For some spaced repetition, here’s a review of this week’s content:
Trigger, Limit, Cycle: The Waterfall we Should Chase? by Max Hockstein
- There are three phases to all breaths delivered by a ventilator: a trigger, a target/limit, and a cycle.
- Triggers start the breath, the target is the variable which is not exceeded during the breath, and the cycle variable is what turns the breath from inhalation to exhalation.
- Understanding each phase of a mechanically-delivered breath lends itself to understanding the enemy of mechanical ventilation, dyssynchrony.
- For more on fundamentals of synchrony, see this related post! (and part 2 here)
- More to come on these topics in future posts!
REBOA Again, But This One Might Sting a Little by Zaf Qasim
- As the evidence evolves for REBOA, the technology must also.
- This device’s arrival is exciting news for those whose systems already support REBOA use and may allow some others who have been on the fence to consider implementing it.
- DOAC drugs may need emergent reversal in patients with serious or life-threatening ICH
- Dabigatran should be reversed with idarucizamab, if available; 4F-PCC if not
- The factor Xa inhibitors have a reversal drug, andexanet, but it has issues related to cost and efficacy; for now, 4F-PCC is the best reversal agent
Teaching the Rare & Life-Saving Procedure: Part 1 by Jenn Repanshek
- Plan ahead when considering how to teach the rare and life-saving procedure.
- Highlighting the importance of effective preparation and using the procedure kit as a teaching tool are helpful ways to up your med ed game!
- Keep your eyes peeled for a few more tips in the next part of this series!
ECMO, Sedation, & Analgesia by Lauren Igneri
- The majority of commonly used sedatives (propofol, midazolam, dexmedetomidine) and analgesics (fentanyl) are highly protein-bound and may be prone to ECMO circuit sequestration. In contrast, hydromorphone and ketamine exhibit low protein binding properties and may be less susceptible to circuit loss.
- A recent study demonstrated a significant increase in delirium-free and coma-free days with hydromorphone vs. fentanyl use in ECMO at 7 and 14 days. Additionally, those treated with hydromorphone had reduced opioid requirements compared to fentanyl which may be attributable to low-protein binding
- Another study evaluating obese (BMI≥30) vs. non-obese (BMI <30) patients requiring ECMO did not find a difference in opioid and midazolam requirements between groups. However, obese patients had lower median RASS scores at days 6 and 7, potentially indicating drug accumulation of highly lipophilic medications
What’s That Flow? High-Flow Nasal Cannula Devices by Seon Adams
- HFNC washes out CO2 in oropharynx, creating a reservoir, and meets patient inspiratory demand
- Improves gas exchange reducing work of breathing
- Extubating to HFNC has shown to reduce reintubation
The Vitals: Pulmonary Artery Catheter by Tim Montrief
- The pulmonary artery catheter (PAC), AKA Swan-Ganz catheter is a balloon-tipped, thermodilution catheter that is inserted percutaneously into a proximal, or central vein (jugular, subclavian, or femoral), then “floated” through the right ventricle and into the pulmonary artery.
- PACs can aid in the diagnosis and management of complex circulatory disease processes, such as pulmonary hypertension or undifferentiated shock by measuring select cardiopulmonary pressures.
Secrets of the Right Ventricle by Haney Mallemat
- Beware of the Right Ventricle Death Spiral
- The RV is thin-walled and has low resistance and low pressures
- As such it is very sensitive to changes in hemodynamics
- Check out the CritBits Video!