Physiology of Body Lateralization on Regional Lung Ventilation Study

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

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).

Eligibility Criteria:
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.