Additional Respiratory Support

How High-Flow Therapies Aid COVID-19 Care Across the Patient Journey

By Megan Headley

In the last 12 months, international societies in the United States and around the world have published guidelines that dictate nasal high-flow (NHF) therapy as a predominant choice for patients who present with a risk of escalating due to COVID-19, says Chris Hutchinson, director of clinical affairs for medical device manufacturer Fisher & Paykel Healthcare of Irvine, California. However, Hutchinson adds, that wasn’t the case at the onset of the COVID-19 pandemic. As a result, some clinicians may be unaware of this solution’s benefits in aiding more effective, streamlined COVID-19 care.

NHF therapy has been in use since at least the 1960s, providing respiratory support to neonatal, pediatric, and adult patients. In adults, NHF consists of the administration of a gas flow via cannula above 30 liters per minute in adults, heated to 37°C and with a humidity (water vapor) content of 44 milligrams per liter. The method is reportedly more comfortable for patients and can minimize the need for more invasive and costly respiratory support if applied early on.

When the COVID-19 pandemic hit, Hutchinson says, hospitals that were already familiar with NHF therapy—that understood the physics and physiology involved—immediately saw that NHF could provide the primary means of respiratory support. Many of these hospitals already used NHF to treat patients who had severe pneumonia, and they observed many of the same symptoms in patients with COVID-19.

Other hospitals, however, aligned their COVID-19 treatment with the SARS virus pandemic in the early 2000s, where the general aim was to keep the patient dry, without humidity, and intubated. “A lot of hospitals abandoned high-flow and noninvasive ventilation as a whole and intubated [patients], and unfortunately saw very high mortality rates,” Hutchinson says.

Professionals were worried, Hutchinson says, that NHF therapy might spread coronavirus particles. “Hospitals were concerned about any respiratory procedure that could generate more aerosols,” he says. “We didn’t understand that actually that’s not the case [with NHF].”

The use of high-flow gas that meets and exceeds the demand of the patient instead reduces the patient’s work of breathing, and with it the risk of generating aerosols. Some guidelines, as an added safety measure, do recommend placing a surgical mask over patients being treated with NHF therapy. “As it was, caregivers were wearing PPE and so if they were following good PPE practices, any potential dispersion was not going to have an effect,” Hutchinson adds.

Streamlined patient care is an additional benefit of NHF, Hutchinson says. As he explains it, the standard practice is often to treat a patient who presents at the emergency department (ED) with a respiratory problem by placing them on a low-level cannula to provide supplemental oxygen while various tests are performed. At that point, should the patient’s condition escalate and they are deemed in need of respiratory support, physicians must turn to more invasive therapies that often see the patient spending time in the ICU.

“Clinical evidence has shown that starting a patient on high-flow therapy rather than the simple low-level cannula can mitigate potential escalation of that patient’s respiratory condition,” Hutchinson says. Subsequently, the patient’s pathway through the hospital may avoid the ICU, moving instead from the ED to a step-down floor’s bed. “Starting the patient early on NHF—pre-hospital or during their stay in the ED and then through the hospital—has been shown to reduce the escalation of the patient, which can affect the length of stay and the patient’s journey through the hospital,” he adds.

Now, with more COVID-19-infected patients returning home with remote monitoring systems in place, NHF therapy can support at-home care as well. “High-flow solutions can stay with a patient from when they first [get] into the hospital until they are discharged,” Hutchinson says. “In many cases there are patients who need respiratory support at home who actually have NHF in the home environment. That in turn means that you’ve got fewer patients who are actually returning back to the hospital.

“If you provide all of this respiratory support in the hospital, and then the patient goes home with no support or they’re on cold, dry oxygen at home, often that means that the patient’s going to come back to the hospital. Having high flow at home can mitigate that challenge,” he adds.

Megan Headley is a freelance writer and owner of ClearStory Publications. She can be reached at megan@clearstorypublications.com.