Which of the following are clinical manifestations that you can expect to see in your patient with obstructive shock?

Choice A rationale Afterload refers to the resistance the heart must pump against. In obstructive shock, the primary issue is a physical blockage of blood flow, such as in a pulmonary embolism or cardiac tamponade. While systemic vascular resistance may increase as a compensatory mechanism to maintain blood pressure, it is not the defining characteristic of the obstructive process itself. The most immediate hemodynamic consequence of many obstructive conditions is the inability of the chambers to fill or empty properly. Choice B rationale Obstructive shock often involves a restriction in the ability of the heart to fill with blood. For example, in cardiac tamponade, fluid in the pericardial sac compresses the heart, significantly decreasing preload. Similarly, in a tension pneumothorax, high intrathoracic pressure prevents venous return to the right atrium. This reduction in preload leads to a decrease in stroke volume and cardiac output, which are the primary reasons why the patient enters a state of shock and hypotension. Choice C rationale Increased cardiac output is the opposite of what occurs in obstructive shock. The hallmark of all shock states, including obstructive, is a failure to maintain adequate cardiac output to meet tissue demands. The physical obstruction prevents the heart from delivering enough blood to the systemic circulation. Normal cardiac output is roughly 4 to 8 L/min, but in obstructive shock, this value drops significantly because the heart cannot overcome the physical barrier to flow or filling. Choice D rationale Decreased afterload is typical of distributive shock, such as septic or anaphylactic shock, where massive vasodilation occurs. In obstructive shock, afterload is often increased as the body tries to compensate for a low cardiac output by constricting peripheral blood vessels. Decreased afterload would worsen the hypotension already present in obstructive shock. Therefore, it is not a clinical manifestation one would expect to see; instead, the body usually maintains or increases resistance to support blood pressure.