Chronic Kidney Disease Flashcards
What is the function of the kidneys?
- Body fluid homeostasis
- Regulation of vascular tone
- Excretory function
- Electrolyte homeostasis
- Acid-base balance
- Endocrine function (erythropoietin, vitamin D)
What is the traditional definition of CRD?
Irreversible and significant loss of renal function… and thus problems kidney function
How do we assess for kidney disease?
- Filtration (excrete out) function
- Filtration (keep in) function
- Anatomy
How do we assess kidney excretory function?
Use estimates of GFR (eGFR) from creatinine blood test
How is stage 1 kidney disease described?
- Kidney Damage / Normal or high GFR
- GFR>90
How is stage 2 kidney disease described?
- Kidney damage/mild reduction in GFR
- GFR 60-89
How is stage 3 kidney disease described?
- Moderately impaired
- GFR 30-59
How is stage 4 kidney disease described?
- Severely impaired
- GFR15-29
How is stage 5 kidney disease described?
- Advanced or on dialysis
- GFR <15
What leads to glomerular filtration?
Pressure differences
What is the relationship between creatinine and GFR?
Creatinine will dramatically increase once 60% of total kidney function is loss
What problems are there with measuring creatinine as a measure of kidney damage?
Variations in muscle mass between:
- Ages
- Ethnicities
- Genders
- Weights
How do we assess kidney filtering function?
Check for presence of blood or protein un urine
What crosses the GBM?
- Water
- Electrolytes
- Urea
- Creatinine
What crosses the GBM but is reabsorbed in the proximal tubule?
- Glucose
- Low molecular weight proteins (a2 macroglobulin)
What does not cross the GBM?
- Cells (RBC, WBC)
- High molecular weight proteins (albumin, globulins)
If urine is filtering properly what should not be in the urine?
Blood or protein
How can urine be examined?
- Urinalysis to check for blood or protein
- Protein quantification (PCR)
How is the anatomy of the kidneys assessed
- Histology
- Radiology
What is the current definition of CKD?
Chronic kidney disease (CKD) is defined by either the presence of kidney damage (abnormal blood, urine or x-ray findings) or GFR<60 ml/min/1.73m^2 that is pre##sent for ≥3 months
What is the prevalence of CKD?
- Estimates vary
- ~8-12% UK
- Mostly stage 3
- Increases with age
What are the potential complications of CKD?
- Acidosis
- Anaemia
- Bone disease
- Cardiovascular
- Death & Dialysis
- Electrolytes
- Fluid overload
- Gout
- Hypertension
- Iatrogenic issues
When are complications more likely to occur in CKD?
With worsening GFR
What does risk of mortality increase with?
Worsening renal function
What is the aetiology of CKD?
- Diabetes
- Glomerulonephritis (and all the causes of that)
- Hypertension
- Renovascular disease
- Polycystic kidney disease
- CKD
- Myeloma
- IgA nephropathy
- Chronic exposure to nephrotoxins
- Reflux nephropathy and scarring
- Chronic obstructive nephropathy
Give examples of renovascular disease which can lead to CKD?
renal artery stenosis from atherosclerosis or fibromuscular dysplasia
Why does renovascular disease lead to CKD?
- It leads to ischaemic nephropathy
- Persistently decreased renal perfusion - ongoing heart failure or cirrhosis
What is the clinical approach to CKD?
Detection of the underlying aetiology
-Treatment for specific disease
Slowing the rate of renal decline
-Generic therapies
Assessment of complications related to reduced GFR
-Prevention and Treatment
Preparation for Renal Replacement Therapy
What are the signs and symptoms of CKD?
- Anaemic pallor
- Hypertension
- SOB
- Kidney abnormalities
- Itch and cramps
- Cognitive changes
- GI symptoms
- Change in urine output
- Haematuria
- Proteinuria
- Peripheral oedema
What is important to explore in the history of CKD?
- Previous evidence of renal disease
- Family history
- Systemic diseases
- Drug exposure
- Pre/post renal factors
- Uraemic symptoms
What is important to explore on examination of CKD?
- Vital signs
- Volume status
- Systemic illness
- Obstruction
What previous evidence of renal disease may there be?
- Raised urea/creatinine
- Proteinuria/haematuria
- Hypertension
- Lower urinary tract symptoms
What may there be a family history of in CKD?
- Polycystic kidney disease
- Alport syndrome
What history of systemic disease may there be in CKD?
- Diabetes mellitus
- Collagen vascular diseases (SLE, scleroderma, vasculitis)
- Malignancy (Myeloma, breast, lung, lymphoma)
- Hypertension
- Sickle cell disease
- Amyloidosis
What drug exposure may there be in CKD?
