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

* Obstructive

* Hypovolemic

* Cardiogenic

* Distributive

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):

30–6)

* 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

Various Vasopressors

Terminology

* 'pressors/catecholamines/inotropes are not so helpful

* Pure Pressors

* Inopressors

* Inodilators (another show)

Why Norepi?

[cite source='pubmed']10966247[/cite]

Should become weight based

Should tolerate tiny doses

Why Not Dopamine?

'cause it is crappy

Vasopressin

Phenylephrine

Epinephrine

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

Methylene Blue

Angiotensin II

ATHOS Trial

Peripheral Vasopressors

EMCrit Episode 107

Very Good Review Article on the Effects of Vasoactive Agents on Microcirculation

Great Review [cite source='pubmed']20811874[/cite]

Review Articles

[cite source='pubmed']12386503[/cite]

[cite source='pubmed']21097695[/cite]

Moving beyond BP cosmetics by Dunser

Understanding Venous Return

[cite source='pubmed']24966066[/cite]