Correct Answer: D

Rationale: Facial expression has consistently been validated as an indicator of pain in infants. Behavioral pain measures are most reliable for sharp procedural pain in infants. Increased heart rate and respirations are indicative of a generalized and complex response to stress, not specific for pain in infants. Thrashing of arms and legs is a reliable indicator in young children, not specifically in infants.

Correct Answer: A

Rationale: Improvement in APIGN is indicated by an increase in urine output and a change in urine color from brown (due to hematuria) to a more normal appearance. This reflects a reduction in glomerular inflammation and improved kidney function. Choice B is incorrect because resting more comfortably is not a direct indicator of kidney function improvement. Choice C is incorrect because a decrease in appetite is not typically associated with improvement in APIGN. Choice D is incorrect because an increased BUN value would suggest worsening kidney function rather than improvement.

Correct Answer: D

Rationale: The correct answer is D, Hemophilus influenzae type B (Hib) vaccine. Hib vaccine is crucial in preventing epiglottitis, a serious respiratory condition caused by Haemophilus influenzae type b bacteria. This vaccine is recommended for toddlers to protect them from developing epiglottitis. Choices A, B, and C are incorrect because while they are important vaccines for children, they do not specifically target the prevention of epiglottitis, unlike the Hib vaccine.

Correct Answer: D

Rationale: Dry mucous membranes and an ill appearance are good indicators of dehydration in infants, often correlating with a fluid deficit of at least 5%. Sunken fontanels and poor skin turgor are also indicative but were not options here.

Correct Answer: B

Rationale: Overeating, swallowing excessive air (leading to frequent burping), and parental smoking are known to contribute to colic in infants. Understimulation is not typically associated with colic.