The Basics of Vasopressors
There is a ton to speak about regarding vasopressors, but before we get to the edge cases, we need to set-up a foundation.
Types of Shock
It's all about flow!
- Should we get rid of blood pressure?
Critical Perfusion Pressures
- CV Collapse 35 mm HG (51 mm Hg in critical AS pts) in one study (Crit Care 2014;18:719)
- SBP < 80 or DBP < 50 lead to trop rise during post-partum hemorrhage (Anesthesiology 2004;100(1):
- MAP of 50 in non-vasculopath dogs for the brain? [cite source='pubmed']9692450[/cite] and Blood Pressure and the Brain: How Low Can You Go? [Anesth Analg 2019;128(4):759]
- MAP of 65 for the heart? (Dunser et al. think it is 45-50 for the heart)
- MAP 65-75 for the Kidneys? [cite source='pubmed']18382191[/cite]
When we put someone on a vasopressor, what are we hoping to accomplish?
- Critical Perfusion Pressures (Heart will get better, but may look worse)
- Increase Venous Return
- Avoid Gut Ischemia and Flow Reduction
Norepi Increases Venous Return as well as Constricting Afterload
- Crit Care Med. 2012;40(12):3146-3153
- Crit Care Med. 2011 Apr;39(4):689-94
- Crit Care Med. 2013 Jan;41(1):143-50
- Critical Care 2007, 11(Suppl 2):P37
- Critical Care 2010, 14:R142
- Anesthesiology 2014; 120:365–77
- Want to understand the physiology of venous return?
MAP of 65 or Higher?
No benefit to 80-85 group [cite source='pubmed']24635770[/cite]
The 65-Trial may indicate that 60 is as good as 65
Vasopressor Flow Chart
Update: The Hinds Perspective
- ‘pressors/catecholamines/inotropes are not so helpful
- Pure Pressors
- Inodilators (another show)
Should become weight based
Should tolerate tiny doses
Why Not Dopamine?
'cause it is crappy
Effects on Mortality
Early norepi was better than later norepi [cite source='pubmed']25277635[/cite], [cite source='pubmed']25072761[/cite]
Up and Coming Vasopressors to be Discussed in Future Episodes
Very Good Review Article on the Effects of Vasoactive Agents on Microcirculation
Great Review [cite source='pubmed']20811874[/cite]
Understanding Venous Return
Must Read Posts By Josh Farkas
- Early MAP Stabilization
- Renoresuscitation 12/2014
- Vasopressin & renal function 12/2014
- VANISH trial & vepinephrine 8/2016
Now on to the Podcast…
- EMCrit 283 – Dexmedetomidine (Precedex) – You'd have to be Delirious Not to Use It - October 16, 2020
- EMCrit 282 – Hicks on the Labors of Trauma (Blunt) - September 30, 2020
- EMCrit 281 – Why Can't Emergency Medicine and Trauma Surgery Just Get Along? - September 4, 2020