Introduction: Understanding how the applicability of non-invasive ventilation can directly affect the anatomy and diaphragmatic function, as well as the opening diameter of the inferior vena cava in healthy individuals is fundamental to knowing how this therapy can interfere with treatment results. Objective: Identify the acute effects of PEEP and ventilatory support pressure on thickening fraction, diaphragmatic mobility and vena cava distension in healthy people. Methods: This is a crossover, randomized study, blinded to the evaluator and the researcher responsible for the statistical analysis. Volunteers will undergo a NIV session, randomized into groups: CPAP, Bi-level and spontaneous breathing, without NIV support (control). The outcomes evaluated will be diaphragmatic ultrasound and inferior vena cava distensibility. The CPAP levels will be: 5, 10 and 15 cmH2O after 5 minutes of use and in the Bi-level group we will maintain the PEEP value at 5cmH2O and modify the pressure support values to the values: 5, 7 and 10 cmH2O pressure support, with all outcomes also being assessed after 5 minutes. Participants will remain in a supine position, with the right upper limb positioned behind the head, throughout the protocol and all measurements will be collected in the inspiratory and expiratory phases with volumes basal currents. For statistical analysis, intention-to-treat analysis will be employed and groups will be compared using Student's t-test, for continuous variables, or chi-square, for categorical variables. ANOVA split-plot, repeated measures for primary occurrences. Analyzes of covariance to identify differences between groups using baseline scores as covariates. Effect sizes and confidence intervals will be calculated using eta squared (η²). Expected results: Elucidate the effects of different blood pressure levels on diaphragmatic function and inferior vena cava distension.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
DOUBLE
Enrollment
98
Ventilation support that does not require an artificial airway that aims to reverse respiratory muscle fatigue and decrease the work of the respiratory muscles, maintaining a positive pressure, allows alveolar recruitment, preventing atelectasis and airway collapse. NIV can be administered using continuous positive airway pressure (CPAP) or two levels of airway pressure (Bi-level).
Federal University of Paraiba
João Pessoa, Paraíba, Brazil
Diaphragmatic thickening fraction
Diaphragmatic ultrasound is a useful technique for evaluating diaphragm function. To evaluate atrophy, it will be necessary to evaluate the thickening fraction (EF). A high-frequency linear transducer (7-13 MHz) will be placed over the ZA, between the eighth and ninth intercostal space, usually 0.5-2.0 cm below the costophrenic angle, between the anterior axillary line and the axillary line. medium, at a depth of 1.5 to 3 cm. The thickening fraction will be measured from the center of the pleural line to the center of the peritoneal line, at the end of expiration (Tdi-exp) and then at the end of inspiration (Tdi-insp), in modes B and M. calculated as follows: FE = Tdi-insp - Tdi-exp × 100 Tdi-exp
Time frame: The assessment will be carried out after 5 minutes of RE, CPAP or Bilevel
Diaphragmatic mobility
Diaphragmatic mobility (MD) is measured by visualizing the hemidiaphragms through the anterior subcostal route with the convex probe below the costal margin between the midclavicular line and the anterior axillary line, the ultrasound shows the diaphragm as a deep curved structure that separates the thorax from the abdomen. To quantify mobility and diaphragmatic thickening objectively, it is necessary to evaluate at least three images and calculate the average of the MD and FE values. During the assessments, we visualize the MD during calm breathing.
Time frame: The assessment will be carried out after 5 minutes of RE, CPAP or Bilevel
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