Factors Associated with Fatigue in COVID-19 ICU Survivors.

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] days including 23 [3-57] days of mechanical ventilation, visited the laboratory on two separate occasions. The first visit occurred 52 ± 15 days after discharge and was dedicated to questionnaires, blood sampling and cardiopulmonary exercise testing, while measurements of the knee extensors neuromuscular function and performance fatigability were performed in the second visit 7 ± 2 days 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 one second, 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 weeks after discharge, that 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 cardiorespiratory and neuromuscular impairments of COVID-19 patients admitted in ICU, especially individuals experiencing fatigue.

Functional hub disruption emphasizes consciousness recovery in severe traumatic brain injury.

Severe traumatic brain injury can lead to transient or even chronic disorder of consciousness. To increase diagnosis and prognosis accuracy of disorder of consciousness, functional neuroimaging is recommended 1 month post-injury. Here, we investigated brain networks remodelling on longitudinal data between 1 and 3 months post severe traumatic brain injury related to change of consciousness. Thirty-four severe traumatic brain-injured patients were included in a cross-sectional and longitudinal clinical study, and their MRI data were compared to those of 20 healthy subjects. Long duration resting-state functional MRI were acquired in minimally conscious and conscious patients at two time points after their brain injury. The first time corresponds to the exit from intensive care unit and the second one to the discharge from post-intensive care rehabilitation ward. Brain networks data were extracted using graph analysis and metrics at each node quantifying local (clustering) and global (degree) connectivity characteristics. Comparison with brain networks of healthy subjects revealed patterns of hyper- and hypo-connectivity that characterize brain networks reorganization through the hub disruption index, a value quantifying the functional disruption in each individual severe traumatic brain injury graph. At discharge from intensive care unit, 24 patients' graphs (9 minimally conscious and 15 conscious) were fully analysed and demonstrated significant network disruption. Clustering and degree nodal metrics, respectively, related to segregation and integration properties of the network, were relevant to distinguish minimally conscious and conscious groups. At discharge from post-intensive care rehabilitation unit, 15 patients' graphs (2 minimally conscious, 13 conscious) were fully analysed. The conscious group still presented a significant difference with healthy subjects. Using mixed effects models, we showed that consciousness state, rather than time, explained the hub disruption index differences between minimally conscious and conscious groups. While severe traumatic brain-injured patients recovered full consciousness, regional functional connectivity evolved towards a healthy pattern. More specifically, the restoration of a healthy brain functional segregation could be necessary for consciousness recovery after severe traumatic brain injury. For the first time, extracting the hub disruption index directly from each patient's graph, we were able to track the clinical alteration and subsequent recovery of consciousness during the first 3 months following a severe traumatic brain injury.

Cardiorespiratory Fitness and Neuromuscular Function of Mechanically Ventilated ICU COVID-19 Patients.

OBJECTIVES: The aim of the current study was to investigate the level of cardiorespiratory fitness and neuromuscular function of ICU survivors after COVID-19 and to examine whether these outcomes are related to ICU stay/mechanical ventilation duration. DESIGN: Prospective nonrandomized study. SETTING: Patients hospitalized in ICU for COVID-19 infection. PATIENTS: Sixty patients hospitalized in ICU (mean duration: 31.9 ± 18.2 d) were recruited 4-8 weeks post discharge from ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients visited the laboratory on two separate occasions. The first visit was dedicated to quality of life questionnaire, cardiopulmonary exercise testing, whereas measurements of the knee extensors neuromuscular function were performed in the second visit. Maximal oxygen uptake (V o2 max) was 18.3 ± 4.5 mL·min -1 ·kg -1 , representing 49% ± 12% of predicted value, and was significantly correlated with ICU stay/mechanical ventilation (MV) duration ( R = -0.337 to -0.446; p < 0.01 to 0.001), as were maximal voluntary contraction and electrically evoked peak twitch. V o2 max (either predicted or in mL· min -1 ·kg -1 ) was also significantly correlated with key indices of pulmonary function such as predicted forced vital capacity or predicted forced expiratory volume in 1 second ( R = 0.430-0.465; p ≤ 0.001) and neuromuscular function. Both cardiorespiratory fitness and neuromuscular function were correlated with self-reported physical functioning and general health status. CONCLUSIONS: V o2 max was on average only slightly above the 18 mL·min -1 ·kg -1 , that is, the cut-off value known to induce difficulty in performing daily tasks. Overall, although low physical capacities at admission in ICU COVID-19 patients cannot be ruled out to explain the association between V o2 max or neuromuscular function and ICU stay/MV duration, altered cardiorespiratory fitness and neuromuscular function observed in the present study may not be specific to COVID-19 disease but seem applicable to all ICU/MV patients of similar duration.

