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Chronic Renal Failure

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Chronic Renal Failure, Chronic Kidney Failure, Chronic Kidney Disease, Chronic Kidney Insufficiency, Chronic Renal Insufficiency, CRF, Renal Insufficiency

  • Definitions
  1. Chronic Kidney Disease
    1. Abnormal Kidney structure or function lasting more than 3 months, with associated health implications
    2. Estimated Glomerular Filtration Rate (eGFR) <60 ml/min OR
    3. Positive Kidney damage markers (e.g. albuminuria) OR
    4. Polycystic or dysplastic Kidneys
  2. End Stage Renal Disease
    1. Kidney Function not adequate for longterm survival without Dialysis or Renal Transplant
    2. Stage 5 Chronic Kidney Disease (GFR <15 ml/min/1.73m2)
  • Epidemiology
  1. Chronic Kidney Disease (2016)
    1. Prevalence in U.S.: 47 million (14-15% of the adult U.S. population)
    2. Accounts for 20% of all medicare costs ($52 Billion/year in 2014)
  2. End Stage Renal Diseases
    1. Prevalence 2002: 435,000 in U.S.
    2. Prevalence 2016: 660,000 in U.S.
    3. Prevalence 2018: 750,000 in U.S.
    4. Accounts for 10% of all medicare fee-for-service costs
  • Precautions
  1. Chronic Kidney Disease diagnosis and prevention has a significant impact on morbidity and mortality
    1. Yet up to 90% of those with CKD are undiagnosed
  2. However, there is also an expected physiologic decrease in eGFR with age
    1. There is an associated overdiagnosis of CKD without microabluminuria in over age 65 to 75 years old
    2. In elderly patients, eGFR alone does not predict who will advance to ESRD
    3. Employ Shared Decision Making in CKD at advanced age and Exercise caution in aggressive management
    4. Ellam (2016) BMJ 352: h6559 [PubMed]
    5. Liu (2021) JAMA Intern Med 181(10): 1359-66 [PubMed]
    6. Roth (2023) Am Fam Physician 107(6): 657-8 [PubMed]
  • Causes (Percentage is that of conditions responsible for ESRD)
  1. Diabetes Mellitus (37%)
    1. See Diabetic Nephropathy
    2. Glycemic control is critical to slow progression
    3. Type I Diabetes Mellitus (represents 5% of ESRD patients)
      1. Progresses to ESRD in 40% of patients
    4. Type II Diabetes Mellitus (represents 32% of ESRD patients)
      1. Progresses to ESRD in 20% of patients
      2. Type II Diabetes is 10 times as common as Type
  2. Hypertension or Hypertensive Kidney Disease (30% overall, 40% in black patients)
  3. Human Immunodeficiency Virus Infection (HIV Infection)
  4. Chronic Viral Hepatitis (Hepatitis B, Hepatitis C)
  5. Malignancy (Multiple Myeloma, Renal Cell Cancer)
  6. Glomerulonephritis and other glomerular diseases (21%)
    1. Includes Vasculitis and Autoimmune Conditions (e.g. Systemic Lupus Erythematosus)
  7. Hereditary conditions
    1. Polycystic Kidney Disease (7%)
    2. Alport Syndrome
    3. Medullary Cystic disease
  8. Tubulointerstitial disease (4%)
    1. Infection with scarring
      1. Chronic Urinary Tract Infections (Pyelonephritis)
      2. Reflux nephropathy in children
    2. Urologic obstruction
      1. Nephrolithiasis (obstruction)
      2. Benign Prostatic Hyperplasia (BPH)
    3. Medication-induced Nephrotoxicity
      1. See Nephrotoxins
      2. See Intravenous Contrast Related Acute Renal Failure
      3. See Risk Score for Prediction of Contrast-Induced Nephropathy After Percutaneous Coronary Intervention
  • Risk Factors
  1. Diabetes Mellitus (leading cause)
  2. Autoimmune Conditions
