EMS1 Staff Originals
Preventing aerosol-generating procedures while treating prehospital COVID-19 patients
After seeing a number of inquiries about the potential uses for CPAP in COVID-19 treatment, we reached out to EMS1 contributors from the Montgomery County Hospital District, Robert Dickson, MD, FAAEM, FACEP, FACEM, MCHD medical director; and Casey Patrick, MD, MCHD assistant medical director, to get their take.
“The COVID-19 pandemic has forced EMS and all emergency providers to reassess our approach to airway management and treatment. This is especially true when we must care for patients with cough, fever and difficulty breathing, prior to knowing their infectious status,” Dr. Dickson said. “Coronaviruses are transmitted via patient droplets. However, prehospital providers can increase the risk of viral transmission by aerosolizing patient droplets.” This is thought to occur in several situations, he noted, including:
- Utilizing a BVM
- During non-invasive positive pressure ventilation (NIPPV)
- With high-flow oxygen use (>6L/min)
- When administering nebulized medications.
“The bottom line is to avoid all nebs in patients who are not in frank respiratory failure – and, if you have to give them – do it “in line” with NIV, only if you have the proper kit with filter.”
Dr. Patrick agrees. “I would avoid NIPPV if at all possible. From all the critical care information I’ve read (e.g., PulmCrit/EMCrit, and various anesthesia society recommendations) it seems that they even prefer high flow nasal cannula (HFNC) to NIPPV (not that we have access to HFNC in the field). I would stick to <6L NC, if at all possible, at this time to avoid aerosol generation.”
He noted he has seen some CPAP setups online that utilize O2 at 6L/peep valve/Ambu/viral filter and NIV mask that are nearly a closed circuit. Dr. Patrick said if he were going to use NIV, he would have two main considerations:
- Do I think the patient has an exacerbation of obstructive lung disease or acute pulmonary edema? If not, NIV is unlikely to be of significant benefit in the first place (in pneumonia specifically).
- If the answer to No. 1 is yes, then I want to have a system set up with a viral filter as close to the patient as possible. Also, I want the system to be as closed-circuit as possible with an additional viral filter on the inhalation limb as well. Ideally, NIV would be used in a negative pressure/flow environment as well (realizing that these stipulations are often not available on the ambulance).
If you decide to use CPAP/NIV, be sure to put a surgical mask over the NIV mask for an additional layer of protection, he cautioned.
“It seems that COVID patients demonstrate ‘silent’ hypoxia and atalectasis, which is seen clinically with oxygen saturation values in the mid/low 80s with minimal distress,” Dr. Patrick reported. “In the EMS setting, we need to be vigilant in treating patients and not numbers. If a patient is relatively comfortable and hemodynamically stable at 82% on 4L NC, then in the age of COVID-19, less is more. Transport and allow the ED/ICU folks to further sort the patient (HFNC likely). Do not further increase viral transmission risk to fix an O2 sat value.”
How to protect yourself during airway interventions
MCHD shared the following video, in which Dr. Dickson and MCHD Paramedic Brad Ward discuss how providers can stay safe while caring for respiratory failure patients. The strategy behind minimizing risk of any aerosolizing is focused on either filtering the exhaled air or utilizing a surgical mask barrier to contain potential airborne viral particles when utilizing high flow oxygen by face mask.
“We are all working without a net in the era of COVID-19, as this is a new world for everyone. This isn’t the only way, it’s just MCHD’s best way following synthesizing heaps of current data and best practice guidelines. There are many new methods and ideas surrounding airway management and preventing aerosol-generating procedures. Collaboration is key, so please reply and share any variations or other protocols you may be utilizing in your service.”
Additional COVID-19 airway management resources
Learn more about safety precautions for ventilating patients with COVID-19 with these resources from Montgomery County Hospital District: