Critical Illness
Conditions
Keywords
critical illness, ultrasound, Inter-rater reliability, physical therapist
Brief summary
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.
Interventions
None listed
Sponsors
Clinica Indisa
University of Chile
Study design
Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Inter-rater reliability of quadriceps muscle ultrasound measurements | Assessed once within 60 days following ICU admission | Intraclass correlation coefficient (ICC) between three evaluators for ultrasound variables including quadriceps muscle thickness, rectus femoris and vastus intermedius cross-sectional area, and pennation angle. |
| Peripheral Nerve Ultrasound Inter-Rater Reliability | Assessed once within 60 days following ICU admission | Intraclass correlation coefficient (ICC) between three evaluators for cross-sectional area and echogenicity of peripheral nerves (median, ulnar, tibial, and fibular) measured by ultrasound. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Inter-rater agreement of Functional Status Score for the ICU (FSS-ICU) | Assessed once within 60 days following ICU admission | Kendall's W coefficient to assess the level of agreement among three physical therapists applying the FSS-ICU scale in critically ill patients. |
| Inter-Rater Agreement of MRC Sum Score | Assessed once within 60 days following ICU admission | Kendall's W coefficient to determine the agreement between three physical therapists applying the MRC-SS to assess muscle strength in ICU patients. |
| Correlation between clinical scales and ultrasound findings | Assessed once within 60 days following ICU admission | Pearson or Spearman correlation coefficients between MRC-SS/FSS-ICU results and quantitative ultrasound parameters. |
Countries
Chile
Contacts
Primary ContactÓscar L Arellano, MSc. PhD Candidate
Backup ContactBenito J Arévalo, MSc.
Outcome results
None listed