  3. Chemical exposures (Lead, Cadmium, Arsenic, Mercury, Uranium)
  4. Nephrotoxin exposure (e.g. Intravenous Contrast Related Acute Renal Failure)
  5. Family History of Chronic Kidney Disease
  6. Hypertension
  7. Low birth weight
  8. Lower Urinary Tract Obstruction
  9. Cancer
  10. Nephrolithiasis
  11. Older age (>60 years)
  12. Acute Kidney Injury in past
  13. Decreased Renal Mass
  14. Serious systemic infection (e.g. Sepsis)
  15. Recurrent Urinary Tract Infections
  16. Minority status (blacks, native american, asian, pacific islander)
    1. Black patients have 3 fold greater risk of CKD than white patients
  17. Gender-related risk
    1. Chronic Kidney Disease (CKD) is more common in women
    2. Men are more likely to progress to End-stage Renal Disease (ESRD)
  • History
  1. Recent infections
    1. Poststreptococcal Glomerulonephritis
  2. Sexually Transmitted Infection (STI, STD) risk factors including IV Drug Abuse
    1. HIV Infection
    2. Hepatitis B Infection
    3. Hepatitis C Infection
  3. Arthritis or dermatitis
    1. Systemic Lupus Erythematosus
    2. Cryoglobulinemia
  4. Urinary symptoms
    1. Urinary Tract Infection
    2. Nephrolithiasis
    3. Urinary Outflow Obstruction
  5. PMH
    1. Diabetes Mellitus
      1. Present for 5-10 years: Microalbuminuria, Pre-Hypertension
      2. Present for 10-15 years: Albuminuria, Retinopathy, Hypertension
    2. Hypertension
      1. Severe Hypertension
      2. End-organ effects
  6. Family History
    1. Autosomal Dominant Polycystic Kidney Disease
      1. Affects men and women in every generation
      2. May also occur less frequently if Autosomal Recessive
    2. Alport Syndrome (X-linked recessive)
      1. Affects men in every generation
  • Exam
  • Symptoms
  • Stage 4-5
  1. Fatigue (75% of patients)
  2. Pruritus (75% of patients)
  3. Weakness
  4. Headaches
  5. Anorexia
  6. Nausea
  7. Vomiting
  8. Polyuria
  9. Nocturia
  10. Edema
  11. Pain
    1. Musculoskeletal pain
    2. Dialysis associated pain
    3. Peripheral Neuropathy
    4. Peripheral Vascular Disease related pain
  • Criteria
  • Chronic Kidney Disease (at least one of the following criteria)
  1. GFR < 60 ml/min/1.73 m2 (based on two GFR calculations 3 months or more apart)
    1. Men: Serum Creatinine >1.5 mg/dl
    2. Women: Serum Creatinine >1.3 mg/dl
  2. Significant Proteinuria or albuminuria for >3 months (positive on 2 of 3 samples in 3-6 months)
    1. Urine Albumin to Creatinine Ratio >30 mg/g (Microalbuminuria, moderate) or >300 mg/g (severe)
      1. Urine Protein to Creatinine Ratio is less sensitive (but useful in albumin ratio >500 mg/g)
  3. Structural Kidney Disease or Kidney damage for >3 months
    1. Identify with renal Ultrasound
  4. Other criteria
    1. All Renal Transplant patients have Chronic Kidney Disease regardless of GFR or Proteinuria
  • Stages
  • NKF Classification System
  1. Stage 1: GFR >90 ml/min despite Kidney damage
    1. Microalbuminuria present
  2. Stage 2: Mild reduction (GFR 60-89 min/min)
    1. GFR of 60 ml/min may represent 50% loss in function
    2. Parathyroid Hormone starts to increase
  3. Stage 3: Moderate reduction (GFR 30-59 ml/min, 3a: 45-59, 3b: 30-44)
    1. Calcium absorption decreases
    2. Malnutrition onset
    3. Anemia secondary to Erythropoietin deficiency
    4. Left Ventricular Hypertrophy
  4. Stage 4: Severe reduction (GFR 15-29 ml/min)
    1. Serum Triglycerides increase
    2. Hyperphosphatemia
    3. Metabolic Acidosis
    4. Hyperkalemia
