ABSTRACT
Aim and background: A high interleukin-6 (IL-6) level in COVID- 19 plays a major role in the pathophysiology and is considered a relevant parameter in predicting the most severe course of the disease. In COVID-19 extracorporeal blood, purification is proposed as adjuvant therapy and aims at controlling the dysregulation in the autoimmune system. It essentially reduces high levels of several mediators and by this controls the cytokine storm, rather than actively targeting individual pathways of inflammation. Positive IL-6 balance post polymethyl methacrylate (PMMA) filter used for cytokine storm in COVID-19 patients with dialysis has shown to be an independent predictor of mortality. We present outcomes of severe COVID pneumonia patients with cytokine storm, acute kidney injury, chronic kidney disease, sepsis, and septic shock at our centre over a year. Objective: A retrospective analysis of data to understand the effect of hemofiltration for severe COVID-19 pneumonia. Materials and methods: All patients admitted to our unit, with severe COVID pneumonia with chronic kidney disease, sepsis, septic shock, and cytokine storm were included from August to December 2020. Demographic variable, clinical, and laboratory data were compared pre and post filtration with PMMA filters. Dialysis vintage, duration of mechanical ventilation, length of stay, and hospital were analysed. Results: We analysed 17 severe COVID patients (P/F ratio < 100) requiring ventilator support in whom hemofiltration was used for cytokine storm with dialysis, sepsis, and septic shock. The average age of these patients was 70.2 ± 18.2 years with no difference in the distribution of age and comorbidities. They all were divided as responders or non-responders groups based on the decrease or no change and increase, respectively, in their pre and post filtration levels of IL-6. Non-responders (N = 11) had 3.6-fold increase in IL-6 levels post hemofiltration with the majority of them on vasopressors;pre (8/11-72.7%) and post (9/11-81.8%) hemofiltration. None of the non-responders survived and we noted 54.5% of this group received hemofiltration post intubation. The non-responders also had a positive IL-6 balance post-hemofiltration which guided us to use this therapy early in the disease. Therefore, subsequent 6 patients were offered hemofiltration early, where we found a decrease in IL-6 levels by 21.4%. Out of the 6 responders, 4 survived and demonstrated a reduction in the IL-6 of 66.7%. None of these survivors required vasopressor support and we were able to avoid or reduce the need for ventilator support in them. Survivors had an average length of stay in ICU of 24 days and were discharged by the 30th day. One of the two non-survivors had succumbed secondary to a cardiac event, while the other was intubated before filtration in view of heart failure. Conclusion: The most prominent finding was the distinct increase in the IL-6 levels in non-survivors which was directed towards the early use of hemofiltration treatment. The present data though limited to a small subgroup of severe COVID patients suggest the need to prevent the positive IL-6 balance. Hemofiltration may be an alternative to be considered early in to prevent the cytokine storm and its ill effects.