Study on the Measurement Method of the Left Diaphragm (LD)

To Study the Consistency of Multiple Measurement Methods of Left Diaphragm Mobility in Critically Ill Patients

This study intends to use ultrasound to measure the bilateral diaphragmatic ultrasound indicators in critically ill patients, focusing on the left diaphragm, and to explore the consistency and reliability among various ultrasound indicators to evaluate the diaphragmatic mobility

Study Overview

• Status: Not yet recruiting
• Conditions: Critical Illness

• Study Type: Observational
• Enrollment (Estimated): 35

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Critically ill patients

Description

Inclusion Criteria:

• ①Adult patients (≥18 years old) of both sexes;

  • In invasive group, intubation or tracheotomy was changed to 5L/min T-tube or tracheotomy mask oxygen inhalation;

    • Patients in non-invasive group were treated with mask oxygen 5L/min;

      • agree to participate in the trial and sign the informed consent;

Exclusion Criteria:

• ①The diaphragm ultrasound operation site was too large to obtain images.

  • Diaphragmatic ultrasound images could not be obtained in any section;

    • The ultrasound image quality of any section was poor;

      • the presence of phrenic nerve injury/paralysis ⑤ pregnant women; ⑥ Neuromuscular diseases such as ALS and myasthenia gravis affect the evaluation of spontaneous breathing ⑦ Patients deemed by the investigator to be ineligible.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Invasive respiratory support group; The subjects of ultrasound measurement were patients with invasive mechanical ventilation
Noninvasive respiratory support group; The subjects of ultrasound measurement were patients with non-invasive respiratory support

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Consistency of diaphragmatic mobility measurements between the standard and modified positions on the left side.	The main purpose is to verify the consistency of the two methods, Measurements were performed after switching patients in the invasive group (intubated patients to T-piece oxygen at 5 L/min and tracheostomized patients to face mask oxygen at 5 L/min following weaning), and patients in the non-invasive group (those receiving non-invasive ventilation or high-flow oxygen therapy) to conventional face mask oxygen at 5 L/min.	Measurements were performed 5 minutes after all patients were switched to conventional oxygen therapy at 5 L/min for the first time, once breathing had stabilized.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Consistency of diaphragmatic excursion measurements between the standard position and the other four positions on the left side.	Consistency of measurement methods，Measurements were performed after switching patients in the invasive group (intubated patients to T-piece oxygen at 5 L/min and tracheostomized patients to face mask oxygen at 5 L/min following weaning), and patients in the non-invasive group (those receiving non-invasive ventilation or high-flow oxygen therapy) to conventional face mask oxygen at 5 L/min.	Measurements were performed 5 minutes after all patients were switched to conventional oxygen therapy at 5 L/min for the first time, once breathing had stabilized.
Consistency of diaphragmatic excursion measurements between the standard position and the other five positions on the right side.	Consistency of measurement methods，Measurements were performed after switching patients in the invasive group (intubated patients to T-piece oxygen at 5 L/min and tracheostomized patients to face mask oxygen at 5 L/min following weaning), and patients in the non-invasive group (those receiving non-invasive ventilation or high-flow oxygen therapy) to conventional face mask oxygen at 5 L/min.	Measurements were performed 5 minutes after all patients were switched to conventional oxygen therapy at 5 L/min for the first time, once breathing had stabilized.

Collaborators and Investigators

• Sponsor: Shanghai Zhongshan Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): May 5, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: April 12, 2026
• First Submitted That Met QC Criteria: April 23, 2026
• First Posted (Actual): April 30, 2026

Study Record Updates

• Last Update Posted (Actual): April 30, 2026
• Last Update Submitted That Met QC Criteria: April 23, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: critical illness; Diaphragm ultrasound
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Pathological Conditions, Signs and Symptoms; Critical Illness
• Other Study ID Numbers: B2026-162

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No