[4] Chronic Kidney Disease Flashcards
What is chronic kidney disease?
A type of kidney disease in which there is gradual loss of kidney function over a period of months or years
What does the term CKD embrace?
The majority of renal conditions
What are the causes of CKD?
- Diabetes mellitus
- High blood pressure
- High cholesterol
- Glomerulonephritis
- Infections of kidney
- Polycystic kidney disease
- Blockage to flow of urine, e.g. due to recurrent kidney stones or enlarged prostate
- Long term use of certain drugs
Give two examples of drugs that can cause CKD
- NSAIDs
- Lithium
What are the symptoms of CKD in the early stages?
Usually asymptomatic
How is CKD discovered in the early stages?
Usually on opportunistic blood or urine tests
What are the symptoms of more advanced CKD?
- Tiredness
- Oedema
- Shortness of break
- Haematuria
- Pruritis
- Anaemia
- Raised or high blood pressure
- Polydipsia and polyuria
How is CKD investigated?
- History and examination
- Measurement of kidney function
- Urine testing
- Blood tests
- Ultrasound imaging
- Histology
How is a measurement of kidney function made in CKD?
Using a creatinine-based estimate of GFR
What should a CKD history focus on?
Possible causes, as well as current symptoms
What past medical history should be obtained in a history for CKD?
- History of UTIs or LUTS
- Hypertension
- Diabetes mellitus
- IHD
- Systemic disorders
- Renal colic
What drug history do you need to obtain in CKD?
Need to know about drug ingestion, including NSAIDs, analgesics, and other medicatins
What should be included in the family history in CKD?
- Renal disease
- Subarachnoid haemorrhages
What is the purpose of systems review in CKD?
To look for symptoms suggestive of systemic disease or malignancy
What may be found on blood tests in CKD?
- Normochromic, normocytic anaemia
- Abnormal glucose
- Decreased calcium
- Increased phosphate
- Increased PTH
What is the significance of a finding of abnormal glucose in CKD?
It indicates diabetes mellitus is the cause
What blood tests can be done in the directed investigations of intrinsic renal disease?
- ANA
- ANCA
- Anti-phospholipid antibodies
- Complement
What should be done in urine testing in CKD?
- MC&S
- Albumin:creatinine ratio, or protein:creatinine ratio
- Bence Jones protein
What is Bence Jones protein?
An immunoglobulin light chain found in the urine
What might Bence Jones protein suggest if found?
May be suggestive of multiple myeloma
When in particular is the finding of Bence Jones protein in the urine suggestive of multiple myeloma?
In the context of target organ manifestations, scuh as renal failure, lytic bone lesions, or anaemia
What proportion of multiple myeloma cases is Bence Jones protein found in?
2/3
What should be looked for on ultrasound imaging in CKD?
- Size
- Symmetry
- Anatomy
- Corticomedullary differentiation
- Signs of obstruction
- Scarring
What size might the kidneys be in CKD?
May be small (<9cm), except in infiltrative disorders, APKD, and diabetes
What diagnosis should you consider if the kidneys are asymmetrical on ultrasound?
Renovascular disease
When should you consider renal biopsy?
- Progressive disease
- Nephrotic syndrome
- Systemic disease
- AKI without recovery
What is the limitation of kidney biopsy as an investigation?
It is unlikely to change the treatment if GFR is stable and protein:creatinine ratio is <150
What is CKD classified according to?
The estimated GFR and the albumin creatinine ratio
What eGFR is classified as kidney failure?
<15ml/min
What monitoring should be done in CKD?
GFR and albuminuria should be monitored at least annually, according to risk
How often should a patient with CKD be monitored if they are high risk?
Every 6 months
How often should a patient with CKD be monitored if they are very high risk?
Every 3-4 months
What monitoring finding is significant in CKD?
Small fluctations are common, but a drop in eGFR >25% is significant
What is the aim of treatment in CKD?
There is no cure for CKD, so treatment is aimed at stopping progression and giving symptomatic relief
What does appropriate management of CKD include?
- Appropriate referral to nephrology
- Treatment to slow renal disease progression
- Renal replacement therapy
- Treatment of complications
When should a referral to nephrology be considered in CKD?
- Stage G4 or G5 CKD
- Moderate proteinuria, with albumin:creatinine ratio >70mg/mmol, unless due to diabetes and already treated
- Proteinuria with albumin:creatinine ratio >30mg/mmol with haematuria
- Decrease in eGFR by >25%, and a decrease in GFR category, or sustained eGFR reduction by >15% within 12 months
- Increase BP with poor control, despite 4 or more antihypertensive drugs at therapeutic dose
- Known or suspected rare or genetic cause of CKD
What risks can be modified to prevent or delay progression of CKD?
- Management of blood pressure
- Glycaemic control
- Lifestyle changes
- Reduce cholesterol, using diet or statins
What is the target HbA1c in CKD?
7%, unless risk of hypoglycaemia, co-morbidity, or limited life expectancy
What blood pressure should be aimed for in people with CKD?
Below 140/90mmHg
When should you aim to keep blood pressure below 130/80mmHg in CKD?
