Construct and criterion validity of muscle ultrasonography for assessment of skeletal muscle in patients recovering from COVID-19

Background: The purpose was to investigate the content, construct, and criterion validity of muscle ultrasound in a mixed cohort of participants recovering from mild and critical COVID-19. Methods: A secondary analysis of a prospective cross-sectional study was conducted on data obtained from a battery of muscle and physical function assessments including a muscle biopsy and muscle ultrasonography (US). Rectus femoris (RF) muscle thickness (mT), quadricep complex (QC) mT, RF muscle cross-sectional area (CSA) using 2D freeform trace and estimated from Feret's diameter, and RF echo intensity (EI) were assessed with US. Muscle fiber CSA, fiber type, protein content in muscle fibers, extracellular matrix content (ECM; wheat-germ agglutin), and percent area of collagen in ECM (picrosirius red) were examined from vastus lateralis muscle biopsies. Spearman rho correlations (r) were performed to assess validity of ultrasound parameters. Results: Thirty-three individuals participated including 11 patients surviving critical COVID-19, 15 individuals recovering from mild-COVID, and 7 controls. There were several significant correlations between RF mT, QC mT, RF CSA, and RF EI with age, comorbid burden, body-mass index, and measures of muscle strength, muscle power, and physical function (range r = 0.35-0.83). RF Feret's CSA correlated to CSA of type II muscle fibers (r = 0.41, p = 0.022) and the average size of all muscle fibers (r = 0.39, p = 0.031). RF EI was correlated with collagen in muscle ECM (r = 0.53, p = 0.003) and protein content in muscle tissue (r = -0.52, p = 0.012). Conclusion: Muscle size and quality measured using US has moderate content and construct validity, and to lesser extent, fair to moderate criterion validity in a mixed cohort of individuals recovering from COVID. Muscle ultrasound quality (EI) appears to be sensitive at detecting muscle dysfunction as it is associated with strength, power, physical function, and collagen distribution in a mixed group of individuals recovering from COVID-19.

Nutrition in the intensive care unit and early recovery influence functional outcomes for survivors of critical illness: A prospective cohort study

BACKGROUND

Patients who are critically ill may receive suboptimal nutrition that leads to weight loss and increased risk of functional deficits.

METHODS

Our overarching hypothesis is that nutrition in the intensive care unit (ICU) and the early recovery phase associates with functional outcomes at short-term follow-up. We enrolled adult patients who attended the University of Kentucky ICU recovery clinic (ICU-RC) from November 2021 to June 2022. Patients participated in muscle and functional assessments. Nutrition intake and status during the ICU stay were analyzed. The Subjective Global Assessment and a nutrition questionnaire were used to identify changes in intake, ongoing gastrointestinal symptoms, and patient's access to food at the ICU-RC appointment.

RESULTS

Forty-one patients enrolled with a median hospital length of stay (LOS) of 23 days. Patients with 0 days of nil per os (NPO) status throughout hospitalization had a shorter LOS (P = 0.05), were able to complete the five times sit-to-stand test (P = 0.02), and were less likely to experience ICU-acquired weakness (P = 0.04) at short-term follow-up compared with patients with ≥1 day of NPO status. Twenty (48%) patients reported changes in nutrition intake in early recovery compared with before hospitalization. Eight (20%) patients reported symptoms leading to decreased intake and four (10%) reported access to food as a barrier to intake.

CONCLUSION

Barriers to nutrition exist during critical illness and persist after discharge, with almost half of patients reporting a change in intake. Inpatient nutrition intake is associated with functional outcomes and warrants further exploration.

Post-intensive care syndrome and pulmonary fibrosis in patients surviving ARDS-pneumonia of COVID-19 and non-COVID-19 etiologies

