Radioaerossol Pulmonary Deposition Using Mesh in Normal Subjects

Study Overview
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Brief Summary
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In vivo deposition studies of aerosol administration during noninvasive ventilation are scarce in the current literature. We assessed 10 normal subjects in a crossover study evaluated by pulmonary scintigraphy aiming to compare radiaoaerosol pulmonary index and radioaerosol mass balance in the different compartments (pulmonary and extrapulmonary) of radiotagged aerosol administered using vibrating mesh nebulizers (VMN) and conventional jet nebulizer (JN) during noninvasive ventilation (NIV).

Official Title
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RADIOAEROSSOL PULMONARY DEPOSiTION USING MESH AND JET NEBULIZERS DURING NONINVASIVE VENTILATION IN NORMAL SUBJECTS: A RANDOMIZED CROSSOVER CLINICAL TRIAL

Conditions
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Normal Subjects

Intervention / Treatment
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* Other: Mesh nebulizer
* Other: Jet nebulizer
* Other: Noninvasive ventilation-NIV


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: No history of lung disease; Forced vital capacity (FVC) or forced expiratory volume in the first second (FEV1) higher or equal to 80% from predicted values (Pereira et al., 1992), No history of smoking; Without respiratory or cardiovascular disease; Ability to understand verbal commands; Willing to provide signed consent to participate in this study. Exclusion Criteria: Pregnant; Were unable to tolerate NIV (Metha and Hill, 2001).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: NIV plus jet<br>Noninvasive ventilation-NIV plus jet nebulizer | Other: Jet nebulizer<br>* The JN (Misty Max, Air Life, Yorba Linda, USA) with a particle MMAD of 5 µm (according to the manufacturer information) was positioned in the circuit using a T piece placed between the circuit leak and the mask, and operated with oxygen flow at 8 L/min. Inhalation was performed using diethilene triamine penta-acetic technetium (99mTc-DTPA) with radioactivity of 25 millicuries (Nobre et al., 2007). Both nebulizers were charged with 2.5 mg of salbutamol and 0.25 mg of ipratropium bromide and normal saline solution to complete a fill volume of 3 mL.<br>Other: Noninvasive ventilation-NIV<br>* Bilevel positive airway pressure (BiPAP Synchrony, Respironics®, Murrysville, Pennsylvania, USA) was applied through face mask (Comfort Full 2, Respironics®, Murrysville, Pennsylvania, USA) attached with straps and pressure adjusted to12 cmH2O peak inspiratory pressure and 5 cmH2O of expiratory pressure at the beginning of the procedure. Patients were adapted to use NIV before starting measurements, pressures were titrated before reaching the established levels and just after this period masks were fitted using the straps. They were oriented to use a breathing pattern inspiring deeply and exhaling slowing to avoid ventilator-patient asynchrony.<br>|
| Experimental: NIV plus Mesh<br>Noninvasive ventilation- NIV plus Mesh nebulizer | Other: Mesh nebulizer<br>* VMN (NIVO, Respironics®, Murrysville, Pennsylvania, USA) with an MMAD of 3.0 µm was placed in the elbow adapter at the mask. Inhalation was performed using diethilene triamine penta-acetic technetium (99mTc-DTPA) with radioactivity of 25 millicuries (Nobre et al., 2007). Both nebulizers were charged with 2.5 mg of salbutamol and 0.25 mg of ipratropium bromide and normal saline solution to complete a fill volume of 3 mL.<br>Other: Noninvasive ventilation-NIV<br>* Bilevel positive airway pressure (BiPAP Synchrony, Respironics®, Murrysville, Pennsylvania, USA) was applied through face mask (Comfort Full 2, Respironics®, Murrysville, Pennsylvania, USA) attached with straps and pressure adjusted to12 cmH2O peak inspiratory pressure and 5 cmH2O of expiratory pressure at the beginning of the procedure. Patients were adapted to use NIV before starting measurements, pressures were titrated before reaching the established levels and just after this period masks were fitted using the straps. They were oriented to use a breathing pattern inspiring deeply and exhaling slowing to avoid ventilator-patient asynchrony.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Radioaerosol deposition index | Inhalation was performed using diethilene triamine penta-acetic technetium (99mTc-DTPA) with radioactivity of 25 millicuries (Nobre et al., 2007). Both nebulizers were charged with 2.5 mg of salbutamol and 0.25 mg of ipratropium bromide and normal saline solution to complete a fill volume of 3 mL. The JN (Misty Max, Air Life, Yorba Linda, USA) with a particle MMAD of 5 µm (according to the manufacturer information) was positioned in the circuit using a T piece placed between the circuit leak and the mask, and operated with oxygen flow at 8 L/min. VMN (NIVO, Respironics®, Murrysville, Pennsylvania, USA) with an MMAD of 3.0 µm was placed in the elbow adapter at the mask. | 4 m | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Radioaerosol mass balance in pulmonary and extrapulmonary compartments | the same procedure was performed to analysis deposition in the nebulizer, circuits, inspiratory filter, expiratory filter and face mask. Counts representing stomach were obtained from posterior thorax and corrections for decay of technetium were used during extrapulmonary measurements. The analysis of deposition in pulmonary and extrapulmonary compartments was expressed as a percentage from the cumulative count in each compartment representing the total radioaerosol mass. | 4 m |