What Changed Between the Peak and the Plateau Periods of the First COVID-19 Pandemic Wave? A Multicentric Portuguese Cohort Study in Intensive Care.

Abstract

BackgroundThe COVID-19 pandemic represented a challenge for intensive care units (ICU) with overwhelming demand, heterogenous outcomes and clinical practices. To improve care a profound knowledge on severe COVID-19 patients during different time points is crucial. This data is still scarce. We aimed to analyze and compare COVID-19 patient demographics, clinical management, and outcomes between two periods from the first pandemic wave.MethodsWe performed a multicentric ambispective cohort study including severe COVID-19 patients between March and August 2020 from 16 Portuguese ICUs. A peak and a plateau period were defined, corresponding to weeks 10-16 and 17-34 of the first pandemic wave. All patients had SARS-CoV-2 pneumonia diagnosis and complete hospital follow-up.ResultsWe included 541 adult patients with a median age of 65 [57-74] years and mostly male (71.2%). Severe acute respiratory distress syndrome developed in 63.9% of cases. Overall, 28-day mortality rate was 23.7% with age and SAPSII (both p<0.001) as independent risk factors.Between peak and plateau periods there were no significant differences in age (65 vs. 66, p=0.6), SAPS II (40 vs. 39, p=0.8), PaO2/FiO2 ratio (139 vs. 136, p=0.6), and antibiotic therapy (57.2% vs. 63.8%, p=0.2) at admission, nor in 28-day mortality (24.4% vs. 22.8%, p=0.7). Adjuvant therapy with corticosteroids had no impact on 28-day mortality (26.9% vs. 22.5% without, p=0.4). The peak period included 53.8% of patients and they had less comorbidities (no comorbidities 29% vs. 36%, p=0.01), presented at admission a higher use of vasopressors (81% vs. 63%, p<0.001), invasive mechanical ventilation (58 vs 49%, p<0.001), prone positioning (60% vs 48%, p=0.009), and hydroxychloroquine (80.2% vs. 13.4%; p<0.001) and lopinavir/ritonavir (60.4% vs. 13.4%; p<0.001) prescription, as compared with the plateau period. In the plateau period, there was a greater use of high flow nasal canula (5% vs 16%, p<0.001) on admission, remdesivir (0.5% vs. 19.9%; p<0.001) and corticosteroid (39% vs. 61%, p<0.001) therapy, and a shorter ICU length-of-stay for survivors (12 days vs. 7, p<0.001).ConclusionThere were significant changes in patient comorbidities, therapies and ICU length-of-stay between peak and plateau periods of the first COVID-19 wave with similar 28-day mortality.