Chronic Kidney Disease Flashcards
What may urinanalysis show for CKD?
Haematuria +/- proteinuria
Renal replacement therapy consists of dialysis and filtration.
Long-term dialysis is started when it is necessary to manage one or more symptoms of renal failure - which 4 possible symptoms does this include?
- Inability to control volume status, incl pulmonary oedema
- Inability to control BP
- Acid-base or electrolyte abnormalities
- Cognitive impairment
For patients with renal failure, the management options are renal replacement therapy (RRT), to take over the physiology of the kidneys, or conservative management, which will be palliative.
What are the 3 key types of renal replacement therapy?
- Haemodialysis
- Peritoneal dialysis
- Renal transplant
Option is chosen depending on: predicted QoL, life expectancy, pt preference and co-existing med conditions
Treatment of renal complications of CKD
What is the treatment for oedema?
- Restrict fluid and sodium intake
- High doses of loop diuretics may be needed
- Combo of loop diuretic and thiazide diuretic have powerful effect
What is an example regime for immunosuppression for transplant?
- Initial → ciclosporin/tacrolimus with a monoclonal antibody
- Maintenance → ciclosporin/tacrolimus with MMF or sirolimus
- Add steroids if more than one steroid responsive acute rejection episode
CKD patients may be asymptomatic, symptoms usually develop if GFR < 30.
What are clinical features of CKD?
- Fluid overload (SoB, periph oedema)
- Anorexia / Nausea / Vomiting
- Restless legs
- Fatigue / Weakness
- Pruritis
- Bone pain
- Amenorrhoea
- Impotence
Treatment of renal complications of CKD
What is the treatment for acidosis?
Consider sodum bicarb supplements for pts with eGFR < 30 and low serum bicarb (< 20 mmol/L)
How is CKD classified by GFR?
Factors which may affect result = pregnancy, muscle mass, eating red meat 12hrs prior to sample being taken
CKD can also be classified by albuminuria
What are the risk factors for CKD?
- Diabetes mellitus
- Hypertension
- Age > 50 yrs
- Childhood kidney disease
- Smoking
- Obesity
- Autoimmune disorder
- Long-term NSAIDs
Renal transplant is considered for every patient with, or progressing towards, stage G5 kidney disease.
What are contraindications to transplant?
- Absolute: cancer with metastases
- Temp: active infection, HIV w/ viral replication, unstable CVD
- Relative: congestive heart failure, CVD
Immunosuppression for renal transplantation
What is Tacrolimus used for?
- Calcineurin inhibitors
- Eg. tacrolimus / ciclosporin
- Inhibit T cell activation and proliferation
- Clearance depends on P450
Tacrolimus has lower incidence of acute rejection compared to ciclosporin but has increased risk of impaired glucose tolerance and diabetes
Treatment of renal complications of CKD
What is the treatment for CKD bone mineral disorders?
- CKD causes hyperphosphataemia and reduced hydroxylation of Vit D by kidneys
- Measure Ca / PO4 / ALP / PTH / Vit D
- Treat if phosphate > 1.5 mmol/L w/ dietary restriction
- Give Vit D supplements (colecalfierol) if deficient
What are potential problems with haemodialysis?
- AV fistula → thrombosis, stenosis, steal syndrome, tunnelled venous line, infection, blockage
- Dialysis equilibrium (between cerebral and blood solutes) → cerebral oedema (avoided by starting haemodialysis gradually)
What are complications of renal transplant?
- Surgical → bleed / thrombosis / infection / urinary leaks / hernia
- Delayed graft function (40%)
- Hyperacute rejection
- Acute graft failure
- Chronic graft failure
- Infection
- Malignancy (esp skin, 25x higher risk)
- Cardiovascular disease
What is acute graft failure?
- < 6 months
- Usually due to mismatched HLA
- Cell-mediated (cytotoxic T cells)
- Othre causes → CMV infection
- May be reversible with steroids and immunosuppressants
O/E for CKD patients, how might oedema present?
- Periorbital oedema
- Peripheral oedema
Due to salt and water retention as GFR declines
Which imaging modality is used to diagnose CKD?
- Renal USS
- Helps to diagnose CKD if kidney atrophy is present and diagnoses obstruction with hydronephrosis or bladder retention
What will blood tests show for CKD?
