Fulminant Onset COVID – Predictors and Outcome

Background: During COVID-19 infection, organ dysfunction like respiratory failure tends to occur towards the second week of illness, however in a subset, there may be rapid onset of organ dysfunction as early as symptom onset. We define fulminant onset COVID as rapid onset of organ dysfunction like acute respiratory failure, acute kidney injury, acute encephalopathy or shock within four days of symptom onset.&nbsp; Fulminant onset COVID is yet to be systematically studied. We aimed to identify predictors and prognosis of fulminant onset COVID.<br><br>Methods: This retrospective cohort study was carried out on patients admitted to a referral hospital in South-India between June-2020 and January-2022. &nbsp;Patients were categorised into fulminant and non-fulminant onset COVID. Candidate predictors for fulminant onset were chosen by an intuitive approach and analysed using logistic regression. Then, the outcome of fulminant onset COVID at 30-days was studied.<br><br>Findings: Out of 2016 patients with confirmed COVID-19, 653 (32.4%) had fulminant onset COVID. Age &gt; 60-years (a-OR 1.57, 95% CI 1.30-1.90, p &lt; 0.001), hypertension (a-OR 1.29, 95% CI 1.03-1.61, p = 0.03), and immune-suppressed state (a-OR 5.62, 95% CI 1.7-18.7, p = 0.005) were significant predictors of fulminant onset COVID. Complete vaccination lowered the odds of fulminant onset COVID significantly (a-OR 0.61, 95% CI 0.43-0.85, p = 0.004).&nbsp;<br><br>The fulminant onset COVID group had worse outcomes at 30-days compared to non-fulminant onset group with a c-OR of 3.60 (95% CI 2.63 – 4.92, p &lt; 0.001) for mortality, 2.68 (95% CI 1.84 – 3.91, p &lt; 0.001) for acute respiratory distress syndrome, 2.88 (95% CI 1.80 – 4.60, p &lt; 0.001) for invasive mechanical ventilation, 4.58 (95% CI 2.22 – 9.46, p &lt; 0.001) for renal replacement therapy.<br><br>Interpretation: Fulminant onset COVID is common, carries poor prognosis and deserves recognition as a distinct phenotype of COVID-19.<br><br>Funding Information: No funding was received for the conduct of this study from any source.<br> <br>Declaration of Interests: We declare no competing interests.<br><br>Ethics Approval Statement: This study was approved by the Institutional research board and conforms to the ethical mandates of Declaration of Helsinki.<br>