Heliox on the Work of Breathing in Adult Patients With Lower Airway Stenosis
NCT Number: NCT06457399
Status: ACTIVE_NOT_RECRUITING
Study Type: OBSERVATIONAL
Conditions: Airway Obstruction
Interventions: DRUG: Heliox|DRUG: Oxygen
Sponsor: Hospital Universitario 12 de Octubre
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 18
Study Design: Observational Model: |Time Perspective: p
Start Date: 2022-04-27
Completion Date: 2024-11
Locations: Marta Corral Blanco, Madrid, 28041, Spain

Summary:
Heliox (a mixture of Helium and Oxygen) can reduce the work of breathing in patients with airway stenosis by modifying turbulent flow into laminar flow. The aim of this study was to analyze the effect of Heliox versus conventional oxygen therapy in patients with lower airway stenosis on muscular effort measured by electromyography and diaphragmatic ultrasound, thoracoabdominal synchrony assessed with plethysmographic bands, dyspnea, stridor, oxygen saturation, transcutaneous carbon dioxide value, blood pressure, heart rate and respiratory rate.

Primary Outcome Measures: Changes in Neural Ventilatory Drive (%):, Percentage over the Root Mean Square peak for parasternal electromyography (EMG): averaged of the square root of the peak value and the area under the curve of parasternal EMG (%RootMeanSquare) adjusted for respiratory frequency, as a surrogate of diaphragmatic EMG, and sternocleidomastoid EMG, which will give us information on accessory muscle activation., 30 minutes with Heliox and 30 minutes with Oxygen 31%
Secondary Outcome Measures: Diaphragmatic excursion assessed with ultrasound, Assessment of muscular effort by measuring the diaphragmatic excursion (mm) at tidal volume and at vital capacity., At minute 15 during the Heliox test and at minute 15 during the Oxygen 31% test.|Thickening fraction of the diaphragm assessed by ultrasound, Assessment of muscular effort by measuring the thickening fraction of the diaphragm in the apposition zone (%)., At minute 15 during the Heliox test and at minute 15 during the Oxygen 31% test.|Changes in thoracoabdominal synchrony, Assessment of thoracoabdominal synchrony using thoracic and abdominal belts by calculating the phase angle with the Lissajoux loop method (plotting abdominal motion on the x-axis against thoracic motion on the y-axis)., Phase angle was calculated from 10 consecutive breaths at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.|Borg Scale Dyspnea evolution (points), Degree of dyspnea will be determined by this validated scale with a result between 1 and 10 points.0: Not at all 0.5: Very, very light (hardly noticeable) 1: Very light, 2: Light, 3: Moderate , 4: Somewhat intense, 5: Intense, 6: Between 5 and 7, 7: Very intense, 8: Between 7 and 9, 9: Very, very intense (almost maximum ), 10: Maximum, Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.|Oxygen saturation, Measured by pulse-oximetry, Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.|Transcutaneous partial pressure of carbon dioxide, Transcutaneous monitor uses a noninvasive technique to measure the skin-surface partial pressure of carbon dioxide (PtcCO2), Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.|Blood pressure, Non-invasive measurement with a sphygmomanometer, Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.|Heart rate, number of beats per minute, Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.|Respiratory rate, Number of breaths per minute, Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.