- NSAIDs
- Penicillins/aminoglycosides
- Chemotherapeutic drugs
- Narcotic abuse
- ACE inhibitor / ARBs
What pre-post renal factors may be present in a CKD history?
- Congestive cardiac failure
- Diuretic use
- Nausea, vomiting, diarrhoea
- Cirrhosis
- LUTS / pelvic disease
What uraemic symptoms may be present in a CKD history?
- Nausea, anorexia, vomiting
- Pruritis
- Weight loss
- Weakness, fatigue, drowsiness
What signs of obstruction may be present on examination of CKD?
- Percussible bladder
- Enlarged prostate
- Flank masses
What signs of volume deplete may there be on examination of CKD?
- Orthostatic BP
- Skin turgor/temperature
What signs of fluid overload may there be on examination of CKD?
- Raised JVP
- Crepitation’s
- Ascites
- Oedema
What signs of systemic illness in CKD may be present on examination of the skin?
Rash
- Malar (lupus)
- Purpuric (vasculitis)
- Macular (AIN)
What signs of systemic illness in CKD may be present on auscultation?
Cardiac murmurs (endocarditis)
What signs of systemic illness in CKD may be present on examination of the abdomen?
- Bruits
- Palpable organs
What signs of systemic illness in CKD may be present on examination of the skin?
- Livedo reticularis (vasculitis, atheroembolism),
- Splinter haemorrhages (endocarditis)
What signs of systemic illness in CKD may be present on examination of the bones and joints?
- Tender (malignancy)
- Inflammed (lupus)
- Gouty tophi
What signs of systemic illness in CKD may be present on examination of the pulses?
Absent (vascular disease)
What blood tests should be carried out to identify the underlying aetiology of CKD?
- U+Es
- FBCs
What urine tests should be carried out to identify the underlying aetiology of CKD?
- Urine dip
- Urine PCR or ACR
- 24 hour collection
What biochemistry could be carried out to help identify the aetiology of CKD?
- Urea, creatinine, electrolytes (Na, K, Cl)
- Bicarbonate
- Total protein, albumin
- Calcium, phosphate
- Liver function tests
- Creatine kinase
- Immunoglobulins, serum protein electrophoresis
What haematology tests could be carried out to help identify the aetiology of CKD?
FBC
- Hb
- MCV
- MCH
- WBC
- Platelets
- % hypochromic RBCs
What should be looked at in a coagulation screen to help identify the aetiology of CKD?
- PT
- APPT
- +/- Fibrinogen
What investigation should be carried out to detect haemolytic uraemic syndrome?
Blood count and film
What investigation should be carried out to detect Myeloma?
Serum and urine electrophoresis
What investigation should be carried out to detect intrinsic renal disease?
Urine protein: creatinine ratio
What investigation should be carried out to detect rhabdomyolysis?
CK
What investigation should be carried out to detect anti-GBM disease?
Anti-GBM
What investigation should be carried out to detect ANCA associated vasculitides?
- ANCA
- ELISA for anti MPO or PR3
What investigation should be carried out to detect Connective tissue diseases, SLE, MCGN, Cryoglobulinaemia, Infection related glomerulonephritis?
C3, C4, Auto antibody screen
How does renal disease often present?
Renal disease is often asymptomatic – only sign may be abnormal BP or urinalysis
What is involved in protein quantification?
- Protein creatinine ratio (PCR)
- Albumin creatinine ratio
- 24 hour urine collection
What imaging techniques can be used to detect the aetiology of CKD?
- Ultrasound
- Plain radiology
- CT
- Nuclear medicine
- MRI
What are the benefits of ultrasound?
- Non-invasive
- No ionising radiation
- May provide information about chronicity of renal disease
What are the disadvantages of ultrasound?
- No functional data
- Operator dependent
What potential interventions are there to slow the rate of renal decline?
- BP control
- Control proteinuria
- Reverse contributing factors
- Allopurinol
- Dietary protein restriction
- Fish oils
- Lipid lowering
- Control acidosis
What is high BP associated with regard to renal decline?
Faster decline in GFR
Treating high BP slows progression particularly when they have…
Proteinuria
How can acidosis be assessed?
- Bicarbonate
- pH
How can anaemia be assessed?
- Blood count
- Blood film
- Haematinics
How can bone disease be assessed?
- Calcium phosphate
- Albumin
- Parathyroid hormone
How can CV risk be assessed?
- History of chest pain
- BP
- Cholesterol
How can risk of death and dialysis be assessed?
Renal function including urea, creatinine and eGFR
How can electrolyte abnormalities be assessed?
Electrolytes in serum including potassium
How can fluid overload be assessed?
Examination including
- BP
- Oedema
- JVP
- CXR
How can gout be assessed?
History and examination
How can hypertension be assessed?
