Assessment of muscle wasting in intensive care unit patients with and without COVID-19 using ultrasound imaging and bioimpedance analysis.

Both COVID-19 and non-COVID-19 ICU patients experienced significant within-group reductions in muscle thickness over time, with no statistically significant between-group differences.

• Muscle thickness was assessed using ultrasound (US) on ICU days 1, 5, and 7
• Significant within-group reductions in muscle thickness were observed over time in both matched cohorts
• No statistically significant between-group differences in muscle thickness change were found after propensity score matching
• US measurements appeared less affected by differences in fluid balance compared to BIA

BIA-derived phase angle values were consistently lower in patients with COVID-19, but between-group differences in phase angle change lost statistical significance after propensity score matching.

• Body composition was assessed using bioelectrical impedance analysis (BIA) on ICU days 1, 5, and 7
• Phase angle (PhA) values were consistently lower in the COVID-19 group
• Between-group differences in PhA change were no longer statistically significant after matching
• BIA-derived phase angle was noted to be more closely related to hydration status than US measurements

Handgrip dynamometry revealed a higher incidence of muscle weakness in patients with COVID-19 initially, but this difference was non-significant after matching, with absolute and residual strength remaining similar between groups.

• Functional strength was assessed using handgrip dynamometry
• A significantly higher incidence of muscle weakness was initially observed in patients with COVID-19 before matching
• After propensity score matching, the between-group difference in muscle weakness incidence was non-significant
• Absolute and residual strength remained similar between groups
• Handgrip dynamometry provided a simple, objective measure of functional muscle strength at ICU discharge

The study included 143 patients in total, with 101 without COVID-19 and 42 with COVID-19, of whom 23 matched pairs were analysed after propensity score matching.

• Total sample: 143 patients (101 without COVID-19, 42 with COVID-19)
• All patients remained in the ICU for ≥7 days
• Propensity score matching was applied using illness severity, nutritional risk, and mechanical ventilation parameters
• After matching, 23 pairs were analysed
• The study was described as a 'small, non-concurrent, propensity score-matched ICU study'

ICU-acquired weakness appears more closely associated with the severity of critical illness and ICU treatments than with SARS-CoV-2 infection itself.

• After adjustment for baseline characteristics, comparable degrees of muscle wasting and weakness were found in both groups
• Illness severity, nutritional risk, and mechanical ventilation were used as matching variables, suggesting these factors drive muscle wasting
• Viral myopathy and established ICU-related risk factors were noted to predispose COVID-19 patients to muscle dysfunction
• The finding challenges the assumption that COVID-19 independently worsens muscle outcomes beyond general critical illness effects