Note to readers: This blog consists of my study notes on topics I’ve reviewed. I often excerpt and copy from blog posts I have reviewed. I do so because it helps me retain the material.
Readers should skip this post and go straight to Preoxygenation, Reoxygenation and Deoxygenation.
All that follows is from Dr. Weingart’s post.
What is this page about?
Scott Weingart, MD and Richard Levitan, MD published an article in the Annals of Emergency Medicine entitled Preoxygenation and Prevention of Desaturation during Emergency Airway Management.
This page serves as a repository for supplementary material on the subjects raised in the article.
*The above article is outstanding and I’ve included direct links to all the sections:
- What is the Rationale for Providing Preoxygenation Before Tracheal Intubation?
- What is the Best Source of High FiO2 for Preoxygenation?
- For What Period of Time Should the Patient Receive Preoxygenation?
- Can Increasing Mean Airway Pressure Augment Preoxygenation?
- In What Position Should the Patient Receive Preoxygenation?
- How Long Will it Take for the Patient to Desaturate After Preoxygenation?
- Can Apneic Oxygenation Extend the Duration of Safe Apnea?
- When and How Should We Provide Manual Ventilations During the Apneic Period?
- What Positioning and Maneuvers Should the Patient Receive During the Apneic Period?
- Does the Choice of Paralytic Agent Affect Preoxygenation?
- Risk Stratification and Conclusions
Updated Recs for Preox of All Patients
Rule of 15’s
- All patients get NC @15lpm and NRB at >=15lpm (Flush rate/the higher the better)
- If you cannot achieve Sat of 100, replace NRB with CPAP at up to 15 cmH20
listen to this Wee for more
Flush rate NRB is as good as BVM1
CPAP for Preoxygenation
In a patient with shunt, CPAP is needed for preoxygenation. In my ED, we make this happen with the ventilators installed next to every resuscitation bed.
However, not every ED has ventilators readily available and it might take >15 minutes to have respiratory bring a NIV machine or a vent. In that case, you want to use a BVM with a PEEP valve.
Put in fig 1 when server ready.
However, this device provides CPAP only when the patient is expiring. In a patient who is not breathing rapidly, most of the cycle will be spent at zero PEEP. Once the patient is apneic, the device won’t supply PEEP unless you manually give ventilations–even then the PEEP will only be there immediately following the ventilation. However, if you add a constant source of flow, like a nasal cannula set to 15 lpm then the BVM/PEEP Valve combo will give continuous PEEP regardless of the patients resp rate or even when they become apneic. In the following video, a PEEP valve set to 10 cm H20 provides between 6-8 cm H2) of PEEP throughout the cycle. This same nasal cannula should be on the patient anyway for apenic oxygenation and NO DESAT (Nasal Oxygen During Efforts Securing A Tube) during the intubation procedure