Chronic Kidney Disease LCDR Perry, MSC, US Navy

Chronic Kidney Disease Topics Background Causes Clinical findings Labs and imaging Complications Treatment Prognosis

Topics

Background

Causes

Clinical findings

Labs and imaging

Complications

Treatment

Prognosis

Chronic Kidney Disease Essentials of diagnosis Progressive azotemia over months to years Symptoms and signs of uremia when nearing end-stage dz HTN in majority Isosthenuria and broad casts in urinary sediment are common Bilateral small kidneys on US

Essentials of diagnosis

Progressive azotemia over months to years

Symptoms and signs of uremia when nearing end-stage dz

HTN in majority

Isosthenuria and broad casts in urinary sediment are common

Bilateral small kidneys on US

Chronic Kidney Disease National Kidney Foundation (NKF) defines CKD as evidence of renal damage (based on abnormal UA [proteinuria, hematuria] or structural abnormalities found with US) or GFR < 60 mL/min for 3 or more months

National Kidney Foundation (NKF) defines CKD as evidence of renal damage (based on abnormal UA [proteinuria, hematuria] or structural abnormalities found with US) or GFR < 60 mL/min for 3 or more months

Chronic Kidney Disease Five stages of CKD

Five stages of CKD

Chronic Kidney Disease Over 28 million affected…number increasing daily Over 400,000 Americans currently treated with renal replacement therapy Most common RF for CKD include DM, HTN, CVD, FHx of CKD, and age > 60 yrs Major outcomes of CKD include CVD, progression to renal failure, and development of complications of impaired renal function, such as anemia, d/o of mineral metabolism, and secondary hyperparathyroidism

Over 28 million affected…number increasing daily

Over 400,000 Americans currently treated with renal replacement therapy

Most common RF for CKD include DM, HTN, CVD, FHx of CKD, and age > 60 yrs

Major outcomes of CKD include CVD, progression to renal failure, and development of complications of impaired renal function, such as anemia, d/o of mineral metabolism, and secondary hyperparathyroidism

Chronic Kidney Disease In CKD, reduced clearance of certain solutes principally excreted by the kidney results in their retention in the body fluids. The solutes are end products of the metabolism of substances of exogenous origin (eg, food) or endogenous origin (eg, catabolism of tissue)

In CKD, reduced clearance of certain solutes principally excreted by the kidney results in their retention in the body fluids. The solutes are end products of the metabolism of substances of exogenous origin (eg, food) or endogenous origin (eg, catabolism of tissue)

Chronic Kidney Disease CKD is rarely reversible and leads to progressive decline in renal function. Reduction in renal mass leads to hypertrophy of the remaining nephrons with hyperfiltration, and the glomerular filtration rate in these nephrons is transiently at supranormal levels. These adaptations place a burden on remaining nephrons, leading to progressive glomerular sclerosis and interstitial fibrosis, suggesting that hyperfiltration may worsen renal function

CKD is rarely reversible and leads to progressive decline in renal function. Reduction in renal mass leads to hypertrophy of the remaining nephrons with hyperfiltration, and the glomerular filtration rate in these nephrons is transiently at supranormal levels. These adaptations place a burden on remaining nephrons, leading to progressive glomerular sclerosis and interstitial fibrosis, suggesting that hyperfiltration may worsen renal function

Chronic Kidney Disease Symptoms develop slowly and are nonspecific Pts may remain asymptomatic until renal failure is far-advanced (GFR < 10-15 ml/min) Manifestations can include fatigue, malaise, weakness, pruritis GI c/o anorexia, n/v, metallic taste and hiccups are common

Symptoms develop slowly and are nonspecific

Pts may remain asymptomatic until renal failure is far-advanced (GFR < 10-15 ml/min)

Manifestations can include fatigue, malaise, weakness, pruritis

GI c/o anorexia, n/v, metallic taste and hiccups are common

Chronic Kidney Disease Neurologic problems include irritability, difficulty concentrating, insomnia, and forgetfulness Menstrual irregularities, infertility, and loss of libido are also common as condition progresses

Neurologic problems include irritability, difficulty concentrating, insomnia, and forgetfulness

Menstrual irregularities, infertility,

and loss of libido are also

common as condition

progresses

Chronic Kidney Disease PE reveals a chronically ill-appearing pt Look for possible underlying cause (DM, lupus) HTN is common Skin may be yellow, with evidence of easy bruising Uremic fetor (fishy breath) may be present Cardiopulmonary and mental status changes are frequently noted also. See CMDT

