Characteristics and outcomes of patients admitted to Swedish intensive care units for COVID-19 during the first 60 days of the 2020 pandemic: a registry-based, multicenter, observational study.

Chew, M. S.; Blixt, P.; Ahman, R.; Engerstrom, L.; Andersson, H.; Berggren, R. K.; Tegnell, A.; McIntyre, S.

Background The mortality of patients admitted to the intensive care unit (ICU) with COVID-19 is unclear due to variable censoring and substantial proportions of undischarged patients at follow-up. Nationwide data have not been previously reported. We studied the outcomes of Swedish patients at 30 days after ICU admission. Methods We conducted a registry-based cohort study of all adult patients admitted to Swedish ICUs from 6 March-6 May, 2020 with laboratory confirmed COVID-19 disease and complete 30-day follow-up. Data including baseline characteristics, comorbidities, intensive care treatments, organ failures and outcomes were collected. The primary outcome was 30-day all-cause mortality. A multivariable model was used to determine the independent association between potential predictor variables and the primary outcome. Results A total of 1563 patients were identified. Median ICU length of stay was 12 (5-21) days, and fifteen patients remained in ICU at the time of follow-up. Median age was 61 (52-69), median Simplified Acute Physiology Score III (SAPS III) was 53 (46-59), and 66.8% had at least one comorbidity. Median PaO2/FiO2 on admission was 97.5 (75.0-140.6) mmHg, 74.7% suffered from moderate to severe acute respiratory distress syndrome (ARDS). The 30-day all-cause mortality was 26.7%. The majority of deaths occurred during ICU admission. Age, male sex (adjusted odds ratio [aOR] 1.5 [1.1-2.1]), SAPS III score (aOR 1.3 [1.2-1.4]), severe ARDS (aOR 3.1 [2.0-4.8], specific COVID-19 pharmacotherapy (aOR 1.4 [1.0-1.9]), and CRRT (aOR 2.2 [1.6-3.0]), were associated with increased mortality. With the exception of chronic lung disease, the presence of comorbidities was not independently associated with mortality. Conclusions Thirty-day mortality rate in COVID-19 patients admitted to Swedish intensive care units is generally lower than previously reported. Mortality appears to be driven by age, baseline disease severity, the degree of organ failure and ICU treatment, rather than preexisting comorbidities.