chronic kidney disease
DESCRIPTION
2011TRANSCRIPT
Chronic Kidney Disease
Internal Medicine
August 2011
Definition Structural or functional abnormalities of the
kidneys for ≥3months, as manifested by either:1. Kidney damage, with or without decreased
GFR, as defined by pathologic abnormalities markers of kidney damage, including
abnormalities in the composition of the blood or urine or abnormalities in imaging tests
Kidney transplantation2. GFR <60 ml/min/1.73 m2, with or without
kidney damage
Definition Kidney Failure is defined as either
(1) a level of GFR to <15 mL/min/1.73 m2, which is accompanied in most cases by uremia, or
(2) a need for initiation of kidney replacement therapy (dialysis or transplantation) for complications of decreased GFR.
End-Stage Renal Disease (ESRD) administrative term for disbursement by
Medicare, specifically the level of GFR (creatinine of 8mg/dl) and occurrence of kidney failure symptoms necessitating replacement therapy. ESRD includes patients treated by dialysis or transplantation.
Causes and Incidence Chronic renal failure occurs in
approximately 1 out of 1,000 people. Causative diseases include any type:
1. Diabetes mellitus - most common cause2. Hypertension3. Glomerulonephritis4. Others
chronic pyelonephritis, PKD /polycystic kidney disease, obstructive uropathy (stones, BPH, cancer, etc), Alport syndrome, and drug-induced nephropathy
Estimation of GFR Cockcroft- Gault Formula
MDRD Study Equation
CrCl (ml/min)=( 140 – age ) x Weight in Kg
72 x Serum Creat (mg/dl)x ( 0.85 if female )
GFR (mil/min/1.73 m2) = 186 x (SCr) -1.154 x (age) -.203
x (0.724 if female) x (1.210 if African American)
Stages of Chronic Kidney Disease
Symptoms INITIAL (non-specific)
unintentional weight loss
nausea, vomiting general ill feeling fatigue headache frequent hiccups generalized itching
(pruritus)
LATER increase or decrease
urine output need to urinate at night anasarca easy bruising or bleeding blood in the vomit or
stools breath odor (uremic
fetor) muscle twitching or
cramps restless legs syndrome increased skin
pigmentation uremic frost decreased sensation decreased alertness/
lethargy
Uremic Syndrome attributed to a variety of toxic substances, mainly
nitrogenous (protein and amino acid byproducts urea (when >50 mmol/l) and cyanate (CNO‑) guanidino compounds (eg guanidinosuccinic
acid) middle molecules (mw 300‑3,500) ‑ mainly
polypeptides urates and other metabolites of nucleic acids aliphatic amines and metabolites of aromatic
amino acids hormones (eg PTH) advanced glycation end-products
other factors already considered – bone disease, acidosis, and fluid and electrolyte disturbances – also contribute to the picture of full‑blown uremia.
Signs and Tests Blood pressure may be high Urinalysis may show protein, blood, pus or other
abnormalities Creatinine and BUN levels progressively increase Creatinine clearance progressively decreases Potassium elevated Calcium low and Phosphorus high Arterial blood gas show metabolic acidosis Xray of bones may show osteodystrophy
Signs and Tests Changes that indicate chronic renal failure,
including both kidneys being smaller than normal, may be seen on: abdominal ultrasound plain KUB X-ray abdominal CT scan or MRI
However, CKD with normal sized or enlarged kidneys: amyloidosis, diabetes multiple myeloma polycystic kidneys accelerated hypertension
Determinants of Rate of Progression Type of Renal Disease
rate of decline in PCKD and interstitial nephritis slower than in CGN
membranous Nephropathy may spontaneously remit with or without treatment
Hypertension Proteinuria Race – blacks fare worse Sex – women with PCKD fare better Pregnancy – GFR falls faster Diabetics – high sugar accelerates Smokers
Importance of Proteinuria
Interpretation Explanation
Marker of kidney damage
Spot urine albumin-to-creatinine ratio >30 mg/g or spot urine total protein-to-creatinine ratio >200 mg/g for >3 months defines CKD
Clue to the type (diagnosis) of CKD
Spot urine total protein-to-creatinine ratio >500-1000 mg/g suggests diabetic kidney disease, glomerular diseases, or transplant glomerulopathy.
Risk factor for adverse outcomes
Higher proteinuria predicts faster progression of kidney disease and increased risk of CVD.
Effect modifier for interventions
Strict blood pressure control and ACE inhibitors are more effective in slowing kidney disease progression in patients with higher baseline proteinuria.
