AHA New Guidelines for Oxygenation and Ventilation of COVID-19 Patients Released April 9, 2020 Module 1: Noninvasive Support Overview

AHA New Guidelines for Oxygenation and Ventilation of COVID-19 Patients Released April 9, 2020

Oxygenation and Ventilation of COVID-19 Patients Module 1: Noninvasive Support Overview

Objectives 

To provide just-in-time training for the non–intensive-care-unit healthcare provider for patients requiring ventilation assistance who are under investigation for or confirmed to have COVID-19 

To mitigate risks frequently associated with ventilation-assistance devices, such as noninvasive ventilation (NIV) and high-flow nasal cannula (HFNC) in the COVID-19 pandemic 

To briefly review the benefits and functionality of NIV and HFNC

Risk mitigation 

Attempt to use ventilation equipment and methods with the least aerosol generation 

Noninvasive positive pressure ventilation (NIPPV) and HFNC have a higher risk of aerosol generation than invasive mechanical ventilation and therefore are not routinely recommended in confirmed COVID-19 cases 

Requirements if NIV or HFNC 

Room: Airborne precautions 

Equipment: Full face mask and filtered circuits

Nasal Intermittent Positive Pressure Ventilation (NIPPV): 

Initiation of NIPPV (bilevel positive airway pressure [BiPAP]/ continuous positive airway pressure [CPAP]) requires attending approval; 

It is strongly recommended to avoid NIPPV (BiPAP/CPAP) in persons under investigation and confirmed COVID-19 cases 

Rare exceptions are 

No intubation for those with acute indications for NIV or HFNC 

Patients who use NIV chronically or are currently stable or improving on NIV or HFNC 

Exacerbations that are expected to have a rapid reversal such as congestive heart failure 

Extubation failure or high risk for reintubation 

Equipment shortages in which milder disease could be managed to save invasive ventilation devices

High Flow Nasal Cannula (HFNC) is recommended over NIV 

Use minimal flow to maintain SpO2 greater than 88% to 94%; lower flow rates under 30 L/min may have less aerosolization 

To minimize flow, titrate fraction of inspired oxygen (FIO2) to maximum support before increasing flow greater than 30 L/min 

Ensure proper size and fit of nasal canula 

Once High Flow Nasal Cannula (HFNC) has been initiated, an attending needs to assess the patient after 1 hour and after 3 hours to determine if the patient needs to be intubated 

While on HFNC, the patient should have on a loosely fitting surgical mask or face tent 

Do not delay intubation if there is a lack of improvement

Review of device set-up 

Requirements 

Gas source and blender 

Flowmeter: 40 to 60 L/min 

FIO2 analyzer 

Humidifier 

Surgical mask to reduce aerosol

Quick review of Nasal Intermittent Positive Pressure Ventilation (NIPPV) 

NIV provides ventilation assistance with positive pressure at 2 levels: 

Unload respiratory muscles 

Lung volumes 

Successful NIV attempt requires that the patient 

Can maintain an airway 

Is alert and oriented with a strong respiratory drive 

Has no facial abnormalities that would prohibit a mask seal 

Typical settings 

Spontaneous mode Peak airway pressure range from 8 to 20 cm H2O 

CPAP or positive end-expiratory pressure (PEEP) range from 5-15 

General guidelines 

If you need more ventilation (more carbon dioxide [CO2] removal), adjust the peak airway pressure 

If you need better oxygenation, adjust the CPAP/PEEP

NIV starting settings 

NIV typical starting pressures 

Inspiratory pressure (peak inspiratory pressure [PIP], inspiratory positive airway pressure [IPAP]) 10 cm H2O 

Expiratory pressure (CPAP/PEEP) 5 cm H2O 

FIO2 1.0 

Titrate to effect 

If FIO2 >0.6 to keep SpO2 greater than 92%, consider increasing expiratory pressure level 

If respiratory rate continues to be high, consider increasing the inspiratory pressure level

Some common devices 

Several brands and devices available 

Many critical care ventilators can provide NIV 

Requirements for COVID-19 

FIO2 .21-1.0 

CPAP/BiPAP or Bi-level 

Filtering of exhaled gases 

Full face mask

Limitation of NIV in COVID-19 

Potential aerosol generation 

Device limitations 

Some lower-end devices cannot provide a high level of oxygen 

Circuit configuration