- In people with CKD and diabetes
- In people with an albumin:creatinine ratio of 70mg/mmol or more
How should you manage hypertension in CKD in a patient with an ACR of less than 30mg/mmol?
Follow normal hypertension guidelines
How should you manage hypertension in a patient withCKD and diabetes and an ACR of 3mg/mmol or more, or an ACR of 30mg/mmol or more?
ACE inhibitor or ARB
Should you offer a combination of ACE inhibitor and ARBs to people with CKD?
No
What should be done before starting ARBs or ACE inhibitors in CKD?
Measure serum potassium concentration and estimate the GFR
What monitoring should be done when a patient with CKD is on ARBs or ACE inhibitors?
You should repeat between 1 and 2 weeks after starting, or after each dose increase
What lifestyle advice should be given in CKD?
- Encourage regular exercise
- Achieve healthy weight
- Stop smoking
What dietary advice should be given in CKD?
Dietary advice about potassium, phosphate, calorite and salt intake appropriate to severity of CKD
Should you offer low-protein diets in CKD?
No
When is renal replacement therapy usually required in CKD?
When native renal function is no longer adequate to support health, usually when GFR <10ml/min
What are the options for RRT?
- Haemodialysis
- Peritoneal dialysis
- Renal transplant
What are the indications for dialysis in CKD?
- Inability to control volume status, including pulmonary oedema
- Inability to control blood pressure
- Serositis
- Acid-base or electrolyte abnormalities
- Pruritus
- Nausea, vomiting, or deterioration in nutritional status
- Cognitive impairment
What is the mechanism of action of haemodialysis?
Blood is passed over a semi-permeable membrane against dialysis fluid flowing in the opposite direction. Diffusion of solutes occurs down the concentration gradient. A hydrostatic gradient is used to clear excess fluid if required
What is dialysis fluid?
Highly purified water
How is access gained in haemodialysis?
Preferentially via an arteriovenous fistula
What does an AV fistula provide for dialysis?
Increased blood flow and longevity
When should a fistula be created?
Prior to the need for RRT
Why should the fistula be created prior to the need for RRT?
To avoid infection risk associated with central venous dialysis catheters
How often is haemodialysis required?
At least 3 times a week
What is the effect of daily haemodialysis?
It increases the ‘dose’, and so improves the prognosis
Who should home haemodialysis be offered too?
All suitable patients
What are the advantages of haemodialysis?
- Effective
- Potential for 4/7 days free from treatment
- Dialysis dose easily prescribed
How long can patients survive on dialysis?
>25 years
What are the disadvantages of haemodialysis?
- Fluid and diet restriction
- Limits holidays
- Access problems, including thrombosis, stenosis, and steal syndrome of the arteriovenous fistula
- CVS instability, including hypotension
- High capital cost
- Need for long-term anticoagulation
What does peritoneal dialysis require?
- Peritoneal membrane
- Blood flow
- Peritoneal dialysis fluid
How is peritoneal dialysis performed?
The fluid is put into the peritoneal cavity, and dialysis occurs across the peritoneal membrane
How is ultrafiltration achieved in peritoneal dialysis?
By adding osmotic agents, e.g. glucose and glucose polymers, to the dialysis fluid
What happens to the peritoneal dialysis fluid after it has performed its function?
It is drained away and disposed of
What are the advantages of peritoneal dialysis?
- Low technology
- Home technique that can be easily learnt
- Allows mobility
- CVS stability
- Less restrictions
What are the disadvantages of peritoneal dialysis?
- Frequent exchanges, can be 4/day
- No long term survivors yet
- Risk of catheter site infection
- Risk of peritonitis
- Limited dialysis loss range
- May get loss of membrane function over time
Who should be considered for renal transplantation in chronic kidney disease?
Renal transplant should be considered for all patient with, or progressing towards, stage 5 kidney disease
When is renal transplantation the treatment of choice in CKD?
In all patient when risks to not exceed beenfit
Why will many people not make the transplant list?
Due to co-morbidities or frailty
What are the contraindications for renal transplantation?
- Metastastic cancer
- Current active infection
- HIV with viral replication
- Unstable CVD
- Congestive heart failure, if risks outweigh benefits
- CVD, if risks outweigh benefits
What are the sources of kidneys for transplant?
- Living donor
- Decreased donor
What is the advantage of a living kidney donor for transplant?
It conveys the best graft function and survival, especially if HLA matched
What are the types of decreased kidney donors?
- Heart-beating donor (donor after brain death)
- Expanded criteria donor
- Donor after cardiac death (non-heart beating donor
What is an expanded criteria kidney donor?
A donor from an older kidney, or from a patient with a history of CVD, BP, or CKD
What is the trade off with an expanded criteria donor?
The person receiving the kidney has a worse prognosis than a transplant from a donor after brain death, but a better outcome than remaining on long term dialysis
What will all patients receiving a renal transplant require?
Life-long immunosuppression
What is the aim of a combination of drugs in immunosuppression for a kidney transplant?
It aims to use the minimal effective dose with the lowest drug-related toxicity
What does immunosuppression protocol depend on in renal transplant?
