Correct Answer: D

Rationale: Verifying tube placement by checking the pH of gastric contents is crucial to ensure the nasogastric tube is correctly positioned in the stomach. This action helps prevent complications such as aspiration. Flushing the tube with normal saline every 8 hours is not necessary for ensuring proper functioning of the tube. Clamping the tube when not in use may lead to the build-up of gastric secretions and blockages. Positioning the client in a supine position is not directly related to ensuring the proper functioning of the nasogastric tube.

Correct Answer: D

Rationale: The correct answer is D: 'When the lesions are crusted over.' Varicella is no longer contagious once the lesions are dry and crusted. This stage indicates that the active viral shedding has significantly decreased, reducing the risk of transmission. Choice A, 'When the fever dissipates,' is incorrect because the presence of fever does not necessarily correlate with the contagiousness of varicella. Choice B, 'After the incubation period,' is incorrect as the incubation period occurs before the onset of symptoms and is not relevant to determining contagiousness. Choice C, 'When the lesions have healed,' is incorrect as healed lesions can still be contagious if they are not crusted over.

Correct Answer: A

Rationale: The correct answer is A: 'Report any signs of a sore throat or fever immediately.' Phenytoin can cause blood dyscrasias, which can manifest as a sore throat or fever. These symptoms could indicate a serious side effect that requires immediate medical attention. Choice B is incorrect because phenytoin should not be taken with antacids as they can decrease its absorption. Choice C is incorrect because discontinuing phenytoin abruptly can lead to rebound seizures; drowsiness is a common side effect that may improve with time. Choice D is incorrect because adjusting the dosage of phenytoin should only be done under healthcare provider supervision, not based on experiencing an aura.

Correct Answer: B

Rationale: Chest pain unrelieved after taking 3 sequential nitroglycerin tablets indicates a possible myocardial infarction and requires immediate medical attention.

Correct Answer: B

Rationale: The correct answer is B because while the exact causes of depression in children are not fully understood, research indicates that children are more likely to experience depression if their parents have a major affective disorder. Choice A is incorrect because it suggests that the causes of major depression are entirely unknown, which is not accurate. Choice C is incorrect as there is no conclusive evidence that boys are more likely than girls to be depressed. Choice D is incorrect as the prevalence rate of depression is not necessarily higher in prepubescent children specifically.