ABSTRACT
Introduction: COVID-19 presents a complex pathophysiology and evidence collected points towards an intricated interaction of viraldependent and individual immunological mechanisms. The identification of phenotypes, through clinical and biological markers, may provide a better understanding of the subjacent mechanisms and an early patient-tailored characterization of illness severity. Method(s): Multicenter prospective cohort study performed in 5 hospitals of Portugal and Brazil, during one year, between 2020-2021. All adult patients with an Intensive Care Unit admission with SARS-CoV-2 pneumonia were eligible. COVID-19 was diagnosed using clinical and radiologic criteria with a SARS-CoV-2 positive RT-PCR test. A two-step hierarchical cluster analysis was made using several class-defining variables. Result(s): 814 patients were included. The cluster analysis revealed a three-class model, allowing for the definition of three distinct COVID- 19 phenotypes: 244 patients in phenotype A, 163 patients in phenotype B, and 407 patients in phenotype C. Patients included in the phenotype C were significantly older, with higher baseline inflammatory biomarkers profile, and significantly higher requirement of organ support and mortality rate (Table 1 ( P062)). Phenotypes A and B demonstrated some overlapping clinical characteristics but different outcomes. Phenotype B patients presented a lower mortality rate, with consistently lower C-reactive protein, but higher procalcitonin and interleukin-6 serum levels, describing an immunological profile significantly different from phenotype A (Table 1). Conclusion(s): Severe COVID-19 patients exhibit three different clinical phenotypes with distinct profiles and outcomes. Their identification could have an impact in patients' care, justifying different therapy responses and inconsistencies identified across different randomized control trials results.
ABSTRACT
Objective: To analyze and compare COVID-19 patient characteristics, clinical management and outcomes between the peak and plateau periods of the first pandemic wave in Portugal. Methods: This was a multicentric ambispective cohort study including consecutive severe COVID-19 patients between March and August 2020 from 16 Portuguese intensive care units. The peak and plateau periods, respectively, weeks 10 - 16 and 17 - 34, were defined. Results: Five hundred forty-one adult patients with a median age of 65 [57 - 74] years, mostly male (71.2%), were included. There were no significant differences in median age (p = 0.3), Simplified Acute Physiology Score II (40 versus 39;p = 0.8), partial arterial oxygen pressure/fraction of inspired oxygen ratio (139 versus 136;p = 0.6), antibiotic therapy (57% versus 64%;p = 0.2) at admission, or 28-day mortality (24.4% versus 22.8%;p = 0.7) between the peak and plateau periods. During the peak period, patients had fewer comorbidities (1 [0 - 3] versus 2 [0 - 5];p = 0.002) and presented a higher use of vasopressors (47% versus 36%;p < 0.001) and invasive mechanical ventilation (58.1 versus 49.2%;p < 0.001) at admission, prone positioning (45% versus 36%;p = 0.04), and hydroxychloroquine (59% versus 10%;p < 0.001) and lopinavir/ ritonavir (41% versus 10%;p < 0.001) prescriptions. However, a greater use of high-flow nasal cannulas (5% versus 16%, p < 0.001) on admission, remdesivir (0.3% versus 15%;p < 0.001) and corticosteroid (29% versus 52%, p < 0.001) therapy, and a shorter ICU length of stay (12 days versus 8, p < 0.001) were observed during the plateau. Conclusion: There were significant changes in patient comorbidities, intensive care unit therapies and length of stay between the peak and plateau periods of the first COVID-19 wave. © 2023 Associacao de Medicina Intensiva Brasileira - AMIB. All rights reserved.