Bedside Ultrasound Is a Practical and Reliable Measurement Tool for Assessing Quadriceps Muscle Layer Thickness

Abstract

Background Critically ill patients commonly experience skeletal muscle wasting that may predict clinical outcome. Ultrasound is a noninvasive method that can measure muscle quadriceps muscle layer thickness (QMLT) and subsequently lean body mass (LBM) at the bedside. However, currently the reliability of these measurements are unknown. The objectives of this study were to evaluate the intra- and interreliability of measuring QMLT using bedside ultrasound. Methods Ultrasound measurements of QMLT were conducted at 7 centers on healthy volunteers. Trainers were instructed to perform measurements twice on each patient, and then a second trainee repeated the measurement. Intrarater reliability measured how consistently the same person measured the subject according to intraclass correlation (ICC). Interrater reliability measured how consistently trainer and trainee agreed when measuring the same subject according to the ICC. Results We collected 42 pairs of within operator measurements with an ICC of .98 and 78 pairs of trainer-to-trainee measurements with an ICC of .95. There were no statistically significant differences between the trainer and trainee results (trainer and trainee mean = −0.028 cm, 95% CI = −0.067 to −0.011, P = .1607). Conclusions Excellent intra- and interrater reliability for ultrasound measurements of QMLT in healthy volunteers was observed when performed by a range of providers with no prior ultrasound experience, including dietitians, nurses, physicians, and research assistants. This technique shows promise as a method to evaluate LBM status in ICU or hospital settings and as a method to assess the effects of nutrition and exercise-based interventions on muscle wasting.

Development of a bedside viable ultrasound protocol to quantify appendicular lean tissue mass

“…The four‐site protocol imaged the anterior surface of the left and right rectus femoris and vastus intermedialis muscles at (i) the mid‐point between the anterior superior iliac spine and the upper pole of the patella and (ii) two‐thirds distal from the anterior superior iliac spine to the upper pole of the patella 20. Each landmark was imaged twice, using minimal and maximal compression.…”

Morphological and functional relationships with ultrasound measured muscle thickness of the lower extremity: a brief review

“…Reported estimates of reliability were good to high. [13][14][15][16][17][18][19][20][21] With the exception of a study reported by Thoirs and Englsh, 15 the reported intrarater correlation coefficients (ICC) among studies ranged between 0.90 and 0.99. Thoirs and Englsh 15 reported that high test-retest reliability was indicated in the lower extremity when subjects were measured in a standing position (ICC, 0.70-0.89; 95% confidence interval (CI), 0.79-0.94 for anterior thigh and 0.49-0.84 for posterior thigh, respectively).…”

“…Two studies 16,21 reported interrater reliability in the lower extremity muscles and the values demonstrated high reliability (ICC, 0.82 and 0.95). Furthermore, a study 19 investigated inter-machine reliability of different ultrasound machines and found that inter-machine reliability was considered excellent.…”

Rectus femoris (RF) ultrasound for the assessment of muscle mass in older people

“…Ultrasound is of lower cost than DEXA and the size of the equipment allows its use in field studies or at bedside in hospitalized patients. RF was chosen to perform the measurements because it is commonly assessed in ultrasound studies (Tillquist et al, 2014) and changes in its cross sectional area after training are may be more prominent than in other muscles (Seynnes, de Boer, & Narici, 1985). Most studies have compared muscle volumes measured by different methods but have not included precise determinations of muscle mass.…”