Chronic Kidney Disease (CKD)

  • The presence of markers of kidney damage for ≥ 3 months, as defined by structural or functional abnormalities of the kidney with or without decreased glomerular filtration rate (GFR), that can lead to decreased GFR, manifest by either pathological abnormalities or other markers of kidney damage, including abnormalities in the composition of blood or urine, or abnormalities in imaging tests. OR
  • The presence of GFR < 60 ml/min/1.73m2 for ≥ 3 months, with or without other signs of kidney damage as described above.
  • either decreased kidney function (GFR <60 mL/min) or kidney damage (structural or functional abnormalities) for at least 3 months, regardless of cause
  • irreversible
  • in early stages is characterised by kidney damage and level of kidney function.
  • in later stages is defined as an estimated glomerular filtration rate (eGFR) for at least 3 months of – eGFR < 60 mL/min/1.73m2
  • Stages of CKD are ranked by classifying severity of disease with declining eGFR and kidney damage.

Stages

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Albuminuria in CKD

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Risk Factors

  • most common causes of ESRD are:
    Diabetes, Vascular nephropathies including hypertensive nephropathy, Glomerulopathies, Polycystic kidney disease
  • prevalent in diabetology and cardiology practices

Diagnosis

  • silent and under-diagnosed in earlier stages.
  • GFR can be measured using filtration markers such as inulin, iohexol or iothalamate but such methods are costly and cumbersome
  • sCr is an alternative that is easily measured but affected by factors such as age, gender, race & body size
  • eGFR is used to assess kidney function

Serum Creatinine

  • is Not a Good Measure of eGFR
  • Depends on: Age, Gender, Body weight, Muscle mass, Race

eGFR

  • can be more accurately predicted from variables such as age, gender, race and body sizes with sCr
  • Commonly used prediction equations:
    Cockcroft-Gault uses sCr, age, weight and sex
    MDRD (Modification of Diet in Renal Disease) in its simplest form uses sCr, age, sex and race
  • eGFR is a better indicator of renal function than sCr alone
  • eGFR= 186 x [creatinine/88.4 ]-1,154 x age -0,203 x 0,742 x 1,210*.
  • *- women
  • **- Afro-American

Cockcroft – Gault formula

eGFR={(140-age) x weight/ (creatinine x 72) x 0,85 for women}

Management

Progression Factors

  • Persistent activity of underlying disease
  • Elevated blood pressure (BP)
  • Persistent proteinuria
  • High protein/phosphate diet
  • Hyperlipidaemia, Hyperphosphataemia, Anaemia,
  • Cardiovascular disease (CVD), Smoking

Modifying Progression Factors to Slow CKD

  • Strict BP control, ACE inhibitors, ARBs.
  • Timely treatment of CKD anaemia, Cholesterol and lipids
  • Diabetes, Low protein diet, low phosphate diet
  • Avoid nephrotoxic agents, Use of statins
  • Lifestyle adjustment (smoking cessation)

Hypertension

  • Treatment goal is to lower BP and slow CKD progression but also to reduce risk of CVD
  • Strict BP control should modify targets to renal ranges <130/80 mmHg
  • BP target when protein excretion >1 g/d should be <125/75 mmHg

ACE inhibitors/ARBs

  • Target a 50% reduction in proteinuria within the first 6 months of treatment
  • Use maximum tolerated doses of ACE inhibitors as higher doses have greater anti- proteinuric effect
  • ARBs - first line therapy for ACE inhibitor resistance

Diabetes

  • Optimal glycaemic control (Hb A1c <7%)
    – Preprandial glucose 80-120 mg/dL
    – Bedtime glucose 100-140 mg/dL

Additional

  • Dietary counselling including low protein diets and cholesterol control
  • Use of statins to control dyslipidaemia
  • Phosphate and parathyroid hormone control
  • Smoking cessation

CKD Anaemia

  • A Common Complication in CKD
  • Hb decreases progressively with degree of renal impairment
  • CKD anaemia occurs earlier in patients with Type 1 diabetes
  • CKD patients should be treated with epoetin to reach and maintain Hb >11 g/dL
  • This gives the potential to provide
    – Survival benefit
    – Slow renal deterioration
    – Improve LV abnormalities
    – Increase quality of life

The uremic syndrome (symptoms of CKD)

  • General and miscellaneous symptoms:
    polyuria, polydipsia, thirst, diminished libido, impotence
    uremic foetor, hypothermia
  • Nervous system:
    Fatigue, stupor, coma, Dementia, Malaise
    Insomnia, Headache, Restless legs, Flapping tremor Polyneuritis, Convulsions, Motor weakness, Concentration disturbances Drowsiness, Irritability, Cramps
  • Gastrointestinal system:
    stomatitis, gastritis, anorexia, nausea, vomiting, pancreatitis gastrointestinal ulcers
  • Hemalotogical system:
    anaemia, bleeding diathesis
  • Cardiovascular system:
    pericarditis, hypertension, accelerated atheromatosis, edema, cardiomyopathy, chronic heart failure
  • Pulmonary system:
    pulmonary edema, pleuritis, uremic lung
  • Skin:
    dry skin, pruritus, retarded wound healing, melanosis, nail atrophy
  • Bone disease:
    Vit. D metabolism defect, secondary hyperparathyroidism
    osteodystrophy, soft tissue calcifications, b2M amyloidosis

Azotemia (elevated BUN and Cr)

  • CKD progression can be slowed
  • Transplantation