Critical Care Nursing Cardiac Questions

Correct Answer: D

Rationale: The correct answer is D because when a reliable 24-hour urine collection is not possible, a standardized formula can be used to estimate GFR. The Cockcroft-Gault equation or the Modification of Diet in Renal Disease (MDRD) equation are commonly used formulas to estimate GFR based on serum creatinine levels, age, gender, and race. These formulas provide a reasonable estimation of kidney function in the absence of a 24-hour urine collection. Choice A is incorrect because there are alternative methods available to estimate GFR. Choice B is incorrect because BUN alone is not sufficient to accurately determine renal function. Choice C is incorrect because an elevated BUN/creatinine ratio is not a direct measure of GFR and may be influenced by factors other than kidney function, such as hydration status or liver function.

Correct Answer: D

Rationale: Step-by-step rationale for Answer D being correct: 1. PA catheter measures PA pressures. 2. PAWP reflects left atrial pressure. 3. Correct placement shows typical PAWP tracing. 4. PA pressure waveform (A) is not specific to PAWP. 5. Systemic arterial pressure tracing (B) is unrelated. 6. Systemic vascular resistance tracing (C) is not monitored by PA catheter.

Correct Answer: B

Rationale: The correct answer is B: a decreased risk of peritonitis exists. Peritoneal dialysis involves the insertion of a catheter into the peritoneal cavity, which can introduce bacteria and increase the risk of peritonitis. However, compared to hemodialysis, peritoneal dialysis has a lower risk of bloodstream infections and vascular access-related complications, leading to a decreased risk of peritonitis. This advantage makes peritoneal dialysis a favorable option for some patients. Incorrect choices: A: peritoneal dialysis is actually less time-intensive compared to hemodialysis. C: biochemical disturbances are corrected more gradually in peritoneal dialysis. D: the danger of hemorrhage is not specific to peritoneal dialysis.

Correct Answer: A

Rationale: The correct answer is A because in ARDS, there is a severe impairment in gas exchange leading to hypoxemia. Decreasing PaO2 levels despite increased FiO2 administration indicate poor oxygenation, a hallmark of ARDS. Elevated alveolar surfactant levels (Choice B) do not directly correlate with ARDS pathophysiology. Increased lung compliance with increased FiO2 administration (Choice C) is not characteristic of ARDS, as ARDS leads to decreased lung compliance. Respiratory acidosis associated with hyperventilation (Choice D) is not a typical finding in ARDS, as hyperventilation is usually present in an attempt to compensate for hypoxemia.

Correct Answer: C

Rationale: The correct answer is C: Respiratory acidosis may occur if the patient continues at these ventilator settings. Respiratory acidosis happens when the lungs cannot remove enough of the carbon dioxide (CO2) produced by the body. In this case, the low respiratory rate of 14 breaths/min may not be sufficient to adequately remove CO2, leading to its accumulation in the blood. This results in a decrease in blood pH, causing respiratory acidosis. Summary of other choices: A: Metabolic acidosis - Not the correct answer as the ventilator settings are more likely to affect the respiratory system rather than the metabolic system. B: Metabolic alkalosis - Not the correct answer as the ventilator settings are not related to causing an increase in blood pH, which is characteristic of metabolic alkalosis. D: Respiratory alkalosis - Not the correct answer as the low respiratory rate would not lead to excessive elimination of CO2, causing alkalosis.