pandemic periods, critical disease (vs. moderate) was associated with a greater risk of death (aHR: 1.27; 95%CI: 1.14-1.142), whereas ICU admission (aHR: 0.39; 95%CI: 0.27-0.56), IRS (aHR: 0.37; 95%CI: 0.26-0.54), the ratio of oxygen saturation (ROX) index ≥ 5.3 (aHR: 0.87; 95%CI: 0.80-0.94), and the ratio of SatO2/FiO2 ≥ 122.6 (aHR: 0.96; 95%CI: 0.93-0.98) were associated with a lower risk of death. The risk factors described here may be useful in assisting decision making and resource allocation.

Surgical masks and filtering facepiece class 2 respirators (FFP2) have no major physiological effects at rest and during moderate exercise at 3000 m altitude. A randomised controlled trial.

BACKGROUND: During the COVID-19 pandemic, the use of face masks has been recommended or enforced in several situations, however their effects on physiological parameters and cognitive performance at high altitude are unknown. METHODS: Eight healthy participants (four females) rested and exercised (cycling, 1 W/kg) while wearing no mask, a surgical mask, or a filtering facepiece class 2 respirator (FFP2), both in normoxia and hypobaric hypoxia corresponding to an altitude of 3000 m. Arterialised oxygen saturation (SaO2), partial pressure of oxygen (PaO2) and carbon dioxide (PaCO2), heart and respiratory rate, pulse oximetry (SpO2), cerebral oxygenation, visual analogue scales for dyspnoea and mask's discomfort were systematically investigated. Resting cognitive performance and exercising tympanic temperature were also assessed. RESULTS: Mask use had a significant effect on PaCO2 (overall +1.2 ± 1.7 mmHg). There was no effect of mask use on all other investigated parameters except for dyspnoea and discomfort, which were highest with FFP2. Both masks were associated with a similar non-significant decrease in SaO2 during exercise in normoxia (-0.5% ± 0.4%) and, especially, in hypobaric hypoxia (-1.8% ± 1.5%), with similar trends for PaO2 and SpO2. CONCLUSIONS: Although mask use was associated with higher rates of dyspnoea, it had no clinically relevant impact on gas exchange at 3000 m at rest and during moderate exercise, and no detectable effect on resting cognitive performance. Wearing a surgical mask or an FFP2 can be considered safe for healthy people living, working, or spending their leisure time in mountains, high-altitude cities, or other hypobaric environments (e.g. aircrafts) up to an altitude of 3000 m.

Disparities in COVID-19 incidence and fatality rates at high-altitude.

Background: SARS-CoV-2 has affected every demography disproportionately, including even the native highland populations. Hypobaric-hypoxic settings at high-altitude (HA, >2,500 masl) present an extreme environment that impacts the survival of permanent residents, possibly including SARS-CoV-2. Conflicting hypotheses have been presented for COVID-19 incidence and fatality at HA. Objectives: To evaluate protection or risk against COVID-19 incidence and fatality in humans under hypobaric-hypoxic environment of high-altitude (>2,501 masl). Methods: Global COVID-19 data of March 2020-21, employed from official websites of the Indian Government, John Hopkins University, and Worldometer were clustered into 6 altitude categories. Clinical cofactors and comorbidities data were evaluated with COVID-19 incidence and fatality. Extensive comparisons and correlations using several statistical tools estimated the risk and protection. Results: Of relevance, data analyses revealed four distinct responses, namely, partial risk, total risk, partial protection, and total protection from COVID-19 at high-altitude indicating a mixed baggage and complexity of the infection. Surprisingly, it included the countries within the same geographic region. Moreover, body mass index, hypertension, and diabetes correlated significantly with COVID-19 incidence and fatality rate (P ≤ 0.05). Conclusions: Varied patterns of protection and risk against COVID-19 incidence and fatality were observed among the high-altitude populations. It is though premature to generalize COVID-19 effects on any particular demography without further extensive studies.

Anxiety, depression, and somatic symptom disorders in health care workers at high altitude during the rapid spread of the SARS-CoV-2 Omicron variant: A prospective cohort study.

