Severe COVID-19 pneumonia in an intensive care setting and comparisons with historic severe viral pneumonia due to other viruses (preprint)

Purpose Severe viral pneumonia is associated with significant morbidity and mortality. Recent COVID-19 pandemic continues to impose significant health burden worldwide and individual pandemic waves often leads to a large surge in the ICU admissions for respiratory support. Comparisons of severe SARS-CoV-2 pneumonia with other seasonal and non-seasonal severe viral infections are rarely studied in an intensive care setting.Methods A retrospective cohort study comparing patients admitted to ICU with COVID-19 between March-June 2020 and those with viral pneumonias between January-December 2019. We compared patient specific demographic variables, duration of illness, ICU organ supportive measures and outcomes between both groups.Results Analysis of 93 COVID-19 (group 1) and 52 other viral pneumonia patients (group 2) showed an increased proportion of obesity (42% vs 23%, p = 0.02), non-white ethnicities (41% vs 6%, p < 0.001) and diabetes mellitus (30% vs 13%, p = 0.03) in group 1, with lower prevalence of COPD/asthma (16% vs 34%, p = 0.02). In group 1, the neutrophil to lymphocyte ratio was much lower (6.7 vs 10, p = 0.006) and invasive mechanical ventilation (58% vs 26%, p < 0.001) was more common. Length of ICU (8 vs 4, p < 0.001) and hospital stay (22 vs 11, p < 0.001) was prolonged in group 1, with no significant difference in mortality. Influenza A and rhinovirus were the most common pathogens in group 2 (26% each).Conclusions Key differences were identified within demographics (obesity, ethnicity, age, ICU scores, co-morbidities) and organ support. Despite these variations, there was no significant differences in mortality between both groups. Further studies with larger sample sizes would allow for further assessment of clinical parameters in these patients.

Can a Quantitative Assessment of SARS-CoV-2 PCR Predict Degree of Severity and Outcomes in Critical Care Patients with COVID-19 (preprint)

Real-Time polymerase chain reaction (qPCR) is the gold standard diagnostic method for acute SARS-CoV-2 infection. Cycle threshold (Ct) is defined as the number of heating and cooling cycles required during the PCR process. Ct-values are inversely proportional to the amount of target nucleic acid in a sample. Our aim in this retrospective study was to determine the impact of serial SARS-CoV-2 qPCR Ct-values, among critically ill COVID-19 patients both prior and during intensive care unit (ICU) stay, on: mortality, need for mechanical ventilation (MV) and development of acute kidney injury (AKI). There was a continuous increment in Ct-values over the ICU stay from 1st-week through to 3rd-week. Although not significant, lower ICU 1st-week Ct-values were associated with Black ethnicity, increased need for MV and mortality. However, patients who had developed AKI at any stage of their illness had significantly lower Ct-values compared to those with normal renal function. When ICU 1st-week Ct-values are subcategorised as <20, 20-30 and >30 the 28-day survival probability was less for patients with Ct-values of <20.To our knowledge this is the first report showing the impact of Ct-values and outcomes, especially AKI, among patients at different time point’s prior to and during ICU stay.