Cardiac Clinical Medicine Part 5: Shock Flashcards
What are the major physiologic determinants of tissue perfusion (BP)?
BP = CO X SVR
What does CO equal?
CO = HR X SV
Stroke volume is determined by?
1) Preload
2) Myocardial contractility
3) Afterload
What is shock?
Inadequate tissue perfusion to meet metabolic demand and tissue oxygenation
What stage of shock is characterized by when reflex mechanisms are activated and perfusion (BP) to vital organs is maintained?
Compensated
What occurs during compensated stage of shock?
1) Sympathetic vascular tone increased
2) Catecholamines are released
3) Renin-angiotensin system activated
What stage of shock is characterized by tissue hypoperfusion and onset of worsening circulatory and metabolic derangement?
Decompensated
What does decompensated stage of shock lead to?
Hypotension and metabolic lactic acidosis
What stage of shock is characterized by organ and tissue injury is so severe that even if the hemodynamic defects are corrected, survival is not possible?
Irreversible
What shock category according to physiological etiology is caused by poor pumps?
Cardiogenic
What are examples of the cardiogenic category of shock?
1) Cardiomyopathy (AMI, Myocarditis, drugs/toxins)
2) Arrhythmias
3) Mechanical (VSD, valve stenosis)
What shock category according to physiological etiology is caused by decreased intravascular volume?
Hypovolemic
What are examples of the hypovolemic category of shock?
1) Hemorrhage
2) Dehydration
What shock category according to physiological etiology is caused by dilated peripheral vasculature (decreased SVR)?
Distributive
What are examples of the distributive category of shock?
1) Sepsis
2) Anaphylaxis
What shock category according to physiological etiology is caused by mechanical blockage of circulatory system?
Obstructive
What are examples of the obstructive category of shock?
1) PE
2) Tension pneumothorax
Cardiogenic shock has what effect on cardiac output?
On systemic vascular resistance?
On pulmonary capillary wedge pressure or central venous pressure?
1) Decrease
2) Increase
3) Increase
Hypovolemic shock has what effect on cardiac output?
On systemic vascular resistance?
On pulmonary capillary wedge pressure or central venous pressure?
1) Decrease
2) Increase
3) Decrease
Distributive shock has what effect on cardiac output?
On systemic vascular resistance?
On pulmonary capillary wedge pressure or central venous pressure?
1) Increase
2) Decrease
3) Decrease
Obstructive shock has what effect on cardiac output?
On systemic vascular resistance?
On pulmonary capillary wedge pressure or central venous pressure?
1) Decrease
2) Increase
3) Variable
What are signs of shock?
1) Hypotension
2) Tachycardia
3) Tachypnea
4) Abnormal mental status
5) Cool clammy skin
6) Metabolic acidosis
7) Elevated serum lactate
What part of the ABC mnemonic is vital when stabilizing a shock patient?
Circulation
How is shock treated?
1) IV fluids
2) Vasopressors
3) US evaluation
4) Broad spectrum antibiotics if infection (sepsis) is cause
