Coronavirus: Nasal High Flow Therapy Alternative to Ventilator Care

Compared to ventilator care, nasal high flow therapy for seriously ill coronavirus patients has several benefits, including the ability to mobilize patients.

Nasal high flow (NHF) therapy is a less invasive alternative to ventilator care for many seriously ill coronavirus patients, UnityPoint Health experts say.

During the coronavirus disease 2019 (COVID-19) pandemic, ventilator care has been used commonly for coronavirus patients experiencing acute respiratory distress. However, ventilator care has posed several challenges, including shortages ventilators and the staff needed to manage patients on mechanical ventilation.

NHF therapy is delivered to a patient through a high flow nasal cannula. According to the American Association for Respiratory Care (AARC), an NHF therapy system usually features four elements:

• Gas blender
   
• Flow meter display
   
• Nasal interface and heated circuit
   
• Humidification system

"One of the hallmarks of an efficient NHF system is to be able to deliver optimally humidified gas at body temperature pressure and humidification," an AARC document says.

At three UnityPoint Health hospitals in Iowa, using NHF therapy has allowed clinicians to keep 73% of seriously ill COVID-19 patients off ventilators. In addition, the duration of NHF therapy for these patients has averaged about three days compared to about eight days for patients placed on mechanical ventilation.

For seriously ill COVID-19 patients, several criteria indicate or contraindicate use of NHF therapy, says Matthew Trump, DO, medical director of UnityPoint Health pulmonary rehabilitation, and co-medical director of the Palliative Care Department at The Iowa Clinic, which is based in West Des Moines, Iowa.

Seriously ill COVID-19 patients are good candidates for NHF therapy if they are awake, breathing spontaneously, and hemodynamically stable, he says. Seriously ill COVID-19 patients are poor candidates for NHF therapy if they cannot maintain their airway and/or have severe respiratory acidosis with a pH of less than 7.2, he says.

Advantages of NHF therapy

In the treatment of severe COVID-19, there are several benefits to using NHF therapy rather than mechanical ventilation, according to Trump and Julie Jackson, respiratory care services manager at UnityPoint Health.

• With NHF therapy, the patient is able to be awake, able to mobilize, able to communicate, and able to eat and drink. The ability to mobilize patients avoids some of the weakness and debilitation patients experience when they are on mechanical ventilation.
   
• A physiologic benefit is that the patient's lungs are not subjected to potentially injurious pressure from a ventilator.
   
• Patients receiving NHF therapy can be managed in an inpatient ward as opposed to the ICU setting, which generates multiple benefits including lower demand for ICU beds and avoidance of ICU-related complications such as infections.
   
• Unlike patients placed on mechanical ventilation, patients receiving NHF therapy can be active participants in their care such as involvement in medical decision-making and self-proning. "They can move themselves into a prone position, so their oxygenation is improved. Whereas, if the patient is on a ventilator, it takes a lot of resources and a lot of staff to prone the patient," Jackson says.
   
• NHF therapy can be used when a patient is extubated, which has lowered the rate of re-intubation at the UnityPoint Health hospitals.
   
• When small community hospitals need to transfer a seriously ill COVID-19 patient to a larger hospital for advanced care, many of the patients can receive NHF therapy during transport rather than being intubated.