PE reveals a chronically ill-appearing pt

Look for possible underlying cause (DM, lupus)

HTN is common

Skin may be yellow, with evidence of easy bruising

Uremic fetor (fishy breath) may be present

Cardiopulmonary and mental status changes are frequently noted also. See CMDT

Chronic Kidney Disease Labs Dx made by documenting elevations of BUN and serum creatinine concentrations GFR…once < 60, refer to Nephrologist Persistent proteinuria is suggestive of CKD, regardless of GFR level UA: broad, waxy casts (evidence of loss of tubular concentrating ability)

Labs

Dx made by documenting elevations of BUN and serum creatinine concentrations

GFR…once < 60, refer to Nephrologist

Persistent proteinuria is suggestive of CKD, regardless of GFR level

UA: broad, waxy casts (evidence of loss of tubular concentrating ability)

Chronic Kidney Disease Labs (cont) May see anemia, metabolic acidosis, hyperphosphatemia, hypocalcemia, and hyperkalemia…with both acute and chronic renal failure Further eval needed to differentiate between acute and chronic renal failure Evidence of previously elevated BUN and creatinine, abnormal prior UA, and stable but abnormal serum creatinine on successive days is most consistent with a chronic process

Labs (cont)

May see anemia, metabolic acidosis, hyperphosphatemia, hypocalcemia, and hyperkalemia…with both acute and chronic renal failure

Further eval needed to differentiate between acute and chronic renal failure

Evidence of previously elevated BUN and creatinine, abnormal prior UA, and stable but abnormal serum creatinine on successive days is most consistent with a chronic process

Chronic Kidney Disease Imaging Finding of small echogenic kidneys b/l (<10 cm) by US supports dx of CKD/irrev. dz Radiological evidence of renal osteodystrophy is another helpful finding Check phalanges of hands

Imaging

Finding of small echogenic

kidneys b/l (<10 cm) by US

supports dx of CKD/irrev. dz

Radiological evidence of renal

osteodystrophy is another helpful

finding

Check phalanges of hands

Chronic Kidney Disease Complications (of uremia) Hyperkalemia Acid-base d/o Cardiovascular Hematologic Neurologic Disorders of mineral metabolism Endocrine d/o

Complications (of uremia)

Hyperkalemia

Acid-base d/o

Cardiovascular

Hematologic

Neurologic

Disorders of mineral metabolism

Endocrine d/o

Chronic Kidney Disease Hyperkalemia Potassium balance usually remains intact until GFR < 10-20 mL/min Tx of acute hyperkalemia involves cardiac monitoring, IV calcium chloride or gluconate, insulin with glucose, bicarbonate, and sodium polystyrene sulfonate Chronic hyperkalemia tx’d with dietary potassium restriction, and sodium polystyrene PRN

Hyperkalemia

Potassium balance usually remains intact until GFR < 10-20 mL/min

Tx of acute hyperkalemia involves cardiac monitoring, IV calcium chloride or gluconate, insulin with glucose, bicarbonate, and sodium polystyrene sulfonate

Chronic hyperkalemia tx’d with dietary potassium restriction, and sodium polystyrene PRN

Chronic Kidney Disease Acid-base d/o Damaged kidneys are unable to excrete the 1 mEq/kg/d of acid generated by metabolism of dietary proteins. The resultant metabolic acidosis is primarily due to loss of renal mass Tx Maintain serum bicarb level at > 21 mEq/L Alkali supplements include sodium bicarbonate, calcium bicarbonate, and sodium citrate

Acid-base d/o

Damaged kidneys are unable to excrete the 1 mEq/kg/d of acid generated by metabolism of dietary proteins. The resultant metabolic acidosis is primarily due to loss of renal mass

Tx

Maintain serum bicarb level at > 21 mEq/L

Alkali supplements include sodium bicarbonate, calcium bicarbonate, and sodium citrate

Chronic Kidney Disease Cardiovascular complications (HTN) HTN is most common complication of ESRD HTN control with weight loss and tobacco cessation Salt intake reduced to 2g/day Initial RX to include ACE inhibitor or angiotensin II receptor blocker (ARB) If serum potassium and GFR permit (recheck 1 wk) Goal BP is <130/80 mm Hg; for those with proteinuria > 1-2 g/d, goal is < 125/75 mm Hg

Cardiovascular complications (HTN)

