Chronic Kidney Disease (CKD) Flashcards
Define Chronic Kidney Disease (CKD).
Longstanding, usually progressive, impairment in renal function
(haematuria, proteinuria or anatomical abnormality) for more than 3 months.
- Defined as a GFR < 60mL/min/1.73 m2 for more than 3 months with/without evidence of kidney damage (haematuria, proteinuria or anatomical abnormality).
What is the classification of CKD stages?
Stages:
1 - kidney damage but GFR >90
2. - kidney damage GFR 60-90
3A - GFR 45-60
3b - GFR 30-45
4 - GFR 15-30
5 - established renal failure with GFR <15
What is the GFR for end stage renal failure?
15 or less
How is GFR calculated?
eGFR - creatinine
gold standard - inulin - but v invasive
Give 4 pathophysiological effects of declining kidney function.
- Fluid balance/BP regulation disrupted - hypervolaemia / hypertension
- Vitamin D metabolism poor - bone reabsorbed
- Hyperkalaemia, uraemia
- Decreased EPO = normocytic anaemia
- Metabolic acidosis - as less H+ excretion and less bicarbonate production
Give 5 causes of CKD.
- Diabetes mellitus.
- Hypertension.
- Atherosclerotic renal vascular disease.
- Congenital e.g. PKD, VHL
- Urinary tract obstruction - stones, tumours, BPH
- Nephrotoxic drugs - NSAIDs, ACEIs, PPIs, lithium, many antibiotics
- Glomerulonephritis - nephrotic VS nephritic
- Age-related decline
- Persistent pyelonephritis
What is the most common cause of CKD?
Diabetes Mellitus
(Damage to efferent arteriole)
Give 5 risk factors for CKD.
- Diabetes Mellitus
- Smoking
- Hypertension
- Old age
- SLE
- Recurrent UTIs
- AKI
Give 5 signs + symptoms of CKD.
- Fluid retention - oedema and raised JVP
- Nocturia + polyuria - 0.5 mL/kg/h or <500mL/day
- Effects of uraemia:
- Pruritus
- Uraemic frost, yellow/grey complexion
- Nausea
- Reduced appetite
- Cardiac arrhythmias and muscle cramps- hyper K+
- Fatigue, pallor - anaemia
- Bone pain - hyperphosphatemia (CKD-MBD)
- Hypertension
Investigations for CKD.
- Bloods
- FBC (anaemia) - Urinalysis
- Urine dipstick = a significant result is 1+ of blood = haematuria
- Urine albumin:creatinine ratio (ACR) = A result of ≥ 3mg/mmol is significant = proteinuria
- Glycosuria
- UTI
- Renal ultrasound
- Serum biochemistry
- U+Es = HIGH urea + creatinine, phosphate, potassium
- Low eGFR
- Raised alkaline phosphatase
What does FBC show in CKD?
Normocytic anaemia
What is ACR and what does it show/mean?
Albumin/creatinine ratio.
More than 3 means proteinuria.
How is phosphate affected in CKD?
Hyperphosphataemia.
The kidneys normally excrete phosphate, they can’t do that as well in CKD.
What happens to calcium in CKD?
Hypocalcaemia
Why might someone with advanced CKD also have hyperparathyroidism?
Advanced CKD = calcitriol deficiency.
Calcitriol suppresses PTH therefore deficiency -> hyperparathyroidism.
Describe the management for CKD.
- Treat the underlying cause.
- Limit progression + complications.
- Control symptoms.
- Reduce CV risk.
- ESRF -> dialysis or transplant.
Management of CKD 1: Identify & treat reversible causes.
- Relieve obstruction
- Stop nephrotoxic drugs
- Stop smoking and achieve healthy weight to deal with cardiovascular risk
- Tight glucose control in diabetes
Management of CKD 2: Limit progression & complications.
- BP
- Optimise hypertensive control
- Target BP is < 130/80
- ACEi / ARB / Diuretic / CCB - Renal Bone disease
(Chronic kidney disease-mineral and bone disorder (CKD-MBD))
- Check PTH and treat if raised - phosphate further increases PTH
- Restrict diet
- Give phosphate binders to decrease gut absorption and avoidance of phosphate food e.g. milk, cheese, eggs
- Vitamin D e.g. CALCITRIOL and Ca2+ supplements
- Bisphosphonates can be used to treat osteoporosis - Optimise diabetic control
- Metformin, pioglitazone, sulphonylurea - Treat glomerulonephritis
Management of CKD 3: Control symptoms.
- Anaemia
- Iron/folate/folic acid
- Exogenous Erythropoietin (EPO) - Metabolic Acidosis
- Systemic acidosis accompanies the decline in kidney function and may contribute to increased serum potassium levels as well as dyspneoa and lethargy
- Treat with SODIUM BICARBONATE - Oedema
- Furosemide
- Fluid and sodium restriction
Management of CKD 4: Reduce CVD.
- Lower cholesterol with statins e.g. Simvastatin
- Give ASPIRIN
- Smoking cessation
Management of CKD 5: End-stage renal failure.
- Renal replacement therapy (RRT) - transplant
- Dialysis
What are the 3 types of dialysis?
- Haemofiltration
- Haemodialysis
- Peritoneal dialysis
Why do advanced CKD patients need regular fluid assessment?
They may be oligouric or anuric.
What are the indications for dialysis?
- Symptomatic uraemia including pericarditis or tamponade
- Hyperkalaemia not controlled by conservative measures
- Pulmonary oedema thats unresponsive to diuretics
- Severe acids
- High potassium
- Tall T waves, low flat p waves, broad QRS or arrhythmias on ECG
- Metabolic acidosis
- Fluid overload that is resistant to diuretics
