Shock

Question 1

Shock: definition

Answer 1

SBP<90 mmHg

or

40 mmHg below baseline sbp

and

Evidence of end-organ hypoperfusion

Question 2

What are the 4 major etiologies

Answer 2

Hypovolemic

Cardiogenic

Extracardiac obstructive

Distributive

Question 3

Hypovolemic shock- examples

Answer 3

Hemorrhage: trauma, GI, retroperitoneal, intraperitoneal, pleural

Fluid depletion: diarrhea, vomiting, sweat (CF), cutaneous burn, fluid deprivation

Question 4

Cardiogenic shock: examples

Answer 4

Myopathic: acute MI, dilated cardiomyopathy, acute myocarditis, myocardial depression - sepsis/CBP

Mechanical: mitral regurg (acute), aortic insufficiency (acute), ventricular aneurism, LV outflow obstruction (aortic stenosis, hypertrophic cardiomyopathy)

Arrhythmic: bardyarrhythmia, tachyarrhythmia, VFib, Pulseless electrical activity

Question 5

Extracardiac obstructive etiology

Answer 5

Pericardial tamponade

Pulmonary embolism

Pulmonary hypertension

Question 6

Distributive: examples

Answer 6

Sepsis- overwhelmingly most common

Vasodilator overdose

Irreversible shock

Glucocorticoid deficiency

Hepatic failure

Anaphylaxis

Question 7

What are the clinical manifestations of shock?

Answer 7

Hypotension, tachycardia, clouded sensorium, oliguria, lactici acidosis

Low flow: cold extremities, mottling

• hypovolemia: S/Sx bleed
• cardiogenic/obstructive: S/Sx CHF +/- murmurs, pulsus paradoxus/distant HS

High flow: +/- warm extremities, S/Sx infection

Question 8

What’s the pathophysiological cascade of sepsis?

Answer 8

Infection or trauma/burns/pancreatitis (SIRS) –>

inflammatory cytokines from monocytes & endothelial cells –> vasorelaxants (histamine, bradykinin, NO)

+ coagulation cascade activation –> capillary leak syndrome

–> hypotension….can leads to metabolic acidosis, which increases hypotension –> multiple organ failure –> death

Question 9

How do you treat septic shock?

Answer 9

0) prevent it
2) broad spectrum antibiotics post panculture
2) early goal-directed therapy: volume CVP 12, Hct>30, SpO2>70, dobutamine
3) Vasoconstrictors: norepinephrine, vasopressin

Question 10

Vasopressin

Answer 10

Decreases water excretion by the kidney

Constricts isolated arteries

Has no effect on blood pressure in normal subjects but in septic shock, it helps restore bp! Because in vasodilatory shock, you get vasopressin deficiency and hypersensitivity

Question 11

When should you give vasopressin in septic shock?

Answer 11

Poor distal limb perfusion

Hyperbilirubinemia

Cardiac or bowel ischemia

Oliguria with impending HD

Tachyarrhythmia

Baselein htn with ostensible need for renal head pressure

Pulm htn or fontan circulation