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Review
. 2021 Apr;48(4):3863-3869.
doi: 10.1007/s11033-021-06358-1. Epub 2021 Apr 23.

Silent hypoxia in COVID-19: pathomechanism and possible management strategy

Ahsab Rahman  1 , Tahani Tabassum  1 , Yusha Araf  2 , Abdullah Al Nahid  3 , Md Asad Ullah  4 , Mohammad Jakir Hosen  5
Affiliations
Review

Silent hypoxia in COVID-19: pathomechanism and possible management strategy

Ahsab Rahman et al. Mol Biol Rep. 2021 Apr.

Abstract

The novel coronavirus disease 2019 (COVID-19) has become a severe health issue, especially to the patients who develop silent hypoxia condition after SARS-CoV-2 infection. Due to the lack of dyspnoea and extremely low oxygen saturation level, these patients are at exceptionally higher risk. Although the prevalence of silent hypoxia in COVID-19 patients has been evident in several cases, the underlying pathomechanism behind this condition is still unclear. Silent hypoxia in SARS-CoV-2 infected patients can be diagnosed with the help of a pulse oximeter, blood gas levels, and a 6-min walking test. While the clinicians and researchers figure out the exact reason for this phenomenon, the patients must be under strict day-to-day monitoring. In this article, we aim to provide comprehensive insights into the underlying symptoms, mechanism, and possible factors behind the occurrence of silent hypoxia among COVID-19 patients.

Keywords: COVID-19; Dyspnoea; Management; Pathomechanism; Silent hypoxia.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Fig. 1
Fig. 1
Hypoxia Inducing Factor 1α is the prime mediator of hypoxia in cells. The factor under normal hypoxic conditions is degraded by the proteasome, therefore, the cell does not experience hypoxic symptoms. However, the factor can have several impacts on the hypoxic condition. HIF-1α moves inside the nucleus and drives the transcription of HRE genes, which results in several hypoxic symptoms. Besides, it may also drive the transcription of several inflammatory genes through NF-kB activation. NF-kB transcription factor activation has also been associated with increased serum ferritin accumulation. Moreover, HIF-1α may increase the expression of the ACE-2 receptor on cells, suggesting an enhanced risk of COVID-19 infestation
Fig. 2
Fig. 2
Possible silent hypoxia associated factors involved in COVID-19. Silent Hypoxia has been associated with several COVID-19 related symptoms. The condition can result in overexpression of ACE-2 receptors thereby increasing the risk of damage through COVID-19 infection. Besides, the condition can further contribute to the mechanism of “cytokine storm” by recruiting different mediators of inflammation. Moreover, silent hypoxia can cause serious endothelial damage through NF-kB transcription factor activation. Silent hypoxia can also signal a different immune-metabolism pathway and cause secondary organ damage. All these factors lead to the critical condition of patients along with an increased mortality rate among COVID-19 patients
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References

    1. Coronavirus disease (COVID-19)—World Health Organization [Internet]. Who.int. 2020 [cited 2 September 2020]. Available from: https://www.who.int/emergencies/diseases/novel-coronavirus 2019
    1. Coronavirus Update (Live): 133,450,721 Cases and 2,892,333 Deaths from COVID-19 Virus Pandemic—Worldometer [Internet]. Worldometers.info. 2021 [cited 7 April 2021]. Available from: https://www.worldometers.info/coronavirus/
    1. Rothan H, Byrareddy S. The epidemiology and pathogenesis of coronavirus disease(COVID-19) outbreak. J Autoimmun. 2020;109:102433. doi: 10.1016/j.jaut.2020.102433. - DOI - PMC - PubMed
    1. Lu R, Zhao X, Li J, Niu P, Yang B, Wu H, et al. Genomic characterization and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding. The Lancet. 2020;395(10224):565–574. doi: 10.1016/S0140-6736(20)30251-8. - DOI - PMC - PubMed
    1. Zou X, Chen K, Zou J, Han P, Hao J, Han Z. Single-cell RNA-seq data analysis on the receptor ACE2 expression reveals the potential risk of different human organs vulnerable to 2019-nCoV infection. Frontiers of Medicine. 2020;14(2):185–192. doi: 10.1007/s11684-020-0754-0. - DOI - PMC - PubMed

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