Shock

Question 1

What is shock?

Answer 1

condition in which tissue perfusion is inadequate to support vital organs, cellular function
Affects all body systems
Hypoperfusion leads to activation of SNS which leads to hypermetabolism and inflammation

Question 2

Hypovolemic shock

Answer 2

shock state resulting from ↓ intravascular volume due to fluid and/or blood loss

Question 3

Cardiogenic Shock

Answer 3

shock state resulting from impairment or failure of myocardium and ↓ cardiac output, dopamine is most commonly used to treat

Question 4

Neurogenic Shock

Answer 4

shock state resulting from loss of sympathetic tone causing relative hypovolemia; spinal cord injury T6 or higher

Question 5

Anaphylactic shock

Answer 5

circulatory shock state resulting from severe allergic reaction producing overwhelming systemic vasodilation, relative hypovolemia; Bee stings, seafood, meds

Question 6

Septic shock

Answer 6

circulatory shock state resulting from overwhelming bloodstream infection causing relative hypovolemia

Question 7

BP Regulation

Answer 7

Mean Arterial BP (MAP) must be >65 mmHg for adequate cellular aerobic metabolism
MAP = Cardiac Output X Peripheral Vascular Resistance- SV x HR diameter of arterioles
MAP = SBP + 2 (DBP)/3

Question 8

Initial stage of shock

Answer 8

Not enough oxygen delivery
* Anerobic metabolism occurs in hypoxic state
* Patient exhibits no Signs or Symptoms

Question 9

Compensatory stage of shock

Answer 9

SNS causes vasoconstriction, ↑ HR, ↑ heart contractility
* This maintains BP, CO
* Systolic BP – Diastolic BP = Pulse pressure (watch for narrowing ~ normal is 30-40 mm Hg)
* Body shunts blood from skin, kidneys, GI tract, resulting in cool, clammy skin, hypoactive bowel sounds, decreased urine output
* Perfusion of tissues is inadequate
* Acidosis occurs from anaerobic metabolism
* Respiratory rate ↑ due to acidosis, may cause compensatory respiratory alkalosis
* Confusion may occur

Question 10

Progressive stage of Shock

Answer 10

Mechanisms that regulate BP can no longer compensate, BP and MAP ↓
* All organs suffer from hypoperfusion
* Vasoconstriction continues further compromising cellular perfusion
* Mental status further deteriorates from ↓ cerebral perfusion, hypoxia
Lungs begin to fail, ↓ pulmonary blood flow causes further hypoxemia, CO2
levels ↑, alveoli collapse, pulmonary edema occurs —-> ARDs
* Inadequate perfusion of heart leads to dysrhythmias, ischemia, impaired pump
* As MAP falls < 70, GFR cannot be maintained
* AKI may occur
* Liver function, GI function, hematological function all affected
* Disseminated intravascular coagulation (DIC) may occur as cause or complication
of shock (bleeding!)
* Agitation, confusion, giving way to lethargy and ↓ LOC

Question 11

Irreversible stage of shock

Answer 11

At this point, organ damage so severe that patient does not respond to treatment and cannot survive
* BP remains low
* Renal, liver function fail
* Anaerobic metabolism worsens acidosis
* Multiple organ dysfunction progresses to complete organ failure
* Judgment that shock is irreversible only made in retrospect
* End of life discussions are necessary

Question 12

General shock care

Answer 12

• Early identification
• Timely treatment
• Identify, treat underlying cause
• Sequence of events for different
  types of shock will vary
• Management, care of patient will vary
  Use MEWS and SOFA/qSOFA scores to monitor

Question 13

General management strategies in shock

Answer 13

1 hour Sepsis Bundle
* Fluid replacement
* Crystalloid, colloid solutions
* Complications of fluid administration
* Vasoactive medication therapy
* Nutritional support
* Glycemic control (140 – 180 mg/dl)
* Enteral/or parenteral nutrition as soon as possible
* Stress ulcer prevention