Acute Kidney Injury Nclex Questions

Acute Kidney Injury (AKI): Mastering the NCELX Questions

Acute Kidney Injury (AKI), previously known as acute renal failure (ARF), is a sudden episode of kidney failure or damage that causes a buildup of waste products in the blood and makes it hard for your kidneys to filter waste. Understanding AKI is crucial for aspiring nurses, and the NCLEX exam frequently tests this knowledge. This comprehensive guide will delve into the key aspects of AKI, providing you with the information needed to confidently answer related NCLEX questions. We'll cover risk factors, pathophysiology, assessment findings, diagnostic tests, nursing interventions, and common complications. By the end, you'll be well-equipped to tackle any AKI-related questions on the exam.

Understanding Acute Kidney Injury (AKI)

What is AKI? AKI is characterized by a rapid loss of kidney function, resulting in the accumulation of nitrogenous wastes (such as creatinine and urea) in the blood, electrolyte imbalances, and fluid overload. This impairment can range from mild to severe and can be reversible depending on the underlying cause and the extent of kidney damage.

Types of AKI: AKI is classified into three categories based on the location of the injury:

• Pre-renal AKI: This occurs before the kidney itself is damaged. The cause is usually a reduction in blood flow to the kidneys (hypoperfusion), often due to dehydration, hypotension, heart failure, or sepsis. This is often reversible if the underlying cause is addressed promptly.

• Intra-renal AKI: This involves direct damage to the kidney tissue itself. Causes include nephrotoxic drugs (e.g., aminoglycosides, NSAIDs), acute glomerulonephritis, acute tubular necrosis (ATN), and ischemia. This type can be more challenging to treat and may lead to permanent kidney damage.

• Post-renal AKI: This is caused by an obstruction in the urinary tract that prevents urine from draining from the kidneys. Common causes include kidney stones, bladder tumors, benign prostatic hyperplasia (BPH), and urethral strictures. This type is often reversible once the obstruction is relieved.

Risk Factors for AKI

Several factors increase the risk of developing AKI. These include:

• Advanced age: Older adults are more susceptible to AKI due to decreased kidney function and increased prevalence of comorbidities.

• Pre-existing kidney disease: Individuals with chronic kidney disease (CKD) are at significantly higher risk of developing AKI.

• Diabetes mellitus: Diabetic nephropathy is a leading cause of CKD and AKI.

• Hypertension: Uncontrolled hypertension can damage blood vessels in the kidneys, leading to AKI.

• Heart failure: Reduced cardiac output can impair renal perfusion, leading to pre-renal AKI.

• Sepsis: Septic shock can cause widespread organ damage, including the kidneys.

• Use of nephrotoxic drugs: Certain medications, such as aminoglycosides, NSAIDs, and contrast dyes, can directly damage kidney cells.

• Dehydration: Severe dehydration reduces blood flow to the kidneys.

• Trauma: Major trauma can lead to hypovolemic shock and AKI.

• Surgical procedures: Major surgeries, especially cardiac and vascular surgeries, increase the risk of AKI.

Pathophysiology of AKI

The pathophysiology of AKI varies depending on the type. However, the common outcome is a reduction in glomerular filtration rate (GFR), the rate at which blood is filtered by the kidneys.

• Pre-renal AKI: Decreased renal perfusion leads to decreased GFR due to vasoconstriction and reduced blood flow to the nephrons.

• Intra-renal AKI: Direct damage to the nephrons, such as tubular necrosis, impairs filtration and reabsorption functions. Inflammation and cellular damage contribute to reduced GFR.

• Post-renal AKI: Obstruction of the urinary tract increases pressure within the kidneys, impairing filtration and potentially causing damage to the nephrons. This back pressure reduces GFR. In severe cases, it can lead to intra-renal damage.

Assessment and Diagnostic Tests for AKI

Assessing a patient for AKI involves a comprehensive approach including:

• History: Obtain a thorough history focusing on risk factors, medications, recent illnesses, and symptoms.

• Physical Examination: Assess for signs of fluid overload (edema, hypertension, crackles in lungs), dehydration (dry mucous membranes, poor skin turgor), and signs of underlying conditions.

• Laboratory Tests: Key tests include:

  • Serum creatinine: Elevated creatinine indicates impaired kidney function.
  • Blood urea nitrogen (BUN): Elevated BUN also signifies impaired kidney function. The BUN/Creatinine ratio can help differentiate between pre-renal and intra-renal AKI.
  • Electrolytes: Monitor for imbalances in sodium, potassium, calcium, and phosphorus.
  • Complete blood count (CBC): Assess for anemia and signs of infection.
  • Urinalysis: Examine for blood, protein, casts, and specific gravity.

• Imaging Studies: Ultrasound, CT scan, or other imaging may be used to identify structural abnormalities such as kidney stones or tumors (especially for post-renal AKI).

Nursing Interventions for AKI

Nursing care for patients with AKI focuses on supporting kidney function, managing complications, and preventing further kidney damage. Key interventions include:

• Fluid Balance Management: Careful monitoring of intake and output (I&O) is crucial. Fluid restriction may be necessary in cases of fluid overload.

