A patient is complaining of a sharp pain along the costovertebral angles (CVA) during percussion.
The nurse knows that this symptom most often indicates:

Choice A rationale

A drug allergy is an adverse immune-mediated reaction to a drug, involving antibodies or sensitized lymphocytes. Symptoms can range from rash and itching to anaphylaxis, occurring upon re-exposure. This client's reaction, wakefulness instead of sedation, does not align with typical allergic manifestations involving the immune system.

Choice B rationale

Drug tolerance is a diminished physiological response to a drug after repeated administration, requiring higher doses to achieve the same effect. This develops due to adaptive changes in drug receptors or metabolism. The client's experience of wakefulness, an opposite effect, is not indicative of tolerance to the drug's intended hypnotic action.

Choice C rationale

A toxic effect occurs when drug levels in the body exceed the therapeutic range, leading to harmful effects on organs or systems. This is often dose-dependent and can manifest as organ damage or severe side effects. While adverse, the described reaction of wakefulness is not typically classified as a toxic effect of Ambien.

Choice D rationale

An idiosyncratic reaction is an uncharacteristic or unpredictable response to a drug that is not an allergic reaction and does not involve known pharmacological properties. These reactions are often genetically determined and represent an individual's unique sensitivity. The paradoxical wakefulness from a sedative like Ambien is a classic example of an idiosyncratic drug response.

Choice A rationale

Frostbite causes localized tissue damage due to ice crystal formation and cellular dehydration, leading to impaired circulation. While frostbite can affect capillary refill, a 5-second refill time in the absence of cold exposure or other correlating symptoms makes frostbite a less likely primary consideration and requires broader assessment.

Choice B rationale

Venous insufficiency involves impaired blood return to the heart, leading to venous stasis and edema. Capillary refill primarily assesses arterial perfusion and microcirculatory integrity, not venous outflow. Therefore, venous insufficiency would not typically manifest as a prolonged capillary refill time as a primary symptom.

Choice C rationale

Normal capillary refill time in adults is typically less than 2 seconds. A 5-second capillary refill time indicates impaired peripheral perfusion, suggesting inadequate blood flow to the capillaries. This delay warrants further investigation to identify underlying causes such as dehydration, hypovolemia, or peripheral vascular compromise.

Choice D rationale

Normal capillary refill time is typically less than 2 seconds. A 5-second refill time is significantly prolonged and indicates compromised peripheral circulation. Considering this normal would lead to a missed opportunity to identify and address a potentially serious underlying physiological issue affecting tissue perfusion.