  5. Stage 5: Kidney Failure (GFR <15 ml/min)
    1. Azotemia
  6. References
    1. (2002) Am J Kidney Dis 39:S1 [PubMed]
    2. Snively (2004) Am Fam Physician 70:1921-30 [PubMed]
  • Labs
  • Screening for Chronic Kidney Disease
  1. Indications
    1. Diabetes Mellitus
    2. Hypertension
    3. Cardiovascular disease
    4. Age over 55-60 years old
    5. Consider in Family History of Chronic Kidney Disease (see causes listed above)
  2. Tests
    1. Serum Creatinine (with Estimated Glomerular Filtration Rate)
      1. Serum Cystatin C may be used for confirmation (but not in AKI, inflammation or Thyroid dysfunction)
    2. Urine Albumin to Creatinine Ratio
    3. Urinalysis with microscopy
  3. Assess Glomerular Filtration Rate (GFR)
    1. Estimations generally as accurate as 24 hour urine
      1. See Creatinine Clearance for exceptions
      2. GFR may also be estimated from Serum Cystatin C instead of Serum Creatinine
        1. Consider if abnormal GFR based on Creatinine Clearance suspected to be False Positive
    2. Formulas
      1. Chronic Kidney Disease Epidemiology Collaboration Equation or CKD-EPI (preferred standard)
        1. https://www.kidney.org/professionals/kdoqi/gfr_calculator
        2. Do not use the race variable in the calculation
      2. Cockcroft-Gault equation
        1. Used only to calculate medication Renal Dosing
      3. Modification of Diet in Renal Disease (MDRD)
        1. CKD-EPI is preferred
  4. Assess for Proteinuria
    1. Proteinuria (and albuminuria) is a stronger predictor for CKD progression than eGFR
    2. Urine Albumin to Creatinine Ratio
      1. First morning void is preferred
      2. Persistently elevated levels >3 months is sufficient diagnostic criteria alone for Chronic Kidney Disease
    3. Background
      1. Previously Urinalysis dipstick was used to triage testing for spot Urine Protein or albumin
      2. As of 2012, Urinalysis is no longer recommended for Urine Protein screening
      3. Urine Albumin to Creatinine Ratio is recommended instead as a first-line study
      4. Urine Albumin to Creatinine Ratio is standardized whereas Protein to Creatinine ratio is lab assay specific
  5. Assess other urinary sediment on Urinalysis
    1. Microscopic Hematuria
    2. Urine White Blood Cells (pyuria)
    3. Cellular Casts
    4. Lipiduria (seen in nephrotic sediment)
      1. Indicated by Fatty Casts, oval fat bodies, or free fat in urine sediment
      2. Increases significance of Proteinuria
    5. Eosinophiluria
      1. Tubulointerstitial disease
      2. Atheroembolic dsisease
  • Labs
  • Urine sediment found in causes of Chronic Kidney Disease
  1. Polycystic Kidney Disease
    1. Protein to Creatinine ratio 200-1000 mg/g
    2. Red Blood Cells present
  2. Diabetic Nephropathy
    1. Albumin to Creatinine ratio 30-300 early (and exceeds 300 in later disease)
  3. Hereditary Nephritis
    1. Protein to Creatinine ratio <1000 mg/g
    2. Red Blood Cells, tubular cells and Granular Casts present
  4. Hypertensive Nephropathy
    1. Protein to Creatinine ratio 200-1000 mg/g
  5. Noninflammatory Glomerular Disease
    1. Protein to Creatinine ratio >1000 mg/g
  6. Proliferative Glomerulonephritis
    1. Protein to Creatinine ratio >500 mg/g
    2. Red Blood Cells, Red Blood Cell Casts, White Blood Cells, White Blood Cell Casts present
  7. Tubulointerstitial Nephritis
    1. Protein to Creatinine ratio 200-1000 mg/g
    2. Red Blood Cells, White Blood Cells, White Blood Cell Casts present
