Cardiogenic Shock Flashcards
What is cardiogenic shock?
Cardiogenic shock occurs when the heart fails to pump blood sufficiently to meet the body’s demands.
What are the key indicators of cardiogenic shock?
Decreased CO, hypotension, hypoperfusion, and indications of tissue hypoxia despite adequate intravascular volume.
What is the most common cause of cardiogenic shock?
Myocardial infarction (MI).
What happens to stroke volume (SV) and cardiac output (CO) in cardiogenic shock?
Both SV and CO decrease, resulting in insufficient perfusion to meet cellular demands.
What mediators contribute to the deterioration of cardiac function in cardiogenic shock?
Norepinephrine, which increases systemic vascular resistance.
What role does preload play in cardiogenic shock?
Preload increases as blood returning to the heart is added to blood that was not pumped forward.
What happens to coronary artery perfusion in cardiogenic shock?
Coronary artery perfusion is impaired due to increased preload and afterload.
What are the clinical manifestations of cardiogenic shock?
Hypoperfusion with hypotension, cyanosis, decreased urine output, neurologic changes, and elevated preload.
What is the primary goal of treatment for cardiogenic shock?
To improve CO, reduce myocardial workload and oxygen needs, and increase coronary perfusion.
Name two pharmacologic treatments for cardiogenic shock.
Vasodilators (e.g., nitroprusside, nitroglycerin) and positive inotropic agents (e.g., dobutamine, milrinone).
What is the function of the intra-aortic balloon pump in treating cardiogenic shock?
Enhances coronary and systemic perfusion while decreasing afterload and myocardial oxygen demands.
What is hypovolemic shock?
Diminished blood volume causing inadequate filling of the vascular compartment.
What percentage of circulating blood volume loss can lead to hypovolemic shock?
An acute loss of 15% to 20%.
What compensatory mechanisms occur in hypovolemic shock?
Sympathetic-mediated responses such as tachycardia, increased cardiac contractility, and vasoconstriction.
What laboratory tests are used to assess hypovolemic shock?
Hemoglobin and hematocrit, serum lactate, arterial pH, and arterial blood gas measurement.
What is the primary treatment goal in hypovolemic shock?
To restore vascular volume.
Name two types of fluids used in the treatment of hypovolemic shock.
Crystalloids (e.g., isotonic saline, Ringer lactate) and plasma volume expanders (e.g., pentastarch, colloidal albumin).
What characterizes distributive shock?
Loss of blood vessel tone, enlargement of the vascular compartment, and displacement of vascular volume away from the heart.
True or False: In hypovolemic shock, urine output decreases very quickly.
True.
Fill in the blank: The most immediate compensatory mechanism in shock is __________.
sympathetic-mediated responses.
What is distributive shock?
Distributive shock is characterized by loss of blood vessel tone, enlargement of the vascular compartment, and displacement of the vascular volume away from the heart and central circulation.
Distributive shock is also referred to as normovolemic shock.
What are the main causes of distributive shock?
The main causes are:
* Decrease in sympathetic control of vasomotor tone
* Release of excessive vasodilator substances
* Complications from vessel damage due to hemorrhage
What are the three shock states that share the basic circulatory pattern of distributive shock?
The three shock states are:
* Neurogenic shock
* Anaphylactic shock
* Septic shock
What causes neurogenic shock?
Neurogenic shock is caused by decreased sympathetic control of blood vessel tone due to defects in the vasomotor center in the brain stem or sympathetic outflow to blood vessels.