Shock
UC Irvine Medicine Residency
Mini Lecture Series
Case Vignette
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54 year old female with lupus on chronic
steroids and methotrexate presents with fatigue,
decreased appetite, and worsening cough with
thick yellow sputum x 2 days. This morning
she became diaphoretic and began experiencing
shortness of breath.
In the ED, T 101.3F, HR 107, BP 96/56, RR
20, SpO2 94% RA, with increasing lethargy
Objectives
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

Learn the definition of shock
Understand its pathophysiology
Identify different types of shock
Key Elements of Blood Pressure

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Fluid
Pump
Pipes
Shock: Definition
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Impaired tissue perfusion
Oxygen consumption > delivery
Cell death > End-organ damage > Multi-system
organ failure > Death
Signs: tachycardia, tachypnea, acidosis, oliguria,
confusion
Mean Arterial Pressure (MAP)

MAP - CVP
=
Cardiac Output x SVR

Cardiac Output (CO)= HR x Stroke Volume
MAP - CVP = (HR x SV) x SVR
Heart Rate,
Contractility (ß1)
Resistance
Etiologies of Shock
MAP – CVP = (SV x HR) x SVR

Abnormal heart rate:
“Cardiogenic”
Heart Rate,
Tachycardia (short filling time)
Bradycardia

Low vascular resistance:
“Distributive”
Sepsis, anaphylaxis
Other: adrenal insufficiency,
myxedema coma, drug reaction, toxic
shock syndrome, neurogenic
Resistance
Etiologies of Shock (2)
MAP – CVP = (SV x HR) x SVR

Low Stroke Volume:
Intravascular volume:
“Hypovolemic”
Dehydration, hemorrhage, 3rd space
Venous return & Outflow obstruction
“Obstructive”
Tamponade, tension pneumothorax,
PEEP, Pulmonary embolism
Ejection: “Cardiogenic
Myocardial infarct, valvular defect
Types of Shock
Cardiogenic
(Obstructive)
Hypovolemic
Distributive
Case 1, Re-visited


54 year old female with lupus on chronic
steroids presents with fatigue, decreased
appetite, and worsening cough with thick
yellow sputum x 2 days. This morning she
became diaphoretic and began experiencing
new shortness of breath.
In the ED, T 101.3F, HR 107, BP 96/56, RR
20, SpO2 94% RA with increasing lethargy
Case 2


27 year old male with chronic alcohol abuse
presents with lightheadedness, nausea, and sharp
epigastric abdominal pain radiating to back. He
reports alcohol binge over past 3 nights,
followed by intractable vomiting.
In the ED, T 98.7, HR 112, BP 96/56, RR 12,
SpO2 99% RA, 10/10 pain. Repeat BP after 5L
normal saline bolus, 88/43. Urine output 15cc/h
Case 3
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62 year old female hospitalized for right hip
fracture s/p ORIF on POD#2, develops acute
onset shortness of breath and substernal chest
pain with respirations.
Vitals: T 98.5F, HR 109, BP 87/56, RR 22,
SpO2 86%. JVP 13 cm H2O. Lactate 5.1
Take Home Points
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Shock = tissue hypoperfusion
Remember the 3 elements of circulation to
identify the type of shock
References
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Gaieski, David. Shock in adults: Types, presentation, and
diagnostic approach. Uptodate.com
Maier RV. Chapter 270. Approach to the Patient with Shock.
In: Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson
JL, Loscalzo J, eds. Harrison's Principles of Internal
Medicine. 18th ed. New York: McGraw-Hill; 2012.
Neligan, Patrick. Critical Care Medicine Tutorials, UPenn
Young WF. Chapter 11. Shock. In: Humphries RL, Stone C,
eds. CURRENT Diagnosis & Treatment Emergency
Medicine. 7th ed. New York: McGraw-Hill; 2011.