  8. IgA Nephropathy or Rapidly Progressive Glomerulonephritis (RPGN)
    1. Dysmorphic urinary Red Blood Cells or
    2. Red Blood Cell Casts
  • Labs
  • Findings in Chronic Kidney Disease Stages 3-4
  1. Anemia (Normochromic, Normocytic)
    1. Hematocrit decreases
      1. Serum Creatinine > 2-3
      2. Glomerular Filtration Rate <20-30
    2. Results from decreased Erythropoietin synthesis
  2. Azotemia
  3. Decreased Serum Protein
  4. Serum chemistry abnormalities
    1. Hyperkalemia or Hypokalemia
    2. Metabolic Acidosis
    3. Hypocalcemia
    4. Hyperphosphatemia
  • Labs
  • Initial
  1. Screening labs (see above)
    1. Serum Creatinine (with Estimated Glomerular Filtration Rate)
    2. Urine Albumin to Creatinine Ratio
    3. Urinalysis with microscopy
      1. Evaluates for intrinsic renal disease causes
  2. Basic labs
    1. Basic metabolic panel (includes serum Electrolytes and Serum Calcium)
    2. Fasting lipid profile
    3. Hemoglobin A1C
    4. Complete Blood Count (CBC)
    5. Serum Phosphorus (in CKD stage 4 to 5)
    6. 25-hydroxyvitamin D (in CKD stage 4 to 5)
  3. Other diagnostics
    1. Renal Ultrasound (see below)
    2. Baseline Electrocardiogram
      1. Coronary disease is a common complication of CKD
  4. Additional labs as indicated
    1. Antinuclear Antibody (ANA)
      1. Lupus Nephritis
    2. Urine and Serum Protein Electrophoresis
      1. Multiple Myeloma
    3. Hepatitis B Serology (HBsAg)
      1. Membranous Nephropathy
      2. Membranoproliferative nephritis)
    4. Hepatitis C Serology (xHBC Antibody)
      1. Membranous Nephropathy
      2. Membranoproliferative Glomerulonephritis
      3. Mixed Cryoglobulinemia
    5. HIV Test
      1. Focal and segmental glomerulosclerosis
    6. Antistreptolysin O Antibody (ASO Titer)
      1. Post-Streptococcal Glomerulonephritis
    7. Antineutrophil Cytoplasmic Antibody (ANCA)
      1. Granulomatosis with Polyangiitis (previously known as Wegener's Granulomatosis)
      2. Microscopic Polyangiitis
      3. Pauci-immune Rapidly Progressive Glomerulonephritis
    8. Anti-Glomerular Basement Membrane Antibody (Anti-GBM Antibody)
      1. Goodpasture Syndrome (xGBM Antibody associated with rapid progression)
    9. Consider serum complement studies (C3, C4, CH50)
      1. Post-Streptococcal Glomerulonephritis
      2. Membranoproliferative Glomerulonephritis
      3. Lupus Nephritis
      4. Cryoglobulinemia
    10. Cryoglubulin Test
      1. Cryoglobulinemia
    11. Eosinophiluria
      1. Tubulointerstitial Disease
  • Labs
  • Monitoring in Advanced Disease (Stage 4 to 5 CKD)
  1. General labs
    1. Basic metabolic panel (Serum Creatinine and serum Electrolytes) every 3-12 months or more
    2. Urine Albumin to Creatinine Ratio every 12 months
  2. Anemia monitoring (at least annually, or more often as indicated)
    1. Complete Blood Count with differential
      1. Screen for Anemia every 6 months in CKD 4 to 5 (every 12 months in CKD 3)
    2. Other labs to obtain at baseline in Anemia, and then as indicated
      1. Reticulocyte Count
      2. Serum Iron
      3. Serum Ferritin
      4. Serum Transferrin
      5. Vitamin B12
      6. Serum Folate
  3. Malnutrition monitoring (every 6-12 months, up to every 1 to 3 months in stage 4-5 CKD)
    1. Serum Albumin
    2. Body weight
    3. Dietary history
  4. Bone disorders
    1. See Chronic Kidney Disease related Bone Disease (Renal Osteodystrophy)
    2. Alkaline Phosphatase
      1. Obtain at baseline
