The reliability of ultrasound assessment of muscle mass in end-stage renal disease patients receiving hemodialysis

Abstract

Introduction: Muscle wasting is a major complication of end-stage renal disease (ESRD) particularly for patients undergoing hemodialysis. Muscle wasting is associated with morbidity, increased hospitalization, and mortality in ESRD patients. With the increasing prevalence of ESRD disease, it is important to routinely assess and monitor changes in muscle size to guide interventions and monitor disease progression in this population. Ultrasound is a reliable tool for muscle thickness assessment, however, its routine application in ESRD population undergoing hemodialysis is limited by the higher rate lower limb amputation. This often makes the rectus femoris muscle, which is commonly used as a surrogate for overall muscle mass inaccessible. Therefore, there was a need to explore different muscle sites for potential ultrasound muscle thickness assessment in this population. This study aimed to explore upper limb muscles including the biceps brachii and the triceps brachii muscles as potential and reliable alternative ultrasound muscle thickness assessment sites to the rectus femoris muscle and further explore the perception of healthcare professionals and patients on the integration of ultrasound assessment of muscle thickness into routine renal care. Methods: This study was a convergent parallel design. The quantitative aspect was a longitudinal design with 50 ESRD patients (30 males and 20 females) recruited for baseline ultrasound muscle thickness measurement with recruited patients reducing to 45 (27 males and 18 females) at 3 months follow up measurements. Muscle thickness, measured in centimeters (cm) of the rectus femoris muscle, biceps brachii muscle, and triceps brachii muscle A and B were performed by two dietitians. Measurements were performed during patients’ hemodialysis session by the first dietitian and immediately by the second dietitian blinded to the results of the first rater. Interclass correlation coefficient (ICC) was conducted to assess the inter-rater reliability of ultrasound-derived muscle thickness between the raters (dietitians) across timepoint. Pearson’s correlation and Spearman’s correlation were conducted to assess the association between the thickness of the rectus femoris muscle and the biceps brachii muscle thickness and the triceps brachii muscle A and B thickness. The qualitative aspect was conducted through a semi-structured interview. Nine participants (three dietitians, two nurses, a nephrologist, and three patients) were recruited and interviewed with guided interview scripts. Interviews were analysed using the Braun and Clarke (2006) approach to thematic analysis. Results: At baseline, inter-rater reliability of rectus femoris muscle thickness was excellent (ICC (2,1)=.91, 95% CI [.83, .96], n=33), good for biceps brachii muscle thickness (ICC (2,1)=.87, 95% CI [.76, .93], n=38), moderate for triceps brachii muscle A thickness (ICC (2,1)=.53, 95% CI [.27, .73], n=38), and moderate for triceps brachii muscle B thickness (ICC (2,1)=.66, 95% CI [.44, .81], n=38). At 3 months, the biceps brachii muscle thickness retained good inter-rater reliability (ICC (2,1)=.84, 95% CI [.68, .92], n=30), and the rectus femoris muscle thickness declined to good inter-rater reliability (ICC (2,1)=.75, 95% CI [.27, .91], n=21). Both triceps brachii muscle A thickness and triceps brachii muscle B thickness declined to poor inter-rater reliability (ICC (2,1)=.32, 95% CI [-.02, .60], n=30); and (ICC =.41, 95% CI [.05, .67], n=30) respectively. There was a moderate, positive, and significant association between the rectus femoris muscle and the biceps brachii muscle thickness for rater 1 at baseline (r=.44, 95% CI [.16, .66], n=42, p=.004), at 3 months (ρ=.42, 95% CI [.10, .67], n=36, p=.01). There was a moderate, positive, and significant association between the rectus femoris muscle and the biceps brachii muscle thickness for rater 2 (r=.53, 95% CI [.12, .77], n=22, p=.01) and triceps brachii muscle B thickness (r =.45, 95% CI [-.06, .67], n=22, p=.04) at 3 months. The themes identified in the interviews included (1) current assessment of muscle status, (2) ultrasound as a valuable clinical instrument, (3) competency, (4) application of ultrasound in hemodialysis care, (5) patients’ experience and acceptance, and (6) ultrasound data as potential motivational evidence. Conclusion: The biceps brachii muscle is a potential alternative muscle site for muscle thickness assessment but future validation with gold standard criterion is warranted for the hemodialysis population. Also, healthcare professionals and patients are receptive to the integration of ultrasound muscle thickness assessment into routine care as they perceive it to improve education, communication, and motivation.