Once patients are markedly improving and fit to be discharged from tertiary care, what is the risk that they will deteriorate again and need to be readmitted? 

Posted on April 20, 2020 by Tomas Rapaport


A brief review of the literature on PubMed and reputable online databases did no yield any specific quantitative risks of acute deterioration in patients who are clearly improving in their disease course, and there were no identified reports of patients having secondary bouts of the illness once clearly improving (resolution of fever, improvement of respiratory symptoms).  Sources simply state that discharge should be done when clinically indicated.

I.   Typically Clinical Progression of Severe COVID-19 as per the US CDC (1)

  • Dyspnea 5-8 days post symptom onset
  • ARDS 8-12 days post symptom onset (~15% of all hospitalized patients [2]) with risk greatest in ICU 
  • ICU admission 10-12 days post symptom onset for 26%-32% of patients -> mortality among these patients is 39%-72%
  • Median length of hospitalization 10-13 days among survivors
  • There are NO data on the possibility of re-infection at this time, and we know that viral shedding may continue for days to weeks post resolution of symptoms
  • Clinical recovery has been correlated with detection of IgM and IgG antibodies
  • Discharge should be considered as clinically indicated
  • There is no direct mention of a biphasic or second reaction in the US CDC reviews, or in other identified primary literature (3,4,5)

II.   Risk Factors to consider when assessing disease course

While general Risk Factors (age, chronic lung disease, DM, etc)  for poorer outcomes with COVID-19 are becoming more well known, we don’t enough at this time to determine the specific risk for each underlying risk factor (6) 

III.   Classification of COVID-19 Disease States by Siddiqi and Mehra has been widely cited and serves as a different way of determining disease course [Figure 1] (7)

  • There are two overlapping subsets of the disease, the first triggered by the virus itself and the second triggered by the host response 
  • These lead to 3 distinct stages of the disease
    • Stage I (mild) – incubation period and beginning of non-specific symptoms
      • Chest imaging begins to show infiltrates, CBC may show lymphopenia and neutrophilia without other significant abnormalities
      • Excellent prognosis
    • Stage II (moderate) – Pulmonary involvement without hypoxia (IIa) and with hypoxia (IIb)
      • viral multiplication and lung inflammation, pneumonia, cough, fever, hypoxia
      • CBC shows increasing lymphopenia and transaminitis, possibly elevated markers of systemic inflammation
      • Most patients need to be hospitalized for close observation
    • Stage III (severe) – Systemic Hyperinflammation
      • Extrapulmonary hyperinflammation, decreased helper and suppressor T cells, cytokines elevated, D-dimer, CRP, ferritin elevated
      • Poor prognosis
    • There is no discussion on clinical timeline or any biphasic or resurgence after a period of convalescence


Figure 1 from Siddiqi et al, 2020 

Questions? Comments? Does this need to be updated? Do you have valuable points to add ? Please email ask.reakt@ubc.ca.


  1. CDC. Management of Patients with Confirmed 2019-nCoV [Internet]. Centers for Disease Control and Prevention. 2020 [cited 2020 Apr 20]. Available from: https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html
  2. Loeb M, Alhazzani W, Jaeschke R, Rymer W, Wrocynska A. Coronavirus Disease 2019 (COVID-19) [Internet]. Empendium.com. McMaster Textbook of Internal Medicine; 2019 [cited 2020 Apr 20]. Available from: https://empendium.com/mcmtextbook/chapter/B31.II.18.1.12?fbclid=IwAR2o_JowDaGjnCvF4kzt2GEeJDI4ydBZtYE-zbhaI8_8z-qd4VS9-CNzm38
  3. Bhatraju PK, Ghassemieh BJ, Nichols M, Kim R, Jerome KR, Nalla AK, et al. Covid-19 in Critically Ill Patients in the Seattle Region — Case Series. New England Journal of Medicine [Internet]. 2020 Mar 30 [cited 2020 Apr 21]; Available from: https://www-nejm-org.ezproxy.library.ubc.ca/doi/10.1056/NEJMoa2004500
  4. Wang D, Hu B, Hu C, Zhu F, Liu X, Zhang J, et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus–Infected Pneumonia in Wuhan, China. JAMA [Internet]. 2020 Mar 17 [cited 2020 Apr 21];323(11):1061. Available from: https://jamanetwork.com/journals/jama/fullarticle/2761044
  5. Lescure F-X, Bouadma L, Nguyen D, Parisey M, Wicky P-H, Behillil S, et al. Clinical and virological data of the first cases of COVID-19 in Europe: a case series. The Lancet Infectious Diseases [Internet]. 2020 Mar [cited 2020 Apr 21]; Available from: https://www.sciencedirect.com/science/article/pii/S1473309920302000
  6. CDC. Clinical Questions about COVID-19: Questions and Answers [Internet]. Centers for Disease Control and Prevention. 2020 [cited 2020 Apr 20]. Available from: https://www.cdc.gov/coronavirus/2019-ncov/hcp/faq.html
  7. Siddiqi HK, Mehra MR. COVID-19 Illness in Native and Immunosuppressed States: A Clinical-Therapeutic Staging Proposal. The Journal of Heart and Lung Transplantation [Internet]. 2020 Mar [cited 2020 Mar 26]; Available from: https://els-jbs-prod-cdn.literatumonline.com/pb/assets/raw/Health%20Advance/journals/healun/Article_2-1584647583070.pdf


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