      2. Obtain every 12 months in Stage 4 and 5 CKD
    3. Serum Calcium and Serum Phosphorus
      1. Obtain every 6 to 12 months in CKD 3
      2. Obtain every 3 to 6 months in CKD 4
      3. Obtain every 1 to 3 months in CKD 5
    4. Serum Intact Parathyroid Hormone (iPTH)
      1. Obtain baseline, then as indicated
      2. Obtain every 6 to 12 months in CKD 4
      3. Obtain every 3 to 6 months in CKD 5
    5. 25-hydroxyvitamin D
      1. Obtain at baseline, then as indicated
    6. Dual Energy XRAY Absorptiometry (DEXA Scan)
      1. Obtain baseline in CKD 3 to 5, and then as indicated
  • Imaging
  • Renal Ultrasound (indicated in most patients on initial presentation)
  1. Doppler Ultrasound
    1. Renal veins: Venous thrombosis
    2. Renal arteries: Lower efficacy in diagnosing Renal Artery Stenosis
  2. General findings
    1. Nephrocalcinosis
    2. Hydronephrosis
    3. Renal Mass or complex cysts (concerning for malignancy risk)
    4. Renal stones
  3. Increased echogenicity
    1. Renal disease
  4. Enlarged Kidneys
    1. Renal tumors
    2. Infiltrating disease
    3. Nephrotic Syndrome related conditions
  5. Asymmetric Kidney size or scarred Kidneys
    1. Vascular disease
    2. Urologic disease
    3. Tubulointerstitial disease
  6. Small, hyperechoic Kidneys
    1. Chronic Kidney Disease
  • Imaging
  • Other advanced imaging
  1. Consider CT or MRI of Kidneys and Liver
  2. Consider Voiding Cystourethrogram
  • Diagnosis
  • Renal Biopsy
  1. Indications
    1. Hematuria and low Creatinine Clearance or Proteinuria
    2. Nephrotic range Proteinuria
    3. Chronic Renal Failure with normal or large Kidneys
    4. Acute Renal Failure of unknown cause
  2. Contraindications
    1. Renal length <9 cm
    2. Severe Hypertension
    3. Multiple large Renal Cysts
    4. Uncorrected bleeding tendency
    5. Hydronephrosis
    6. Acute infection
  • Management
  • Secondary Prevention
  • Management
  • Nephrology Referral
  1. Goals of Nephrology Care
    1. Initiate disease specific management including complications and related comorbidity
    2. Intervene to slow Chronic Kidney Disease progression
    3. Planning for Hemodialysis, conservative management or Renal Transplantation
    4. Coordinate with multidisciplinary care
  2. Indications
    1. Chronic Kidney Disease Stage 4 (GFR <30 ml/minute)
      1. One or more GFR values in past 12 months <30 mL/min
      2. Unexplained decline in GFR >15 mL/min between two readings
      3. Consider initial evaluation when GFR <60 ml/minute
        1. Blood Pressure > 130/80 (consistently) despite Antihypertensive medications
        2. Hemoglobin < 10 g/dL
        3. Hyperparathyroidism (PTH > 72 pg/mL) despite correcting for any Vitamin D Deficiency
    2. Chronic Kidney Disease with rapid progression
      1. Unexplained decrease in GFR >30% over 4 months
      2. Annual GFR decline >5 ml/min/1.73m2
      3. Kidney Failure Risk Calculator estimates one year ESRD risk >10-20%
        1. https://www.mdcalc.com/kidney-failure-risk-calculator
    3. Acute failure complicating Chronic Kidney Disease
    4. Unclear etiology for Renal Failure
    5. Hereditary Kidney Disease
    6. Renal biopsy
    7. Nephrotic sediment (e.g. lipiduria)
    8. Unexplained Microscopic Hematuria
      1. RBC Casts (indicates an urgent referral)
    9. Extensive or recurrent Nephrolithiasis
    10. Urine Eosinophils
    11. Refractory Hypertension despite at least 3 Antihypertensives
    12. Significant Proteinuria