Objective: The ongoing spread of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Omicron variant and hypoxia exposure to high altitude are the susceptible factors of people's psychological abnormalities, especially the health care workers (HCWs) in the front line of the epidemic. There is no dynamic observation data on the prevalence of mental health disorders among HCWs at high altitude. The study is to assess the prevalence of mental health outcomes and its influencing factors among HCWs at high altitude exposed to the SARS-CoV-2 Omicron variant. Methods: This prospective cohort study collected sociodemographic data and mental health measurements from 647 HCWs in 3 hospitals in Xining, Qinghai province from 13 April to 4 May 2022. After the mental health intervention for the above-mentioned people in the Chengdong district, we collected mental health indicators on days 7 and 14, respectively. We used the generalized linear model and the generalized estimation equation and for further analysis. Results: The baseline cross-sectional survey of 647 HCWs in the Chengdong and Chengbei districts of Xining, Qinghai province shows that the prevalence of depression, anxiety, and somatic disorders were 45.75, 46.52, and 52.55%, respectively. The multivariable model showed that chronic diseases and nucleic acid collection were associated with increased scores of GAD-7, PHQ-9, and PHQ-15. And the GAD-7 score of HCWs with elderly people at home increased by 0.92 points. Subsequent repeated measurements of the mental health of HCWs in Chengdong district in Xining, Qinghai province, showed that anxiety, depression, and somatic disorders were significantly relieved, and physical exercise showed a significant protective effect, while loans and nucleic acid collection showed an adverse effect after 2 weeks of intervention. Additionally, engaged in nucleic acid collection was the risk factor of anxiety and depression. Conclusion: In this survey of HCWs on frontline at high altitude during the rapid spread of the SARS-CoV-2 Omicron variant, participants reported experiencing mental health disorders, especially in those with chronic disease, loans, and those who worked with longer hours and engaged in nucleic acid collection in Xining, Qinghai province, China. Exercise may help to improve anxiety and physical disorders.

Mountain spa rehabilitation improved health of patients with post-COVID-19 syndrome: pilot study.

European Association of Spa Rehabilitation (ESPA) recommends spa rehabilitation for patients with post-COVID-19 syndrome. We tested the hypothesis that a high-altitude environment with clean air and targeted spa rehabilitation (MR - mountain spa rehabilitation) can contribute to the improving platelet mitochondrial bioenergetics, to accelerating patient health and to the reducing socioeconomic problems. Fifteen healthy volunteers and fourteen patients with post-COVID-19 syndrome were included in the study. All parameters were determined before MR (MR1) and 16-18 days after MR (MR2). Platelet mitochondrial respiration and OXPHOS were evaluated using high resolution respirometry method, coenzyme Q10 level was determined by HPLC, and concentration of thiobarbituric acid reactive substances (TBARS) as a parameter of lipid peroxidation was determined spectrophotometrically. This pilot study showed significant improvement of clinical symptoms, lungs function, and regeneration of reduced CI-linked platelet mitochondrial respiration after MR in patients with post-COVID-19 syndrome. High-altitude environment with spa rehabilitation can be recommended for the acceleration of recovery of patients with post-COVID-19 syndrome.

Incidence, etiology, sociodemographic and clinical characterization of acute respiratory failure in pediatric patients at a high-altitude city: A multicenter cohort study.

Background: Acute respiratory failure is a life-threatening medical condition, associated with a variety of conditions and risk factors, including acute respiratory diseases which are a frequent cause of pediatric morbidity and mortality worldwide. In Colombia, the literature related to ARF is scarce. Objective: To determine the incidence, causes, and sociodemographic and clinical characteristics of ARF in three hospitals in Bogota, a high-altitude city located in Colombia, during the COVID-19 pandemic. Methods: A multicenter prospective cohort study called the FARA cohort was developed between April 2020 - December 2021. Patients older than one month and younger than 18 years with respiratory distress who developed ARF were included. Results: 685 patients with respiratory distress were recruited in 21 months. The incidence density of ARF was found to be 41.7 cases per 100 person-year CI 95%, (37.3-47.7). The median age was 4.5 years.. Most of the patients consulted during the first 72 h after the onset of symptoms. Upon admission, 67.2% were potentially unstable. The most frequent pathologies were asthma, bronchiolitis, pneumonia, and sepsis. At admission, 75.6% of the patients required different oxygen delivery systems, 29,5% a low-flow oxygen system, 36,8% a high-flow oxygen system, and 9,28% invasive mechanical ventilation. SARS-COV-2, respiratory syncytial virus, rhinovirus/enterovirus, and adenovirus were the most frequently isolated viral agents. The coinfection cases were scarce. Conclusions: This multicenter study, the FARA cohort, developed at 2,600 meters above sea level, shows the first data on incidence, etiology, sociodemographic and clinical characterization in a pediatric population with ARF that also concurs with the COVID-19 pandemic. These results, not only have implications for public health but also contribute to the scientific and epidemiological literature on a disease developed at a high altitude.

