Kennouche D; Universitaire de Saint-Etienne, Saint-Etienne, FRANCE.
Foschia C; Brownstein CG; Lapole T; Rimaud D; Royer N; LE Mat
F; Thiery G; Gauthier V; Giraux P; Oujamaa L; Sorg M; Verges S; Doutreleau
S; Marillier M; Prudent M; Bitker L; Feasson L; Gergele L; Stauffer E;
Guichon C; Gondin J; Morel J; Millet GY

Medicine & Science in Sports & Exercise. 56(9):1563-1573, 2024 Sep 01.

PURPOSE: Approximately 30% of people infected with COVID-19 require
hospitalization, and 20% of them are admitted to an intensive care unit
(ICU). Most of these patients experience symptoms of fatigue weeks
post-ICU, so understanding the factors associated with fatigue in this
population is crucial.
METHODS: Fifty-nine patients (38-78 yr) hospitalized in ICU for COVID-19
infection for 32 (6-80) d, including 23 (3-57) d of mechanical
ventilation, visited the laboratory on two separate occasions. The first
visit occurred 52 +/- 15 d after discharge and was dedicated to
questionnaires, blood sampling, and cardiopulmonary exercise testing,
whereas measurements of the knee extensors neuromuscular function and
performance fatigability were performed in the second visit 7 +/- 2 d
later.
RESULTS: Using the FACIT-F questionnaire, 56% of patients were classified
as fatigued. Fatigued patients had worse lung function score than
non-fatigued (i.e., 2.9 +/- 0.8 L vs 3.6 +/- 0.8 L; 2.4 +/- 0.7 L vs 3.0
+/- 0.7 L for forced vital capacity and forced expiratory volume in 1 s,
respectively), and forced vital capacity was identified as a predictor of
being fatigued. Maximal voluntary activation was lower in fatigued
patients than non-fatigued patients (82% +/- 14% vs 91% +/- 3%) and was
the only neuromuscular variable that discriminated between fatigued and
non-fatigued patients. Patient-reported outcomes also showed differences
between fatigued and non-fatigued patients for sleep, physical activity,
depression, and quality of life ( P < 0.05).
CONCLUSIONS: COVID-19 survivors showed altered respiratory function 4 to
8 wk after discharge, which was further deteriorated in fatigued patients.
Fatigue was also associated with lower voluntary activation and
patient-reported impairments (i.e., sleep satisfaction, quality of life,
or depressive state). The present study reinforces the importance of
exercise intervention and rehabilitation to counteract cardiorespir