Nasal High Flow (NHF) in COPD - Effects on Ventilation in Wakefulness

Study Overview
=================
Brief Summary
-----------------
Controlled randomized crossover trial in patients with chronic obstructive respiratory disease (COPD), who are treated with Nasal High Flow (NHF) therapy during wakefulness with a small amount of CO2 added to the inhaled air to keep the patients' PaCO2 stable despite the washout effect. Aim of the study is to examine respiratory rate, tidal volume and work of breathing under NHF without the CO2 washout effect.

Detailed Description
-----------------
In this controlled randomized crossover trial, 10 stable patients with chronic obstructive respiratory disease (COPD) are treated with Nasal High Flow (NHF) therapy during wakefulness. NHF treatment will inevitably result in increased upper airway washout and thus in a slight reduction of PaCO2 of approximately 2 mmHg. For compensation, a small amount of CO2 is added to the inhaled air during this experimental situation, which keeps the patients' PaCO2 stable. This will allow to examine the effects of NHF therapy on respiratory rate, tidal volume and work of breathing, that are not attributable to the CO2 washout effect.

Official Title
-----------------
Nasal High Flow (NHF) Bei COPD - Effekte Auf Die Ventilation im Wachzustand

Conditions
-----------------
COPD

Intervention / Treatment
-----------------
* Device: Nasal High Flow (NHF)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Hospitalized COPD patients GOLD (3 and 4) in stable phase after an acute exacerbation. Written informed consent is required for participation. Exclusion Criteria: Acute respiratory failure with clinical instability or respiratory acidosis defined by pH<7.35 Severe acute physical illness that does not allow the subject to participate in a clinical trial Unable to give consent Language, cognitive, or other impairments that may prevent independent completion of questionnaires

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: NHF - NHF/CO2<br>Patients with chronic respiratory failure are treated with nasal high flow during wakefulness. First with NHF (30l/min) alone, then NHF (30l/min) plus 1% CO2. | Device: Nasal High Flow (NHF)<br>* Patients with chronic respiratory failure are treated for 1 h with NHF therapy and with individual O2 supplementation during wakefulness.<br>* Other names: AIRVO2;|
| Experimental: NHF/CO2 - NHF<br>Patients with chronic respiratory failure are treated with nasal high flow during wakefulness. First with NHF (30l/min) plus 1% CO2 , then NHF (30l/min) alone. | Device: Nasal High Flow (NHF)<br>* Patients with chronic respiratory failure are treated for 1 h with NHF therapy and with individual O2 supplementation during wakefulness.<br>* Other names: AIRVO2;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Minute Ventilation | Difference in respiratory minute volume under NHF versus NHF/CO2. | up to 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tidal Volume | Difference in tidal volume (VT) under NHF versus NHF/CO2 | up to 1 hour | 
| Respiratory Rate | Difference in respiratory rate under NHF versus NHF/CO2. | up to 1 hour | 
| Transcutaneous pCO2 | Difference in transcutaneous pCO2 under NHF versus NHF/CO2. | up to 1 hour | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Nasal High Flow, PaCO2, Tidal Volume, Washout Effect