Heated High Humidity After COPD Exacerbation

Overview

Chronic obstructive pulmonary disease (COPD) is a chronic lung disease usually caused by exposure to tobacco smoke which leads to chronic symptoms of shortness of breath, cough, and phlegm. COPD is one of the leading causes of disability and death in Canada. Individuals with COPD often have periodic worsening of their disease, called exacerbations, consisting of increased shortness of breath and often an increase in cough and phlegm. These exacerbations often lead to hospital admission and are associated with worsening symptoms and lung function over time. After an exacerbation individuals with COPD usually take several weeks to return to their previous state of health and many people with an exacerbation who are discharged from hospital return to the ER within 60. Heated humidified air has been shown to improve the clearance of mucous in the lungs for people with chronic lung disease. By providing patients at St. Joseph's Hospital who are discharged after a COPD exacerbation with a device for delivering heated high humidity air to use overnight it is hoped that these individuals will be able to more easily keep their lungs and airways free of mucous. This in turn may lead to improvement in their symptoms of shortness of breath, cough, and phlegm production as well as decreasing obstruction of the airways to reduce the risk of having to return to the emergency room or hospital.

COPD is a respiratory condition that is often associated with cigarette smoking, and defined by incompletely reversible airflow obstruction and complicated by exacerbations. Mucous hypersecretion with impaired mucociliary transport are frequently present, and are associated with infective AECOPD, and death related to pulmonary infection. COPD is both common, affecting 1 in 6 Canadians, and burdensome, being the 4th leading cause of death, in the Canadian population. In Canada, the most common primary diagnosis associated with admission to hospital is acute exacerbation of COPD (AECOPD). For moderate to severe COPD, the average patient will have more than 2 AECOPD per year. A single episode conveys a poor prognosis, being associated with death, further AECOPD events, and reduced health-related quality of life. Despite multiple guideline-based management strategies, 1 in 3 patients with AECOPD will have another episode within 8 weeks. Although the technology for heated humidified high-flow nasal cannula (HFNC) has been available for two decades, it has only recently become widely available for adults. The rapid humidification of gas allows this system to achieve flow rates of up to 60 liters per minute. These two factors, in combination, allow for a higher achieved fraction of inspired oxygen, and benefit the expectoration of secretions and ventilatory efficiency. Randomised clinical trials of ICU patients have demonstrated that HFNC is non-inferior to non-invasive ventilation both in the setting of acute hypoxemic respiratory failure and as an adjunct therapy post-extubation. HFNC is a promising treatment for patients with COPD as it can counteract potentially harmful mucous abnormalities by reducing mucous viscosity and restoring mucociliary transport. Randomised studies have also demonstrated that HFNC administered at home results in an increased the time to first exacerbation, fewer AECOPD, improved quality-of-life, and reduced PaCO2. However, the efficacy of HFNC during hospital admission, when mucous abnormalities and poor expectoration could be most pronounced, has not yet been studied. Furthermore, the feasibility and efficacy of this device as a patient transitions from the hospital to the community after an AECOPD remains to be elucidated. The objectives of this study are to test the efficacy of a heated humidified high-flow nasal cannula used during and after a hospital admission for AECOPD to reduce the risk of return to ER or readmission, and the feasibility of implementing such a device starting in hospital with transition to the home environment. This is an open-label, non-randomized pilot study of in-hospital and home HFNC in patients with COPD. Patients who consent to participate will have an a heated humidified high-flow nasal cannula device configured by a respiratory therapist and available at their bedside in hospital. Fraction of inspired oxygen will be adjusted as needed to obtain a pulse oximetry reading between 88-92%. If hypoxemia is not present (peripheral oxygen saturation (SpO2) ≥88%) on room air, then the device will be used without supplemental oxygen. Temperature and flow rate will be titrated for patient comfort with a target temperature of 37 degrees Celsius and flow rate of ≥20 liters per minute if tolerated. Participants will be instructed to use the device overnight and as much as they like during the day targeting at least 6 hours of use per 24 hour period. At discharge, subjects will be provided with a heated humidified high-flow nasal cannula home device. Targeted use and oxygen titration will remain unchanged from inpatient use. A respiratory therapist from will perform a home visit within 24 hours of hospital discharge to educate the patient on home use and ensure proper set up of the device, and an additional visit 2 weeks post-discharge. Patients will have access to a 24 hour emergency telephone number if they have any concerns. The duration of the trial will be 60 days post-discharge after which the device will be returned.