Chronic Kidney Disease (CKD) Flashcards
What are the Sx of CKD?
Often asymptomatic until advanced (fatigue/anorexia)
Polyuria/nocturia
Restless legs syndrome
Sexual dysfunction
Nausea & Pruritis
Yellow pigmentation, encephalopathy, pericarditis
Pedal/pulmonary oedema
What are the signs of CKD?
Pallor due to anaemia
Excoriations due to pruritis
HTN/fluid overload signs
Pericardial rub
What are the appropriate initial investigations for CKD?
Bloods - FBC, U&E, LFTs, Ca, PO4, PTH, Glucose
Urinalysis & MCS - quantify proteinuria, exclude infection
24h urinary protein - assess severity
CXR - suspected pulmonary oedema
Renal USS - suspected obstructive causes
How is CKD diagnosed?
Two tests 3/12 apart showing reduced eGFR
How is CKD staged?
According to eGFR
Describe Stage 1 CKD
eGFR >90
Normal kidney function
Urine findings/structural abnormalities/genetic traits point to kidney disease
Describe Stage 2 CKD
eGFR 60-89
Mildly reduced kidney function
Urine findings/structural abnormalities/genetic traits point to kidney disease
Describe Stage 3 CKD
eGFR 30-59
Moderately reduced kidney function
Describe Stage 4 CKD
eGFR 15-29
Severely reduced kidney function
Describe Stage 5 CKD
eGFR <15
V. severe/established renal failure
What is eGFR?
An estimate of GFR based on a plasma level of creatinine
What are the common causes of CKD?
DM (20-40%) HTN Chronic glomerulonephritis Chronic pyelonephritis Obstructive uropathy Renovascular disease Drugs (NSAIDs) Polycystic kidney disease
What additional specialist investigations may be required in CKD?
DTPA scan (investigates vascular supply)
Renal biopsy
Bone imaging
What are the management options for CKD?
Treat reversible causes (obstruction, nephrotoxic drugs) BP/DM control -BP <130/80 OR <125/75 if proteinuric -ACEIs 1st line, also statin + ld aspirin Complication control -EPO -ca/vit D supplementation -K+ restriction if hyperkalaemic Renal replacement therapy (Stage 5)
When should renal replacement therapy be started?
Any symptomatic CKD Stage 5 pt
-often try to delay dialysis
What are the three main complications of CKD?
Renal anaemia
Renal bone disease
2o HTN
What is the underlying pathophysiology of renal anaemia in CKD?
Loses ability to secrete EPO –> anaemia
How is renal anaemia managed?
Recombinant EPO as part of renal replacement therapy
What factors contribute to renal anaemia?
CKD
Bone marrow toxins
Increased blood loss
Abnormal red cell membrane
What is the underlying pathophysiology of renal bone disease in CKD?
Low vit D –> hypocalcaemia, hyperphosphataemia, osteomalacia –> 2o hyperparathyroidism –> cyst formation & marrow fibrosis –> 3o hyperparathyroidism –> osteopenia
How can osteopenia be detected radiologically?
Pseudofractures
Subperiosteal erosions
How is renal bone disease managed?
Restrict dietary phosphate
Give phosphate binders
AdCal supplementation
What is the underlying pathophysiology of 2o HTN in CKD?
Overactivation of RAAS –> HTN
Thickened renal artery walls (afferent)
Chronic ischaemia, progressive loss of glomeruli
What are the different options for renal replacement therapy?
Haemodialysis
Peritoneal dialysis
Transplantation
What is haemodialysis?
Diffusion of solutes b/w blood & dialysate
- flow in opposite directions
- semi-permeable membrane b/w
How is vascular access typically achieved for haemodialysis?
Arteriovenous Fistula
- wrist/cubital fossa
- can also use double lumen venous lines
How often must haemodialysis occur?
4hrs, 3x/wk, normally in hospital
What is the main issue in haemodialysis?
Haemodynamic instability during dialysis
What is haemofiltration?
Variant of haemodialysis where blood is continuously filtered across highly permeable membrane
- more efficient
- more haemodynamically stable
- more expensive
How is peritoneal dialysis performed?
2l of isotonic/hypertonic solution inserted into peritoneal cavity
-equilibrates w/ blood in peritoneal capillaries through peritoneal membrane
How often must peritoneal dialysis occur?
3-4x/daily
Fluid drained after 4-6hrs
-can be performed at night (automated peritoneal dialysis)
What is the main risk of peritoneal dialysis?
Peritonitis
What are the complications of dialysis?
Mortality 20% Infection CVD Renal bone disease/anaemia Bleeding Renal malignancies
What factors must be measured in a patient assessment pre-transplantation?
Virology/TB status (active infection = contraindication)
Blood group/HLA monitoring
Full systemic examination (co-morbid disease = contraindication)
What are the potential complications of renal transplantation?
Operative complications
Rejection
Ciclosporin/tacrolimus toxicity (immunosuppressants)
Infection/malignancy (immunosupression)
What are the potential operative complications of renal transplantation?
Bleed
Thrombosis
Infection
Urinary leaks
Describe the risk of rejection in renal transplantation
Risk highest in 3mo
Lifelong immunosuppression
Episodes of rejection reversible
Immunological tolerance develops
What malignancies are most likely post renal transplant?
Skin cancer
Anal cancer
Lymphoma
What is the prognosis of a renal transplant?
Good
1yr graft survival rate 80-95%
What three ways can DM affect the kidney?
Direct glomerular damage
Ischaemia
Ascending infection
Describe direct glomerular damage caused by DM
Basement membrane thickening
- increased leakiness of capillary wall
- proteinuria
- glomerular hyalinisation –> CKD
How is polycystic kidney disease inherited?
AD or AR
-AD more common (1/800)
What is the long term consequence of PKD?
Both kidneys replaced by enlarging fluid filled cysts
How do ADPKD sufferers present?
Systemic HTN
CKD
Abdo swelling (bilateral, ballotable kidneys)
Renal failure (later in life)
Where else may cysts develop in ADPKD?
Liver
Lungs
Pancreas
How do ARPKD sufferers present?
Earlier onset
Chronic renal failure earlier in life
What is the potential effect of liver cysts in PKD?
Portal HTN
Fibrosis
What is the main condition associated w/ PKD?
Berry aneurysms –> SAH
How is PKD managed?
As CKD
Screen for berry aneurysms
What are the two forms of chronic interstitial nephritis?
Reflux associated
Obstructive
Describe reflux associated chronic interstitial nephritis
Incompetent vesicoureteric valves
-predisposition to inflammation/scarring
Presents in eraly adulthood w/ deteriorating renal funcn
Describe obstructive chronic interstitial nephritis?
Recurrent episodes of infection due to anatomical abnormality/stone
What are the histological hallmarks of chronic interstitial nephritis?
Irregular areas of scarring
Chronic inflammatory infiltrate
What drugs typically require dose reduction in the presence of a decreased eGFR?
Gentamicin Cephalosporins Heparin Lithium Opiates Digoxin
