An elderly female patient has presented to the emergency department with altered mental status, hypothermia, and clinical signs of heart failure. Myxedema is suspected. Which of the following laboratory findings support this diagnosis?

Correct Answer: C

Rationale: Rationale for Correct Answer (C): Elevated T and T3/T4 levels are indicative of primary hypothyroidism, such as myxedema. In this case, the patient presents with classic symptoms of hypothyroidism, including altered mental status, hypothermia, and heart failure. Elevated T3/T4 levels confirm the diagnosis. Summary of Incorrect Choices: A: Elevated adrenocorticotropic hormone is associated with adrenal disorders, not hypothyroidism. B: Elevated cortisol levels suggest Cushing's syndrome, a condition of excess cortisol production, not hypothyroidism. D: Elevated thyroid-stimulating hormone is seen in primary hypothyroidism, but in myxedema, the issue is not with TSH but with T3/T4 levels.

Correct Answer: B

Rationale: The correct answer is B: prepare for intubation and mechanical ventilation. The patient's arterial blood gas results indicate metabolic acidosis (low pH, low bicarbonate) with respiratory compensation (low PCO). In this scenario, the patient is likely experiencing respiratory fatigue due to tachypnea from metabolic acidosis. Intubation and mechanical ventilation are needed to support the patient's respiratory effort and correct the acid-base imbalance. Administering morphine (choice A) can further depress the respiratory drive. Administering intravenous sodium bicarbonate (choice C) can temporarily correct the pH but does not address the underlying respiratory distress. Canceling dialysis (choice D) is not indicated as it does not address the acute respiratory compromise.

Correct Answer: C

Rationale: Step 1: Syndrome of inappropriate antidiuretic hormone (SIADH) leads to excess water retention, diluting sodium levels in the blood. Step 2: Fluid restriction is the mainstay of treatment to prevent further dilution of sodium. Step 3: Administering 3% normal saline (choice A) can worsen the condition by further increasing sodium levels. Step 4: Exogenous vasopressin (choice B) would exacerbate the problem by increasing water retention. Step 5: Low sodium diet (choice D) may be beneficial in the long term but is not the immediate priority.

Correct Answer: B

Rationale: The correct answer is B: evaluate the patient for signs and symptoms of infection. After 5 days, infection risk increases. Signs of infection include fever, redness, swelling, and tenderness at the catheter site. Monitoring for these signs is crucial to prevent complications. A: Routine dialysis catheter change is not indicated after 5 days. C: Teaching long-term use is incorrect as temporary catheters are not meant for extended use. D: Using lumens for fluid administration can increase infection risk and is not recommended.

Correct Answer: A

Rationale: The correct answer is A: Kidney, ureter, bladder (KUB) x-ray. KUB x-ray is a noninvasive diagnostic procedure that provides information about the size, shape, and position of the kidneys, ureters, and bladder. It can help detect abnormalities such as kidney stones or structural issues. Rationale: 1. KUB x-ray is noninvasive, meaning it does not require any incisions or insertion of instruments into the body. 2. It is commonly used as an initial screening tool to assess kidney function. 3. Renal ultrasound (Choice B) is also noninvasive but primarily used for imaging the kidneys and not the entire urinary system. 4. MRI (Choice C) and IVP (Choice D) are more invasive procedures that involve injecting contrast agents and may not be routinely used for initial kidney function assessment. In summary, the KUB x-ray is the correct choice as it is a noninvasive procedure specifically designed to evaluate kidney

Correct Answer: D

Rationale: Step-by-step rationale: 1. CRRT removes solutes and water slowly to avoid hemodynamic instability. 2. Slow removal better tolerates fluid and electrolyte shifts in critically ill patients. 3. Unlike intermittent hemodialysis, CRRT provides continuous, gentle therapy. 4. Choice A is incorrect as both CRRT and intermittent hemodialysis use a hemofilter. 5. Choice B is incorrect as CRRT does not provide faster solute and water removal. 6. Choice C is incorrect as CRRT allows for diffusion to occur, albeit at a slower rate. Summary: Continuous renal replacement therapy (CRRT) removes solutes and water slowly to prevent hemodynamic instability, making it a gentler and more continuous process compared to intermittent hemodialysis. The other choices are incorrect as CRRT does use a hemofilter, does not provide faster removal, and still allows for diffusion to occur.

Correct Answer: D

Rationale: The correct answer is D: Discontinue the IV infusion and administer the Lantus insulin at bedtime. This is the correct approach because insulin glargine (Lantus) is a long-acting basal insulin that provides a steady level of insulin throughout the day and night. By administering it at bedtime, it mimics the basal insulin secretion in a person without diabetes. This helps maintain stable blood sugar levels overnight. Choice A is incorrect because continuing the IV insulin infusion for 24 hours alongside insulin glargine is unnecessary and may lead to insulin overdose. Choice B is incorrect because discontinuing the IV infusion in several hours without administering the long-acting insulin can lead to inadequate insulin coverage. Choice C is incorrect because insulin aspart is a rapid-acting insulin that should be given with meals, not as a basal insulin replacement at bedtime.

Correct Answer: C

Rationale: Rationale for Correct Answer (C): Elevated T and T3/T4 levels are indicative of primary hypothyroidism, such as myxedema. In this case, the patient presents with classic symptoms of hypothyroidism, including altered mental status, hypothermia, and heart failure. Elevated T3/T4 levels confirm the diagnosis. Summary of Incorrect Choices: A: Elevated adrenocorticotropic hormone is associated with adrenal disorders, not hypothyroidism. B: Elevated cortisol levels suggest Cushing's syndrome, a condition of excess cortisol production, not hypothyroidism. D: Elevated thyroid-stimulating hormone is seen in primary hypothyroidism, but in myxedema, the issue is not with TSH but with T3/T4 levels.

Correct Answer: C

Rationale: Rationale: Acute tubular necrosis (ATN) is the most common intrarenal condition causing acute kidney injury. ATN is characterized by damage to the renal tubules due to ischemia or nephrotoxic substances. Prolonged ischemia (choice A) and exposure to nephrotoxic substances (choice B) can lead to ATN. Hypotension for several hours (choice D) can result in ischemic injury, which may lead to ATN but is not the direct cause. Therefore, choice C is correct as it directly relates to the primary intrarenal condition of ATN.