Estimation of patients hospitalized for COVID-19 in an intensive care unit at the peak of the pandemic in Porto Alegre: Study with epidemiological model SEIHDR

Abstract

Objective: Estimate the maximum number of prevalent cases of COVID-19, admitted to intensive care units, and the time of this peak, in Porto Alegre. Methods: A mathematical model of differential equations called SEIHDR (Susceptible, Exposed, Infected, Hospitalized, Dead, Recovered) have been used to analyze the cases of hospitalization for COVID-19 in Porto Alegre and RS, from March 9 to July 25, 2020 in order to extract the parameters to make up an epidemiological curve of the prevalent cases hospitalized in general ward and in intensive care units, as well as how to estimate the prevalence of patients on invasive mechanical ventilation. Finally, we adjusted some parameters of this curve based on the current prevalent cases hospitalized. Results: The mathematical model corrected for the pandemic data until July 25 projected a peak of 1,354 prevalent hospitalized cases: 562 patients admitted to the intensive care unit with 378 under mechanical ventilation on September 12, 2020 (37th epidemiological week). In addition, there would be a peak of 62,514 prevalent cases of infected with COVID-19 at the beginning of the same month (36th epidemiological week. We calculated for the pandemic a basic reproduction number of 1.53 and effective reproduction number of 1.29 to July 25, 2020. Conclusion: As the current number of beds in the intensive care unit would be insufficient to meet this demand, we suggest an increase in the number of critical beds in order to avoid the collapse of the health system in Porto Alegre.