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1.
Int J Environ Res Public Health ; 19(22)2022 Nov 08.
Article in English | MEDLINE | ID: covidwho-2110072

ABSTRACT

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.


Subject(s)
Altitude , COVID-19 , Young Adult , Humans , Female , COVID-19/epidemiology , Cross-Sectional Studies , SARS-CoV-2
2.
BMC Public Health ; 22(1): 1962, 2022 10 25.
Article in English | MEDLINE | ID: covidwho-2089184

ABSTRACT

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.


Subject(s)
COVID-19 , Female , Humans , Young Adult , Adult , Male , COVID-19/epidemiology , Pandemics , Cross-Sectional Studies , Prevalence , Peru/epidemiology , Cities , Retrospective Studies , Quality of Life , Altitude , Food Supply , Food Insecurity
3.
Sci Rep ; 12(1): 18048, 2022 Oct 27.
Article in English | MEDLINE | ID: covidwho-2087287

ABSTRACT

The emergence of COVID-19 virus has led to a pandemic with staggering morbidity and mortality. There is evidence showing that pre-existing conditions and environmental factors are associated with worse COVID-19 outcomes. Among these conditions, altitude is of particular interest. Altitude has been shown to influence the morbidity and mortality of multiple chronic pathologies such as cardiovascular disease, chronic obstructive pulmonary disease and lung cancer. COVID-19 fatality rate has been associated with as altitude as well, but findings are disputed. Therefore, we revisit this assessment with a comprehensive analysis of the relationship between COVID-19 fatality rates and altitude for the Mountain region of the United States while considering the effect of additional comorbidities and sociodemographic factors. A Generalized Additive Model (GAM) approach using one year of county data adjusted by population density was performed to evaluate associations within states and for the whole region. Our analysis revealed a consistent effect where COVID-19 case-fatality rate is decreased with higher altitude, even when controlling for pre-existing conditions and certain demographic variables. In summary, the work presented provides evidence that suggests that the protective effects of high altitude are likely to be influenced by physiologic factors but demographic trends that are associated with life at high altitude must also be considered.


Subject(s)
COVID-19 , United States/epidemiology , Humans , Altitude , SARS-CoV-2 , Pandemics , Morbidity
4.
Vaccine ; 40(48): 6987-6997, 2022 Nov 15.
Article in English | MEDLINE | ID: covidwho-2086811

ABSTRACT

Attitudes toward vaccination are doubtless an important determinant of public health, and this became evident after the first year of the last COVID-19 pandemic. The issue, long-debated within European societies, especially with respect to occasional surges of diseases in given years, has become a crucial determinant of the wellbeing of a country since 2021. In this study, using microdata from a 2019 Eurobarometer survey, we frame and deepen our knowledge about the main determinants of vaccination attitudes as observed by the related literature. We argue that a positive attitude toward vaccination may be due to individualistic or altruistic reasons, or various incentives; our analysis aims to improve our knowledge about the determinants of such a complex decision. Our findings, obtained by means of a quantitative analysis that employs Ordered Probit, Ordered Logit and Generalized Ordered Logit estimations, provide complete support for some of the theories that have been debated in the literature, limited support for others because of mixed evidence, and no support for some.


Subject(s)
COVID-19 , Vaccines , Humans , Altitude , Pandemics/prevention & control , COVID-19/prevention & control , Vaccination , Attitude
5.
Sci Rep ; 12(1): 17179, 2022 Oct 13.
Article in English | MEDLINE | ID: covidwho-2062252