Severe Respiratory Failure Developing in the Course of High-Altitude Pulmonary Edema in an Alpinist with COVID-19 Pneumonia: A Case Report.

Pigon, Katarzyna, Ryszard Grzanka, Ewa Nowalany-Kozielska, and Andrzej Tomasik. Severe respiratory failure developing in the course of high-altitude pulmonary edema in an alpinist with COVID-19 pneumonia: a case report. High Alt Med Biol. 23:372-376, 2022.-The case of a 38-year-old Polish alpinist, evacuated from base camp (4,200 m) under Lenin's Peak due to severe high-altitude pulmonary edema (HAPE) and symptoms of acute mountain sickness/high-altitude cerebral edema (HACE), is presented. Starting the expedition, the man was asymptomatic and had a negative COVID-19 molecular test. After a few days of trekking, he developed typical HAPE and HACE. After evacuation to the hospital in Bishkek, a diagnosis of acute bronchopneumonia was made by computed tomography (CT) imaging. A COVID-19 test was not performed at that time. After returning to Poland, a complete noninvasive cardiac and pulmonary assessment disclosed no pathology. The initial chest CT reassessment was read as demonstrating the densities typical for COVID-19 pneumonia, and a SARS-CoV-2 antibody test corroborated the diagnosis. Pre-existing lung disease increases the risk of developing HAPE. In the era of the COVID-19 pandemic, people traveling at a high altitude and unaware of the infection are at particular risk.

Long COVID at Different Altitudes: A Countrywide Epidemiological Analysis.

BACKGROUND: Several reports from around the world have reported that some patients who have recovered from COVID-19 have experienced a range of persistent or new clinical symptoms after a SARS-CoV-2 infection. These symptoms can last from weeks to months, impacting everyday functioning to a significant number of patients. METHODS: A cross-sectional analysis based on an online, self-reporting questionnaire was conducted in Ecuador from April to July 2022. Participants were invited by social media, radio, and TV to voluntarily participate in our study. A total of 2103 surveys were included in this study. We compared socio-demographic variables and long-term persisting symptoms at low (<2500 m) and high altitude (>2500 m). RESULTS: Overall, 1100 (52.3%) responders claimed to have Long-COVID symptoms after SARS-CoV-2 infection. Most of these were reported by women (64.0%); the most affected group was young adults between 21 to 40 years (68.5%), and most long-haulers were mestizos (91.6%). We found that high altitude residents were more likely to report persisting symptoms (71.7%) versus those living at lower altitudes (29.3%). The most common symptoms were fatigue or tiredness (8.4%), hair loss (5.1%) and difficulty concentrating (5.0%). The highest proportion of symptoms was observed in the group that received less than 2 doses. CONCLUSIONS: This is the first study describing post-COVID symptoms' persistence in low and high-altitude residents. Our findings demonstrate that women, especially those aging between 21-40, are more likely to describe Long-COVID. We also found that living at a high altitude was associated with higher reports of mood changes, tachycardia, decreased libido, insomnia, and palpitations compared to lowlanders. Finally, we found a greater risk to report Long-COVID symptoms among women, those with previous comorbidities and those who had a severer acute SARS-CoV-2 infection.

Prevalence and factors associated with food insecurity in eight high-altitude cities in Peru during the second wave of the COVID-19 pandemic: a retrospective, cross-sectional study.

