Chronic Kidney Disease

Question 1

What is Acute Kidney Disease?

Answer 1

• Rapid loss of kidney function (hours to days)
• Commonly reversible
• Usually caused by dehydration, blood loss, medication, IV contrast, obstruction

Question 2

What is

Chronic Kidney Disease?

Answer 2

• Progressive loss of renal function that persists for more than 3 months
• Commonly irreversible
• Usually caused by long-term diseases such as DM, HTN

Question 3

What is Glomerular Filtration Rate (GFR)?

Answer 3

• Measure of how well the kidneys are removing wastes and excess fluid from the blood
• Calculated from the serum creatinine level using your age, weight, gender and body size
• The normal value for GFR is 90 or above
• A GFR below 60 is a sign that the kidneys are not working properly
• A GFR below 15 indicates that a treatment plan for kidney failure, such as dialysis or a kidney transplant is needed

Question 4

What is the Estimated GFR (glomerular filtration rate)?

Answer 4

-Cockcroft-Gault Equation:
CrCl = (140 – age) X (IBW)
Scr X 72

• Modification of Diet in Renal Disease Study (MDRDS) Equation:
  1. 86 𝑥 〖(𝑃𝑐𝑟)〗^(−1.154) x 〖(𝑎𝑔𝑒)〗^(−0.203)
• Multiply by 0.742 for women
• Multiply by 1.21 for African Americans

Question 5

What are the Clinical Manifestations Advanced Stages of Uremic Syndrome?

Answer 5

Symptomatic manifestations associated with Azotemia = the accumulation of urea and other nitrogenous compounds and toxins caused by the decline in renal function

Question 6

What are the Complications of progressive chronic kidney disease?

Answer 6

• Anemia
• Metabolic acidosis
• Derangements in vitamin D, calcium and phosphorus metabolism
• Volume overload
• Hyperkalemia
• Uremia
• Cardiovascular consequences

Question 7

What is the Approach to the patient with new renal dysfunction?

Answer 7

• Consider pre-renal, renal, post-renal etiologies
• Careful history (contrast exposure, meds, dehydration)
• PE
• Serum creatinine (GFR)
• Urine dipstick; microscopy & spot protein
• Renal ultrasound (consider other imaging)
• Urinalysis
• Consider checking for multiple myeloma (serum protein electrophoresis, urine protein electrophoresis)

Question 8

What is Proteinuria?

Answer 8

• > 150-160 mg/24hr
• > 1-2gram/24hr signifies underlying kidney abnormality, usually glomerular
• > 3.5 g/24hr is consistent with nephrotic range proteinuria
• 24hr urine collection vs random ‘spot’ urine sample (Urine protein/Urine Creatine ratio)
• For spot urine < 0.2 is normal

Question 9

Why is anemia a complication of chronic kidney disease?

Answer 9

• Occurs secondary to decreased production of EPO by the kidney
• After work-up for anemia, if no other explanation is found, then CKD is declared to be the cause
• EPO-stimulating agents should be provided if Hgb falls <10 mg/dL (goal 11-12 mg/dL) *higher goals are associated with increase mortality

Question 10

Whys is Vitamin D Deficiency a complication of chronic kidney disease?

Answer 10

• Secondary to decreased production of 1,25-OH vitamin D (active form/short half life) as kidney is responsible for 1-hydroxylation process
• Only measure 25-OH vitamin D as they represent the storage form (normal is > 30 mg/mL)

Question 11

Why is Metabolic acidosis a complication of kidney dysfunction?

Answer 11

• Secondary to decreased bicarbonate reabsorption and generation by kidneys
• Treat with bicarbonate supplementation after bicarbonate falls < 18 mg/dL (target 22 mg/dL)

Question 12

What is Uremia?

Answer 12

• Hundreds of toxins accumulate
• Urea and creatinine are elevated and used as surrogate markers for toxins
• Systemic inflammation increases

Question 13

What are the Risk Factors to the development of CKD?