HTN is most common complication of ESRD

HTN control with weight loss and tobacco cessation

Salt intake reduced to 2g/day

Initial RX to include ACE inhibitor or angiotensin II receptor blocker (ARB)

If serum potassium and GFR permit (recheck 1 wk)

Goal BP is <130/80 mm Hg; for those with proteinuria > 1-2 g/d, goal is < 125/75 mm Hg

Chronic Kidney Disease Cardiovascular complications (pericarditis) Pericarditis may develop with uremia Cause believed to be retention of metabolic toxins Symptoms include CP and fever. May have pulsus paradoxus and friction rub on exam Pericarditis is an absolute indication for initiation of hemodialysis

Cardiovascular complications (pericarditis)

Pericarditis may develop with uremia

Cause believed to be retention of metabolic toxins

Symptoms include CP and fever. May have pulsus paradoxus and friction rub on exam

Pericarditis is an absolute indication for initiation of hemodialysis

Chronic Kidney Disease Cardiovascular complications (CHF) Pts with ESRD tend toward a high cardiac output. Often have extracellular fluid overload, shunting of blood through AV fistula for dialysis, and anemia. In addition to HTN, this causes increased myocardial work and oxygen demand. There is also increased rate of atherosclerosis. All of this contributes to LVH and dilation, present in 75% of pts starting dialysis. Tx with loop diuretics, ACE inhibitors, and regulation of salt and water

Cardiovascular complications (CHF)

Pts with ESRD tend toward a high cardiac output. Often have extracellular fluid overload, shunting of blood through AV fistula for dialysis, and anemia. In addition to HTN, this causes increased myocardial work and oxygen demand. There is also increased rate of atherosclerosis. All of this contributes to LVH and dilation, present in 75% of pts starting dialysis. Tx with loop diuretics, ACE inhibitors, and regulation of salt and water

Chronic Kidney Disease Hematologic complications Anemia Normochromic, normocytic Due to decreased erythropoiesis and RBC survival Many pts are also iron deficient Recombinant erythropoietin (epoetin alfa) used in pts whose hematocrits are < 33% Iron supplement PRN also

Hematologic complications

Anemia

Normochromic, normocytic

Due to decreased erythropoiesis and RBC survival

Many pts are also iron deficient

Recombinant erythropoietin (epoetin alfa) used in pts whose hematocrits are < 33%

Iron supplement PRN also

Chronic Kidney Disease Hematologic complications Coagulopathy Mainly caused by platelet dysfunction Platelet counts only mildly decreased, but bleeding time is prolonged Platelets show abnormal adhesiveness and aggregation Pts may present with petechiae, purpura, and increased bleeding during surgery Dialysis improves bleeding time but doesn’t normalize it Tx goal = Hct increased to 30%

Hematologic complications

Coagulopathy

Mainly caused by platelet dysfunction

Platelet counts only mildly decreased, but bleeding time is prolonged

Platelets show abnormal adhesiveness and aggregation

Pts may present with petechiae, purpura, and increased bleeding during surgery

Dialysis improves bleeding time but doesn’t normalize it

Tx goal = Hct increased to 30%

Chronic Kidney Disease Neurologic complications Uremic encephalopathy does not occur until GFR falls below 10-15 mL/min Symptoms begin with diff. concentrating and can progress to lethargy, confusion, and coma Neuropathy found in 65% of pts on or nearing dialysis but not until GFR is 10% of normal Earlier initiation of dialysis may prevent peripheral neuropathies

Neurologic complications

Uremic encephalopathy does not occur until GFR falls below 10-15 mL/min

Symptoms begin with diff. concentrating and can progress to lethargy, confusion, and coma

Neuropathy found in 65% of pts on or nearing dialysis but not until GFR is 10% of normal

Earlier initiation of dialysis may prevent peripheral neuropathies

Chronic Kidney Disease Disorders of mineral metabolism D/o of calcium, phosphorus, and bone are referred to as renal osteodystrophy Most common d/o is osteitis fibrosa cystica – the bony changes of secondary hyperparathyroidism…affecting 50% of pts nearing ESRD Radiographically, lesions most prominent in phalanges and lateral ends of clavicles

Disorders of mineral metabolism

D/o of calcium, phosphorus, and bone are referred to as renal osteodystrophy

Most common d/o is osteitis fibrosa cystica – the bony changes of secondary hyperparathyroidism…affecting 50% of pts nearing ESRD

Radiographically, lesions most prominent in phalanges and lateral ends of clavicles

