Cardiogenic Shock and Mechanical Circulatory Support Flashcards
What is cardiogenic shock
A state of critical end organ hypoperfusion due to reduced cardiac output
What is the determinant for cardiogenic shock with regards to hypotension
Systolic blood pressure less than 90 mmHg OR A reduction in MAP of 30 mmHg or more from baseline
What is the determinant for cardiogenic shock with regards to Cardiac Index
Cardiac Index less than 2.2 L/min/m2 for patients receiving vasoactive medications or mechanical support OR Cardiac Index less than 1.8 L/min/m2 for patients not receiving vasoactive medications or mechanical support
What is the determinant for cardiogenic shock with regards to Adequate Filing Pressure
Pulmonary artery wedge pressure (PAWP) greater than 15 -18 mmHg
What is the progression of cardiogenic shock
Myocardial injury cause a reduction in stroke volume reducing cardiac output -> Systemic coronary hypoperfusion with an increase in afterload -> systemic inflammatory response -> more myocardial injury
What are the two major causes of left ventricular pump failure
Acute myocardial infarction (AMI) and End-stage cardiomyopathy
What are some presentations patients will have with cardiogenic shock
Hypotension/tachycardia, decreased urine output, cool extremities, cyanotic (blueish coloring of skin), altered mental status
What are labs findings to aid in seeing if there is cardiogenic shock
Troponin, elevated BNP (greater than 100mmHg), elevated lactate, Mixed venous Saturation (SVO2) less than 70%, elevated creatinine, transaminitis/coagulation abnormalitites
What key findings can be found from the pulmonary artery cathether
PCWP (15-18 mmHg) and Cardiac Index 2.6-4.2 L/min/m2
What happens to cardiac output, afterload, preload, and SVO2
Decreased, increased, increased, decreased
What are the four hemodynamic classes for the heart
Class 1: Warm and Dry (Normal)
Class 2: Warm and Wet (Too much salt)
Class 3: Cold and Dry (bad pump)
Class 4: Cold and Wet (Cardiogenic shock)
What class of drugs should be given for cardiogenic shock
Diuretics PLUS Inotropes PLUS Vaspressors
T/F: Fluids should never be given to a patient who is going through cardiogenic shock as they are already volume overloaded
False: Some patients may require 250-500ml bolus IF NO PULMONARY CONGESTION and no other signs of fluid overload
What diuretics should be given to patients with cardiogenic shock, hemodynamic effect
Loop diuretics: Furosemide 40 mg, Bumetanide 1mg, ethacrynic acid 50 mg, torsemide 20 mg/ less preload leads to increased stroke volume and cardiac output
What are the ionotropes should be given to patients with cardiogenic shock
Dobutamine and Milrinone
What are the benefits of dobutamine
Inotropic effects are desirable, increased cardiac output, attack quickly with a quick half life
What are the adverse effects of dobutamine
Arrhythmias, hypotension, tachphylaxis
T/F: Since a beta-blocker is a negative ionotrope it should be stopped if a patient is being given dobutamine since it is a positive ionotrope
True
Why is milrinone a more potent to effect blood pressure Inotrope
Not only are the ionotropic effects good but milrinone also causes increased calcium at the veins and arteries too causing vasodilation reducing systemic and pulmonary resistance
What are the adverse effects of milrinone
Arrhhythmias and Hypotension
Which ionotrope is renally eliminated, hepatic
Milrinone, Dobutamine
What are the two best vasopressors for cardiogenic shock
Norephinephrine and dopamine
What is the risk of using dopamine
Dopamine causes arrhythmias
What are the types of mechanical circulatory Support
Intra-Aortic Ballon Pump, Left Ventricular Support Device, Extracorporeal Membrane Oxygenation, Left Ventricular Assist Device
What is the most commonly used MCS, when is it used
Intra-Aortic Balloon Pump (IABP)/ Cardiogenic shock, high risk PSI, and refractory heart failure
What is the mechanism for IABP
Counterpulsation: Inflates during diastole (increasing coronary perfusion) and deflates during systole (abruptly decreases afterload and enhances left ventricular ejection) increasing cardiac output
What are cautions associated with IABP
Anticoagulation (heparin), thrombocytopenia, antimicrobials
What is the short term MCS, mechanism, indications
Impella: pumps blood from the LV into the ascending aorta but effectiveness is dependent on the RV, used during high risk PCI or less than 6 days after cardiogenic shock
What are the two ways patients are anticoagulated on impella
Systemic anticoagulation with heparin, purge solution to prevent blood entrance into the motor chamber
How much purge heparin solution are patients given for impella catheter
If they weigh less than 80kg: 25 units/ml, If they weight more than 80kg: 50 units/ml
What is the Impella purge Infusion Rate, maintenance systemic intravenous heparin
2-30 mL/hour, Hperain 25,000 units/250mL Dextrose 5% (units/hour)
What is the equation to calculate INITIAL IV infusion rate
Initial TOTAL Infusion Rate- PURGE Rate
What are the two types of extracorporeal membrane Oxygenation
Venovenous bypass: Bypass lungs: venous circulation -> oxygenator -> right atrium
Venoarterial bypass: Bypasses lungs and heart: Venous circulation -> oxygenator -> (femoral artery) arterial circulation
What are the three type of LVADs
Heartmate 2, Heartware, Heartmate 3
What are the four items that must be present with LVADs
LVAD pump, batteries, driveline, and controller
How does the LVAD work, what type of anticoagulation is used
Pumps blood from left ventricle to aorta/ asprin 81 mg daily and warfarin for an INR between 2-3
What are the ways to classify cold and wet
Cardiac index less than 2.2 (cold) and pulmonary capillary wedge pressure greater than 18 (wet)
