Respiratory Failure
Conditions
Keywords
Diaphragm, Speckle Tracking, PEEP
Brief summary
Study Objective This prospective observational study aims to investigate the role of the Diaphragmatic Physiology Similarity Index (DPSI) derived from speckle tracking ultrasound in titrating high-flow nasal cannula (HFNC) flow settings, and to evaluate its application in patients with acute respiratory failure. Primary Research Questions To characterize the features of the DPSI in healthy individuals and in patients with acute respiratory failure. To assess the behavior of the DPSI under different HFNC flow settings in patients with acute respiratory failure. Secondary Research Questions Feasibility and inter-operator reproducibility of diaphragmatic speckle tracking. Assessment of the Diaphragmatic Contraction Synchrony Index. Evaluation of End-Diaphragmatic Residual Contraction (EDRC). Additional fundamental parameters, including diaphragmatic displacement velocity and maximum displacement.
Interventions
OTHERHigh-flow adjustment sequence
Delivers heated, humidified blended oxygen via HFNC with real-time titration based on diaphragmatic speckle-tracking metrics (e.g., DPSI, contraction synchrony). Flow is adjusted in predefined increments to reach target diaphragmatic physiology while FiO₂ is titrated to maintain target SpO₂. Ultrasound feedback is used for bedside decisions; safety triggers allow clinical override.
Sponsors
Sir Run Run Shaw Hospital
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Caregiver)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Feasibility and reproducibility：adult ICU patients Methodology for diaphragmatic motion synchrony:healthy adults and adult ICU patients Between-group comparisons and flow-titration study Inclusion Criteria: 1. Age ≥18 years old. 2. Clear diagnosis of respiratory failure requiring respiratory support. 3. Expected duration of respiratory support ≥24 hours or (high-flow/non-invasive ventilation) ≥48 hours. 4. Voluntary participation in this study and signed informed consent. If the participant is unable to read or sign the informed consent form due to incapacity (e.g., unconsciousness), the legal guardian must act as a proxy in the informed consent process and sign the form. If the participant cannot read the consent form (e.g., illiterate participants), a witness must observe the informed consent process and sign the form.
Exclusion criteria
1. Severe chest wall deformities or diaphragmatic paralysis. 2. End-stage disease with a predicted life expectancy of less than 24 hours. 3. Inability to acquire STE (strains and echoes) images (e.g., severe subcutaneous emphysema, position limitations). 4. Vulnerable groups other than critically ill patients/elderly/illiterate individuals, including those with mental disorders, cognitive impairments, pregnant women, etc.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diaphragmatic Physiology Similarity Index (DPSI) | Healthy Participants: Baseline； Baseline evaluation at the time of enrollment change with each change in ventilation parameters. | The objective of this prospective observational study is to explore the Diaphragmatic Physiology Similarity Index (DPSI), derived from speckle tracking ultrasound, in guiding the adjustment of high-flow nasal cannula (HFNC) flow settings, and to assess its application in patients with acute respiratory failure. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Adverse events including pneumothorax, hemodynamic instability, and other complications | At baseline (upon enrollment), 1 hour / 6 hours / 24 hours after intervention, and during daily morning assessments until extubation or day 28. | — |
| Arterial blood gas analysis (ABG analysis) | At baseline (upon enrollment), 1 hour / 6 hours / 24 hours after intervention, and during daily morning assessments until extubation or day 28. | — |
| Diaphragmatic Contraction Synchrony Index | After each HFNC flow adjustment: Measure contraction synchrony during each flow setting period. | Evaluate the diaphragmatic contraction synchrony index, assessing the degree to which the diaphragm contracts as a coordinated unit. |
| ICC (Intraclass Correlation Coefficient) | At each ultrasound assessment, record the percentage of analyzable images. Compare measurements at the beginning and throughout the study among operators. | Evaluate the feasibility and inter-operator reproducibility of diaphragmatic speckle tracking ultrasound. |
| Evaluation of End-Diaphragmatic Residual Contraction (EDRC) | After each mechanical ventilation period: Measure EDRC at the end of the mechanical ventilation phase, noting the diaphragm's ability to recover. | Assess the residual contraction of the diaphragm after mechanical ventilation to understand its recovery ability. |
| Diaphragmatic Displacement Velocity and Maximum Displacement | At each flow setting change: Measure the diaphragm's displacement velocity and maximum displacement at each HFNC flow rate adjustment. | Displacement Velocity: The speed at which the diaphragm moves during each breath cycle. Maximum Displacement: The maximum distance the diaphragm moves during inhalation and exhalation. |
| Diaphragmatic ultrasound parameters (maximum displacement, thickening fraction, etc.) | At baseline (upon enrollment), 1 hour / 6 hours / 24 hours after the intervention, and daily morning assessments until extubation or day 28. | — |
Countries
China
Contacts
CONTACTHuiqing Ge
CONTACTYiqing Xu
STUDY_CHAIRHuiqing Ge
Sir Run Run Shaw Hospital
Outcome results
None listed