Impact of Muscle Changes Assessed by Ultrasonography on Muscle Strength and Functioning after ICU Discharge: A Systematic Review with Meta-Analysis

Background: Ultrasonography has been used to identify structural, quantitative, and qualitative muscle changes. These changes have been assessed in different muscles during ICU stays; however, it is unclear if it can predict functioning after ICU discharge. Objective: To analyze the relationship between muscle changes assessed by ultrasonography and the strength and functioning of ICU survivors. Methods: A systematic review with a meta-analysis was performed according to the MOOSE guidelines and registered in PROSPERO. Searches of the following databases were performed by two of the authors: PubMed, Cinahl, Embase, Scopus, LILACS, Web of Science, and Science Direct. Qualitative analysis was performed using NOS and AHRQ scales. Meta-analysis was performed using the “R”, “metafor” package. Heterogeneity was assessed by I2 and Cochran’s Q test. Meta-regression analyses were performed to verify the moderators, and funnel plots and Egger’s regression intercept test were used to analyze the publication bias. Results: Sixteen articles were included in the qualitative assessment, and nine were used in the quantitative assessment. There is evidence of correlations between MT and muscle strength (r = 0.20 [0.11; 0.27]; p < 0.0001), and MT (r = 0.35 [0.19; 0.49]; p < 0.0001), CSA (r = 0.30 [0.10; 0.47]; p = 0.0038), EI (r = −0.29 [−0.53; −0.01]; p = 0.043) and mobility. In the subgroup analyses, some evidence of a correlation between specific muscles and strength and mobility were found. Conclusions: There is evidence for the correlation between muscle characteristics assessed by US and functioning outcomes.