BP +/- 24 hour tape
How can iatrogenic issues be assessed?
Ask about medication
When is metabolic acidosis usually seen in CKD?.
GFR <20mls/min
When is metabolic acidosis most marked?
In tubular interstitial disease
What can metabolic acidosis make worse?
- Hyperkalaemia
- Renal bone disease
How is metabolic acidosis treated?
- Oral Na
- Bicarbonate
When is anaemia usually seen in CKD?
GFR <20mils/min
Why does anaemia occur in CKD?
- Normochronic, normocytic
- Reduced erythropoietin production
- Reduced red cell survival
- Increased blood loss
When is anaemia usually treated in CKD
Usually treat if < 10g/dl or symptomatic
What is the treatment for anaemia in CKD?
- Iron replacement
- ESA therapy
What leads to hyperphosphataemia?
Reduced GFR
What does loss of renal tissue lead to lack of?
Activated Vitamin D which leads to an indirect reduction in calcium absorption
What are the clinical features of renal bond disease?
- Low calcium
- High phosphate
- Secondary hyperparathyroidism (elevated PTH)
- May progress to tertiary hyperparathyroidism
What does vitamin D derived from sunlight or diet require to become active?
Hydroxylation by 1a hydroxylase in the kidney
Why is there lack of activation of vitamin D in renal disease?
There is low 1s hydroxylase so low activation of vitamin D
Why does low vitamin D lead to low calcium?
- Reduced intestinal absorption
- Reduced tubular reabsorption
Why is secondary hyperparathyroidism associated with renal bone disease?
There is resulting stimulation of PTH secretion in order to try to correct everything through increased action on the bone, gut and kidneys
Why can secondary hyperparathyroidism sometime progress to tertiary?
Prolonged hypersecretion can become uncontrolled
What is high phosphate associated with?
Vascular and cardiac calcification
How does increased PTH increased bone turnover?
Increases the number and activity of osteoclasts and osteoblasts
How is renal bone disease managed?
Control of phosphate
- Diet
- Phosphate binders (CaCO3 Ca acetate, sevelamer, lanthanum)
Normalise calcium and PTH
- Active vitamin D analogues (calcitriol)
- Tertiary disease: parathyroidectomy and calcimetics
Why does hyperkalaemia occur in renal disease?
- Normally excreted by exchange with Na + in distal tubule
- Reduced delivery of Na+ to distal tubule as GFR falls
Give examples of foods to avoid if you have high serum potassium.
- Orange
- Banana
- Potato based foods
- Tomato
- Chocolate
When may hyperkalaemia become fatal?
K > 7mmol/l (NR 3.5-4.5) may induce a fatal cardiac arrhythmia
What is the treatment for acute hyperkalaemia?
Stabilise
-Calcium gluconate
Shift
- Salbutamol
- Insulin-dextrose
Remove
- Dialysis
- Calcium resonium
What is the treatment for chronic hyperkalaemia?
- Diet
- Drug modifications
When is fluid/volume overload usually problematic?
Usually problematic when GFR < 20mls/min
Why does fluid/volume overload occur in renal disease?
- Unable to excrete an excess Na+ load
- Na+ and Water retention
How does fluid/volume overload present?
- Oedema
- Hypertension
What is the treatment for fluid/volume overload?
- Na restriction
- Fluid restriction
- Loop diuretics
What is hypertension often associated with in renal disease?
Volume overload
How should hypertension in renal disease be treated?
- Treatment as per slowing rate of progression
- Most important in proteinuric renal disease
- ACEI may offer additional advantage
- Otherwise tailored therapy
- Aim <125/75 in CKD with significant proteinuria, 130/80 no proteinuria
What drugs can cause AKI on top of CKD?
- Contrast agents
- Antibiotics
What is build up of urea toxin called?
Uraemic pericarditis
How should acidosis in reduced GFR be managed?
Bicarb
How should anaemia in reduced GFR be managed?
- EPO
- Iron
How should bone disease CV risk in reduced GFR be managed?
Diet and phosphate binders
How should in reduced GFR be managed?
- BP
- Aspirin
- Cholesterol
- Exercise
- Weight
How should death and dialysis in reduced GFR be managed?
Counsel and prepare
How should electrolytes in reduced GFR be managed?
Diet and consider drugs
How should fluid overload in reduced GFR be managed?
- Salt and fluid restriction
- Diuretics
How should gout in reduced GFR be managed?
Optimise +/- meds
How should hypertension in reduced GFR be managed?
- Weight
- Diet
- Fluid balance
- Drugs
How should iatrogenic issues in reduced GFR be managed?
BE AWARE
What preparation is there for ESRD and RRT?
- Education & information
- Selection of modality
- Planning access
- Deciding when to start RRT
- Multidisciplinary team
