
Chronic Kidney Disease Dr. Pooran Kumar kohistani FCPS Nephrology.
Objectives • CKD • Definition • Epidemiology • Management • Treatment to delay progression • Treatment to prevent secondary complications
Literature sources • National Kidney Foundation Practice Guidelines for CKD (N/KDOQI) • ADA Position Statement on Screening for Diabetic nephropathy • Oxford handbook of nephrology
CHRONIC KIDNEY DISEASE • Chronic Kidney Disease (CKD) is a world wide public health problem. • There is a rising incidence and prevalence of kidney failure, with poor outcomes and high cost. • There is an even higher prevalence of earlier stages of CKD. • Adverse outcomes of CKD can often be prevented or delayed.
Rise in ESRD, World Wide • Global epidemic of DM • Aging of population. UK renal registry, USRDS Annual report 2004.
Definitions • Chronic Kidney Disease (CKD): • irreversible, Kidney damage or decreased kidney function (decreased GFR) for 3 or more months • Azotemia: • Elevated blood urea and creatinine • Uremia: • Azotemia with symptoms or signs of renal failure
Definition: Chronic Kidney Disease • Kidney Damage • Proteinuria • Abnormal urine sediment • Abnormal serum or urine chemistries • Abnormal imaging study
Proteinuria • A spot urine test is preferred to a 24 hour urine test. • Protein (mg/dl) / Cr (mg/dl) • Ratio approximates the grams of protein excreted in the urine per day
Abnormal Sediment • Granular casts
Abnormal sediment • White blood cell cast
Abnormal sediment • Red blood cell cast
Definition: Chronic Kidney Disease • Decreased function • Renal clearance • Ideal agent = inulin • Practical agent = creatinine
Renal Function Measurement • Creatinine clearance • Can be calculated with 24 hour urine and a blood draw CrCl = UCr (mg/dl) x Uvolume (ml) (SCr (mg/dl) (1440)
Renal Function Measurement • Problems with CrCl estimation • CrCl estimates GFR but is 10% higher due to tubular secretion of creatinine • It’s hard for patients to collect and return 24 hour urine specimen.
Renal Function Measurement • Glomerular Filtration Rate (GFR) • Varies with: • Age (after 40 y, decline in GFR 1ml/min/yr) • Sex • Body size (more muscle mass more serum Cr)
Renal Function Measurement • GFR • Normal: 120-130 ml / min / 1.73 m2
Renal Function Measurement • GFR Estimation • Cockcroft-Gault equation CCr(ml/min) = 140-Age x Wt (kg) 72 x Crserum (mg/dl)) Multiply by 0.85 if female
Renal Function Measurement • GFR Estimation • MDRD Equation (abbreviated) GFR (ml/min/1.73 m2) = (186) (SCr) -1.154 (Age) -0.203 Adjustment factor: Female: Multiple by 0.742
High S.Creatinine with Normal GFR • Spurious elevation: • Cephalosporin • DKA • Alcohol intoxication • Blocking tubular secretion: • Cimetidine or trimethoprim • Increased creatinine production: • Exogenous: ingestion of large quantities of cooked meat • Endogenous: Muscular disorders, or increases in muscular mass
Normal S.Creatinine with CRF • Poor production of creatinine: • Severely malnourished patients • Elderly • Small children • Ladies of small size
Classification of CKD • Stage 0: At risk patients • Stage 1: Kidney damage with normal GFR • Stage 2: GFR 60-89 • Stage 3: GFR 30-59 • Stage 4: GFR 15-29 • Stage 5: GFR <15 (RRT)
Causes of chronic kidney disease: • Diabetes Mellitus • Hypertension • Glomerulonephritis • Chronic pyelonephritis/reflux • Polycystic kidney disease • Interstitial nephritis • Obstruction • Unknown
