Chronic Kidney Disease

Question 1

What is chronic kidney disease (CKD)?

Answer 1

A progressive loss of kidney function over a period of months or years. Chronic kidney disease (CKD) refers to significantly impaired renal function for ≥3 months.

Question 2

A 48-year-old man presents to the primary care clinic for a follow-up appointment. The patient was last seen in the clinic six months ago and has not followed up since then. Past medical history is significant for chronic hepatitis B virus infection, cirrhosis, and congestive heart failure with an ejection fraction of 45%. Current medications include carvedilol and lactulose. Temperature is 37.0 °C (98.6 °F), pulse is 84/min, and blood pressure is 152/91 mmHg. Physical exam is significant for 3+ bilateral lower extremity edema. Serum creatinine is 3.17 mg/dL (was 2.0 mg/dL six months ago) and albumin is 3.0 g/dL. In-office dipstick urinalysis shows 3+ proteinuria. 24-hour urine protein shows protein of 3.9 g/24 hours. Which of the following additional findings is most likely to be present?

Answer 2

Chronic kidney disease (CKD) refers to significantly impaired renal function for ≥3 months. In the United States, it is most commonly caused by diabetes mellitus and hypertension, but many other causes exist. Patients with previously undiagnosed CKD often present with insidious onset of declining renal function. Patients can present with nephritic or nephrotic syndrome. In nephrotic syndrome, severe proteinuria leads to rapid loss of oncotic pressure and subsequent edema. This patient with a history of hepatitis B who presents with findings consistent with nephrotic syndrome likely has HBV-associated secondary membranous nephropathy. Classic findings of nephrotic syndrome include peripheral and periorbital edema, proteinuria, a bland urine sediment, weight gain, and fatigue. History in patients with newly diagnosed kidney disease should focus on medical history with attention to risk factors (e.g. diabetes mellitus, HIV, hypertension, chronic viral hepatitis), family history (e.g. polycystic kidney disease), and personal risk factors (e.g. frequent NSAID use). Symptoms may be nonspecific and consist of decreased urination or generalized fatigue and poor appetite. Physical examination may show peripheral edema. Patients with advanced CKD may have signs of anemia (e.g. pale conjunctiva). Uremic frost is a hallmark sign of severe untreated CKD but is extremely rare in developed countries.

Question 3

Fill in the blank: The primary test used to assess kidney function is the _______.

Answer 3

Glomerular filtration rate (GFR).

Question 4

What is the primary prevention strategy for CKD?

Answer 4

Control of diabetes and hypertension.

Question 5

What is the primary cause of CKD?

Answer 5

Diabetes mellitus and hypertension.

Question 6

True or False: CKD can lead to cardiovascular disease.

Answer 6

True.

Question 7

What is the most common symptom of CKD?

Answer 7

Fatigue.

Question 8

Fill in the blank: The presence of _______ in urine is a marker for kidney injury.

Answer 8

Albumin.

Question 9

What is a common cardiovascular complication associated with CKD?

Answer 9

Heart failure. All patients with newly diagnosed CKD should be screened for cardiovascular risk factors.

Question 10

What is the target blood pressure for patients with CKD?

Answer 10

Less than 130/80 mmHg.

Question 11

What is the role of erythropoietin in CKD?

Answer 11

It stimulates red blood cell production, which is often deficient in CKD.

CKD-related hypoproliferative anemia is often treated with EPO-stimulating agents (ESAs), such as supplemental EPO, to stimulate red blood cell production within the bone marrow. However, vigorous hematopoiesis after ESA administration can cause rapid depletion of iron stores, even if iron levels are normal on initiation; therefore, patients who require ESAs (eg, many CKD patients with hemoglobin <10 g/dL) should have iron levels checked prior to initiation of EPO and at scheduled intervals while on therapy.

Question 12

What is the significance of a 24-hour urine collection in CKD?

Answer 12

It helps assess kidney function and proteinuria levels.

Question 13

What laboratory test is used to monitor CKD progression?

Answer 13

Serum creatinine.

Question 14

What is the common term for the accumulation of waste products due to CKD?

Answer 14

Uremia.

Question 15

What lifestyle change can help manage CKD?

Answer 15

Smoking cessation.

Question 16

What is the primary goal of CKD management?

Answer 16

To slow disease progression and manage complications.

Question 17

True or False: All patients with CKD progress to dialysis.

Answer 17

False.

Question 18

What is the role of nephrology in CKD?

Answer 18

To provide specialized care for patients with kidney diseases.

Question 19

What is the effect of CKD on potassium levels?

Answer 19

It can lead to hyperkalemia (elevated potassium levels).

