Shock

Front 1

Define shock

Back 1

A clinical syndrome; a systemic imbalance between oxygen/nutrients supply and demand.

Front 2

Inadequate perfusion

Back 2

Inadequate blood flow to body organs and tissue. It can lead to life threatening cellular dysfunction.

Front 3

What are the three things necessary for perfusion?

Back 3

1) Cardiac output
2) Blood volume
3) Peripheral vascular resistance
*4) Tissues that are able to use and extract oxygen and nutrients from the blood.

Front 4

What are the three stages of shock

Back 4

1) Compensatory
2) Progressive/Intermediate
3) Irreversible/Refractory

Front 5

Signs and symptoms of compensatory shock

Back 5

Bp normal
Tachycardia >100bpm
Tachypnea > 20bpm /
Respiratory alkalosis
Cool clammy skin
Decreased Urine output
Confusion

Front 6

Intermediate/Progressive stage of shock

Back 6

1) Systolic BP <80-90 mm Hg
2) Increased HR >150 bpm
3) Rapid shallow respiration, crackles, hypoxemia
4) Skin mottled, petechiae
5) Urine output <30ml/hr
6) Confusion, lethargy

Hint 6

More severe effects on tissue and organs which become ischemic and anoxic (release of chemical mediators cause capillary leaks and vasoconstriction and blockage)

Front 7

Refractory or Irreversible shock

Back 7

1) BP requires mechanical or pharmacological support
2) HR; erratic or asytole
3) Respiratory failure will require intubation or mechanical intervention
4) Skin; jaundice
5) Urine output; anuric and requires dialysis
6) Unconscious; coma
7) Profound acidosis

Hint 7

Organ damage is severe
Too much damage to restore homeostasis of tissue

Front 8

Physiology of Shock

Back 8

1) Affects all body system (Multiple Organ Dysfunction Snydrome - MODS)
2) May develop rapidly or slowly
3) Produces energy through anaerobic metabolism
4) Lactic acid accumulates (metabolic acidosis)

Front 9

Circulatory Shock

Back 9

An imbalance between supply of blood to the tissues and the amount of blood they need to meet metabolic demands

Front 10

Causes of Circulatory Shock

Back 10

1) Cardiogenic - cardiac malfunction - decrease cardiac output - decreased pump pressure
2) Hypovolemic - loss of blood volume - normal heart and vessel function
3) Vascular - (Distributive or circulatory) shock - Changes in vascular system. Results from widespread systemic dilation of the arterioles [anaphylactic, septic, and neurogenic

Front 11

Hypovolemic shock

Back 11

Most common kind of shock. It can occur by fluid loss or fluid shift between intravascular and interstitial compartments

Front 12

Most common cause of hypovolemic shock

Back 12

1) Hemorrhagic
2) A decrease in intravascular volume of about 15%-25%
3) This would represent a loss of 750 - 1300 ml of blood volume. A decline in circulating blood volume (500cc or less) activates baroreceptors
4) In the elderly, dehydration may be the cause of shock

Front 13

Causes of Hypovolemic shock

Back 13

1) External fluid loss
* Hemorrhagic - most common cause - massive trauma or severe bleeding.
* Excessive perspiration
* Prolonged vomiting and diarrhea (GI tract)
* Severe dehydration from inadequate intake

2) Internal fluid shift between intravascular and interstitial compartment - fluid losses due to vascular changes increase permeability allowing fluid to go into the tissues - severe edema - without loss of whole blood from vessels. This causes a decrease in venous return, decreased output.
* severe inflammation
* burns (damged tissues cause plasma/protein to be lost into the tissues - tissue osmotic pressure draws fluid from the vessels into the tissue by osmosis..

Front 14

Circulatory shock (Vascular or Distributive)

Back 14

1) Massive widespread vasodilation - loss of blood vessel tone, the capacity of the vascular compartment expands to the extent that a normal volume of blood does not fill the circulatory system - NO blood loss

2) Vascular tone is determined both by central (loss of sympathetic one) and local (biochemical vasodilator substances release from cell) regulatory systems

Front 15

Initial vasodilation in vascular or distributive shock is further divided into three types

Back 15

1) Neurogenic
2) Anaphylactic
3) Septic

Front 16

Septic shock (causes)

Back 16

1) Peritonitis
2) Noscomial infections - most frequently occuring in the blood (bacteremia), lungs (pneumonia), and the urinary tract (indwelling catheter)
3) Widespread use of antibiotics (cause resistance)
4) Wound
5) Intravascular catheters

Front 17

What are the two hemodynamic phases associated with septic shock?

Back 17

1) Early 1st phase - Hyperdynamic (warm shock)
2) 2nd phase - Hypodynamic (cold shock)