Extended longevity at high altitude: Benefits of exposure to chronic hypoxia

BACKGROUND: Acute exposure to hypobaric hypoxia can give rise to acute mountain sickness, and rarely, high altitude pulmonary edema, and high altitude cerebral edema. However, with gradual adaptation to “chronic hypoxia”, following the Adaptation to High Altitude Formula (Adaptation = time / altitudeΔ), the organism does remarkably well. High altitude residents are perfectly adapted to their environment. The cities of La Paz (3100–4100 m) and El Alto (4100 m) stand as living proof of this with 2.7 million inhabitants living perfectly normal lives, undisturbed by hypoxia and most even unaware of its existence. All the cells of the organism adapt to a lower arterial oxygen arterial partial pressure (PaO2) and likewise to a lower arterial partial pressure of carbon dioxide (PaCO2), an essential component that linked to an increased compensatory hemoglobin explain the paradox of increased “tolerance to hypoxia” at high altitude. METHODS: We reviewed the > 70 years old population historic records of the official Bolivian registration service SEGIP. Two groups were analyzed: those greater than 90 years of age, and those greater than 100 years of age according to the different altitude departments in Bolivia. RESULTS: As the altitude increases, the longevity increases. Santa Cruz at 416m and La Paz at 3800m (average), both with around 2.7 million inhabitants each, have 6 versus 48 centenarians respectively. CONCLUSIONS: Life under chronic hypoxia is not only tolerable, but also is, in fact, favorable to improve or treat many pathological conditions such as asthma, coronary artery disease, obesity and even giving rise to improved longevity. Sea level residents (when compared to high altitude residents) suffer a disability: poor tolerance to hypoxia

Understanding the pathophysiology of typical acute respiratory distress syndrome and severe COVID-19

reserved7Introduction: : Typical acute respiratory distress syndrome (ARDS) and severe coronavirus-19 (COVID-19) pneumonia share complex pathophysiology, a high mortality rate, and an unmet need for efficient therapeutics. Areas covered: : This review discusses the current advances in understanding the pathophysiologic mechanisms underlying typical ARDS and severe COVID-19 pneumonia, highlighting specific aspects of COVID-19-related acute hypoxemic respiratory failure that require attention. Two models have been proposed to describe the mechanisms of respiratory failure associated with typical ARDS and severe COVID-19 pneumonia. Expert opinion: : ARDS is defined as a syndrome rather than a distinct pathologic entity. There is great heterogeneity regarding the pathophysiologic, clinical, radiologic, and biological phenotypes in patients with ARDS, challenging clinicians, and scientists to discover new therapies. COVID-19 has been described as a cause of pulmonary ARDS and has reopened many questions regarding the pathophysiology of ARDS itself. COVID-19 lung injury involves direct viral epithelial cell damage and thrombotic and inflammatory reactions. There are some differences between ARDS and COVID-19 lung injury in aspects of aeration distribution, perfusion, and pulmonary vascular responses.mixedBall, Lorenzo; Silva, Pedro Leme; Giacobbe, Daniele Roberto; Bassetti, Matteo; Zubieta-Calleja, Gustavo R; Rocco, Patricia R M; Pelosi, PaoloBall, Lorenzo; Silva, Pedro Leme; Giacobbe, Daniele Roberto; Bassetti, Matteo; Zubieta-Calleja, Gustavo R; Rocco, Patricia R M; Pelosi, Paol

Coping with hypoxemia: Could erythropoietin (EPO) be an adjuvant treatment of COVID-19?

A very recent epidemiological study provides preliminary evidence that living in habitats located at 2500 m above sea level (masl) might protect from the development of severe respiratory symptoms following infection with the novel SARS-CoV-2 virus. This epidemiological finding raises the question of whether physiological mechanisms underlying the acclimatization to high altitude identifies therapeutic targets for the effective treatment of severe acute respiratory syndrome pivotal to the reduction of global mortality during the COVID-19 pandemic. This article compares the symptoms of acute mountain sickness (AMS) with those of SARS-CoV-2 infection and explores overlapping patho-physiological mechanisms of the respiratory system including impaired oxygen transport, pulmonary gas exchange and brainstem circuits controlling respiration. In this context, we also discuss the potential impact of SARS-CoV-2 infection on oxygen sensing in the carotid body. Finally, since erythropoietin (EPO) is an effective prophylactic treatment for AMS, this article reviews the potential benefits of implementing FDA-approved erythropoietin-based (EPO) drug therapies to counteract a variety of acute respiratory and non-respiratory (e.g. excessive inflammation of vascular beds) symptoms of SARS-CoV-2 infection