Dynamics of clinical recovery during the early phase of rehabilitation in patients with severe traumatic and non-traumatic brain injury.

PURPOSE: Our aim was to describe the changes in the functional outcome at the early phase of rehabilitation following severe brain injury and to identify the factors associated with faster recovery. METHODS: This retrospective analysis included 182 patients who were transferred from the intensive care unit (ICU) to a post-ICU neurorehabilitation unit following traumatic brain injury (TBI) (n = 82) or cerebrovascular accident (CVA) (n = 100). Admission, discharge and changes in scores were calculated for the Functional Independent Measurement (FIM) and the Wessex Head Injury Matrix (WHIM). Patients with high dynamics of clinical recovery were defined by delta FIM scores ≥22. RESULTS: Upon admission to the neurorehabilitation unit, 97% of patients had a FIM score <50 and 41% a WHIM score <32. Patients showed significantly improved FIM (+17 points; 7-37) and WHIM (+11 points; 3-19) scores with an over 22-day stay (14-38). Those with faster recovery (45%) were more likely those with high FIM and WHIM scores at admission. The nature and severity of the brain insult were not associated with the dynamics of recovery. CONCLUSIONS: Within a 2-6 week stay in a post-ICU neurorehabilitation unit, patients with severe disability could achieve partial functional independence and showed cognitive improvements.

Transcranial Doppler to Predict Neurologic Outcome after Mild to Moderate Traumatic Brain Injury.

BACKGROUND: To assess the performance of transcranial Doppler (TCD) in predicting neurologic worsening after mild to moderate traumatic brain injury. METHODS: The authors conducted a prospective observational study across 17 sites. TCD was performed upon admission in 356 patients (Glasgow Coma Score [GCS], 9 to 15) with mild lesions on cerebral computed tomography scan. Normal TCD was defined as a pulsatility index of less than 1.25 and diastolic blood flow velocity higher than 25 cm/s in the two middle cerebral arteries. The primary endpoint was secondary neurologic deterioration on day 7. RESULTS: Twenty patients (6%) developed secondary neurologic deterioration within the first posttraumatic week. TCD thresholds had 80% sensitivity (95% CI, 56 to 94%) and 79% specificity (95% CI, 74 to 83%) to predict neurologic worsening. The negative predictive values and positive predictive values of TCD were 98% (95% CI, 96 to 100%) and 18% (95% CI, 11to 28%), respectively. In patients with minor traumatic brain injury (GCS, 14 to 15), the sensitivity and specificity of TCD were 91% (95% CI, 59 to 100%) and 80% (95% CI, 75 to 85%), respectively. The area under the receiver operating characteristic curve of a multivariate predictive model including age and GCS was significantly improved with the adjunction of TCD. Patients with abnormal TCD on admission (n = 86 patients) showed a more altered score for the disability rating scale on day 28 compared to those with normal TCD (n = 257 patients). CONCLUSIONS: TCD measurements upon admission may provide additional information about neurologic outcome after mild to moderate traumatic brain injury. This technique could be useful for in-hospital triage in this context. (Anesthesiology 2016; 125:346-54).