Interrater reliability of quantitative ultrasound measures of muscle in critically ill patients

Abstract

Background Quantitative neuromuscular ultrasound is increasingly used to study muscle pathology and changes in muscle mass during critical illness. Advantages of ultrasound are high axial resolution, low procedural risks, no ionizing radiation, and ease of use early in the course of disease. However, ultrasound is known to be an operator dependent imaging modality and the intensive care unit setting poses additional challenges to obtaining reliable measurements. There is limited evidence validating the feasibility and reliability of its application in this setting. Objective To conduct a standardized protocol for measuring muscle linear depth and cross‐sectional area in critically ill populations with a high degree of interrater agreement and feasibility. Design Prospective observational cohort study of interrater reliability. Setting Medical intensive care unit at an academic medical center and a level one trauma and burn center. Patients Fifteen critically ill patients were evaluated using a standardized ultrasound protocol measuring total elbow flexor, knee extensor, and tibialis anterior depth, as well as rectus femoris cross‐sectional area. Each site was independently scanned by two investigators. Reliability of measurements between observers was determined by calculating intraclass correlation coefficients (ICCs) using a two‐way random effects model and absolute agreement. An ICC > 0.75 was considered good and >0.90 was considered excellent. Results In critically ill patients, interrater reliability of linear depth measured at elbow flexor, knee extensor, tibialis anterior, and cross‐sectional area of rectus femoris sites was good to excellent with ICC between 0.87 (0.54–0.97) and 0.99 (0.97–1.00). Interrater reliability was improved by creating a summary index of measures resulting in an ICC of 0.99 (0.98–1.00). Feasibility, as definite by the percentage of each measure that was obtainable, ranged from 75%–100%. Conclusions Using a standardized protocol, ultrasound measures obtained in critically ill patients demonstrated high levels of interrater agreement with good to excellent feasibility.

Inter-Examiner and Intra-Examiner Reliability of Quantitative and Qualitative Ultrasonography Assessment of Peripheral and Respiratory Muscles in Critically Ill Patients

“…Finally, the muscles of the upper limb are less analyzed in relation to the quadriceps femoris. Our results corroborate the findings in the literature for the biceps brachii [18,32,33] and forearm flexors group [37]. There was less agreement, despite the excellent result, for interobserver reliability in the forearm flexor group.…”

“…Considering the muscles evaluated in this study, the quadriceps femoris is the muscle most analyzed in studies [5,17,18,33], probably because it has large dimensions and well-defined anatomical conditions, a fact that can make its assessment easier [17]. This study corroborates previous studies that demonstrated excellent inter-and intra-examiner reliability in assessing the quadriceps femoris in the ICU and with examiners with different levels of experience [5,17,18,33].…”

“…In association with the quadriceps femoris, some studies also analyzed the inter-and intra-examiner reliability of the Tibialis anterior thickness assessment [18,33]. Comparing the results between experienced and inexperienced examiners with different professional backgrounds, Mayer et al [18] found excellent inter-examiner (ICC: 0.886) and intraexaminer (ICC: 0.761-0.857) reliability for Tibialis anterior thickness assessment, as well as quadriceps femoris (ICC: 0.915 and 0.884-0.901) and biceps brachii (ICC: 0.958 and 0.924-0.962) [18].…”

Intra- and Inter-Rater Reliability and Agreement of Ultrasound Imaging of Muscle Architecture and Patellar Tendon in Post-COVID-19 Patients Who Had Experienced Moderate or Severe COVID-19 Infection

“…An ultrasound assessment may be a convenient, non-invasive tool to evaluate muscle wasting and quality, especially when assessing muscle thickness and echogenicity [ 45 , 46 ]. Here, our results demonstrated a high or very high intra- and inter-rater reliability for these two measurements.…”

"SARCOPENIA MEASURED BY ULTRASOUND IN HOSPITALIZED OLDER ADULTS" (ECOSARC): multi-centre, prospective observational study protocol

“…As there were no previous normative data regarding muscle ultrasound values in hospitalized older patients, and also because our study was exploratory, we used information from previous research in Intensive Care Units to calculate the sample size. In the study from Baston et al, using Bland–Altman plots for inter-rater reliability, a measurement bias of 0.2 cm 2 for the cross-sectional area of avQRF was described [ 46 ], allowing us to use this surrogate measure as the minimum significant value to detect real differences between measurements. Accepting an alpha risk of 0.05 and a beta risk of 0.2 in a two-sided test, 157 subjects were necessary to recognize as statistically significant a difference greater than or equal to 0.2 cm 2 in the cross-sectional area of the avQRF.…”