Question 20

What is the common term for the build-up of fluid in tissues due to CKD?

Answer 20

Edema.

Question 21

What is the term for the clinical syndrome characterized by the accumulation of nitrogenous waste products in the blood?

Answer 21

Uremia. This can progress to pericarditis and bleeding diaphysis.

Question 22

What is the recommended frequency for monitoring kidney function in CKD patients?

Answer 22

At least once a year.

Question 23

Fill in the blank: CKD can lead to _______ due to imbalances in calcium and phosphate.

Answer 23

Bone disease.

Question 24

What is a common complication of CKD related to bone health?

Answer 24

Renal osteodystrophy.

Question 25

What is the role of calcium and vitamin D supplementation in CKD?

Answer 25

To prevent bone disease and manage mineral imbalances.

Question 26

What is the primary goal of pharmacologic therapy in CKD?

Answer 26

To manage symptoms and prevent complications.

Question 27

What is the recommended initial treatment for hypertension in CKD patients?

Answer 27

ACE inhibitors or angiotensin receptor blockers (ARBs).

Question 28

A 62-year-old man was sent to the emergency department due to abnormal labs that his primary care doctor had performed yesterday. The patient has had viral gastroenteritis with several episodes of vomiting and diarrhea over the past few days, his symptoms are now resolved. He has a past medical history of hypertension and chronic kidney disease. Temperature is 37.0 °C (98.6 °F), pulse is 90/min, blood pressure is 98/56 mmHg, and SpO2 is 100% on room air. On physical examination, the patient has dry mucous membranes. There is no abdominal tenderness to palpation. Mild pitting edema is present in both lower extremities up to the mid-tibia. Electrocardiogram is performed and shows normal sinus rhythm with no abnormalities. Bloodwork is drawn and results are shown below. The patient is given nebulized albuterol as well as IV calcium gluconate, insulin, and 50% dextrose solution. Which of the following is the next best step in management? A) Repeat electrocardiogram B) Administer oral sodium polystyrene sulfonate C) Administer IV calcium chloride D) Perform hemodialysis E) Administer oral sodium bicarbonate

Answer 28

Chronic kidney disease management should include treating associated acute complications (e.g. acute kidney injury, hyperkalemia, metabolic acidosis) and evaluating to determine the underlying causes of worsening kidney function. Chronic kidney disease (CKD) refers to significantly impaired renal function for ≥3 months, which in the United States is most commonly caused by diabetes mellitus and hypertension. CKD is graded based on the estimated glomerular filtration rate (eGFR and degree of albuminuria. Patients with CKD are at increased risk for developing renal complications such as acute kidney injury (AKI), hyperkalemia, and metabolic acidosis. This patient with CKD (as evidenced by the elevated baseline serum creatinine) presents with superimposed acute kidney injury and hyperkalemia. Hyperkalemia at this level is considered an emergency and should be managed with medications that stabilize the myocardium and drive potassium into the cells, as well as therapy to rapidly remove excess potassium from the body. Albuterol, insulin, and sodium bicarbonate are administered to drive potassium into cells. Calcium gluconate stabilizes the myocardium and reduces the risk of electrocardiographic changes, but it does not significantly encourage potassium movement into cells. Loop diuretics (bumetanide, furosemide, torsemide) or oral potassium-binding resins (e.g., sodium polystyrene sulfonate, sodium zirconium cyclosilicate) should be given to promote removal of excess potassium from the body.

Question 29

A 63-year-old woman presents to the emergency department due to two weeks of worsening fatigue, decreased urination, and lower extremity swelling. The patient was previously seen one year ago in the clinic, but she did not follow up at that time. She takes no medications. Temperature is 37.4 °C (99.3 °F), pulse is 84/min, and blood pressure is 146/88 mmHg. On physical examination, there is mild pitting edema bilaterally up to the proximal tibia. Urinalysis shows no white blood cells. Bloodwork is obtained and results are shown below. CT of the abdomen and pelvis without contrast shows no acute abnormalities. Which of the following should be ordered next to help make a diagnosis in this patient? A) Kidney biopsy B) Urine culture C) Serum protein electrophoresis D) Urine eosinophil stain E) Ultrasound of kidneys

