Predictors of Activities of Daily Living in Intensive Care Unit Survivors: A Propensity Score Matching Analysis.

Objectives: Increased long-term impairment is common among intensive care unit (ICU) survivors. However, predictors of activities of daily living (ADL) in ICU survivors are poorly understood. We aimed to focus on the trajectory of physical function and explore the clinical variables that affect ADL at hospital discharge. Methods: We enrolled 411 patients admitted to the ICU from April 2018 to October 2020. Physical function was evaluated at ICU admission, ICU discharge, and hospital discharge. We assessed physical function (grip strength, arm and calf circumference, quadriceps thickness, and Barthel index). Patients were assigned to the high or low ADL group based on their Barthel index at discharge. Propensity score matching analysis was performed to minimize selection biases and differences in clinical characteristics. Results: After matching propensity scores, 114 of the 411 patients (aged 65±15 years) were evaluated. The high ADL group showed better physical function at ICU discharge and hospital discharge than the low ADL group. An overall decreasing trend in muscle mass was observed over time; the rates of decline were lower in the high ADL group than in the low ADL group. The cutoff values for relative changes in calf circumference and quadriceps thickness to predict high ADL were -7.89% (sensitivity: 77.8%, specificity: 55.6%) and -28.1% (sensitivity: 81.0%, specificity: 58.8%), respectively. Conclusions: The relative decreases in calf circumference and quadriceps thickness during hospitalization were lower in patients who maintained their ADL. Assessment of the trajectory of physical function can predict ADL status at hospital discharge among ICU survivors.

Reliability and Validity of Quadriceps Muscle Thickness Measurements in Ultrasonography: A Comparison with Muscle Mass and Strength.

Objectives: Measurement of skeletal muscle using ultrasonography (US) has received considerable attention as an alternative method of muscle assessment. However, intra- and inter-rater reliability remains controversial. Furthermore, there is no consensus regarding the relationship between muscle assessment using US and muscle mass or physical assessment. We aimed to verify the validity and reliability of muscle measurements using US and its relationships with muscle strength and physical assessment. Methods: The 22 participants were all healthy men. Quadriceps muscle thickness was measured by US by three different raters. Intraclass correlation coefficient (ICC) was used to assess inter- and intra-rater reliability. The maximum isokinetic strength of the quadriceps and handgrip strength were used as measures of lower and upper muscle strength, respectively. Leg muscle mass was assessed using the leg skeletal muscle index (SMI), measured by body impedance analysis, and calf circumference. Results: The intra-rater reliability was excellent which the ICC(1,1) ranges 0.957-0.993, and ICC(1,3) ranges 0.985-0.998. For inter-rater reliability, the values of 0.904 for ICC(2,1) and 0.966 for ICC(2,3) indicated excellent reliability. Leg SMI was significantly correlated with quadriceps thickness (r=0.36). Maximum isokinetic strength and handgrip strength showed weak but statistically significant correlations with quadriceps thickness (r=0.20, r=0.30, respectively). The correlation between quadriceps thickness and calf circumference was not statistically significant. Conclusions: Quadriceps muscle assessment using US is a valid and reliable technique for healthy individuals. Quadriceps muscle thickness was significantly positively correlated with upper and lower muscle strength and leg SMI. Muscle thickness assessment could replace full body muscle assessment in clinical settings.