BACKGROUND: Food insecurity has increased during the COVID-19 pandemic, affecting an estimated 260 million people. However, little evidence is available on how pandemic-related characteristics influence food security in a high-altitude population. The objective of this study was to assess factors associated with food insecurity in high-altitude Peruvian cities during the second epidemic wave of COVID-19. METHODS: A retrospective, cross-sectional study was conducted in eight Peruvian cities over 1,500 m above sea level. An online survey measuring food security, presence of anxiety & depressive symptoms, sleep quality, post-traumatic stress disorder (PTSD), resilience, and sociodemographic characteristics was disseminated through social networks between December 2020 and February 2021. Generalized linear models were used to identify an association between the study variables. RESULTS: Of 700 participants, the median age was 23 years, and more than half were female (56.7%). The prevalence of food insecurity was 37.1%. Anxiety symptoms, depressive symptoms, and PTSD were present in 72.7%, 64.1%, and 15% of respondents, respectively. The prevalence of food insecurity was higher in people with fair (PR: 1.60, 95% CI: 1.23-2.07) and very bad perception of their health (PR: 4.06, 95% CI: 2.63-6.26), individuals seeking mental health support (PR: 1.42, 95% CI: 1.25-1.62), and in those who lost their job due to the pandemic (PR: 1.82, 95% CI: 1.62-2.04). Having moderate (PR: 1.52, 95% CI: 1.26-1.83) and moderate to severe depressive symptoms (PR: 1.58, 95% CI: 1.11-2.27) also increased the prevalence of food insecurity. CONCLUSION: During the pandemic, the prevalence of food insecurity has increased in the Peruvian high-altitude population, revealing the need for preventive strategies. Identification of pandemic-related characteristics that influence food insecurity can guide interventions in at-risk individuals and reduce the long-term impact of this problem on overall health and quality of life.

INNOVATIONS IN EMERGENCY AIRWAY MANAGEMENT: LESSONSLEARNED FROM EARLY CROSS-CULTURAL MANAGEMENT OF COVID-19

The Texas Tech University Center for Emerging Energy Sciences Research Group implemented rapid translation and analytics of Chinese COVID-19 medical literature in February 2020, which enabled emerging innovations in patient care. Specifically, techniques to optimize patient care through improved ventilation and oxygenation recognizing newly discovered pathophysiology were designed and prototyped in this invention. COVID-19 respiratory distress distinguishes itself from acute respiratory distress syndrome (ARDS) and pathophysiology of SARS-COV-2 by requiring higher O2 and lower pressure requirements for adequate oxygenation. Specifically, low positive end-expiratory pressure ventilator parameters are necessary to optimize patient care. Paradoxically, COVID-19 patients display severe "silent" hypoxemia often associated with near normal respiratory compliance. This clinical presentation is considered unusual for severe ARDS patients and implies non-uniformity in disease management of acute respiratory and pre-hospital patients. A clinical need for new innovative approaches to management that may also benefit decompression sickness, high altitude pulmonary edema and other chronic respiratory disease patients. We present these observations as an example of the need for closely-collaborating, plinary teams to rapid innovation when sudden, severe health threats first emerge. This approach is invaluable to medical innovations needed to counter threats due natural to man-made conditions.

Investigating the effect of High-altitude Platform Positioning on Latency and Coverage of 4G Cellular Systems

Wireless communication technologies are rapidly being adopted and developed by countries all over the world as a strategy for sustaining a digital economy. This has proven very useful for economic recovery from the crises brought about by the COVID-19 pandemic of the year 2020. The latency and coverage area of a wireless network are two major areas that are always seeking improvement. The High-Altitude Platform communication technology can provide improvement in speed and coverage area for 4G cellular systems. This work investigated the effect of positioning High Altitude Platforms on the latency and coverage of 4G cellular Systems. A quantitative approach was used in the methodology of this paper. A HAP model showing a single platform flying in a circular trajectory over Base Transceiver Stations BTSs and serving as a relay mobile station was presented. A detailed simulation algorithm for the HAP and results for the simulation were given. Results showed that using the HAP as a relay mobile station in a network can give a latency reduction of up to 58.9%. Also, the altitude of the HAP directly affects the angle of reception which was found to improve the coverage.