Hypothesized surrogate outcomes and target for interventions
If validated, then lowering proteinuria would be a goal of therapy.
Dietary Requirements1. Protein
0.6-0.8 gm/k/day supplements of essential amino acids at 0.3
gm/k/day may allow lower protein intake to 0.4 gm/k/day intake for uremic patient not yet dialysed: 0.4 -
0.6gm/k/day for dialysed patients: increase to 1.0 - 1.2
gm/k/day2. Energy
35 kcal/k/day for sedentary, stable, non-obese HD patients
higher with strenuous labor, underweight or hypercatabolic
Dietary Requirements3. Fat
limit cholesterol <300 mg/day more proportion of mono- or polyunsaturated
than saturated4. Na+
7-10 gm/day (table salt) if with adequate urine <6 gm/day or <100 mmol/day if with fluid
retention/edema5. K+
HD: restrict to 2-3 gm/day (50-75 meq/day) PD: 3-4 gm/day or 75-100 meq/day
Dietary Requirements6. Ca++
restrict milk products so supplemental Ca++ is needed (1-1.5 gm/day) + Vitamin D to keep serum Ca++ >2.5 mg/dl
7. Phosphorus restrict to 0.6 - 1.2 gm/day to maintain s.Phos <4.5 to
5.5 mg/dl phosphate binders as needed such as calcium carbonate
and calcium acetate
8. Vitamins/ Minerals ascorbic acid < 150-200 mg maximum to avoid oxalosis folic acid 1000 mcg; vit.B1 30 or > mg/day; B6 20 or
more mg/day; Other water soluble vitamins based on RDA
provide selenium and zinc vitamin A preparations must be avoided
Management with Progressive Renal Disease1. early recognition 2. monitoring the progression 3. detection and correction of reversible causes 4. institution of interventions to delay progression,
eg diet, ACEinhibitors, BP, and sugar control 5. avoidance of additional renal injury,
eg smoking, NSAIDs, radiocontrast, aminoglycosides
6. treatment of complications, eg acid-base, mineral, and fluid-electrolyte abnormalities
7. planning ahead for renal replacement therapy (dialysis or transplantation)
Prevention to ESRD ACEI/ ARBs
established renoprotection with proteinuria reduction
higher doses recommended Blood Pressure
BP target of <130/85mmHg and when proteinuria >1gm/day or GFR <55ml/min; aim for ≤125/75
Cholesterol ideal LDL-C <100mg/dl and HDL-C >50mg/dl statins have the most benefit
Fasting Sugar intensive sugar control with target HbA1c of <7%
Prevention to ESRD Diet
Modified protein intake with 1.0gm/k/day for normal GFR 0.8gm/k/day for CRI; and 0.4-0.6gm/k/day for severe CRF Very low protein diet 0.3-0.4gm/k/day with ketoAA
supplements Educate
Exercise/ weight reduction, smoking cessation, alcohol avoidance, early nephro referral
Gases Acid-base control with giving of alkali such as NaHCO3
tablets to achieve HCO3 level ≥20mmol/L
Hemoglobin Hgb target 11-12g/L beneficial in CKD Erythropoietin replacement – best treatment
Clinical Practice Guideline for Detection, Evaluation, and Management of CKD
STAGE DESCRIPTION GFR EVALUATION MANAGEMENT
At increased risk
Test for CKD Risk factor management
1Kidney damage with normal or GFR
>90
DiagnosisComorbid conditionsCVD and CVD risk factors
Specific therapy, based on diagnosisManagement of comorbid conditionsTreatment of CVD and CVD risk factors
2Kidney damage with mild GFR
60-89Rate of progression
Slowing rate of loss of kidney function 1
3 Moderate GFR 30-59 ComplicationsPrevention and treatment of complications
4 Severe GFR 15-29Preparation for kidney replacement therapyReferral to Nephrologist
5 Kidney Failure <15 Kidney replacement therapy
1Target blood pressure less than 130/80 mm Hg. Angiotension converting enzyme inhibitors (ACEI) or angiotension receptor blocker (ARB) for diabetic or non-diabetic kidney disease with spot urine total protein-to-creatinine ratio of greater than 200 mg/g.
Prognosis There is no cure for chronic renal failure.
Untreated, usually progresses to end-stage renal disease. Lifelong treatment may control the symptoms of chronic renal failure. Dialysis or kidney transplant required eventually. Otherwise, condition is terminal.
Support Groups The stress of illness can often be helped by joining
a support group where members share common experiences and problems.
Thank You!