Chronic Kidney Disease Disorders of mineral metabolism May also have osteomalacia or adynamic bone dz All of the above may cause bony pain, proximal muscle weakness, and spontaneous bone fractures Tx may consist of dietary phosphorus restriction, oral phosphorus-binding agents such as calcium carbonate or Renogel, and vitamin D Hyperparathyroidism tx’d with calcitriol or Sensipar

Disorders of mineral metabolism

May also have osteomalacia or adynamic bone dz

All of the above may cause bony pain, proximal muscle weakness, and spontaneous bone fractures

Tx may consist of dietary phosphorus restriction, oral phosphorus-binding agents such as calcium carbonate or Renogel, and vitamin D

Hyperparathyroidism tx’d with calcitriol or Sensipar

Chronic Kidney Disease Endocrine d/o Circulating insulin levels are higher because of decreased renal insulin clearance Glucose intolerance can occur in chronic renal failure when GFR is < 10-20 mL/min. This is mainly due to peripheral insulin resistance Decreased libido and impotence are common. Men have decreased testosterone; women are often anovulatory

Endocrine d/o

Circulating insulin levels are higher because of decreased renal insulin clearance

Glucose intolerance can occur in chronic renal failure when GFR is < 10-20 mL/min. This is mainly due to peripheral insulin resistance

Decreased libido and impotence are common. Men have decreased testosterone; women are often anovulatory

Chronic Kidney Disease Tx ACE/ARB to slow progression of proteinuria and CVD Maintain excellent diabetes control…keep HgA1C < 7 Tx (Consults): early nephrology, vascular, general surgery Tx (Dietary) Every pt should be eval by renal nutritionist Protein restriction In general, protein intake should not exceed 1 g/kg/d Salt and water restriction For the nondialysis pt approaching ESRD, 2 g/d of sodium is an initial recommendation

Tx

ACE/ARB to slow progression of proteinuria and CVD

Maintain excellent diabetes control…keep HgA1C < 7

Tx (Consults): early nephrology, vascular, general surgery

Tx (Dietary)

Every pt should be eval by renal nutritionist

Protein restriction

In general, protein intake should not exceed 1 g/kg/d

Salt and water restriction

For the nondialysis pt approaching ESRD, 2 g/d of sodium is an initial recommendation

Chronic Kidney Disease Potassium restriction Once GFR has fallen below 10-20 mL/min, potassium intake should be limited to < 60-70 mEq/d Phosphorus restriction Phosphorus level should be < 4.6 mg/dL Phosphorus binders required if GFR < 20-30 mL/min Magnesium restriction No magnesium-containing laxatives or antacids

Potassium restriction

Once GFR has fallen below 10-20 mL/min, potassium intake should be limited to < 60-70 mEq/d

Phosphorus restriction

Phosphorus level should be < 4.6 mg/dL

Phosphorus binders required if GFR < 20-30 mL/min

Magnesium restriction

No magnesium-containing laxatives or antacids

Chronic Kidney Disease Treatment (Dialysis) When conservative management of ESRD is inadequate, hemodialysis, peritoneal dialysis, and kidney transplantation are alternatives Dialysis should be started when pt has GFR of 10 mL/min or serum creatinine of 8 mg/dL Diabetics should start when GFR reaches 15 mL/min or serum creatinine is 6 mg/dL

Treatment (Dialysis)

When conservative management of ESRD is inadequate, hemodialysis, peritoneal dialysis, and kidney transplantation are alternatives

Dialysis should be started when pt has GFR of 10 mL/min or serum creatinine of 8 mg/dL

Diabetics should start when GFR reaches 15 mL/min or serum creatinine is 6 mg/dL

Chronic Kidney Disease Treatment (Dialysis) Other absolute indications for dialysis include Uremic symptoms such as pericarditis, encephalopathy, or coagulopathy Fluid overload unresponsive to diuresis Refractory hyperkalemia…>7 Severe metabolic acidosis (pH < 7.20) Neurologic symptoms such as seizures or neuropathy

Treatment (Dialysis)

Other absolute indications for dialysis include

Uremic symptoms such as pericarditis, encephalopathy, or coagulopathy

Fluid overload unresponsive to diuresis

Refractory hyperkalemia…>7

Severe metabolic acidosis (pH < 7.20)