Distribution of hydrogen peroxide over Europe during the BLUESKY aircraft campaign

In this work we present airborne in situ trace gas observations of hydrogen peroxide (H2O2) and the sum of organic hydroperoxides over Europe during the Chemistry of the Atmosphere – Field Experiments in Europe (CAFE-EU, also known as BLUESKY) aircraft campaign using a wet chemical monitoring system, the HYdrogen Peroxide and Higher Organic Peroxide (HYPHOP) monitor. The campaign took place in May–June 2020 over central and southern Europe with two additional flights dedicated to the North Atlantic flight corridor. Airborne measurements were performed on the High Altitude and LOng-range (HALO) research operating out of Oberpfaffenhofen (southern Germany). We report average mixing ratios for H2O2 of 0.32 ± 0.25, 0.39 ± 0.23 and 0.38 ± 0.21 ppbv in the upper and middle troposphere and the boundary layer over Europe, respectively. Vertical profiles of measured H2O2 reveal a significant decrease, in particular above the boundary layer, contrary to previous observations, most likely due to cloud scavenging and subsequent rainout of soluble species. In general, the expected inverted C-shaped vertical trend with maximum hydrogen peroxide mixing ratios at 3–7 km was not found during BLUESKY. This deviates from observations during previous airborne studies over Europe, i.e., 1.64 ± 0.83 ppbv during the HOOVER campaign and 1.67 ± 0.97 ppbv during UTOPIHAN-ACT II/III. Simulations with the global chemistry–transport model EMAC partly reproduce the strong effect of rainout loss on the vertical profile of H2O2. A sensitivity study without H2O2 scavenging performed using EMAC confirms the strong influence of clouds and precipitation scavenging on hydrogen peroxide concentrations. Differences between model simulations and observations are most likely due to difficulties in the simulation of wet scavenging processes due to the limited model resolution.

A Puzzling Diagnosis of Cerebral Vein Thrombosis in a COVID-19-Vaccinated Patient.

Cerebral vein thrombosis (CVT) is a rare condition equivalent to deep vein thrombosis of the intracranial veins. Delayed diagnosis will result in severe and disabling complications. We report a case of a 59-year-old man with CVT with no significant past medical or surgical history. On admission, he reported right-sided numbness and weakness concerns, preceded by the sudden onset of bilateral vision loss and dysarthria. Magnetic resonance imaging and computed tomography scans confirmed the diagnosis of CVT. The most interesting relative risk factor was flying overseas twice a month for the last 10 years; each flight was longer than eight hours. Another possible contributing factor to our patient's condition was polycythemia, with a hemoglobin level of 19, but the most questionable and puzzling is the recent coronavirus disease 2019 (COVID-19) vaccination two months, eight months, and one year prior to admission. Our case highlights a rare COVID-19 vaccine-related CVT diagnosis and that close monitoring for new symptoms and signs is vital to prevent life-threatening complications, herniation, and hemorrhagic transformation.

SARS-CoV-2 Viral Load Analysis at Low and High Altitude: A Case Study from Ecuador.

SARS-CoV-2 has spread throughout the world, including remote areas such as those located at high altitudes. There is a debate about the role of hypobaric hypoxia on viral transmission and COVID-19 incidence. A descriptive cross-sectional analysis of SARS-CoV-2 infection and viral load among patients living at low (230 m) and high altitude (3800 m) in Ecuador was completed. Within these two communities, the total number of infected people at the time of the study was 108 cases (40.3%). The COVID-19 incidence proportion at low altitude was 64% while at high altitude was 30.3%. The mean viral load from those patients who tested positive was 3,499,184 copies/mL (SD = 23,931,479 copies/mL). At low altitude (Limoncocha), the average viral load was 140,223.8 copies/mL (SD = 990,840.9 copies/mL), while for the high altitude group (Oyacachi), the mean viral load was 6,394,789 copies/mL (SD = 32,493,469 copies/mL). We found no statistically significant differences when both results were compared (p = 0.056). We found no significant differences across people living at low or high altitude; however, men and younger populations had higher viral load than women older populations, respectively.

Severe acute reentry high altitude pulmonary edema in pediatric patients: report of three cases and literature review.

