Correct Answer: C

Rationale: In a child newly diagnosed with cystic fibrosis (CF), noisy respirations and a dry, non-productive cough are typically the first respiratory signs to appear. The other options, including a positive sweat test, bulky greasy stools, and meconium ileus, are among the earliest findings of CF. CF is a genetic condition that affects the production of mucus, sweat, saliva, and digestive juices. Due to a defective gene, these secretions become thick and sticky instead of thin and slippery, leading to blockages in various passageways, especially in the pancreas and lungs. Respiratory failure is a severe consequence of CF, making it crucial to monitor respiratory symptoms closely in affected individuals. Therefore, a moist, productive cough would not be an expected finding in a newly diagnosed child with CF.

Correct Answer: B

Rationale: The correct pediatric dose of diphenhydramine is 5 mg/kg/day. This child weighs 30 kg, so the calculated dose would be 5 mg/kg x 30 kg = 150 mg/day. Since the prescription is for 25 mg 3 times a day, the total daily dose is 25 mg x 3 = 75 mg/day, which is lower than the calculated dose of 150 mg/day. Therefore, the prescribed dose of 25 mg 3 times a day is too low for this child. The dose should be adjusted to meet the correct dosage of 150 mg/day, which would be 50 mg 3 times a day. It is important not to titrate the dosage based on symptoms without consulting a physician, as this can lead to inappropriate medication administration.

Correct Answer: D

Rationale: The correct answer is D: Left ventricular functioning. The purpose of inserting a pulmonary artery catheter is to obtain information about left ventricular functioning when the catheter balloon is inflated. Choices A, B, and C are incorrect because while a pulmonary artery catheter can provide information on stroke volume, cardiac output, and venous pressure, its primary purpose is to assess left ventricular function.

Correct Answer: A

Rationale: Lyme disease, the most common vector-borne disease in the United States, is caused by the bacterium Borrelia burgdorferi. Borrelia burgdorferi is transmitted to humans through the bite of infected black-legged ticks. Streptococcus pyogenes is associated with strep throat and other infections, not Lyme disease. Bacillus anthracis causes anthrax, a separate infectious disease. Enterococcus faecalis is more commonly linked to urinary tract infections and other healthcare-associated infections, not Lyme disease.

Correct Answer: C

Rationale: In this case, the correct answer is autonomic neuropathy. Autonomic neuropathy affects the autonomic nerves, which control various bodily functions including the bladder. In diabetes, it can lead to bladder paralysis, resulting in symptoms like urgency to urinate and difficulty initiating urination. Atherosclerosis (choice A) is a condition involving the hardening and narrowing of arteries, not directly related to the inability to urinate in this context. Diabetic nephropathy (choice B) primarily affects the kidneys, leading to kidney damage, but does not typically cause urinary retention. Somatic neuropathy (choice D) involves damage to sensory nerves, not the autonomic nerves responsible for bladder control, making it less likely to be the cause of the urinary issue described in the question.