What is cardiogenic shock
the result of the heart's failure to pump blood forward effectively
Most common cause of cardiogenic shock
Acute MI; about 15%
Other causes of cardiogenic shock
ventricular ischemia, structural problems, dysrhythmias
Cardiogenic shock falls under this classification of post MI heart failure and is diagnosed with this specific criteria
Class IV heart failure; >40% necrosis of the left ventricle
Initial s/s related to decreased CO
SBP <90 mm Hg; restlessness, anxiety, lethargy, confusion, decrease sensorium, cool, pale, moist skin, UO<30cc, angina
Left ventricular failure symptoms
breath sounds have crackles (fluid), rhonchi (mucus-hear when coughing b/c moves mucus); S3 & S4 heart sounds
Right ventricular failure s/s
JVD, peripheral or dependent edema, hepatomegaly, splenomegaly, wt gain
Hemodynamically this would decrease in cardiogenic shock
CO and Cardiac index
Hemodynamically this would increase in cardiogenic shock
CVP, PCWP, SVR
Cardiogenic shock pts responding well to drug therapy when these goals are met
improved tissue perfusion, decrease cardiac workload and increase contractility
Med used to increase renal perfusion, but this is the unwanted SE
dopamine at 2-5mcg/kg/min; tachycardia
Levophed
drug improves BP but also increases afterload which leads to loss of a limb or digit
NTG
drug ordered with levophed to counteract vasoconstriction but it can cause a decrease in BP
Vasopressors and positive inotropes
drugs used to maintain organ perfusion but also end up increasing myocardial oxygen demand and can worsen ischemia
When the cardiogenic shock pt does not respond to drug therapy, this may be inserted
Intra-aortic balloon pump (IABP)- which is an intra-aortic counter pulsation device or a blood volume displacement device)
Coronary perfusion via these arteries occurs during this phase of the cardiac cycle
coronary arteries (which originate just above the cusps of the aortic valve of the heart) and diastole
Coronary artery flow is decreased during this phase of the cardiac cycle because of this reason
Systole- during contraction, heart muscles compress the coronary capillaries creating an increase in coronary vascular resistance
IABP provides assistance to...
the left ventricle
The IABP can be inserted in these places in the hospital
OR, cath lab or ICU at pt's bedside
The balloon is positioned in this area of the body
in the descending thoracic aorta just distal to the take off of the left subclavian artery
The balloon is inflated during this and does this to the blood
inflated during the diastole (which is like the heart having an extra systole); the blood in the aorta is displaced back toward the heart and forward to the systemic circulation
When the balloon inflates the position of the aortic valve is this and the blood is forced into this area of the heart
aortic valves are closed and the blood is forced into the coronary arteries
Blood volume in the aorta below the level of the balloon will be propelled this way which may improve circulation to this...
forward and kidneys
The balloon is deflated during this...and creates this type of effect
deflated just before systole of the cardiac cycle and creates a vacuum effect
Benefits when balloon deflates
decreases afterload, facilitates ventricular emptying and reduces myocardial O2 demand
This is essential for the IABP to work properly and can be synchronized according to...
timing is essential; synchronized according to EKG or arterial blood pressure tracing
This can adversely affect the timing of the balloon inflation and deflation
dysrrhythmias
hemodynamically these parameters will decrease b/c of IABP
CVP, PCWP, SVR
hemodynamically these parameters will increase b/c of IABP
CO and MAP
Assessments for legs for IABP
pulsesness (DP, PT quality & presence), pallor (color), temp, cap refill, paralysis (motor fxn), paresthesia (sensory fxn)
Due to possible migration of the balloon this should be assessed
left radial pulse and UO
Activities and positioning for IABP
avoid flexing leg, move by logrolling from side to side, HOB should be flat
This lab value should be monitored closely for an IABP pt
platelets b/c thrombocytopenia may occur b/c mechanical destruction of platelets by the pumping action of the balloon
What does RVAD and LVAD stand for
Right or left ventricular assist device
VADS are inserted b/c of this reason
when pts need circulatory support until heart transplantation can be performed
VADs should not be implanted unless pt has someone at home that can do these 2 things
recharge the battery every few hours and resuscitate the pt in the event of an emergency
Heart transplantation is generally not performed in pts with these conditions
over 65-70 y/o, other medical conditions are expected to limit their lifespan, pts who cannot be counted on to comply with the demanding medical regimen