Hospitalized patients with acute respiratory failure can benefit from high-flow nasal oxygen in certain settings, according to a new clinical guideline from the American College of Physicians.
High-flow nasal oxygen (HFNO) has demonstrated advantages including improved oxygenation and ventilation, wrote Arianne K. Baldomero, MD, of Minneapolis Veterans Affairs Health Care System and the University of Minnesota, Minneapolis, and colleagues. “However, the comparative benefits and harms of HFNO in clinical outcomes, including mortality, intubation, hospital length of stay, patient comfort, clearance of airway secretions, and reduced work of breathing are not well known.”
In the guideline, published in Annals of Internal Medicine, the authors recommend the use of high-flow nasal oxygen in hospitalized patients for initial or postextubation management of acute respiratory failure. The target population includes those patients treated in hospital wards, EDs, intermediate/step-down units, and ICUs.
Use of HFNO therapy as a form of noninvasive respiratory support for hospitalized patients has increased in recent years. The treatment involves delivering warm, humidified oxygen via nasal cannula at a flow level higher than the patient’s inspiratory flow.
Potential benefits of HFNO include greater patient comfort, improved compliance, and psychological benefits, according to the authors. HFNO also can be used as respiratory support in critically ill patients for a number of indications including respiratory failure or support post extubation; however, treatment of patients with COVID-19 and related conditions were not considered in the guideline.
The guideline was based on evidence comparing HFNO with conventional oxygen therapy (COT) and noninvasive ventilation (NIV). The authors reviewed 29 randomized, controlled trials that showed clinically meaningful outcomes in HFNO patients, as well as similar rates of, or reductions in, mortality, intubations, and hospital-acquired pneumonia, and increased reports of patient comfort. Data also supported the safety of HFNO with few, if any, contraindications other than problems with fitting the nasal cannula.
Across several trials comparing HFNO and NIV for initial management of acute respiratory failure, HFNO reduced all-cause mortality, intubation, and hospital-acquired pneumonia, although the authors categorized the results as “low-certainty evidence.” HFNO was not more effective than NIV for postextubation management. Based trials comparing HFNO and COT for postextubation management, the authors concluded that HFNO may reduce rates of reintubation and improve patient comfort, also with low-certainty evidence.
The research was limited by a lack of studies comparing HFNO with NIV or COT for acute respiratory failure in patients who were post lung transplantation, or for those with pulmonary embolism, pulmonary arterial hypertension, or asthma, the authors said. Other limitations included the variation in study design, study populations, and treatment protocols across the included studies. Additional research is needed to better identify the patients most likely to benefit from HFNO, according to type of acute respiratory failure.
Despite these limitations, the results support the guideline recommendation for HFNO in cases of acute respiratory failure and postextubation management. However, “broad applicability, including required clinician and health system experience and resource use, remains unknown,” the authors concluded.
Research catches up with practice
The guidelines are important at this time because “the medical literature over the past 3-4 years is catching up to what hospitalists, pulmonologists, and critical care specialists have been doing clinically over the past 6-8 years with perceived better results, Jacqueline W. Fincher, MD, MACP, President of the American College of Physicians, said in an interview.
Dr. Jacqueline W. Fincher
“HFNO has been used to a varying degree over the last 6-8 years by physicians with much-perceived improved benefit in patients who are hypoxemic on usual noninvasive therapy or conventional oxygen therapy with the impending need for intubation or post extubation,” Dr. Fincher said. “During the COVID pandemic particularly with the attack on the respiratory system with COVID pneumonia and frequently associated ARDS [acute respiratory distress syndrome], the use of HFNO has been enormously helpful in trying to keep patients well oxygenated without having to intubate or reintubate them.
“We now have the medical literature that supports what has been seen clinically to make the recommendations and guidelines based on the scientific evidence,” Dr. Fincher added. “If we can avoid intubation associated with the patient being sedated, unable to eat, talk, or meaningfully participate in their care or get the patient off the ventilator sooner for the same reasons, then we have significantly improved the quality of their care, decreased their risk of infection, decreased their days in the ICU and the hospital, we will have succeeded in providing the best care possible. The availability of HFNO, with much greater comfort to the patient than being intubated, is a great tool in the toolbox of respiratory care.”
Dr. Fincher said she was not surprised by any of the recommendations. “We knew the use of HFNO helped but we were surprised by the evidence of the degree to which it is enormously helpful to patients.
“The good news is that HFNO is readily available at most hospitals, but it really requires an intensive care unit and a team of physicians, nurses, and respiratory therapists to be familiar with its use and work closely together to monitor the patient for significant changes in their respiratory status to titrate therapy,” she noted.
Looking ahead, some areas in need of more research that might impact updates to the guidelines include “What are some areas in need of more research that might impact future updates to these guidelines? Specifics on whether initiating HFNO earlier in the course of the patient’s hypoxemic illness is better or worse, as well as the use of HFNO outside of the ICU setting,” Dr. Fincher said. “The needed monitoring of the patient to know whether their respiratory status was deteriorating and how fast would be critical along with the specific indications for titration of the HFNO.”
The evidence review was commissioned and funded by the ACP. The data come from work supported by and conducted at the Minneapolis VA Health Care System. Lead author Dr. Baldomero was supported in part by the National Institutes of Health National Center for Advancing Translational Sciences.