Análisis de las características de los pacientes mayores que ingresaron en una unidad de cuidados intensivos durante las seis olas de la pandemia por SARS-CoV-2: implicaciones para la atención médica

Objective: to analyze the characteristics of seriously ill elderly patients during the six waves of the COVID-19 pandemic. Method: retrospective, observational and analytical study of patients over 70 years of age admitted to the ICU (March-2020 – March-2022). Patients were categorized into 3 groups based on age: 70-74 years; 75-79 years; and > 80 years. A descriptive and comparative analysis of the sample was initially performed; and a 28-, 60- and 90-day survival analysis using the Kaplan-Meier method. Multivariate survival analysis was performed by fitting a Cox model. Results: of 301 patients, the lowest number of admissions occurred during the first wave (20 (6%)), compared to the wave with the highest number of admissions: the sixth wave (76 (25%)). The survival curves at 28, 60 days and 90 days showed a higher probability of survival in the younger age groups (p<0.01 and p=0.01 respectively). Troponin at admission (per unit, ng/L) showed a significant association with 28- and 60-day mortality (HR: 1.00; CI95%: 1.00-1.01; p<0.05). Taking the 1st wave of the pandemic as a reference, admission in the 3rd wave behaved as a protective factor against mortality at 28 and 60 days of follow-up (HR: 0.18; CI95%: 0.02-0.64; p<0.05; HR: 0.13; CI95%: 0.02-0.64; p<0.05 respectively). Conclusions: the time of admission and biomarkers, such as troponin, constitute prognostic markers independent of age in the elderly population.