Functional Dependence Prior to ICU Admission is Associated with Worse Clinical and Functional Outcomes in Individuals with COVID-19: A Prospective Observational Study

Abstract

Objectives: To determine whether low functional capacity (FC) prior to intensive care unit (ICU) admission due to coronavirus disease 2019 (COVID-19) might be associated with worse clinical outcomes. To monitor FC until discharge from the ICU. To identify associations between physical outcomes and decreased FC at discharge from the ICU. Design: Prospective observational study conducted from March to August 2021. Setting: ICU for adult patients with COVID-19. Participants: Adults (≥18 years) with COVID-19. Interventions: Not applicable. Main outcome measures: Clinical and demographic data were obtained from medical records. At ICU admission, evaluation was made of FC using the Barthel index (BI), and of the level of mobility using the ICU mobility scale. At ICU discharge, FC and mobility level were reassessed, and muscle strength was measured using the Medical Research Council (MRC) scale and the handgrip test. Results: The study was performed with 108 individuals. At the initial assessment, 73.1% of the patients were functionally independent. Length of hospital stay (odds ratio [OR]  =  1.05; 95%confidence interval [CI]  =  1.00-1.10) and death (OR  =  5.27; 95%CI  =  1.37-20.28) were related to functional status prior to ICU admission. Between ICU admission and discharge, the BI evaluation indicated a functional decline of 22.5 points. Low mobility level ( P  =  .003) and low muscle strength assessed by the MRC scale ( P < .001), measured at ICU discharge, were associated with a greater decrease of FC during the ICU stay. Conclusions: Patients with COVID-19 who were functionally dependent prior to ICU admission presented worse clinical outcomes, with low functional status being associated with longer hospitalization and higher mortality. However, irrespective of the initial functionality status, the surviving individuals suffered from functional decline at ICU discharge. Greater functional decline during the ICU stay was associated with lower muscle strength and lower mobility level at ICU discharge.