• Electrolyte Management: Monitor serum electrolytes closely and administer appropriate replacements as needed. Potassium levels require close attention, as hyperkalemia is a serious complication.

• Medication Administration: Administer medications as prescribed, including diuretics (to promote fluid excretion), phosphate binders (to control hyperphosphatemia), and medications to manage electrolyte imbalances. Careful monitoring for nephrotoxic effects is vital.

• Nutritional Management: A diet low in protein, potassium, phosphorus, and sodium may be prescribed to reduce the workload on the kidneys.

• Hemodynamic Monitoring: Closely monitor blood pressure, heart rate, and central venous pressure (CVP) to assess hemodynamic stability.

• Dialysis: Hemodialysis or peritoneal dialysis may be necessary to remove waste products and excess fluid from the blood if kidney function is severely impaired.

• Education: Educate the patient and family about the condition, treatment plan, potential complications, and dietary restrictions.

Complications of AKI

AKI can lead to various life-threatening complications, including:

• Hyperkalemia: Elevated potassium levels can disrupt cardiac rhythm and cause life-threatening arrhythmias.

• Fluid Overload: Excess fluid can lead to pulmonary edema, hypertension, and heart failure.

• Anemia: Reduced erythropoietin production by the kidneys can cause anemia.

• Metabolic Acidosis: The kidneys play a crucial role in acid-base balance, and impaired kidney function can lead to metabolic acidosis.

• Infection: Patients with AKI are at increased risk of infections due to impaired immune function.

• Electrolyte imbalances: Imbalances in sodium, calcium, magnesium, and phosphorus can cause various symptoms and complications.

• Chronic Kidney Disease (CKD): AKI can progress to CKD in some patients.

NCLEX-Style Questions on AKI

Let's test your knowledge with some NCLEX-style questions:

1. A patient with AKI is exhibiting signs of hyperkalemia. Which of the following medications would the nurse anticipate administering?

a) Calcium gluconate b) Sodium bicarbonate c) Loop diuretic d) Potassium chloride

Answer: a) Calcium gluconate. Calcium gluconate is used to stabilize the myocardium and prevent life-threatening arrhythmias associated with hyperkalemia.

2. Which of the following is a priority nursing intervention for a patient with pre-renal AKI?

a) Restrict fluids b) Administer potassium-sparing diuretics c) Increase IV fluids d) Administer phosphate binders

Answer: c) Increase IV fluids. Pre-renal AKI is caused by decreased blood flow to the kidneys; therefore, increasing IV fluids to improve perfusion is a priority intervention.

3. A patient with AKI is receiving hemodialysis. What is a key nursing assessment during dialysis?

a) Monitor for signs of hypoglycemia b) Assess for signs of hypervolemia c) Assess for signs of hyperkalemia d) All of the above

Answer: d) All of the above. All these are important considerations during hemodialysis. Dialysis can correct electrolyte imbalances and fluid overload, but monitoring is crucial.

4. Which lab value is the MOST reliable indicator of AKI?

a) Blood Urea Nitrogen (BUN) b) Serum Creatinine c) GFR e) Urine output

Answer: b) Serum Creatinine. While all options are relevant, serum creatinine is generally considered the most reliable indicator of kidney function because it is less influenced by other factors compared to BUN or urine output. GFR is also a very reliable indicator, but serum creatinine is more readily and routinely available.

5. A patient with AKI is on a restricted diet. Which of the following foods should be limited?

a) Bananas b) Oranges c) Potatoes d) All of the above

Answer: d) All of the above. Bananas, oranges, and potatoes are all high in potassium, which needs to be restricted in AKI.

Frequently Asked Questions (FAQs)

Q: What is the difference between AKI and CKD?

A: AKI is a sudden onset of kidney dysfunction, often reversible with proper treatment. CKD is a progressive, long-term loss of kidney function, usually not reversible.

Q: Can AKI be prevented?

A: While not all cases are preventable, many risk factors can be managed to reduce the likelihood of developing AKI. Controlling blood pressure, managing diabetes, and avoiding nephrotoxic drugs are key preventative measures.

Q: What is the prognosis for AKI?

A: The prognosis for AKI varies depending on the cause, severity, and promptness of treatment. Early intervention and management of the underlying cause often result in complete recovery. However, in severe cases, AKI can lead to permanent kidney damage and chronic kidney disease.

Conclusion

Understanding acute kidney injury is paramount for nurses. This detailed overview provides a solid foundation for mastering AKI-related questions on the NCLEX exam. Remember to focus on the pathophysiology, assessment findings, diagnostic tests, nursing interventions, and potential complications to confidently approach these questions. By understanding the core principles of AKI, you'll be well-prepared to provide optimal care for patients experiencing this critical condition and to excel in your nursing career. Continue practicing with NCLEX-style questions and reviewing relevant materials to ensure your comprehensive understanding of this complex topic.