The nurse is caring for a client who had an appendectomy 4 hours ago. Which finding requires immediate action by the nurse?

a) The client's age: The client is 70 years old, which puts her at a higher risk of having a stroke or other cardiovascular problems. Stroke is a medical emergency that requires prompt treatment to prevent brain damage and disability.

b) The client's facial droop: The client has a noticeable facial droop, which is a sign of facial nerve weakness or paralysis. This can be caused by a stroke, Bell's palsy, or other neurological conditions. Facial droop can affect the client's ability to speak, eat, and express emotions.

c) The client's garbled speech: The client has garbled speech, which means she has difficulty producing or understanding words. This can be caused by a stroke, brain injury, or other disorders that affect the language areas of the brain. Garbled speech can impair the client's communication and cognition.

d) The client's alcohol consumption: The client had a few drinks at a seafood restaurant, which may have interacted with her medications or medical conditions. Alcohol can increase the risk of bleeding, lower blood pressure, and worsen dehydration. Alcohol can also impair the client's judgment and coordination.

e) The client's seafood intake: The client ate seafood at a restaurant, which may have triggered an allergic reaction or food poisoning. Seafood allergies can cause symptoms such as hives, swelling, breathing difficulties, and anaphylaxis. Food poisoning can cause symptoms such as nausea, vomiting, diarrhea, and dehydration.

Choice A: A headache rated at 0 on 0 to 10 scale is not a specific indicator of the effectiveness of an antihistamine. A headache may be caused by other factors, such as dehydration, stress, or sinus congestion.

Choice B: Oxygen saturation level of 99% is a normal finding and does not reflect the effect of an antihistamine. Oxygen saturation measures the amount of oxygen in the blood and can be affected by respiratory conditions, altitude, or smoking.

Choice C: Ambulating easily without vertigo is a sign that the antihistamine is effective. Vertigo is a common symptom of Ménière's disease, which is a disorder of the inner ear that causes episodes of spinning sensation, hearing loss, and tinnitus. Antihistamines can help reduce the fluid buildup in the inner ear and relieve vertigo.

Choice D: Blood pressure of 120/80 mm Hg is a normal finding and does not indicate the effect of an antihistamine. Blood pressure measures the force of blood against the walls of the arteries and can be influenced by factors such as heart rate, cardiac output, blood volume, and vascular resistance.