Answer 13

• Hypertension
• Diabetes mellitus
• Autoimmune disease
• Older age
• African ancestry
• Family history
• Previous episode of acute kidney injury
• Proteinuria
• Abnormal urinary sediment
• Structural abnormalities of the urinary tract

Question 14

What are the Most common causes of Chronic Kidney Disease/End-Stage Renal Disease (ESRD)?

Answer 14

• Diabetic glomerular disease (44%)
• Hypertensive nephropathy (28%)
• Glomerulonephritis (6%)
• Autosomal dominant polycystic kidney disease (2%)
• Other cystic and tubulointerstitial nephropathy

Question 15

What is treatment for Diabetic Nephropathy?

Answer 15

• ACEI/ARB’s – renal protective qualities

- Diuretic – addition of a second agent to aide in BP control

Question 16

What is Hypertensive Nephropathy?

Answer 16

• Develops in patients with proteinuria and hypertension

- Lowering BP Goals in a patient with CKD and HTN

Question 17

What is treatment for Hypertensive Nephropathy?

Answer 17

• Current guidelines advise caution with use of ACEI/ARB’s in the presence of renal impairment
• Evidence that these drugs are effective in reducing progression of CKD and reducing mortality/morbidity in patients with heart failure
• Recommend use of ACEI/ARB’s in stages 1-3 and those with proteinuria

Question 18

When do you Refer to a Nephrologist?

Answer 18

• GFR < 30ml/min (CKD Stages 4 and 5)
• Rapidly progressive CKD
• Poorly controlled hypertension despite four agents
• Rare or genetic causes of CKD
• Suspected renal artery stenosis

Question 19

What are the indications to Dialyze?

Answer 19

1. Severe Acidosis
2. Severe electrolyte abnormalities: especially hyperkalemia.
3. Poison ingestions: overdose
4. Severe volume Overload and inability to urinate due to CKD (anuria)
5. Uremia: many symptoms - CNS (asterixis, seizure, coma), platelet dysfunction (GI bleed, bleeding diathesis, coagulopathies), infectious risk, pleuritis/pericarditis (friction rub), pericardial effusion

Question 20

What is Dialysis?

Answer 20

• Process for removing waste and excess water from the blood, and is used primarily as an artificial replacement for lost kidney function in people with ARF or CKD (stage 5)
• Dialysis is regarded as a “holding measure” until a renal transplant can be performed or as supportive measure in those with acute kidney injury where a transplant unlikely/unecessary

Question 21

What is Hemodialysis?

Answer 21

• Ultrafiltration occurs by increasing the hydrostatic pressure across the dialyzer membrane
• This usually is done by applying a negative pressure to the dialysate compartment of the dialyzer
• This pressure gradient causes water and dissolved solutes to move from blood to dialysate, and allows the removal of several liters of excess fluid during a typical 4-hour treatment

Question 22

What is Peritoneal Dialysis?

Answer 22

• Peritoneal dialysis, a sterile solution containing glucose (called dialysate) is run through a tube into the peritoneal cavity, the abdominal body cavity around the intestine, where the peritoneal membrane acts as a partially permeable membrane
• Diffusion and osmosis drive waste products and excess fluid through the peritoneum into the dialysate until the dialysate approaches equilibrium with the body’s fluids
• Then the dialysate is drained, discarded, and replaced with fresh dialysate
• This exchange is repeated 4-5 times per day; automatic systems can run more frequent exchange cycles overnight
• Peritoneal dialysis is less efficient than hemodialysis, but because it is carried out for a longer period of time the net effect in terms of removal of waste products and of salt and water are similar to hemodialysis

Question 23

When is time for a kidney transplantation?

Answer 23

• end-stage renal disease (ESRD), regardless of the primary cause
• This is defined as a glomerular filtration rate <15ml/min/1.73 sq.m.
• The majority of renal transplant recipients are on dialysis (peritoneal dialysis or hemofiltration) at the time of transplantation
• Individuals with chronic renal failure who have a living donor available may undergo pre-emptive transplantation before dialysis is needed.