CHAPTER 50 CARDIOGENIC SHOCK Flashcards
Most common cause of cardiogenic shock
Extensive myocardial infarction that depresses myocardial contractility
The classic and most common picture of acute cardiogenic shock is due to:
left ventricular (LV) infarction
Physiologic triad of left ventricular (LV) infarction
(1) low cardiac index <2.2 L/min/m2
(2) high systemic vascular resistance indices
(3) increased pulmonary capillary wedge pressure, with peripheral vasoconstriction and pulmonary edema
In the absence of profound hypotension, _____________ is a mainstay of initial pharmacologic treatment
dobutamine
-increases cardiac contractility and is most effective if the systolic blood pressure is ≥90 mm Hg
-Avoid use alone when the systolic blood pressure is <90 mm Hg because of its vasodilatory potential.
Associated with more systemic acidosis, tachycardia, and dysrhythmias compared to the combination of norepinephrine and dobutamine.
Epinephrine
Patients on β-blocker therapy may have an attenuated response to dobutamine, making ___________ a better choice.
milrinone
Remarks on Cardiogenic shock
SBP drops d/t poor CO –> hypoperfusion of vital organs
(-) Increase SVR –> DBP. drops –> coronary artery hypoperfusion –> worsen myocardial ischemia and pump dysfxn –> decompensation
An indicator of LV dysfunction but does not identify the cause
Serum B-type natriuretic peptide
-(<100 picograms/ mL) eliminates cardiogenic shock as the cause of hypoperfusion
POCUS
IVC for volume status
Subcostal 4-chamber view - pericardial effusion/cardiac tamponade (dilated IVC, diastolic RV collapse, systolic RA collapse)
Subcostal/parasternal/apical - EF, cardiac contractility
Concerning for ascending aortic dissection POCUS
Aortic root >3cm
The most important definitive intervention for acute ischemiarelated cardiogenic shock
emergent revascularization
Px is hypotensive, no pulmonary congestion
Crystalloid fluid bolus: 250-500 ml (may repeat after reassessment)
if px still hypotensive after fluid bolus or pulmonary congestion develops
Vasopressors (for hypotension)
Inotropes (for congestion without profound hypotension)
It is a vasopressor with some inotropic effect, but it may increase cardiac work by increasing heart rate and may also increase LVEDP by its β-agonist effect.
Dopamine
Most prefer if SBP <70
NorepinephrineI
