Sunday, April 5, 2020

It's one of the most basic interventions we provide at all levels of EMS. 

Oxygen Element Periodic Table - Free image on Pixabay

COVID has changed how we think about oxygen delivery. 
Many COVID patients need oxygen. 
We know that certain oxygen delivery methods can put us at risk...
So what ARE the best recommendations for providing oxygen to pre-hospital patients??? 
And why do we need to make changes?

First the why.

COVID is a respiratory pathogen. This means is PRIMARILY spreads via respiratory droplets- the little tiny balls of spit we constantly spew into the air when we talk, cough, sneeze (or sing...

File:Sneeze.JPG - Wikipedia
Gross!! These droplets are HEAVY and tend to SETTLE within a few feet of the "sprayer." This is why 6' is recommended for social distancing. These particles also land on surfaces, which can potentially spread the disease when they are fairly fresh (so wipe down high-traffic areas in your homes/stations). This is why we wear the surgical masks- to prevent these big, heavy droplets from getting into our noses/eyes and mouths.

Smoke 32 Free Stock Photo - Public Domain Pictures
UNDER CERTAIN CONDITIONS, these droplets can become teeny tiny and instead of settling down, become more readily spread in the air. This is essentially what "airborne" means. COVID does not do this very readily on its own, but some things WE do CAN cause it to become airborne. 

Procedures that cause COVID to become airborne (aerosolizing procedures) include nebulizers, high flow oxygen, BVM, CPAP. Potentially when we doff PPE after an event like a code, we could shake small amounts into the air. 

Now, the what:

What's an EMS provider to do? How can we care for our sickest patients AND protect ourselves and our crews from airborne particles?? 

We have created the following "cheat sheet" to provide best practice information on the types of oxygen administration we encounter in the field. Use this as a reference- it is designed to be brief and succinct. We plan more posts to discuss particular topics in greater detail...stay tuned and stay safe!

COVID oxygen and airway cheat sheet for EMS

Oxygen administration

-Early oxygen for ANY respiratory distress when COVID is possible
-Goal should be 90%, not 100% (92-93% in pregnant patients)
-Silent hypoxia is a hallmark of COVID; pts can have sats as low as 78% and not appear dyspneic
-Aerosol generating procedures include: nebulizers, CPAP, BVM/CPR, high flow nasal cannula
-Truck ventilation should be non-circulatory mode, with rear exhaust fan used to draw air away from driver

Nasal Cannula
-Up to 6L NC does not aerosolize. 
- Recommended to put surgical mask OVER cannula at all times
>6L creates aerosol-must vent truck and use max PPE

-MUST ensure a tight fit with mask
-Use surgical mask over to cover side ports
- With tight seal and mask over ports, not thought to generate significant aerosol

-No longer first line but still consider for patients in extremis
-Must use max PPE
-Creates significant aerosol but can minimize it by using HEPA filter with a good seal
-Consider administering outdoors long enough to stabilize, then transition to NC or NRB
-If pt on CPAP, stage in ambulance until you communicate with ED for transport plan into department

-AVOID if possible
-Instead of neb: MDI with spacer 
-Subcutaneous epi for patients in severe distress (first dose within protocol; more doses require med control for A-EMT)
-If neb necessary, consider giving outdoors prior to transport
-DISCONTINUE any nebs prior to  entering emergency department

Airway management

Cardiac arrest
-BVM is an aerosolizing procedure- MAX PPE for all codes
-Place SGA as soon as possible to avoid BVM alone
-Attach BVM to SGA prior to placement -use HEPA filter if available
-REMEMBER ALL personnel that are in same room or compartment with patient must be in full PPE (don't forget LEOs, bystanders)
-Stage in ambulance on arrival until you communicate with ED staff for transport plan

-Discouraged due to considerable aerosol risk to provider; RSI best and not widely available for pre-hospital
-Video laryngoscopy preferred method
-Pre-oxygenate as much as possible
-Most experienced provider should do airway- take a minute to prepare so you have best chance of first pass success
-Beware- patients with ARDS (esp young/old/pregnant) can decompensate QUICKLY once intubated.

-Tight seal, HEPA filter to minimize aerosol
-COVID patients with resp arrest likely have an ARDS picture
-Appropriate ventilation in ARDS MUST avoid hyperventilation and baritrauma
-Avoid barotrauma by bagging with two finger technique (Why?—the typical adult BVM has a 1-2 L capacity. The average ideal tidal volume for an adult is HALF that. Compressing the BVM fully leads to over-inflation of the lungs & barotruma->increased intrathoracic pressure-> decreased preload->worsening hypotension-> overall mortality increase
-Use a PEEP valve if available

Stay tuned for more COVID-related clinical information.
Stay safe!


SAS consensus statement on airway management in COVID:

WHO clinical management guidelines for COVID:

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