Physical Therapist Inter-Rater Reliability in Neuro-Muscle Ultrasound in Critically Ill Patients

Official title

Pilot Study: Validation of Operators and Inter-Evaluator Variability in Diagnostic Strategies for ICU-Acquired Weakness (NMusICU-R)

Overview

The goal of this observational study is to evaluate the feasibility and inter-rater reliability of muscle and peripheral nerve ultrasound for the early detection of ICU-acquired weakness (ICU-AW) in critically ill patients. The main questions it aims to answer are: Can ICU physical therapists consistently measure muscle and nerve ultrasound variables such as muscle thickness, cross-sectional area, pennation angle, and echogenicity in critically ill patients? Do clinical scales (MRC-SS and FSS-ICU) show inter-evaluator agreement and correlate with ultrasound findings? Participants are adult ICU patients at Clínica INDISA who are undergoing routine neuromuscular assessments by trained physical therapists. Each patient will be evaluated by three independent raters using ultrasound and standardized clinical scales. Data will be collected and analyzed to determine inter-rater reliability and correlations between clinical and imaging findings.

Detailed description

This observational, cross-sectional pilot study aims to assess the inter-rater reliability of muscle and peripheral nerve ultrasound and functional clinical scales in the diagnosis of ICU-acquired weakness (ICU-AW). The study involves adult patients admitted to the Adult Critical Care Unit at Clínica INDISA (Santiago, Chile). Participants will undergo muscle ultrasound of the quadriceps (measuring anterior compartment thickness, cross-sectional area, and pennation angle) and peripheral nerve ultrasound (assessing cross-sectional area and echogenicity of specific nerves) performed by three trained physical therapists. Clinical assessments using the MRC Sum Score (MRC-SS) and the Functional Status Score for the ICU (FSS-ICU) will also be performed by each rater.

The main aim is to evaluate the agreement between raters using the intraclass correlation coefficient (ICC) for ultrasound variables and Kendall's W for functional scales. The study will also explore correlations between clinical scores and ultrasound findings using Pearson or Spearman correlation coefficients. Echogenicity will be quantified using ImageJ software.

All procedures are performed at bedside using portable ultrasound equipment, and evaluations follow safety guidelines for critically ill patients. The results of this study will contribute to validating physical therapists as reliable operators for early identification of ICU-AW using ultrasound-based tools and standardized clinical assessments.

Primary outcome measures

• Inter-rater reliability of quadriceps muscle ultrasound measurements [Time frame: Assessed once within 60 days following ICU admission]
• Peripheral Nerve Ultrasound Inter-Rater Reliability [Time frame: Assessed once within 60 days following ICU admission]

Secondary outcome measures (3)

• Inter-rater agreement of Functional Status Score for the ICU (FSS-ICU) [Time frame: Assessed once within 60 days following ICU admission]
• Inter-Rater Agreement of MRC Sum Score [Time frame: Assessed once within 60 days following ICU admission]
• Correlation between clinical scales and ultrasound findings [Time frame: Assessed once within 60 days following ICU admission]

Eligibility criteria

Inclusion criteria

• Adult patients (≥18 years old) admitted to the Adult Intensive Care Unit (ICU) of Clínica INDISA.
• Conscious and clinically stable at the time of assessment.
• Able to provide written informed consent.

Exclusion criteria

• Known allergy to ultrasound gel.
• Body mass index (BMI) ≥ 30 kg/m².
• Pre-existing neuromuscular disease.
• Continuous renal replacement therapy or severe hepatic coagulopathy.
• Platelet count < 20,000/µL.
• Lower limb amputation or recent fractures.
• Ongoing chemotherapy or immunosuppressive treatment with corticosteroids.
• Epileptic status or pregnancy.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Case-only

Study locations

Chile · 1 center

• Clínica INDISA — Santiago

Publications

• Lefaucheur JP, Nordine T, Rodriguez P, Brochard L. Origin of ICU acquired paresis determined by direct muscle stimulation. J Neurol Neurosurg Psychiatry. 2006 Apr;77(4):500-6. doi: 10.1136/jnnp.2005.070813. Epub 2005 Nov 23. PMID 16306155
• Formenti P, Umbrello M, Coppola S, Froio S, Chiumello D. Clinical review: peripheral muscular ultrasound in the ICU. Ann Intensive Care. 2019 May 17;9(1):57. doi: 10.1186/s13613-019-0531-x. PMID 31101987
• Paolo F, Valentina G, Silvia C, Tommaso P, Elena C, Martin D, Marini John J, Davide C. The possible predictive value of muscle ultrasound in the diagnosis of ICUAW in long-term critically ill patients. J Crit Care. 2022 Oct;71:154104. doi: 10.1016/j.jcrc.2022.154104. Epub 2022 Jul 4. PMID 35797827
• Lad H, Saumur TM, Herridge MS, Dos Santos CC, Mathur S, Batt J, Gilbert PM. Intensive Care Unit-Acquired Weakness: Not just Another Muscle Atrophying Condition. Int J Mol Sci. 2020 Oct 22;21(21):7840. doi: 10.3390/ijms21217840. PMID 33105809
• Elkalawy H, Sekhar P, Abosena W. Early detection and assessment of intensive care unit-acquired weakness: a comprehensive review. Acute Crit Care. 2023 Nov;38(4):409-424. doi: 10.4266/acc.2023.00703. Epub 2023 Nov 30. PMID 38052508
• Rajagopal K, Vijayan D, Thomas SM. Association of SOFA Score with Severity of Muscle Wasting in Critically Ill Patients: A Prospective Observational Study. Indian J Crit Care Med. 2023 Oct;27(10):743-747. doi: 10.5005/jp-journals-10071-24540. PMID 37908434
• Beekman R, Visser LH. High-resolution sonography of the peripheral nervous system -- a review of the literature. Eur J Neurol. 2004 May;11(5):305-14. doi: 10.1111/j.1468-1331.2004.00773.x. PMID 15142223
• Gruber L, Loizides A, Gruber H, Skalla E, Haushammer S, Horlings C, Beer R, Helbok R, Loscher WN. Differentiation of Critical Illness Myopathy and Critical Illness Neuropathy Using Nerve Ultrasonography. J Clin Neurophysiol. 2023 Nov 1;40(7):600-607. doi: 10.1097/WNP.0000000000000922. Epub 2022 Jan 25. PMID 35089907

Identifiers

NCT: NCT07032870 · 176-25-24

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