BACKGROUND: High Altitude Pulmonary Edema (HAPE) is a fatal form of severe high-altitude illness. It is a form of noncardiogenic, noninfectious pulmonary edema secondary to alveolar hypoxia. The exact incidence of HAPE in children is unknown; however, most literature reports an incidence between 0.5-15%. There are three proposed HAPE types including classic HAPE, reentry HAPE, and high-altitude resident pulmonary edema (HARPE). CASE: We present three pediatric patients who were diagnosed with re-entry high altitude pulmonary edema and did not have any underlying cardiac abnormalities. All patients reside in areas of high altitude with a history of travelling to places of lower altitude. They had respiratory infections prior to the manifestation of HAPE. CONCLUSIONS: These are the first reported cases of children with reentry HAPE in Saudi Arabia. Reentry HAPE can occur in otherwise healthy children. Rapid ascent to high altitude and recent respiratory infections are the most commonly reported triggers. Prognosis is very favorable with a very rapid response to oxygen therapy. Education about HAPE is mandatory for families and health care workers working in high altitude areas.

Effect of High Altitude on the Survival of COVID-19 Patients in Intensive Care Unit: A Cohort Study.

Purpose: The effect of high altitude ( ≥ 1500 m) and its potential association with mortality by COVID-19 remains controversial. We assessed the effect of high altitude on the survival/discharge of COVID-19 patients requiring intensive care unit (ICU) admission for mechanical ventilation compared to individuals treated at sea level. Methods: A retrospective cohort multi-center study of consecutive adults patients with a positive RT-PCR test for COVID-19 who were mechanically ventilated between March and November 2020. Data were collected from two sea-level hospitals and four high-altitude hospitals in Ecuador. The primary outcome was ICU and hospital survival/discharge. Survival analysis was conducted using semi-parametric Cox proportional hazards models. Results: Of the study population (n = 670), 35.2% were female with a mean age of 58.3 ± 12.6 years. On admission, high-altitude patients were more likely to be younger (57.2 vs. 60.5 years old), presented with less comorbidities such as hypertension (25.9% vs. 54.9% with p-value <.001) and diabetes mellitus (20.5% vs. 37.2% with p-value <.001), less probability of having a capillary refill time > 3 sec (13.7% vs. 30.1%, p-value <.001), and less severity-of-illness condition (APACHE II score, 17.5 ± 8.1 vs. 20 ± 8.2, p < .01). After adjusting for key confounders high altitude is associated with significant higher probabilities of ICU survival/discharge (HR: 1.74 [95% CI: 1.46-2.08]) and hospital survival/discharge (HR: 1.35 [95% CI: 1.18-1.55]) than patients treated at sea level. Conclusions: Patients treated at high altitude at any time point during the study period were 74% more likely to experience ICU survival/discharge and 35% more likely to experience hospital survival/discharge than to the sea-level group. Possible reasons for these findings are genetic and physiological adaptations due to exposure to chronic hypoxia.

Living at High Altitude and COVID-19 Mortality in Peru.

Nicolaou, Laura, Anne Steinberg, Rodrigo M. Carrillo-Larco, Stella Hartinger, Andres G. Lescano, and William Checkley. Living at high altitude and COVID-19 mortality in Peru. High Alt Med Biol. 23:146-158, 2022. Background: Previous studies have reported a lower severity of COVID-19 infections at higher altitudes; however, this association may be confounded by various factors. We examined the association between living at altitude and COVID-19 mortality in Peru adjusting for population density, prevalence of comorbidities, indicators of socioeconomic status, and health care access. Methods: Utilizing administrative data across 196 provinces located at varying altitudes (sea level to 4,373 m), we conducted a two-stage analysis of COVID-19 deaths between March 19 and December 31, 2020, Peru's first wave. We first calculated cumulative daily mortality rate for each province and fit lognormal cumulative distribution functions to estimate total mortality rate, and start, peak, and duration of the first wave. We then regressed province-level total mortality rate, start, peak, and duration of the first wave as a function of altitude adjusted for confounders. Results: There were 93,528 recorded deaths from COVID-19 (mean age 66.5 years, 64.5% male) for a cumulative mortality of 272.5 per 100,000 population between March 19 and December 31, 2020. We did not find a consistent monotonic trend between living at higher altitudes and estimated total mortality rate for provinces at 500 - 1,000 m (-12.1 deaths per 100,000 population per 100 m, 95% familywise confidence interval -27.7 to 3.5) or > 1,000 m (-0.3, -2.7 to 2.0). We also did not find consistent monotonic trends for the start, peak, and duration of the first wave beyond the first 500 m. Conclusions: Our findings suggest that living at high altitude may not confer a lower risk of death from COVID-19.