Physiology of Body Lateralization on Regional Lung Ventilation Study

Study Overview
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Brief Summary
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The goal of this experimental study, with crossover design, is to analyze the effects of body lateralization applied at 30 degrees compared to the supine position on the distribution of ventilation and regional lung aeration in healthy individuals. The main study questions to be answered are: Question 1: What are the immediate effects of 30 degree body lateralization on the distribution of regional ventilation and lung aeration in healthy individuals? Question 2: What is the effect of body lateralization on diaphragmatic mobility in the dependent or non-dependent hemithorax? Participants will be submitted to changes in positioning in bed, considering a randomized sequence of interventions, between supine position and body lateralization at 30 degrees, using the Multicare bed (Linet, Czech Republic). The interventions were repeated twice each with a 30-minute washout in each sequence. Participants will perform assessment of lung function and respiratory muscle strength with the instruments: Manovacuometry Spirometry Ventilometry Respiratory Diagnostic Assistant The supine and body lateralization positions will be compared, with the primary outcomes being lung aeration and ventilation distribution assessed using Electrical Impedance Tomography. The secondary outcome will be diaphragmatic mobility measured through lung ultrasound. Groups: Supine position Body lateralization Effects Lung aeration Distribution of ventilation Diaphragmatic mobility

Detailed Description
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Body positioning is a therapy used in the hospital environment to improve oxygenation. Recent studies recommend lateralization therapy to improve lung function locally by positioning the chest region of interest upwards. However, there are still gaps in the description of the effects of body lateralization on lung aeration and ventilation between non-dependent and gravity-dependent regions and on diaphragmatic mobility. The objective of this study is to analyze the acute effects of lateralization on the aeration and distribution of lung ventilation, in comparison with the supine position, in healthy subjects. In addition, the effect of body positioning on diaphragm kinetics was evaluated. This is a crossover study, which will be carried out at the Hospital das Clínicas of the Federal University of Pernambuco (HC-UFPE). The sample will consist of 30 healthy volunteers, aged between 18 and 59 years, of both sexes. The change of body position will be performed using the Multicare bed (Linet, Praga,Czech Republic). Lung ventilation and aeration will be evaluated with an Enlight 1800 electrical impedance tomography (EIT) (Timpel Medical, São Paulo, Brazil). The EIT images will be segmented into four regions of interest (ROIs: anterior right, anterior left, posterior right and posterior left. Diaphragm mobility will be quantified by diaphragmatic ultrasound in the supine and lateral positions. The study was approved by the Research Ethics Committee of the Hospital das Clínicas of the Federal University of Pernambuco (EBSERH), in accordance with the norms of the National Health Council (Resolution 466/12) for research in human beings (opinion number 5,980.254).

Official Title
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Physiological Effects of Lateral Body Positioning on Regional Ventilation and Ultrasound Diaphragmatic Mobility in Healthy Subjects: an Experimental Study

Conditions
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Healthy Individuals

Intervention / Treatment
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* Procedure: Supine Positioning
* Procedure: Body Lateral Positioning


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy individuals Volunteers aged between 18 and 59 years old (youth/adults) Volunteers of both sexes Exclusion Criteria: Individuals with contraindications for the use of manovacuometry, spirometry, ventilometry will be excluded Volunteers who did not tolerate the positioning or interventions Individuals with Grade III obesity (BMI > 40) Participants with below-normal prediction values for manovacuometry and spirometry according to predefined formulas for men and women History of flu syndrome in the last seven days.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 59 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Supine Positioning<br>The participant will be in the supine position. | Procedure: Supine Positioning<br>* The participant will be guided to the Multicare bed and will be positioned supine with the headboard not tilted. At this point, the participant will already have the EIT electrode belt and head, trunk and lower limb cushions around it, providing stability. After the participant has been correctly positioned, ventilatory monitoring will begin using the EIT. The environment must be fully controlled, that is, with adequate lighting, all collection members in silence, as well as the devices in the place, air-conditioned environment, without exposing the participant to heat or cold. Before starting the collection, the volunteer will be asked to try not to sleep or talk, making it clear that any discomfort can be reported at any time. To keep the volunteer awake, visual and sound stimuli can be performed. Furthermore, if you cough or sigh, the collection will restart. The intervention will last 5 minutes and will be repeated twice, with intervals between body lateralization.<br>* Other names: Supine;|
| Experimental: Body Lateral Positioning<br>The participant will be in the body lateral position at 30 degrees. | Procedure: Body Lateral Positioning<br>* The participant will start from the bench press to the 30-degree lateral position. The cushions placed at the beginning of the collection will provide stability so that the inclination does not compromise the correct positioning of the participant, preventing them from sliding on the bed. Furthermore, it is also a safety measure for the participant. The environment will be controlled throughout the intervention and visual and sound effects will also be performed in lateral positioning. The volunteer will remain in this position for five minutes and shortly after will be placed in the supine position again. To start the protocol for the second and final time, the participant will have a washout time of thirty minutes.<br>* Other names: Automatic lateral therapy;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in end-expiratory lung impedance (Delta EELZ) | Lung aeration will be assessed using Electrical Impedance Tomography (EIT). Regional EELZ will be calculated and analyzed concerning intervention times. The change in aeration distribution or change in end-expiratory lung impedance (Delta EELZ) will be determined by comparing pre- and post-intervention EELZ for lung quadrants and dependent/non-dependent regions in each intervention. End-expiratory lung impedance (EELZ) represents the sum of the end-expiratory impedance values of the pixels in a given region of interest. Regions of interest include: right anterior, left anterior, right posterior and left posterior, and functionally, dependent or non-dependent lung. Continuous EIT monitoring will occur, and outcomes will be assessed before and after each intervention, each lasting five minutes. Data are given in: arbitrary units (a.u.) mililiters percentages | Not later than 12 months after primary completion date | 
| Change in distribution of lung ventilation (Delta Z) | The distribution of lung ventilation will also be assessed using electrical impedance tomography. The impedance variation (Delta Z) represents the sum of the impedance values of the pixels in a given region of interest. Regions of interest include: right anterior, left anterior, right posterior and left posterior, and functionally, dependent or non-dependent lung. The change in distribution of lung ventilation will be obtained by the difference between the Delta Z before and after each intervention, comparing the measurements of the lung quadrants and in the dependent and non-dependent lung regions for each intervention. Continuous EIT monitoring will occur, and outcomes will be assessed before and after each intervention, each lasting five minutes. Data are given in: arbitrary units (a.u.) mililiters percentages | Not later than 12 months after primary completion date | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in diaphragmatic mobility measured by ultrasound between the supine and body lateralization positions. | Diaphragmatic mobility will be evaluated in the supine position and in the body lateralization position during the intervention using ultrasound, according to protocol from TESTA, A. et al 2011. Measurements will be carried out with the patient breathing spontaneously in supine and body lateralization position at 30º. Data are given in: • Millimeters. | Not later than 12 months after primary completion date | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Healthy Volunteers, Patient Positioning, Pulmonary Ventilation