Impact of 3D-EIT-Guided Acapella Breathing Training on Lung Ventilation Distribution

N/ANot Yet RecruitingNCT07733843

Shanghai Zhongshan Hospital30 enrolled

Overview

The goal of this randomized clinical trial is to determine whether real-time visual feedback from three-dimensional electrical impedance tomography (3D-EIT) can improve the effects of Acapella breathing exercises in adults recovering from critical illness. 3D-EIT is a noninvasive bedside imaging method that provides real-time information about how ventilation is distributed within the lungs. Participants will be randomly assigned to one of two groups. Both groups will perform a standardized Acapella breathing exercise while 3D-EIT data and vital signs are recorded. Participants in the control group will receive routine verbal and demonstration-based breathing instructions without viewing the EIT images. Participants in the intervention group will receive the same instructions and will also view their own real-time 3D-EIT ventilation images. They will use this visual feedback to adjust their breathing with the goal of increasing ventilation in the dorsal regions of the lungs and/or achieving a more even distribution of ventilation. The main question is whether 3D-EIT-guided visual feedback results in a greater improvement in end-expiratory lung impedance (EELI) after breathing exercise compared with routine instruction alone. The study will also examine changes in regional ventilation distribution, ventilation inhomogeneity, vital signs, breathing discomfort, comfort and tolerance, achievement of the breathing-training target, and adverse events. Approximately 30 participants will be enrolled and randomly assigned in a 1:1 ratio to the two study groups.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Enrollment

Conditions

Interventions

Acapella Oscillating Positive Expiratory Pressure Breathing ExerciseDEVICE

Participants will perform standardized breathing exercises using an Acapella oscillating positive expiratory pressure device. Each session will consist of 3 sets of 8-10 breaths, with 10-15 seconds of rest between breaths and 1-2 minutes of rest between sets. Participants will be instructed to inhale slowly and exhale through the Acapella device. The resistance setting will be predetermined and kept unchanged throughout the session.

Real-Time 3D Electrical Impedance Tomography Visual BiofeedbackDEVICE

Participants in the experimental group will view their own real-time 3D electrical impedance tomography (3D-EIT) ventilation images while performing standardized Acapella breathing exercises. The visual feedback will be used to guide breathing adjustments with the aim of increasing dorsal lung ventilation and/or improving ventilation homogeneity. The 3D-EIT system will also record ventilation data for outcome assessment.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age ≥18 years. * Adult patients in the stable recovery phase following critical illness, breathing spontaneously, alert, and able to follow instructions (suggested Richmond Agitation-Sedation Scale \[RASS\] score of -1 to +1). * Hemodynamically stable, with no vasopressor support or only a low and stable dose of vasopressors. * Receiving stable low-flow oxygen therapy or equivalent non-escalating respiratory support, without an anticipated need for escalation in the short term. * Clinically considered suitable for standardized Acapella breathing exercises. * Able and willing to provide written informed consent. Exclusion Criteria: * Significant hemodynamic instability or clinically significant cardiac arrhythmia. * Untreated pneumothorax or active hemoptysis. * Severe chest wall skin injury or allergy to electrode materials that prevents application of the electrical impedance tomography electrodes. * Significant delirium or inability to understand or follow study instructions. * Any other condition that, in the investigator's judgment, makes the participant unsuitable for participation in the study.

Outcomes

Primary Outcomes

Change From Baseline in End-Expiratory Lung Impedance (ΔEELI)

Change in end-expiratory lung impedance (ΔEELI) will be measured using three-dimensional electrical impedance tomography (3D-EIT). ΔEELI is defined as the EELI measured during the stable breathing period after the intervention minus the EELI measured during the stable breathing period before the intervention.

Time frame: From baseline before the intervention to 10 minutes after completion of the single Acapella training session

Secondary Outcomes

Change From Baseline in Dorsal Lung Ventilation Proportion

The proportion of ventilation distributed to the dorsal lung regions will be measured using 3D electrical impedance tomography (3D-EIT). Change will be calculated as the post-intervention value minus the baseline value.

Time frame: Baseline and after a 10-minute recovery period following the single Acapella training session

Change From Baseline in Global Inhomogeneity Index

Ventilation inhomogeneity will be assessed using the Global Inhomogeneity (GI) Index derived from 3D-EIT data. Change will be calculated as the post-intervention GI Index minus the baseline GI Index.