Patients affected with severe chronic obstructive pulmonary disease (COPD) and other lung disease experience shortness of breath and increased load on respiratory muscles, making it harder to breath. These patients may progressively become dependent on oxygen therapy and sometimes they may need noninvasive ventilation (a mask covering mouth and nose and connected to a blowing machine) to help them in reducing the breathing effort. Optiflow is a nasal high flow oxygen delivery system that, providing warm and humidified air/oxygen blend, could be better tolerated and increase oxygen levels in the blood more than standard oxygen therapy.
Our aim is to generate pilot data that can be used to inform sample size calculations for future studies that will compare outcomes at several different flow rates. We will ask 15 adult patients affected with stable COPD requiring oxygen to participate in our research. Subjects participating in the study will be asked to come in to the sleep lab at Tufts Medical Center. As part of the study 2 small tubes will be inserted through the nostril into the stomach and the esophagus. Baseline data like breathing rate, heart rate, and oxygen level in the blood will be recorded. Then each patient will receive oxygen via High Flow Nasal Cannula, using 3 different settings, and 3 different levels of positive pressure (CPAP) via a nasal mask.
Subjects will be randomized to receive 2 different treatments in a crossover fashion. They will be randomized to different setting within each treatment arm using a computer generated randomization scheme. Each setting will last 1-0 minutes and data will be collected at the end of each setting. Then the tubes will be removed.
We will describe the effects of varying settings of high-flow nasal oxygen on respiratory rate, tidal volume and diaphragmatic work of breathing in patients with severe COPD. We will also describe changes in gas exchange and effects on the subjects' comfort and dyspnea.
- Subjects are 18or more years of age
- Chronic respiratory failure, defined as indication for long-term oxygen therapy
- Underlying diagnosis of severe COPD (GOLD stage III or IV)
- Recent (<1 month) exacerbation as defined as a sudden worsening of COPD symptoms (shortness of breath, quantity and color of phlegm) requiring a change in the baseline therapy
- Respiratory rate at rest >28/min
- Subject requires >66 L/min nasal O2 to maintain SpO2 >88% at rest
The study involves one session only which is around 150-180 minutes in length. The patient's vital signs, oxygen saturation and CO2 level will be monitored throughout the session with percutaneous monitors placed on the ear lobe. The work of breathing will be measured through esophageal and gastric catheters which are small catheters placed through the nasal cavity. The study does not involve collecting blood or obtaining imaging.