The following is the summary of “Rate and assessment of muscle wasting during critical illness: a systematic review and meta-analysis” published in the January 2023 issue of Critical care by Fazzini, et al.

A loss of more than 15% of muscle mass in a single week is associated with long-term negative outcomes for patients with the critical disease. Muscle wasting is a well-studied phenomenon in the intensive care unit (ICU), but the true mean rate of muscle loss across all studies has yet to be discovered because no synthesis of the data of ICU muscle wasting studies exists now. The purpose of this study was, therefore, to comprehensively synthesize data on the pace of muscle loss, to determine the methodologies used to quantify muscle size, and to synthesize data on the prevalence of ICU-acquired weakness in critically ill patients. Using the International Prospective Register of Systematic Reviews (PROSPERO) registration number CRD420222989540, researchers searched MEDLINE, PubMed, AMED, BNI, CINAHL, and EMCARE for relevant articles through January 2022. 

Researchers included research that involved at least 20 critically sick adults and included at least 2 measurements of a muscle mass-related characteristic during the course of the patient’s ICU hospitalization. Researchers evaluated the study quality using the Newcastle-Ottawa Scale and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. As a result, 52 studies with 3,251 patients were included because they met the criteria. The rate of muscle wasting was studied in 1,773 patients (55%) while ICU-acquired muscle weakness was evaluated in 1,478 patients (45%) throughout these trials. 

Ultrasound was employed in 85% (n=28/33) of the studies to measure muscle mass, while computed tomography was used in 15% (n=5/33) of the investigations. A patient’s rectus femoris thickness decreased by -1.75% per day (95% CI: -2.05 to -1.45), and their cross-sectional area decreased by 2.10%  per day (95% CI: -3.17 to -1.02) throughout the first week of severe illness. Overall, 48% (95% CI 39%, 56%) of patients in the intensive care unit developed weakness during their stay. During the first week in the intensive care unit, individuals who are seriously ill lose about 2% of their skeletal muscle mass per day.