Delayed inflammatory pulmonary syndrome: A distinct clinical entity in the spectrum of inflammatory syndromes in COVID-19 infection?

Figure 1 Sequential Organ Failure Assessment score representing degree of organ involvement in Delayed Inflammatory Pulmonary Syndrome. The contribution of respiratory Sequential Organ Failure Assessment (SOFA) to the overall SOFA score is depicted for all the five patients. It is evident that in all patients, respiratory SOFA contributed to > 50% of the total SOFA score. In two patients, there was no extrapulmonary organ dysfunction, while in the remaining three patients, there was some hepatic, renal and cardiovascular dysfunction. DIPS: Delayed Inflammatory Pulmonary Syndrome; SOFA: Sequential Organ Failure Assessment.

Figure 2 Representative Cross sectional computed tomography and plain radiograph images of patients with Delayed Inflammatory Pulmonary Syndrome. A: High resolution transverse computed tomography (CT) sections of patient 4, showing the evolution of infiltrates from day -2 of Delayed Inflammatory Pulmonary Syndrome (DIPS) (A1) till day +15 (A2). The diffuse ground glass opacities seen in A1 have reduced, while the areas of consolidation (marked with yellow arrows) have increased slightly, along with features of tractional bronchiectasis, suggestive of coronavirus disease (COVID) sequelae. The overall improvement in clinical status from A1 to A2 could suggest that the ground glass opacities were part of the inflammatory changes in the lungs and responded to immunomodulation; B: Representative plain radiographs (portable) of patient 1 showing the evolution of infiltrates from day -7 of DIPS (B1) till day 0 (B2), followed by improvement on day +1 (B3), after the initiation of glucocorticoids; C: Representative chest radiograph and coronal high resolution CT sections on day -26 (C1, taken in the index admission for mild COVID on day 10 of symptom onset) before the onset of DIPS, significant increase in diffuse ground glass opacities on day 0 of DIPS (C2), followed by improvement on day +1 of DIPS (C3).

Figure 3 PaO₂/FiO₂ ratio trends of patients prior to, during and post Delayed Inflammatory Pulmonary Syndrome. The PaO2/FiO2 (PF) ratio of the individual patients is shown in the y-axis. The x-axis depicts day 0 as the day of onset of Delayed Inflammatory Pulmonary Syndrome (DIPS). The highest PF ratio of each patient in the period prior to DIPS and following recovery from DIPS is plotted. The figure shows that the respiratory deterioration occurred gradually over several days in 3 patients and acutely over a day in 2 patients. Recovery was gradual over 5 to 10 d. DIPS: Delayed Inflammatory Pulmonary Syndrome; SOFA: Sequential Organ Failure Assessment.