MSN 570 Advanced Pathophysiology Final 2024

Correct Answer: B

Rationale: In this scenario, the rising lactic acid levels in a 65-year-old man after a coronary artery bypass graft could indicate bowel ischemia. Bowel ischemia can lead to anaerobic metabolism, causing an increase in lactic acid levels. Excessive sedation may cause respiratory depression but would not directly lead to rising lactic acid levels. Excessive volume infusion in the operating room might cause fluid overload but would not typically result in rising lactic acid levels. Mild hypothermia postoperatively could lead to shivering and increased oxygen consumption, but it is less likely to be the primary cause of rising lactic acid levels in this context.

Correct Answer: A

Rationale: Abrupt withdrawal or discontinuation of prednisone, a corticosteroid, can lead to adrenal crisis. This occurs due to the suppression of the adrenal glands' natural cortisol production caused by prolonged exogenous steroid administration. Adrenal crisis presents with symptoms such as weakness, fatigue, abdominal pain, and hypotension. Hypercortisolism (Cushing syndrome) results from chronic excessive exposure to cortisol, not abrupt withdrawal. ACTH stimulation would be expected in response to low cortisol levels, not as a direct consequence of prednisone withdrawal. Thyroid crisis (thyroid storm) is associated with severe hyperthyroidism and is not directly related to corticosteroid withdrawal.

Correct Answer: D

Rationale: Macular degeneration is a condition that affects the macula, a part of the retina responsible for central vision. It is primarily caused by impaired blood supply to the macula, leading to cellular waste accumulation and ischemia. This results in the death of photoreceptor cells and ultimately vision loss. Choices A, B, and C are incorrect because macular degeneration is not related to the loss of lens accommodation, detachment of the retina, or increased intraocular pressure. The correct answer directly addresses the underlying pathophysiology of macular degeneration.

Correct Answer: A

Rationale: In a patient with a subconjunctival hemorrhage secondary to allergic rhinitis, the hemorrhage is typically self-limiting and will resolve on its own within 2 weeks without the need for specific treatment. Referring the patient for immediate ophthalmologic examination is not necessary unless there are other concerning symptoms. Starting oral antihistamines may help manage the underlying allergic rhinitis but is not specifically indicated for the hemorrhage. Topical corticosteroids are not routinely prescribed for subconjunctival hemorrhage as they may have limited benefit and could potentially cause complications.

Correct Answer: A

Rationale: Alpha-1 antitrypsin deficiency is a genetic cause of chronic obstructive pulmonary disease (COPD). It is more common in younger patients with a history of smoking at a younger age, like the 30-year-old who has smoked for 3 years. Choices B, C, and D are less likely to be associated with alpha-1 antitrypsin deficiency as COPD in these cases is more likely due to smoking and environmental exposures.