      1. 24 Hour Urine Protein >1000 mg/day
      2. Protein to Creatinine ratio >500-1000 mg/g
      3. Albumin to Creatinine ratio >300 mg/g despite 6 months on ACE Inhibitor (or ARB)
    13. Acute Tubular Necrosis
    14. Significant comorbidity (e.g. cardiovascular disease)
    15. Complications of Chronic Kidney Disease
      1. Anemia of Chronic Kidney Disease
      2. Bone and mineral disorders of Chronic Kidney Disease
      3. Hyperkalemia (Potassium >5.5 meq despite modification of therapy)
  1. See End Stage Renal Disease for renal replacement, Anemia, Anorexia, Advanced Directives and other symptomatic management
  • Complications
  1. Cardiovascular Disorders
    1. See Hypotension in the Dialysis Patient
    2. Coronary Artery Disease (21% of ESRD cases)
    3. Peripheral Vascular Disease
    4. Cardiac Arrhythmias
    5. Congestive Heart Failure
    6. Uremic Cardiomyopathy
    7. Erectile Dysfunction
    8. Severe Refractory Hypertension
    9. Pulmonary Edema
    10. High-output Heart Failure (secondary to Anemia or Arteriovenous Fistula)
    11. Calciphylaxis
      1. Life-threatening, small vessel Occlusion in skin and fatty tissue presenting with necrotic skin lesions
    12. Uremic Pericarditis or Hemodialysis Associated Pericarditis
    13. Uremic Pericardial Effusion
      1. Consider in Chronic Renal Failure with Dyspnea
      2. Risk of Cardiac Tamponade (consider in any ill ESRD patient)
  2. Hematologic
    1. Pancytopenia
      1. Anemia (Normochromic, Normocytic)
      2. Thrombocytopenia
      3. Leukopenia
  3. Neurologic disorders
    1. Subdural Hematoma
      1. Consider in any altered LOC patient with ESRD
    2. Uremic encephalopathy (Memory Loss, slurred speech, asterixis)
    3. Dialysis Dementia
      1. Associated with >2 years on Dialysis
      2. Diagnosis of exclusion
    4. Peripheral Neuropathy (e.g. extremity Paresthesias)
    5. Restless Leg Syndrome
    6. Sleep Disorders
    7. Thiamine deficiency (and Wernicke's Encephalopathy)
      1. Hung (2001) Am J Kidney Dis 38(5):941-7 +PMID:11684545 [PubMed]
  4. Fluids, Electrolytes and Nutrition
    1. Metabolic Acidosis
      1. Associated with increased mortality and other adverse outcomes
      2. Improves with Dialysis
      3. Consider Bicarbonate Supplementation in persistently low serum bicarbonate
    2. Muscle wasting and Malnutrition
    3. Pseudogout
    4. Uremia (Nausea, Vomiting, Anorexia)
    5. Hyperphosphatemia (see Renal Osteodystrophy)
  5. Gastrointestinal disorders
    1. Chronic Constipation
    2. Gastritis
    3. Peptic Ulcers
    4. Uremic Gastroparesis
  6. Skin disorders
    1. Pruritus
    2. Calciphylaxis
    3. Uremic frost
      1. Occurs in end-stage renal disease with high BUN (untreated or missed Hemodialysis)
      2. Crystallized urea from sweat forms and deposits on the skin
      3. Uremic frost resembles Seborrhea
  7. Miscellaneous disorders
    1. Chronic Kidney Disease related Bone Disease (Renal Osteodystrophy)
    2. Amenorrhea
    3. Uremic Platelet disorder
  • Course
  1. Kidney Failure Risk Calculator
    1. https://www.mdcalc.com/calc/10045/kidney-failure-risk-calculator
  2. Progression of Chronic Kidney Disease (<55 mmHg) is predictable
    1. Glomerular Filtration Rate (GFR) decreases -4 ml/min per year if no intervention
    2. Intensive management may halt GFR decline
      1. See Prevention of Kidney Disease Progression
  3. Major causes of death in ESRD
    1. Myocardial Infarction
    2. Cerebrovascular Accident
  • Prognosis