A Relationship Between the SIR Model and the Generalized Logistic Distribution with Applications to SARS and COVID-19

This paper shows that the generalized logistic distribution model is derived from the well-known compartment model, consisting of susceptible, infected and recovered compartments, abbreviated as the SIR model, under certain conditions. In the SIR model, there are uncertainties in predicting the final values for the number of infected population and the infectious parameter. However, by utilizing the information obtained from the generalized logistic distribution model, we can perform the SIR numerical computation more stably and more accurately. Applications to severe acute respiratory syndrome (SARS) and Coronavirus disease 2019 (COVID-19) using this combined method are also introduced. © 2021 IEEE.

Outcomes of extracorporeal membrane oxygenation in influenza vs. COVID-19 during the first wave of COVID-19

Purpose: Extracorporeal membrane oxygenation (ECMO) has historically been used as a refractory treatment for acute respiratory distress syndrome (ARDS) due to influenza and is currently being explored as a refractory treatment for ARDS due to COVID-19. We conducted this study to compare the outcomes in our institution of influenza patients treated with veno-venous-ECMO (VV-ECMO) to COVID-19 patients treated with VV-ECMO, during the first wave of COVID-19. Methods: All adult patients who were placed on VV-ECMO between March 1, 2016 and September 15, 2020 (encompassing the first wave of COVID-19) were identified within an IRB-approved database, and any patient with ARDS due to COVID-19 or influenza was included in this study. The clinical characteristics and outcomes of these patients were extracted and analyzed. Results: 28 COVID-19 patients and 17 influenza patients placed on VV-ECMO were identified and included in this study. ECMO survival rates were 68% (19/28) in COVID-19 patients and 94% (16/17) in influenza patients (p=0.04). 30-day survival rates after ECMO decannulation were 54% (15/28) in COVID-19 patients and 76% (13/17) in influenza patients (p=0.13). The COVID-19 patients had lower rates of pre-ECMO acute renal injury (29% vs. 59%, p=0.045), lower rates of coronary artery disease (0% vs. 18%, p=0.021), and a lower average body surface area (2.0 vs. 2.2, p=0.036). They were more likely to have ECMO initiated at an outside hospital (50% vs. 12%, p=0.009) and spend a longer time on ECMO (21 days vs. 12 days, p=0.025). COVID-19 patients had statistically higher complication rates of new infections during ECMO (50% vs. 18%, p=0.03), bacterial pneumonia (36% vs 6%, p=0.024), and blood culture-positive sepsis (32% vs. 6%, p=0.04). Conclusions: COVID-19 patients who were treated in our institution with VV-ECMO had statistically lower ECMO survival rates than influenza patients with the same treatment. It is possible that COVID-19 immunomodulation therapies may increase the risk of other superimposed infections, as COVID-19 patients developed new infections, sepsis, and bacterial pneumonia more frequently than influenza patients. However, more research is needed to better understand the true efficacy rates of ECMO in treating both influenza and COVID-19.