The purpose was to examine patient-centered outcomes and the occurrence of lung fibrotic changes on Chest computed tomography (CT) imaging following pneumonia-related acute respiratory distress syndrome (ARDS). We sought to investigate outpatient clinic chest CT imaging in survivors of COVID19-related ARDS and non-COVID-related ARDS, to determine group differences and explore relationships between lung fibrotic changes and functional outcomes. A retrospective practice analysis of electronic health records at an ICU Recovery Clinic in a tertiary academic medical center was performed in adult patients surviving ARDS due to COVID-19 and non-COVID etiologies. Ninety-four patients with mean age 53 ± 13 and 51% male were included (n = 64 COVID-19 and n = 30 non-COVID groups). There were no differences for age, sex, hospital length of stay, ICU length of stay, mechanical ventilation duration, or sequential organ failure assessment (SOFA) scores between the two groups. Fibrotic changes visualized on CT imaging occurred in a higher proportion of COVID-19 survivors (70%) compared to the non-COVID group (43%, p < 0.001). Across both groups, patients with fibrotic changes (n = 58) were older, had a lower BMI, longer hospital and ICU LOS, lower mean RASS scores, longer total duration of supplemental oxygen. While not statistically different, patients with fibrotic changes did have reduced respiratory function, worse performance on the six-minute walk test, and had high occurrences of anxiety, depression, emotional distress, and mild cognitive impairment regardless of initial presenting diagnosis. Patients surviving pneumonia-ARDS are at high risk of impairments in physical, emotional, and cognitive health related to Post-Intensive Care Syndrome. Of clinical importance, pulmonary fibrotic changes on chest CT occurred in a higher proportion in COVID-ARDS group; however, no functional differences were measured in spirometry or physical assessments at ICU follow-up. Whether COVID infection imparts a unique recovery is not evident from these data but suggest that long-term follow up is necessary for all survivors of ARDS.

Feasibility of Contrasting Brain Connectivity Patterns in Cognitive and Motor Cerebral Networks to Clinical Outcomes in Patients Surviving Acute Respiratory Failure: A Pilot Study

BACKGROUND

There is a paucity of research regarding the feasibility and association of cerebral cortex function to patient outcomes after acute respiratory failure (ARF).

PURPOSE

To determine the feasibility of functional connectivity measures and examine the association of functional connectivity to a multifaceted battery of outcomes in survivors of ARF.

METHODS

Eight ARF patients (age:58±3.7, ICU days:10.4±8.6) completed functional magnetic resonance imaging (fMRI), cognitive, physical-function, anxiety, depression, and driving simulator tests at one month post-hospital discharge. Pearson's correlations assessed the relationship between functional connectivity within the default mode network (FPN), sensorimotor network (SMN), and frontoparietal network (FPN) to outcomes.

RESULTS

Low physical-function (r=0.75, p=0.03) and divided-attention (r=-0.86, p=0.03) during the driving simulator task correlated with low FPN connectivity. Low SMN connectivity demonstrated relationships to slower gait speed (r=0.82, p=0.01) and low short physical performance battery (SPPB) scores (r=0.81, p=0.01).

CONCLUSIONS

fMRI is feasible to assess ARF patients' post-ICU limitations, as low post-ARF brain connectivity may be linked to low physical function, providing potential development of therapeutic interventions.

Physical Therapy Management of an Individual With Post-COVID Syndrome: A Case Report

OBJECTIVE

The purpose of this case report is to provide the clinical presentation and physical therapist management for a patient with post-COVID syndrome. Secondarily, the report highlights the importance of assessing cognitive and emotional health in patients with post-COVID syndrome.

METHODS (CASE DESCRIPTION)

A 37-year-old woman tested positive for SARS-CoV-2 and developed mild COVID-19 disease but did not require supplemental oxygen or hospitalization. The patient experienced persistent symptoms, including dyspnea, headaches, and cognitive fog. On day 62, they participated in an outpatient physical therapist evaluation that revealed deficits in exercise capacity, obtaining 50% of their age-predicted 6-minute walk distance. They had minor reductions in muscle strength and cognitive function. Self-reported quality of life was 50, and they scored above established cut-off scores for provisional diagnosis of posttraumatic stress disorder (PTSD).

RESULTS

The patient participated in biweekly physical therapist sessions for 8 weeks, which included aerobic training, strengthening exercises, diaphragmatic breathing techniques, and mindfulness training. Metabolic equivalent for task levels increased with variability over the course of the program. The patient's muscle strength, physical function, and exercise capacity improved. 6-Minute walk distance increased by 199 m, equating to 80% of their age-predicted distance. Quality of life and PTSD scores did not improve. At evaluation after physical therapy, the patient was still experiencing migraines, dyspnea, fatigue, and cognitive dysfunction.

CONCLUSION

This case report described the clinical presentation and physical therapist management of a person with post-COVID syndrome, a novel health condition for which little evidence exists to guide rehabilitation examination and interventions. Physical therapists should consider cognitive function and emotional health in their plan of care for patients with post-COVID syndromes.

IMPACT

This case alerts physical therapists to post-COVID syndrome-which can include debilitating symptoms of decreased aerobic tolerance, anxiety, PTSD, and cognitive dysfunction-and to the role that therapists can play in assessing these symptoms and managing these patients.