Continuous venovenous hemofiltration is used to
- A. remove fluids and solutes through the process of convection.
- B. remove plasma water in cases of volume overload.
- C. remove plasma water and solutes by adding dialysate.
- D. combine ultrafiltration, convection, and dialysis.
Correct Answer: A
Rationale: The correct answer is A because continuous venovenous hemofiltration primarily removes fluids and solutes through convection. Convection involves the movement of solutes across a semi-permeable membrane by the force of the fluid flow. This process helps to achieve fluid balance and manage electrolyte levels in patients with renal failure.
Choice B is incorrect because hemofiltration does not specifically target plasma water; it aims to remove both fluids and solutes. Choice C is incorrect as hemofiltration does not involve adding dialysate; it relies on the patient's blood passing through a filter to remove waste products. Choice D is incorrect because while hemofiltration may involve aspects of ultrafiltration and dialysis, the primary mechanism is convection for removing fluids and solutes.
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Acute kidney injury from postrenal etiology is caused by
- A. obstruction of the flow of urine.
- B. conditions that interfere with renal perfusion.
- C. hypovolemia or decreased cardiac output.
- D. conditions that act directly on functioning kidney tissue
Correct Answer: A
Rationale: The correct answer is A because acute kidney injury from postrenal etiology is caused by obstruction of the flow of urine, leading to back pressure and damage to the kidneys. Choices B and C relate to prerenal causes, affecting renal perfusion and volume status. Choice D refers to intrinsic renal causes, directly affecting kidney tissue function, not postrenal obstruction. Therefore, A is correct due to the nature of postrenal etiology.
The patient is getting hemodialysis for the second time when he complains of a headache and nausea and, a little later, of becoming confused. The nurse realizes these are symptoms of
- A. dialyzer membrane incompatibility.
- B. a shift in potassium levels.
- C. dialysis disequilibrium syndrome.
- D. hypothermia.
Correct Answer: C
Rationale: The correct answer is C: dialysis disequilibrium syndrome. This syndrome occurs when there is a rapid shift in electrolytes, especially in the brain, due to the removal of waste products during hemodialysis. The symptoms of headache, nausea, and confusion align with this syndrome as the brain struggles to adjust to the changes. Dialyzer membrane incompatibility (A) is unlikely as it typically presents with allergic reactions, not neurological symptoms. A shift in potassium levels (B) may cause symptoms like muscle weakness or irregular heartbeat, not headache and confusion. Hypothermia (D) would present with low body temperature, shivering, and confusion, but in this case, the symptoms are more indicative of dialysis disequilibrium syndrome.
The critical care nurse knows that in critically ill patients, renal dysfunction
- A. is a very rare problem.
- B. affects nearly two thirds of patients.
- C. has a low mortality rate once renal replacement therapy has been initiated.
- D. has little effect on morbidity, mortality, or quality of life.
Correct Answer: B
Rationale: The correct answer is B because renal dysfunction is a common issue in critically ill patients due to factors like sepsis or hypoperfusion. This affects nearly two thirds of patients, leading to potential complications. Choice A is incorrect as renal dysfunction is common, not rare. Choice C is incorrect as mortality rates can still be high even with renal replacement therapy. Choice D is incorrect as renal dysfunction can significantly impact morbidity, mortality, and quality of life in critically ill patients.
The patient is in a progressive care unit following arteriovenous fistula implantation in his left upper arm, and is due to have blood drawn with his next set of vital signs and assessment. When the nurse assesses the patient, the nurse should
- A. draw blood from the left arm.
- B. take blood pressures from the left arm.
- C. start a new intravenous line in the left lower arm.
- D. auscultate the left arm for a bruit and palpate for a thrill.
Correct Answer: D
Rationale: The correct answer is D. Auscultating the left arm for a bruit and palpating for a thrill post arteriovenous fistula implantation is crucial to assess the patency and functionality of the fistula. A bruit indicates turbulent blood flow, while a thrill signifies the presence of a strong pulse through the fistula. These assessments help identify any complications like stenosis or thrombosis. Drawing blood or taking blood pressures from the arm with the fistula can lead to inaccurate results or damage the fistula. Starting a new IV line in the left lower arm is unnecessary and not relevant to monitoring the arteriovenous fistula.
Peritoneal dialysis is different from hemodialysis in that peritoneal dialysis
- A. is more frequently used for acute kidney injury.
- B. uses the patient’s own semipermeable membrane (peritoneal membrane).
- C. is not useful in cases of drug overdose or electrolyte imbalance.
- D. is not indicated in cases of water intoxication.
Correct Answer: B
Rationale: The correct answer is B because peritoneal dialysis uses the patient's own semipermeable membrane, the peritoneal membrane, to filter waste and excess fluid from the blood. This membrane allows for the exchange of fluids and solutes, making it an effective method for dialysis.
A is incorrect because peritoneal dialysis can be used for acute kidney injury.
C is incorrect as peritoneal dialysis can address drug overdose and electrolyte imbalance by removing toxins and balancing electrolytes.
D is incorrect as peritoneal dialysis can be used in cases of water intoxication by helping to remove excess fluid from the body.