Diaphragm, Healthy Volunteers, Respiratory Rate
Conditions
Keywords
High flow nasal canula, High flow nasal canula therapy, Diaphragm thickening fraction, Work of breathing, Respiratory rate
Brief summary
The use of high-flow nasal cannula (HFNC) has increased. Diaphragmatic ultrasonography is a tool that, as a noninvasive complement to esophageal pressure (Pes) measurement, allows the evaluation of diaphragm function and reflects, through the diaphragm thickening fraction (DTf), the magnitude of diaphragmatic fiber recruitment. The objective of this study was to evaluate the impact of HFNC therapy on the DTf in healthy subjects. Second, this study aimed to assess the behavior of the respiratory rate (RR) and the work of breathing in these subjects.
Interventions
DEVICEHigh flow nasal canula
Measurement of diaphragm thickening fraction, respiratory rate and esophageal pressure swing with calculation of diaphragmatic pressure-time product without the use of HFNC and with the use of HFNC at 20 and 40 Liters per minute
Sponsors
Argentinian Intensive Care Society
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* healthy subjects over 18 years old
Exclusion criteria
* contraindication for esophageal balloon placement * diagnosis of lung disease * smokers
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diaphragm thickening fraction. | Immediately after 5 min of each condition (baseline, 20 and 40 liters per minute) the diaphragmatic thickness was measured at the end of inspiration y de la expiration during 3 consecutive respiratory cycles (each cycle is between 3 and 10 seconds) | ultrasound measurements were performed by an expert operator (the same in all cases). The ultrasound measurement was performed using a high-resolution linear transducer in real-time in B-mode. The diaphragm thickness was measured at the end of expiration and the end of inspiration of the same ventilatory cycle and the average value of 3 ventilatory cycles was recorded. A 2-minute washout period was allowed between each test condition to avoid the summation of effects. The DTf and PTPes/min were calculated for each subject in each available condition (baseline - without flow- , wtih 20 and 40 liters per minute): DTf = End Inspiratory Diaphragm thickening - End Expiratory Diaphragm thickening / End Expiratory Diaphragm thickening x 100 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Respiratory Rate | The number of breaths per minute was recorded in 60 seconds. | The number of breaths per minute was recorded in 60 seconds. |
| Esophageal pressure swing (Pes). | 5 minutes each condition | Difference between basal Pes and maximum inspiratory Pes deflection. |
| Esophageal pressure-time product per minute (PTPes/min). | Through study completion, an average of 24 weeks | It was calculated as the area determined by esophageal deflection multiplied by respiratory rate. An ad hoc software developed in MATLAB R2018b (The MathWorks, Inc. Massachusetts, United States) was used for this purpose. |
Countries
Argentina
Outcome results
None listed