Answer 29

This patient with chronic kidney disease (CKD) based on current and prior elevated creatinine levels, who presents with anemia, fatigue, and hypercalcemia likely has multiple myeloma. Signs of multiple myeloma include Calcium (hypercalcemia), Renal dysfunction, Anemia, and Bony lesions (CRAB mnemonic). Assessing serum (and urine) protein electrophoresis and serum-free kappa and lambda light chains can help make the diagnosis. Chronic kidney disease (CKD) refers to significantly impaired renal function for ≥3 months. In the United States, it is most commonly caused by diabetes mellitus and hypertension, but many other causes exist. CKD is graded as G3, G4, or G5 based on the estimated glomerular filtration rate (30-59 mL/min, 15-29 mL/min, and <15 mL/min, respectively). It is also graded as A1, A2, and A3 based on the degree of albuminuria. A urine albumin-creatinine ratio < 30, 30-299, and >300 indicate stages A1, A2, and A3 respectively. These grading systems help guide management. Evaluation for the cause of CKD depends on the presence of additional signs, symptoms, and comorbidities. Symptoms of vasculitis or presence of urinary erythrocyte casts should prompt ANCA and anti-GBM antibody studies. ANA should be checked if there is suspicion of lupus nephritis. If virus-related nephrotic or nephritic syndromes are suspected, viral testing for HBV, HCV, and HIV is indicated. Other tests may include anti-PLA2R antibodies (for membranous glomerulopathy), C3 and C4 complement levels, and cryoglobulins. If laboratory testing is unrevealing, a kidney biopsy may be required.

Question 30

What classification system is used to stage CKD?

Answer 30

The Kidney Disease Improving Global Outcomes (KDIGO) classification.

Question 31

What is the definition of stage 1 CKD?

Answer 31

Kidney damage with normal or increased GFR (≥ 90 mL/min/1.73 m²).

Question 32

What stage of CKD is characterized by mildly decreased GFR (60-89 mL/min/1.73 m²)?

Answer 32

Stage 2 CKD.

Question 33

What stage of CKD is characterized by mildly decreased GFR (30-59 mL/min/1.73 m²)?

Answer 33

Stage 3 CKD. Patients with stage G3 and G4 disease should have comorbidities like HTN and diabetes managed to delay progression of disease.

Question 34

Can thiazides be used to treat CKD?

Answer 34

Thiazide diuretics like Hydrochlorothiazide are commonly used for the treatment of hypertension. It should be used cautiously or avoided altogether in patients with chronic kidney disease G3 and above. Instead, loop diuretics (bumetanide, furosemide, torsemide) can be used and are often indicated for patients with chronic kidney disease with fluid overload.

Question 35

What stage of CKD is characterized by mildly decreased GFR (15-29 mL/min/1.73 m²)?

Answer 35

Stage 4 CKD. Patients with stage G3 and G4 disease should have comorbidities like HTN and diabetes managed to delay progression of disease.

Question 36

What is the key laboratory finding in end-stage renal disease (ESRD)?

Answer 36

Significantly elevated serum creatinine levels.

Question 37

What is the definition of stage 5 CKD?

Answer 37

Kidney failure with GFR < 15 mL/min/1.73 m², requiring dialysis or transplantation. Once patients reach stage G5 they should be counseled on renal replacement therapy (hemodialysis or peritoneal dialysis) as well as renal transplantation.

Question 38

What is the significance of proteinuria in CKD?

Answer 38

It indicates kidney damage and correlates with disease progression.

Question 39

How is urinary albumin assessed with CKD?

Answer 39

The degree of albuminuria should be used to determine the A stage. Urine albumin-creatinine ratio < 30, 30-299, and >300 indicate stage A1, A2, and A3, respectively. For example, patients with G3 (mild to moderate ) CKD and a history of hypertension with stage A1 (mild) albuminuria and should be started on losartan, a renin-angiotensin-aldosterone system (RAAS) inhibitor (ACE-inhibitor or angiotensin receptor blocker). If hypertension is present, and an SGLT-2 inhibitor (e.g. empagliflozin) if diabetes mellitus is present. All patients with A2 or A3 disease should be started on a RAAS inhibitor and SGLT-2 inhibitor, even if hypertension or diabetes mellitus are not present.

Question 40

When are SGLT-2 inhibitors given for CKD?

Answer 40

SGLT-2 inhibitors like empagliflozin are medications used for diabetes mellitus or congestive heart failure independent of diabetes mellitus. In patients with CKD and HTN but without diabetes mellitus, SGLT-2 inhibitors are not indicated until the albumin-creatinine ratio is ≥30 (A2 stage).

Question 41

When is dialysis initiated for CKD?

Answer 41

The initiation of chronic hemodialysis for CKD is typically delayed until the estimated glomerular filtration rate reaches 7.5-15 mL/min/1.73 m? (sometimes lower) or complications of CKD (eg, uremic symptoms, volume overload) become unmanageable with medications alone.

Question 42

What are the two main types of dialysis?

Answer 42

Hemodialysis and peritoneal dialysis.