Remember that Oxygen Delivery is composed of two parts:
What is Shock?
[Oxygen Delivery] = [Oxygen Content] [Cardiac Output]
In the first video, let’s go over problems with that second part: cardiac output.
How can cardiac output go wrong? All of these can lead to decreased cardiac output.
- Cardiac: problems with the PUMP. The heart won’t push blood forward.
- Blood vessels: problems with the PIPES. The blood vessels are causing either obstruction to flow or are so massively dilated that blood just pools within or leaks out.
- Fluid volume: problems with the TANK. There’s not enough fluid to pump around.
The commonly taught categories of causes of cardiogenic, obstructive, distributive and hypovolemic fit into the above three physiologic groups.
How do you diagnose shock?
You can recognize shock by hypoperfusion of organ systems. So you’ll find measured blood pressure is low. Also, decreased blood flow to the
- kidneys leads to decreased urine output
- brain leads to altered mental status
- skin leads to cyanosis.
Remember that H&P are the best diagnostic tools we have. So search for potential signs and symptoms for diseases of the pump, pipes or tank. Ultrasound (the RUSH protocol) is very helpful as well. Treatment depends on identifying the cause.
How do you treat shock?
Treatment depends on the cause of hypoperfusion.
- PUMP problem? Maybe you need an inotrope or other cardiac support
- TANK problem? Then fill up the tank. Use whatever fluid you need, but remember crystalloid doesn’t carry oxygen.
- PIPE problem? Then, assuming you have a full tank, you need a pressor.
SAEM’s Clerkship Directors in Emergency Medicine (CDEM) and EMRA released a training video for medical students that demonstrates how to tell a compelling story when presenting a patient’s case. This brief video offers handy do’s and don’ts that will help medical students understand how best to efficiently and effectively communicate in the ED.
The ten-minute video features EMRA resident and student members and CDEM leaders: Aditi Mitra, Michael Yip, Zach Jarou, David Gordon with help from Cathey Wise (EMRA) and Melissa McMillan (SAEM), with yours truly playing Mr. Ferguson.
On Tuesday, 8 am in Chicago, Stella Yiu, Rob Cooney, Andrew Petrosoniak, Doug Schiller, Jen Leppard and I will be presenting a Flipped Classroom workshop. The goal is to take you from idea to completed product in the span of four hours (with a much needed coffee break in the middle).
Here’s our worksheet.
Look forward to seeing you in Chicago.
Rob Cooney (@EMEducation) and I are giving a workshop on tools to flip your classroom in Phoenix at CORD this month. Since this is a resource heavy talk, I put the worksheet and slides up here. Here’s also my practice video on the “multimedia principles” portion of the talk.
Flipping Your Classroom (CORD 2015 @ Phoenix) Resources
Richard Mayer’s Multimedia Principles
Odds ratios and risk ratios always confused me. I never really understood the reason behind having an odds ratio. It is so unintuitive to me, even still.
There’s a great article from the Southern Medical Journal that explains it all! Watch the video then read the article.
Viera AJ. Odds ratios and risk ratios: what’s the difference and why does it matter? South Med J. 2008 Jul;101(7):730-4. PMID: 18580722
Drowning 01: Pathophysiology
Drowning 02: Rescue
Drowning 03: Treatment