ABSTRACT

SARS-CoV-2 has spread throughout the world, including areas located at high or very high altitudes. There is a debate about the role of high altitude hypoxia on viral transmission, incidence, and COVID-19 related mortality. This is the first comparison of SARS-CoV-2 viral load across elevations ranging from 0 to 4300 m. To describe the SARS-CoV-2 viral load across samples coming from 62 cities located at low, moderate, high, and very high altitudes in Ecuador. An observational analysis of viral loads among nasopharyngeal swap samples coming from a cohort of 4929 patients with a RT-qPCR test positive for SARS-CoV-2. The relationship between high and low altitude only considering our sample of 4929 persons is equal in both cases and not significative (p-value 0.19). In the case of low altitude, adding the sex variable to the analysis, it was possible to find a significative difference between men and women (p-value < 0.05). Considering initially sex and then altitude, it was possible to find a significative difference between high and low altitude for men (p-value 0.05). There is not enough evidence to state that viral load is affected directly by altitude range but adding a new variable as sex in the analysis shows that the presence of new variables influences the relationship of altitude range and viral load. There is no evidence that viral loads (Ct and copies/ml) differ at low or high altitude. Using sex as a co-factor, we found that men have higher viral loads than women at low and moderate altitude locations, while living at high altitude, no differences were found. When Ct values were aggregated by low, moderate, and high viral load, we found no significant differences when sex was excluded from the analysis. We conclude that viral load is not directly affected by altitude, but COVID-19 incidence and mortality are rather affected by socio-demographic and idiosyncratic dynamics.


Subject(s)
COVID-19 , SARS-CoV-2 , Altitude , Female , Humans , Male , Nasopharynx , Viral Load
6.
High Alt Med Biol ; 23(3): 286-290, 2022 09.
Article in English | MEDLINE | ID: covidwho-2028990

ABSTRACT

Vizcarra-Vizcarra, Cristhian A., Eduardo Chávez-Velázquez, Carmen Asato-Higa, and Abdías Hurtado-Aréstegui. Treatment of focal and segmental glomerulosclerosis secondary to high altitude polycythemia with acetazolamide. High Alt Med Biol. 23:286-290, 2022.-Focal segmental glomerulosclerosis (FSGS) is a morphological pattern, caused by glomerular injury and is the leading cause of nephrotic syndrome in adults. We present the case of a 59-year-old female patient, resident of a high-altitude city (3,824 m), who had polycythemia and nephrotic syndrome. A renal biopsy was performed, and the findings were compatible with FSGS. The patient received phlebotomy 500 ml three times, which reduced, partially, the hemoglobin concentration. However, she had refractory proteinuria, despite the use of enalapril and spironolactone. We observed that proteinuria worsened with the increase in hemoglobin levels. So, she was treated with acetazolamide 250 mg bid for 4 months, which reduced proteinuria and hemoglobin. During the coronavirus disease 2019 (COVID-19) pandemic, the patient did not take acetazolamide and again, she had an increase in hemoglobin and proteinuria levels. We conclude that acetazolamide may be an effective treatment in FSGS due to high altitude polycythemia.


Subject(s)
Altitude Sickness , COVID-19 , Glomerulosclerosis, Focal Segmental , Nephrotic Syndrome , Polycythemia , Acetazolamide/therapeutic use , Adult , Altitude , Altitude Sickness/complications , Altitude Sickness/drug therapy , Female , Glomerulosclerosis, Focal Segmental/complications , Glomerulosclerosis, Focal Segmental/etiology , Humans , Middle Aged , Nephrotic Syndrome/complications , Nephrotic Syndrome/pathology , Polycythemia/complications , Polycythemia/etiology , Proteinuria/etiology
7.
Eur J Appl Physiol ; 122(12): 2565-2574, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2007145

ABSTRACT

PURPOSE: With few cycling races on the calendar in 2020 due to COVID-19, Everesting became a popular challenge: you select one hill and cycle up and down it until you reach the accumulated elevation of Mt. Everest (8,848 m or 29,029ft). With an almost infinite number of different hills across the world, the question arises what the optimal hill for Everesting would be. Here, we address the biomechanics and energetics of up- and downhill cycling to determine the characteristics of this optimal hill. METHODS: During uphill cycling, the mechanical power output equals the power necessary to overcome air resistance, rolling resistance, and work against gravity, and for a fast Everesting time, one should maximize this latter term. To determine the optimal section length (i.e., number of repetitions), we applied the critical power concept and assumed that the U-turn associated with an additional repetition comes with a 6 s time penalty. RESULTS: To use most mechanical power to overcoming gravity, slopes of at least 12% are most suitable, especially since gross efficiency seems only minimally diminished on steeper slopes. Next, we found 24 repetitions to be optimal, yet this number slightly depends on the assumptions made. Finally, we discuss other factors (fueling, altitude, fatigue) not incorporated in the model but also affecting Everesting performances. CONCLUSION: For a fast Everesting time, our model suggests to select a hill climb which preferably starts at (or close to) sea level, with a slope of 12-20% and length of 2-3 km.


