Which physiologic effect characterizes anaphylactic shock?

Get ready for the Paramedic Readiness Exam 5. Study with multiple-choice questions, detailed explanations, and effective strategies. Enhance your exam preparedness today!

In anaphylactic shock, chemical mediators released during an allergic reaction cause rapid, widespread dilation of blood vessels and increased capillary permeability. This combination lowers systemic vascular resistance and allows fluid to leak from the intravascular space into the interstitial tissues, leading to hypotension and edema. The increased permeability also contributes to airway and tissue swelling, which can further compromise breathing.

This pattern fits the scenario because it describes systemic vasodilation with vascular leak, the hallmark of anaphylaxis. The other options describe things that don’t match this mechanism: decreased capillary permeability would reduce fluid leakage; localized vasoconstriction wouldn’t produce the broad, systemic effects seen in anaphylaxis; and cardiac tamponade is a separate condition involving pericardial fluid restricting cardiac filling, not the vascular mediator effects of anaphylaxis.