Physical therapist agreement on muscle and nerve ultrasound for ICU patients

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

This project will test whether trained physical therapists can consistently use bedside ultrasound and clinical scales to detect ICU-acquired weakness in adult ICU patients.

Quick facts

• Study type: Observational
• Enrollment: 37 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: University of Chile (Academic / other)
• Drugs / interventions: chemotherapy
• Locations: 1 site (Santiago, Metropolitan Region)
• Trial ID: NCT07032870 on ClinicalTrials.gov

What this trial studies

This is an observational, cross-sectional pilot conducted in the Adult ICU at Clínica INDISA where each enrolled patient is examined at the bedside by three independent, trained physical therapists. Raters will perform quadriceps muscle ultrasound (anterior compartment thickness, cross-sectional area, pennation angle) and peripheral nerve ultrasound (cross-sectional area and echogenicity), with echogenicity quantified using ImageJ. Each rater will also administer the MRC Sum Score and the FSS-ICU, and analyses will calculate intraclass correlation coefficients for ultrasound measures, Kendall's W for functional scales, and Pearson or Spearman correlations between imaging and clinical scores. All procedures use portable ultrasound and follow ICU safety guidelines with the goal of validating physical therapists as reliable operators for early identification of ICU-acquired weakness.

Who should consider this trial

Good fit: Adults (≥18) admitted to the Adult ICU at Clínica INDISA who are conscious, clinically stable, able to give written consent, and who do not meet exclusion criteria such as BMI ≥30, pre-existing neuromuscular disease, severe coagulopathy, or ongoing renal replacement therapy.

Not a fit: Patients who are sedated or unconscious, have BMI ≥30, recent limb amputation or fractures, pre-existing neuromuscular disease, severe coagulopathy, active chemotherapy or immunosuppression, or are pregnant are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this could enable physical therapists to identify ICU-acquired weakness earlier and more reliably at the bedside, supporting quicker rehabilitation and care decisions.

How similar studies have performed: Prior studies have shown that muscle ultrasound metrics and clinical scales can demonstrate acceptable inter-rater reliability and correlate with weakness, but using physical therapists as independent ultrasound operators in ICU settings is relatively novel and largely limited to pilot work.

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.

Where this trial is running

Santiago, Metropolitan Region

• Clínica INDISA — Santiago, Metropolitan Region, Chile (Recruiting)

Study contacts

• Study coordinator: Óscar L Arellano, MSc. PhD Candidate

Conditions Critical Illness; critical illness; ultrasound; Inter-rater reliability; physical therapist