- The immunological risk of the patient
- The type of donated kidney
What drugs can be used in immunosuppression in renal transplant?
- Monoclonal antibodies
- Calcineurin inhibitors
- Antimetabolites
- Glucocorticosteroids
Give three examples of monoclonal antibodies used after renal transplant
- Basiliximab
- Daclizumab
- Alemtuzumab
What is the purpose of monoclonal antibodies used at the time of renal transplant?
It reduces acute rejection and graft loss
What is the limitation of monoclonal antibodies in immunosuppression after renal transplant?
They can increase infection risk if not selective
What are the complications of CKD?
- Cardiovascular disease
- Anaemia
- Bone conditions
- Metabolic acidosis
By how much does CKD increase in the incidence of CVD?
16x compared to normal population
What cardiovascular conditions occur in excess as GFR declines?
- Sudden cardiac death
- MI
- Cardiac failure
- Stroke
- PVD
- Pericarditis
- Cardiomyopathy
How should CVD be prevented in CKD?
- Statins
- Antiplatelet drugs
On what basis should statins be prescribed in CKD?
Follow standard recommendations
What should you be aware of when offering antiplatelet drugs to people with CKD for the secondary prevention of CVD?
Be aware of increased risk of bleeding
What anti-coagulant should be given in CKD?
Apixiban, in preference to warfarin
When should apixiban be given in preference to warfarin in CKD?
In people with an eGFR of 30-50ml, and a non-valvular atrial fibrillation with one or more of;
- Prior stroke or TIA
- Age 75+
- Hypertension
- Diabetes mellitus
- Symptomatic heart failure
What is the cause of anaemia in CKD?
The main mechanism is decreased production of, or resistance to, erythropoitein
How should anaemia be identified in CKD?
If not already measured, check the haemoglobin in people with a GFR of less than 45 to identify anaemia
How is the frequency of checking for anaemia determined in CKD?
By the Hb and clinical circumstances
Who should be offered iron therapy in CKD?
Those who are iron deficient and not recieving ESA therapy
Should iron therapy in anaemia of CKD be given oral or IV?
For people who are not receiving haemodialysis, consider a trial of oral iron before offering IV therapy. If they are intolerant, or target Hb levels are not reached within 3 months, offer IV therapy
What is ESA?
A synthetic erythropoietin
Why is erythropoietin deficient in CKD?
Because the kidneys can’t release sufficient amounts
How can ESA be administered?
Either IV or SC
How frequently is ESA given?
Can be once a week, once every two weeks, or less often
What are the potential side effects of ESA?
- Hypertension
- Thrombosis
- Skin rashes
- Low iron levels
What is the result for the potential of hypertension in ESA therapy?
Regular monitoring is required
When might a person with anaemia of CKD require a red cell transfusion?
If there is ESA resistance, and all reversible causes of ESA resistance have been excluded, the persons condition is otherwise stable, and the person is receiving adequate dialysis
What are the types of renal bone disease?
- Osteitis fibrosa cystica
- Osteomalacia
- Non-bone (extra-articular) calcification
What causes osteitis fibrosa cystica in CKD?
Decreased GFR means that there is a reduced excretion of phosphate, and so its serum concentration increases. It then forms complexes with free calcium, reducing the effective serum concentration of calcium. This stimulates the production of PTH, causing overactivity of osteoclasts, leading to osteitis fibrosa cystica
What causes osteomalacia in CKD?
Damage to the kidneys means less vitamin D undergoes its 2nd hydroxylation to its active form. This has the effect of causing hyperparathyroidism, as well as causing osteomalacia
How should the possibility of renal bone disease be monitored in CKD?
Measure serum calcium, phosphate, and PTH concentrations in people with a GFR of less than 30. Determine the subsequent frequency of testing by the measured values and clinical circumstances
What medication can be offered to prevent and treat osteoporosis in CKD?
Bisphosphonates
Should you offer vitamin D supplementation to manage or prevent CKD-mineral and bone disorders?
Not routinely
What should be offered to treat vitamin D deficiency in people with CKD and vitamin D deficiency?
Colecalciferol or ergocalciferol
What should be offered if vitamin D deficiency is present after correction in CKD?
Alfacalcidol or calcitriol
What should be monitored in people receiving alfacalcidol or calcitriol?
Serum calcium and phosphate concentrations
When should oral sodium bicarbonate supplementation be considered in CKD?
In people with a GFR of less than 30, and a serum bicarbonate of less than 20mmolL
What effect might uraemia have on the CNS?
- Depressed cerebral function
- Decreased seizure threshold
- Tremor
- Myoclonus
- Anxiety and depression
- Impaired cognition
Can CKD affect the autonomic and peripheral nervous systems?
Yes
What is accelerated progression of chronic kidney disease defined as?
- A sustained decrease in GFR of 25% or more, and a change in GFR category within 12 months, or
- A sustained decrease in GFR of 15ml/min per year
What should happen once you have determined that a person has progressive CKD?
You should obtain a minimum of 3 GFR estimations over a period of 90 days to identify the rate of progression