- FBC → anaemia of CKD due to deficiency of EPO as the GFR declines
- U+Es → serum creatinine to calculate eGFR; hyperkalaemia common as kidney’s can’t excrete
- Ca + PO4 → Vit D deficieny results in phosphorus retention and hypocalcaemia
What is chronic kidney disease?
- Either a pathological abnormality of the kidney such as haematuria and/or proteinuria, or
- A reduction in the glomerular filtration rate to < 60 ml/min for >3 months
What is the most common cause of chronic kidney disease?
- Diabetes - 33% of these pts will develop kidney disease
- Hypertension is second most common
- Less frequent causes: polycystic kidneys, obstructive uropathy, glomerular nephrotic and nephritic syndromes
What are the 2 types of periotoneal dialysis?
- Continuous ambulatory peritoneal dialysis (CAPD) → each exchange lasts 30-40mins and each dwell time lasts 4-8hrs; patient may go about their normal activities with the dialysis solution inside of their abdomen
- Automated peritoneal dialysis (APD) → a dialysis machine fills and drains the abdomen while pt is sleeping, performing 3-5 exchanges over 8-10 hours each night
Immunosuppression for renal transplantation
What are antimetabolites used for?
- Eg. Mycophenolic acid (MPA)
- Block purine synthesis therefore inhibit proliferation of B + T cells
- SE → GI and marrow suppression
Immunosuppression for renal transplantation
What are steroids used for?
1st choice treatment for acute rejection
What is a common cause of obstructive uropathy?
Enlarged prostate
What is the treatment to slow renal disease progression?
-
BP → target systolic BP < 140 and diastolic < 90
- Offer ACE-inhibitor to [DM + A:CR > 3] and [HTN + A:CR >30]
- Glycaemic control → target HbA1c of 53 mmol/mol
What are features of peritoneal dialysis?
- Filtration occurs in pt’s abdomen
- Dialysis solution injected into abdo cavity through permanent catheter
- High dextrose conc of solution draws waste products from blood into abdo cavity across peritoneum
- After several hrs of dwell time → dialysis solution drained, removing waste products from body, and exchanged for new dialysis solution
What are the two main types of grafts for renal transplant?
- Living donor → best graft function and survival, especially if HLA matched
-
Deceased donor
- donor after brain death
- expanded criteria donor is from an older kidney or from a pt w/ history of CVA, BP or CKD
- donor after cardiac death w/ increased risk of delayed graft function
Treatment of renal complications of CKD
What is the treatment for restless legs/cramps?
- Exclude iron-deficiency as exacerbating factor
- Treatment for severe cases → gabapaentin/pregabalin
Treatment of renal complications of CKD
What is the treatment for anaemia?
- Check Hb when eGFR < 60
- Investigate other deficiencies (iron, B12, folate)
- IV Iron therapy may be needed
- EPO stimulating agent if Hb < 110g/L
What are features of haemodyalysis?
- Most common form of RRT
- Needed 3x per week or more / each session 3-5hrs
- Blood is passed over semi-permeable membrane against dialysis fluid flowing in opposite direction → diffusion of solutes occurs down concentration gradient
- Access is preferentially via an arteriovenous fistula → provides increased blood flow and longevity
- AV fistula created 8wks prior to haemodialysis to avoid infection risk associated with central venous dialysis catheters
- Some pts may be trained to perform haemodialysis so they don’t have to go into hospital
What are potential problems with peritoneal dialysis?
- Catheter site infection
- PD peritonitis
- Hernia
- Loss of membrane function over time
What is hyperacute rejection and its management?
- Minutes to hours
- Due to pre-existing antibodies against ABO or HLA antigens
- Example of type II hypersensitivity rxn
- Leads to widespread thrombosis of graft vessels → ischaemia and necrosis of transplanted organ
- No treatment possible, graft must be removed
What are reduced GFR and albuminuria independently associated with a higher risk of?
- Cardiovascular mortality
- Progressive kidney disease + kidney failure
- AKI
Pts with CKD are much more likely to die of cardiovascular disease rather than need renal replacement therapy.
Summary of complications from renal replacement therapy
What are the haemotological consequences of CKD?
- Ecchymosis
- Purpura