Subject(s)
COVID-19 , Humans , Bicycling , Biomechanical Phenomena , Altitude , Gravitation
8.
Int J Environ Res Public Health ; 19(13)2022 06 28.
Article in English | MEDLINE | ID: covidwho-1911387

ABSTRACT

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.


Subject(s)
COVID-19 , SARS-CoV-2 , Altitude , COVID-19/epidemiology , Cross-Sectional Studies , Ecuador/epidemiology , Female , Humans , Male , Viral Load
9.
PLoS One ; 17(3): e0262423, 2022.
Article in English | MEDLINE | ID: covidwho-1910489

ABSTRACT

BACKGROUND: Multiple studies have attempted to elucidate the relationship between chronic hypoxia and SARS-CoV-2 infection. It seems that high-altitude is associated with lower COVID-19 related mortality and incidence rates; nevertheless, all the data came from observational studies, being this the first one looking into prospectively collected clinical data from severely ill patients residing at two significantly different altitudes. METHODS: A prospective cohort, a two-center study among COVID-19 confirmed adult patients admitted to a low (sea level) and high-altitude (2,850 m) ICU unit in Ecuador was conducted. Two hundred and thirty confirmed patients were enrolled from March 15th to July 15th, 2020. RESULTS: From 230 patients, 149 were men (64.8%) and 81 women (35.2%). The median age of all the patients was 60 years, and at least 105 (45.7%) of patients had at least one underlying comorbidity, including hypertension (33.5%), diabetes (16.5%), and chronic kidney failure (5.7%). The APACHE II scale (Score that estimates ICU mortality) at 72 hours was especially higher in the low altitude group with a median of 18 points (IQR: 9.5-24.0), compared to 9 points (IQR: 5.0-22.0) obtained in the high-altitude group. There is evidence of a difference in survival in favor of the high-altitude group (p = 0.006), the median survival being 39 days, compared to 21 days in the low altitude group. CONCLUSION: There has been a substantial improvement in survival amongst people admitted to the high-altitude ICU. Residing at high-altitudes was associated with improved survival, especially among patients with no comorbidities. COVID-19 patients admitted to the high-altitude ICU unit have improved severity-of-disease classification system scores at 72 hours.


Subject(s)
COVID-19 , Adult , Altitude , Critical Illness , Female , Humans , Intensive Care Units , Male , Middle Aged , Prospective Studies , SARS-CoV-2
10.
J Transl Med ; 20(1): 242, 2022 05 26.
Article in English | MEDLINE | ID: covidwho-1902393

Subject(s)
Oxygen , Water , Altitude , Electrolysis
11.
Int J Health Serv ; 52(4): 455-469, 2022 10.
Article in English | MEDLINE | ID: covidwho-1879174

ABSTRACT

In this paper, we study the incidence of COVID-19 and the associated fatality with altitude using high frequency, district level data from India. To understand the implications of the nationwide lockdown after the outbreak, we use data for about four months- two from the lockdown period starting from March 25 till May 31, 2020 and about two months after unlocking was initiated (June 1-July 26, 2020). The multivariate regression result indicates slower growth in average rate of infection during the lockdown period in hilly regions, the gains of which attenuated after the unlocking was initiated. Despite these early gains, the rate of fatalities is significantly higher during the lockdown period in comparison to the plains. The findings remain robust to multiple alternative specifications and methods including one that accounts for confounding possibilities via unobservable and provides consistent estimates of bias adjusted treatment effects. The evidence supports the need for provisioning of public health services and infrastructure upgradation, especially maintenance of adequate stock of life support devices, in high altitude regions. It also underscores the necessity for strengthening and revising the existing Hill Areas Development Programme and integrating important aspects of public health as part of this policy.


