Silent Hypoxia in Coronavirus disease-2019: Is it more dangerous? -A retrospective cohort study

  1. Prashant Sirohiya
  2. Arunmozhimaran Elavarasi
  3. Hari Krishna Raju Sagiraju
  4. Madhusmita Baruah
  5. Nishkarsh Gupta
  6. Rohit Kumar Garg
  7. Saurav Sekhar Paul
  8. Brajesh Kumar Ratre
  9. Ram Singh
  10. Balbir Kumar
  11. Saurabh Vig
  12. Anuja Pandit
  13. Abhishek Kumar
  14. Rakesh Garg
  15. Ved Prakash Meena
  16. Saurabh Mittal
  17. Saurabh Pahuja
  18. Nupur Das
  19. Tanima Dwivedi
  20. Ritu Gupta
  21. Sunil Kumar
  22. Manisha Pandey
  23. Abhinav Mishra
  24. Karanvir Singh Matharoo
  25. Anant Mohan
  26. Randeep Guleria
  27. Sushma Bhatnagar

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Abstract

Hypoxia in patients with COVID-19 is one of the strongest predictors of mortality. Silent hypoxia is characterised by the presence of hypoxia without dyspnoea. Silent hypoxia has been shown to affect the outcome in previous studies.

Methods:

This was a retrospective study of a cohort of patients with SARS-CoV-2 infection who were hypoxic at presentation. Clinical, laboratory and treatment parameters in patients with silent hypoxia and dyspnoeic hypoxia were compared. Multivariate logistic regression models were fitted to identify the factors predicting mortality.

Results:

Among 2080 patients with COVID-19 admitted to our hospital, 811 patients were hypoxic with SpO 2 <94% at the time of presentation. Among them, 174 (21.45%) did not have dyspnoea since the onset of COVID-19 symptoms. Further, 5.2% of patients were completely asymptomatic for COVID-19 and were found to be hypoxic only on pulse oximetry. The case fatality rate in patients with silent hypoxia was 45.4% as compared to 40.03% in dyspnoeic hypoxic patients ( P = 0.202). The odds ratio of death was 1.1 (95% CI: 0.41–2.97) in the patients with silent hypoxia after adjusting for baseline characteristics, laboratory parameters, treatment and in-hospital complications, which did not reach statistical significance ( P = 0.851).

Conclusion:

Silent hypoxia may be the only presenting feature of COVID-19. As the case fatality rate is comparable between silent and dyspnoeic hypoxia, it should be recognised early and treated as aggressively. Because home isolation is recommended in patients with COVID-19, it is essential to use pulse oximetry in the home setting to identify these patients.

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  1. Version published to 10.4103/lungindia.lungindia_601_21
  2. ScreenIT

    SciScore for 10.1101/2021.08.26.21262668: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: The study was approved by the Institutional Ethics Committee of the Institution.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    No key resources detected.

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    The major limitation of the present study is its retrospective nature. Some parameters were missing in the collected data. We have excluded those parameters from our study analysis. We retrospectively obtained pulse oximetry and breathlessness data that is subject to bias. Our findings, however, may be useful for understanding more about silent hypoxia.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  3. Version published to 10.1101/2021.08.26.21262668v1 on medRxiv