All of the following may be useful in the treatment of cardiogenic shock except:

C. Pneumatic antishock garment.

DISCUSSION: Cardiogenic shock occurs when the heart fails to generate adequate cardiac output to maintain tissue perfusion. Intrinsic causes such as myocardial dysfunction secondary to coronary artery disease, or extrinsic causes such as pulmonary embolism, tension pneumothorax, and pericardial tamponade, may produce cardiogenic shock. Principles of treatment of cardiogenic shock are aimed at optimizing preload, cardiac contractility, and afterload. Preload is usually adequate or high in cardiogenic shock. Dobutamine is a useful inotropic agent, particularly when filling pressures are high, because of its mild vasodilatory effect, as well as its effect to enhance cardiac contractility. Afterload-reducing agents, such as sodium nitroprusside, may be beneficial in cardiogenic shock in the setting of elevated filling pressures, low cardiac output, and elevated systemic vascular resistance. Cardiac output may improve with use of afterload-reducing agents by decreasing myocardial wall tension and optimizing the myocardial oxygen supply-demand ratio. The intra-aortic balloon pump (IABP), by providing diastolic augmentation, reducing left ventricular afterload, and reducing myocardial oxygen consumption, is sometimes useful in the treatment of cardiogenic shock. The IABP is especially useful in low–cardiac output postcardiotomy patients, in patients awaiting revascularization, and in patients with acute myocardial infarction complicated by mitral insufficiency or ventricular septal defect. The pneumatic antishock garment (PASG), which causes an increase in systemic vascular resistance, is contraindicated in cardiogenic shock.