Subject(s)
COVID-19 , Altitude , COVID-19/epidemiology , Communicable Disease Control , Humans , India/epidemiology , Policy , SARS-CoV-2
12.
Turk J Pediatr ; 64(2): 400-407, 2022.
Article in English | MEDLINE | ID: covidwho-1876416

ABSTRACT

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.


Subject(s)
Altitude Sickness , Pulmonary Edema , Respiratory Tract Infections , Altitude , Altitude Sickness/complications , Altitude Sickness/diagnosis , Child , Humans , Hypertension, Pulmonary , Hypoxia/complications , Pulmonary Edema/etiology , Respiratory Tract Infections/complications
13.
J Intensive Care Med ; 37(9): 1265-1273, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-1833014

ABSTRACT

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.


Subject(s)
COVID-19 , Adult , Aged , Altitude , Cohort Studies , Female , Hospital Mortality , Humans , Intensive Care Units , Male , Middle Aged , Respiration, Artificial , Retrospective Studies
15.
High Alt Med Biol ; 23(2): 146-158, 2022 06.
Article in English | MEDLINE | ID: covidwho-1815934

ABSTRACT

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.


Subject(s)
Altitude , COVID-19 , Aged , Female , Humans , Male , Peru/epidemiology , Prevalence
16.
Genes (Basel) ; 13(4)2022 03 24.
Article in English | MEDLINE | ID: covidwho-1809805

ABSTRACT

Although high altitude training has been increasingly popular among endurance athletes, the molecular and cellular bases of this adaptation remain poorly understood. We aimed to define the underlying physiological changes and screen for potential biomarkers of adaptation using transcriptional profiling of whole blood. Seven elite female speed skaters were profiled on the 18th day of high-altitude adaptation. Whole blood RNA-seq before and after an intense 1 h skating bout was used to measure gene expression changes associated with exercise. In order to identify the genes specifically regulated at high altitudes, we have leveraged the data from eight previously published microarray datasets studying blood expression changes after exercise at sea level. Using cell type-specific signatures, we were able to deconvolute changes of cell type abundance from individual gene expression changes. Among these were PHOSPHO1, with a known role in erythropoiesis, and MARC1 with a role in endogenic NO metabolism. We find that platelet and erythrocyte counts uniquely respond to altitude exercise, while changes in neutrophils represent a more generic marker of intense exercise. Publicly available data from both single cell atlases and exercise-related blood profiling dramatically increases the value of whole blood RNA-seq for the dynamic evaluation of physiological changes in an athlete's body.


Subject(s)
Altitude , Exercise , Acclimatization , Athletes , Exercise/physiology , Female , Humans , Sequence Analysis, RNA
17.
Environ Res ; 212(Pt B): 113214, 2022 09.
Article in English | MEDLINE | ID: covidwho-1778116

ABSTRACT

Existing studies reported higher altitudes reduce the COVID-19 infection rate in the United States, Colombia, and Peru. However, the underlying reasons for this phenomenon remain unclear. In this study, regression analysis and mediating effect model were used in a combination to explore the altitudes relation with the pattern of transmission under their correlation factors. The preliminary linear regression analysis indicated a negative correlation between altitudes and COVID-19 infection in China. In contrast to environmental factors from low-altitude regions (<1500 m), high-altitude regions (>1500 m) exhibited lower PM2.5, average temperature (AT), and mobility, accompanied by high SO2 and absolute humidity (AH). Non-linear regression analysis further revealed that COVID-19 confirmed cases had a positive correlation with mobility, AH, and AT, whereas negatively correlated with SO2, CO, and DTR. Subsequent mediating effect model with altitude-correlated factors, such as mobility, AT, AH, DTR and SO2, suffice to discriminate the COVID-19 infection rate between low- and high-altitude regions. The mentioned evidence advance our understanding of the altitude-mediated COVID-19 transmission mechanism.


