A child has recently been diagnosed with Duchenne muscular dystrophy (DMD). The parents are receiving genetic counseling prior to planning another pregnancy. Which of the following statements includes the most accurate information?

Correct Answer: A

Rationale: The correct answer is that Duchenne is an X-linked recessive disorder, meaning the affected gene is located on one of the two X chromosomes of a female carrier. If a son receives the X chromosome bearing the gene, he will develop the disease, giving him a 50% chance of being affected. Daughters, on the other hand, are not affected by Duchenne but have a 50% chance of being carriers since they inherit one copy of the defective gene from the mother. The other X chromosome is inherited from the father, who cannot be a carrier. Therefore, choice A is accurate. Choice B is incorrect because daughters do not develop the disease, and sons have a 50% chance of developing, not both having a 50% chance. Choice C is incorrect as it does not consider the X-linked inheritance pattern of Duchenne. Choice D is inaccurate as it incorrectly states that only sons have a 25% chance of developing the disorder, omitting the carrier status of daughters.

Correct Answer: A

Rationale: A non-rebreather mask is used for supplemental oxygen delivery for clients experiencing breathing difficulties. The non-rebreather mask includes a one-way valve that allows exhaled air to escape, preventing the rebreathing of carbon dioxide. The client inhales oxygenated air from a reservoir bag attached to the mask, providing high-concentration oxygen therapy. A non-rebreather mask can deliver FiO2 levels of up to 90%, making it an effective intervention for clients requiring high oxygen concentrations. Therefore, the statement that 'A non-rebreather can provide an FiO2 of 40%' is correct. Choices B, C, and D are incorrect because clients should breathe through their nose and mouth, the mask offers a reservoir for inhaling oxygen, and the mask should be assessed and potentially replaced if soiled or damaged, not routinely changed every 3 hours.

Correct Answer: A

Rationale: A remittent fever is characterized by temperature fluctuations where the fever spikes and then lowers but does not return to normal temperature. Option A best describes this pattern of fever. Option B describes a pattern of fever known as a biphasic fever, where the fever alternates between days of fever and normal temperature. Option C describes a pattern of fever that is more indicative of an intermittent fever, where the fever lasts for a specific duration followed by an interval of normal temperature. Option D does not accurately describe a remittent fever, as it suggests a persistent fever that has lasted over 24 hours, which is not specific to the remittent pattern.

Correct Answer: C

Rationale: The correct answer is 'Water loss is greater than electrolyte loss.' In hypertonic dehydration, there is a higher loss of water compared to electrolytes, leading to elevated concentrations of electrolytes in the body. This condition is characterized by plasma sodium levels above 150 mEq/L. As water moves from the extracellular space to the intracellular space, it results in cellular dehydration. Choice A is incorrect because the plasma sodium levels associated with hypertonic dehydration are typically above 150 mEq/L, not between 130 and 150 mEq/L. Choice B is incorrect as fluid moves from the extracellular space to the intracellular space in hypertonic dehydration. Choice D is incorrect because physical signs and symptoms may not always be grossly apparent in hypertonic dehydration.

Correct Answer: A

Rationale: The key to preventing a pandemic influenza is early detection. Detecting influenza cases early allows for timely public health responses to limit the spread of the virus. Early detection helps in implementing measures such as isolation, treatment, and vaccination to prevent the development of a full-blown pandemic. Antibiotics are not effective against influenza viruses, so early antibiotic treatment is not the key to prevention. While vaccination of at-risk populations is important in controlling the spread of influenza, early detection is crucial as it allows for timely implementation of vaccination strategies. Isolation of suspected cases is a containment measure rather than a prevention strategy; the key to prevention lies in early detection to stop the spread before it becomes a pandemic.