Tolerance and Acute Effects of a New HFNT Nasal Cannula

Overview

In the care of patients experiencing an acute exacerbation of COPD, supplemental oxygen therapy is often required. Oxygen is typically administered at flow rates between 1 and 4 liters per minute. High-flow nasal therapy (HFNT) has been reported to have beneficial effects in patients with hypoxemic respiratory failure and in hospitalized and non-hospitalized patients with severe COPD. Clinical efficacy in improving gas exchange depends upon patient tolerance and device-related properties such as flow rate and creation of turbulent flow in the conducting airways to improve oxygenation and carbon dioxide elimination. Alterations of nasal prong structure, such as nasal prong dimensions, may produce more robust turbulent flow at lower flow rates thereby improving gas exchange as well as patient tolerance. In this pilot study we will assess the impact of a new nasal cannula with asymmetric cannula dimensions that may create more turbulent flow at lower flow rates compared to the current symmetric nasal cannula on patient comfort as well as vital signs, pulse oximetry, breathing pattern and parameters of gas exchange in hospitalized patients with a COPD exacerbation.

AIRVO 2: The AIRVO 2 is a humidifier with integrated flow generator that delivers warmed and humidified respiratory gases to spontaneously breathing patient through a variety of patient interfaces. This is an FDA-approved 510k device for use in hospitals and nursing homes. During HFNT, oxygen will be passed through a heated humidifier (AIRVO 2, Fisher and Paykel Healthcare) and applied continuously through conventional large-bore binasal symmetric prongs or the new asymmetric prongs cannula device, with a gas flow rate of 20-35 liters per minute or as high as the patient will tolerate and an FiO2 to keep SaO2 ≥ 90% (Airvo 2, Fisher and Paykel Healthcare). Gas flow temperature will be adjusted based on patient's comfort and range from 34-37 degrees centigrade. After completion of the study, patients will be switched back to oxygen therapy administered by nasal prongs or mask. This is a pilot study in which the primary outcome is to determine the level of comfort experienced by the patient of using high-flow nasal oxygen administered by two different nasal cannulas. It is not an efficacy trial and there is no formal power analysis. All subjects are randomly assigned to two sequences, and each subject is treated subsequently with two treatments, the order of the treatments depends on its sequence. Initially, the primary endpoint and secondary endpoints will be evaluated for a carryover effect, a period effect, and a treatment effect with the use of two-tailed t-tests. We will then model treatment effects, period effects, and carryover effects using the linear mixed-effects model for this 2x2 crossover study. Subjects may discontinue participation in the study at any point and for any reason. This decision will not be held against them in any way. If a subject decides to withdraw, the physician will assess their clinical condition and determine the best course of action for the subject. This may include alternative methods of oxygen administration. Any data that is collected up to the point of subject withdrawal will be retained for analysis. Risks to Subjects The AIRVO 2 is an FDA cleared device (510k number K131895). There are few expected side effects of using the AIRVO 2 device - if the humidification is too low, the subject may experience nasal/throat discomfort or epistaxis. It has been determined to be a non-significant risk device in that it meets none of the criteria for a significant risk device. Potential Benefits to Subjects Potential benefits of study participation include the subject experiencing a decreased work of breathing with high flow nasal therapy provided by one or both of the nasal cannulas. It is also possible that the subject will experience no direct benefit. Privacy and Confidentiality All data will be stored on the REDCap website. The site is 21 CFR part 11 compliant. All study personnel have been trained in human subjects protections and good clinical practices. Study data will only be accessible to study personnel via password protected websites and computer terminals. A "HIPAA Authorization English (HRP-505)" has been provided with this submission. Economic Burden to Subjects All subjects will need supplemental oxygen as part of their clinical care. The only difference for this research is that the subjects will receive high-flow oxygen through two different nasal cannulas. There is no additional charge for this method of oxygen delivery.