Subject(s)
COVID-19 , Altitude , COVID-19/epidemiology , China/epidemiology , Colombia , Humans , Meteorological Concepts , Meteorology
19.
Respir Physiol Neurobiol ; 299: 103868, 2022 05.
Article in English | MEDLINE | ID: covidwho-1671098

ABSTRACT

Patients admitted to the Intensive Care Unit (ICU) with acute hypoxemic respiratory failure automatically receive oxygen therapy to improve inspiratory oxygen fraction (FiO2). Supplemental oxygen is the most prescribed drug for critically ill patients regardless of altitude of residence. In high altitude dwellers (i.e. in La Paz [≈3,400 m] and El Alto [≈4,150 m] in Bolivia), a peripheral oxygen saturation (SatpO2) of 89-95% and an arterial partial pressure of oxygen (PaO2) of 50-67 mmHg (lower as altitude rises), are considered normal values ​​for arterial blood. Consequently, it has been suggested that limiting oxygen therapy to maintain SatpO2 around normoxia may help avoid episodes of hypoxemia, hyperoxemia, intermittent hypoxemia, and ultimately, mortality. In this study, we evaluated the impact of oxygen therapy on the mortality of critically ill COVID-19 patients who permanently live at high altitudes. A multicenter cross-sectional descriptive observational study was performed on 100 patients admitted to the ICU at the "Clinica Los Andes" (in La Paz city) and "Agramont" and "Del Norte" Hospitals (in El Alto city). Our results show that: 1) as expected, fatal cases were detected only in patients who required intubation and connection to invasive mechanical ventilation as a last resort to overcome their life-threatening desaturation; 2) among intubated patients, prolonged periods in normoxia are associated with survival, prolonged periods in hypoxemia are associated with death, and time spent in hyperoxemia shows no association with survival or mortality; 3) the oxygenation limits required to effectively support the intubated patients' survival in the ICU are between 89% and 93%; 4) among intubated patients with similar periods of normoxemic oxygenation, those with better SOFA scores survive; and 5) a lower frequency of observable reoxygenation events is not associated with survival. In conclusion, our findings indicate that high-altitude patients entering an ICU at altitudes of 3,400 - 4,150 m should undergo oxygen therapy to maintain oxygenation levels between 89 and 93 %.


Subject(s)
COVID-19/physiopathology , COVID-19/therapy , Critical Care/standards , Oxygen Inhalation Therapy/standards , /physiology , Adult , Aged , Altitude , Bolivia , Critical Care/methods , Critical Illness , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Oxygen Inhalation Therapy/methods
20.
Nature ; 601(7893): 380-387, 2022 01.
Article in English | MEDLINE | ID: covidwho-1631307

ABSTRACT

Nitrogen dioxide (NO2) is an important contributor to air pollution and can adversely affect human health1-9. A decrease in NO2 concentrations has been reported as a result of lockdown measures to reduce the spread of COVID-1910-20. Questions remain, however, regarding the relationship of satellite-derived atmospheric column NO2 data with health-relevant ambient ground-level concentrations, and the representativeness of limited ground-based monitoring data for global assessment. Here we derive spatially resolved, global ground-level NO2 concentrations from NO2 column densities observed by the TROPOMI satellite instrument at sufficiently fine resolution (approximately one kilometre) to allow assessment of individual cities during COVID-19 lockdowns in 2020 compared to 2019. We apply these estimates to quantify NO2 changes in more than 200 cities, including 65 cities without available ground monitoring, largely in lower-income regions. Mean country-level population-weighted NO2 concentrations are 29% ± 3% lower in countries with strict lockdown conditions than in those without. Relative to long-term trends, NO2 decreases during COVID-19 lockdowns exceed recent Ozone Monitoring Instrument (OMI)-derived year-to-year decreases from emission controls, comparable to 15 ± 4 years of reductions globally. Our case studies indicate that the sensitivity of NO2 to lockdowns varies by country and emissions sector, demonstrating the critical need for spatially resolved observational information provided by these satellite-derived surface concentration estimates.


Subject(s)
Atmosphere/chemistry , COVID-19/epidemiology , COVID-19/prevention & control , Communicable Disease Control/statistics & numerical data , Environmental Indicators , Nitrogen Dioxide/analysis , Altitude , Humans , Ozone/analysis , Quarantine/statistics & numerical data , Satellite Imagery , Time Factors
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