Circulatory Shock – outline notes

I. Circulatory Shock
Circulatory Shock is an acute circulatory crisis marked by hypotension and decreased peripheral blood flow. It is caused by Hemorrhaging (hypovolemia) or damage to heart.


A. Shock – acute circulatory crisis
1. Hypotension
2. Decreased peripheral blood flow

B. Causes
1. Hemorrhaging (hypovolemia)
2. Damage to heart

C. Symptoms
1. Systolic pressure < 90 mmHg (hypotension)
2. Pale, cool, clammy skin
a. peripheral vasoconstriction
b. Sympathetic Nervous System (SNS) – activity of sweat glands
3. Disorientation – decreased blood flow to brain
4. Tachycardia, rapid weak pulse
5. Cessation of urination
6. Acidosis
a. lactic acid – hypoxic tissue

D. Homeostatic Adjustments
1. Short and long-term mechanisms
2. Loss of 35% of blood volume -decreased blood pressure — decreased
venous return — inadequate CO
3. Central Ischemic Response
a. massive vasoconstriction, except cerebral vessels
b. last-ditch effort
c. kidney, liver, heart ——lose function
4. Circulatory Collapse
a. arterioles and precapillary sphincters — no contraction
b. general vasodilation
c. capillary pressure so low — collapse