Neurologic symptoms such as seizures or neuropathy

Chronic Kidney Disease Hemodialysis (choice for 90% of pts) Vascular access accomplished by an a/v fistula (preferred) or prosthetic graft Infection, thrombosis, and aneurysm formation are complications seen more often in grafts than fistulas. Staphylococcus aureus is most common infecting agent Pts typically require hemodialysis 3x/wk…sessions last 3-5 hrs each Home dialysis also now available Ensure pt getting regular labs to include PTH and ALK PHOS

Hemodialysis (choice for 90% of pts)

Vascular access accomplished by an a/v fistula (preferred) or prosthetic graft

Infection, thrombosis, and aneurysm formation are complications seen more often in grafts than fistulas. Staphylococcus aureus is most common infecting agent

Pts typically require hemodialysis 3x/wk…sessions last 3-5 hrs each

Home dialysis also now available

Ensure pt getting regular labs to include PTH and ALK PHOS

Chronic Kidney Disease Hemodialysis

Hemodialysis

Chronic Kidney Disease Peritoneal dialysis The peritoneal membrane is the “dialyzer” Most common type is continuous ambulatory peritoneal dialysis (CAPD) Pts exchange dialysate 4-6 times/day Continuous cyclic peritoneal dialysis (CCPD) utilizes a cycler machine to automatically perform exchanges at night Most common complication = peritonitis Most common pathogen = S aureus

Peritoneal dialysis

The peritoneal membrane is the “dialyzer”

Most common type is continuous ambulatory peritoneal dialysis (CAPD)

Pts exchange dialysate 4-6 times/day

Continuous cyclic peritoneal dialysis (CCPD) utilizes a cycler machine to automatically perform exchanges at night

Most common complication = peritonitis

Most common pathogen = S aureus

Chronic Kidney Disease Peritoneal dialysis

Peritoneal dialysis

Chronic Kidney Disease Total costs of both types of dialysis are about the same ($35,000 - $60,000/yr) Pts undergoing dialysis have an average life expectancy of 3-4 yrs Studies are conflicting regarding the survival advantage assoc. with either peritoneal dialysis or hemodialysis

Total costs of both types of dialysis are about the same ($35,000 - $60,000/yr)

Pts undergoing dialysis have an average life expectancy of 3-4 yrs

Studies are conflicting regarding the survival advantage assoc. with either peritoneal dialysis or hemodialysis

Chronic Kidney Disease Kidney transplantation 1st - Dr Hamburger in 1952 Up to 50% of all pts with ESRD are suitable for transplant. Age becoming less of a barrier In general, not placed on list until GFR <15 Living donor is best option Two-thirds of kidney transplants come from deceased donors Average wait for cadaveric transplant is 2-4 yrs; becoming longer as more pts go on the list while donor pool does not expand One yr survival rate is approx. 98%

Kidney transplantation

1st - Dr Hamburger in 1952

Up to 50% of all pts with ESRD are suitable for transplant. Age becoming less of a barrier

In general, not placed on list until GFR <15

Living donor is best option

Two-thirds of kidney transplants come from deceased donors

Average wait for cadaveric transplant is 2-4 yrs; becoming longer as more pts go on the list while donor pool does not expand

One yr survival rate is approx. 98%

Chronic Kidney Disease CKD prognosis Mortality higher for pts on dialysis than for age-matched controls Expected remaining lifetime for the age group 55-64 is 22 yrs, whereas that of ESRD population is 5 yrs Most common cause of death is cardiac dysfunction For those who require dialysis to sustain life, but decide against it, death ensues within days to wks

CKD prognosis

Mortality higher for pts on dialysis than for age-matched controls

Expected remaining lifetime for the age group 55-64 is 22 yrs, whereas that of ESRD population is 5 yrs

Most common cause of death is cardiac dysfunction

For those who require dialysis to sustain life, but decide against it, death ensues within days to wks

Chronic Kidney Disease Overall…medical care of CKD focuses on delaying or halting progression of CKD Tx underlying cause(s) Tx HTN and Diabetes Avoid nephrotoxins Tx complications Lastly…watch out for meds that are renally excreted. You will need to adjust dose in pts with renal failure

Overall…medical care of CKD focuses on delaying or halting progression of CKD

Tx underlying cause(s)

Tx HTN and Diabetes

Avoid nephrotoxins

Tx complications

Lastly…watch out for meds that are renally excreted. You will need to adjust dose in pts with renal failure

Review Background Causes Clinical findings Labs and imaging Complications Treatment Prognosis

Background

Causes

Clinical findings

Labs and imaging

Complications

Treatment

Prognosis

Questions?