Effects of COVID-19 variation on the treatment response and disease severity in critical illness: a retrospective observational cohort study

Eur Rev Med Pharmacol Sci. 2022 Apr;26(7):2602-2609. doi: 10.26355/eurrev_202204_28498.


Objective: Even though the treatment of the original variant was not fully determined, variants of COVID-19 emerged. Whether the clinic of COVID-19 has changed because of variation is controversial. The present study aimed to examine the COVID-19 severity and treatment responsiveness of critically ill patients between the original virus and emergent variations with a more comprehensive set of measures.

Patients and methods: Treatment responses, laboratory findings, and clinical conditions of critically ill patients with COVID-19 who were identified with variants between February 1st, and May 30th, 2021, were examined in two medical Intensive Care Units (ICUs) in tertiary care centers. Each patient received treatment in the ICU for at least one week.

Results: Sixty-five (30 patients with the original variant: POV) critically ill patients were included in the study. SOFA scores, blood glucose, total bilirubin, urea-creatinine and lactate dehydrogenase levels decreased significantly in POV (p=.031, p=.002, p=.002, p=.008, and p=.007, respectively). Overall, patients with emergent variants (PEV) (M = 76.58, SD = 8.64) had lower partial-pressure-of-oxygen/fraction-of-inspired-oxygen ratios (P/F) than POV (M = 123.16, SD = 9.49). Use of the prone position and steroid therapy did not result in significant improvements in oxygenation of critically ill PEV. Hypertension was identified as the common comorbidity in PEV (OR=5.287).

Conclusions: We showed that the state of PEV was more severe than POV at the time of ICU admission. However, the prone position and steroids were not efficient in improving the P/F ratios. P/F ratios of PEV were significantly lower in non-invasive ventilation. These results suggest that early intubation might be necessary for PEV.

Publication types

  • Observational Study

MeSH terms

  • COVID-19* / therapy
  • Critical Illness* / therapy
  • Humans
  • Intensive Care Units
  • Oxygen
  • Respiration, Artificial
  • Retrospective Studies
  • SARS-CoV-2
  • Severity of Illness Index


  • Oxygen