Clinical Features • Mild to Moderate renal failure: • Usually no symptoms • Severe renal failure: non specific • Fatigue (anaemia,toxic substances) • Dyspnea • anorexia, nausea, vomiting • Hypertension • Edema • Neurological disturbances (lethargy, confusion,sleep disorders)
Clinical Features • Pruritus (phosphate, calcium, aluminium) • Muscle cramps • Flapping tremors • Restless legs • Nocturia/ polyuria • Seizures • Bone & joint problems (calcium/phosphate imbalances,VitD deficiency,demineralization) • Bone pain
Examination • Skin pigmentation, excoriation • Anemia • Hypertension , postural hypotension • Edema • Half & half nails • LVH • Respiratory crackles, pleural effusion
Examination • Arterial bruits • Palpable kidneys / liver • Abdominal scars • Peripheral vascular disease • Neuropathy • Proximal myopathy • Retinal fundoscopy (HTN/DM)
Recognizing Renal Failure,Investigations • Urinalysis: • Urine dipstick & microscopic exam • => Proteinuria, Hematuria, pyuria, glycosuria • CBC: Hb • Blood chemistry: • S.Creatinine, urea (or BUN), RBS • Electrolytes (Na+, K+, HCO3, Ca++, Phosphate) • Albumin • PTH
Recognizing Renal Failure,Investigations • Lipid & iron profile • HBsAg & AntiHCV • HBeAg & HBeAb in HBsAg +ve pts • ABGs: metabolic acidosis • GFR: • Estimated or measured • Ultrasound • Size.echogenicity,stones, hydronephrosis, corticomedullary distinction, prostate,mass
Recognizing Renal Failure,Investigations • CXRCardiomegally, pulm edema. • ECGLVH & ischemia • Bone X-rayshyperparathyroidism
Noormal size with increased echogenisity Shrunken kidney
Echogenic kidney Polycystic kidney
A specific diagnosis is needed: To consider specific Treatment: obstructive uropathy, analgesic NP, drug-related IN, RPGN, SLE, vasculitis, accelerated HTN, tuberculosis, myeloma, amyloid, .. To be aware of potential complications: SLE, DM.. To advise the family: PKD or other familial renal disease. CKD: Cause
Prevention of progression • Treat modifiable risk factors • Life style modification • Exercise • Cessations of smoking • BP <130/<80
Prevention of progression • Diabetes control • A1C <6.5 (<7 if at risk for unrecognized hypoglycemia) • Strongly consider ACE-I and/or ARB • Microalbuminuria or Proteinuria • HTN • Coexistent risk factors for CAD (HOPE trial)
Prevention of progression • Protein restriction • Low salt diet (for HTN) • Avoid nephrotoxic agents • Contrast dye, NSAIDs, gentamicin
Complications of CKD • Anemia • Bone disease • HTN • CVD
Anemia due to CKD • KDOQI Clinical Practice Guideline and Clinical Practice Recommendations for Anemia in Chronic Kidney Disease: 2007 Update of Hemoglobin Target American Journal of Kidney Diseases, Vol 50, No 3 (September), 2007: pp 477-478
Anemia in CKD • Definition • Hb • <12 (females) • <13.5 (males)
Anemia due to CKD • Screening • All patients with CKD • Annually • Target Hb:11-12g/dl
Anemia in CKD: Treatment • Iron Deficiency • Iron Def: Ferritin <100 ng/ml Transferrin Sat <20% (iron/TIBC) • Treat with FeSO4 • Goal Ferritin 100-500 • Goal Transferrin Sat 20-50 • Start oral. May require parenteral replacement.
Anemia in CKD: Treatment • Erythropoietin Stimulating Agents (ESA) • Utilize if anemia persists with normal iron stores. • Epoetin alfa (Procrit or Epogen) • Starting dose range is 80-120 units/kg/week • Darbepoetin (Aranesp) • 60 mcg S/C every other week • Starting dose is usually 0.45 mcg/kg
Bone Disease in CKD • Metabolic abnormalities • Hyperphosphatemia • Hypocalcaemia • PTH elevation
Bone Disease in CKD • Renal Osteodystrophy • Adynamic bone disease/Osteomalacia / osteitis fibrosis cystica / osteosclerosis • Metastatic calcification • Vascular!