Chronic Kidney Disease Flashcards
What is chronic kidney disease (CKD)?
CKD is deteriorating kidney function and progressive impairment of any underlying cause for >3months
What are the congenital and inherited causes of chronic kidney disease?
Polycystic kidney disease
Medullary cystic disease
Tuberous sclerosis
Congenital obstructive uropathy
What are the primary and secondary glomerular disease causes of chronic kidney disease?
Primary glomerulonephritides
=> inc focal glomerulosclerosis
Secondary glomerular disease => systemic lupus => polyangiitis => granulomatosis with polyangiitis => amyloidosis => diabetic glomerulosclerosis => thrombotic thrombocytopenia purpura => systemic sclerosis => sickle cell disease
What are the vascular causes of chronic kidney disease?
Hypertensive nephrosclerosis (black african)
Renovascular disease
Small and medium sized vessel vasculitis
What are the tubulointersitial causes of chronic kidney disease?
Tubulointersitial nephritis due to i.e. idiopathic, drugs, immunologically mediated
Reflux nephropathy
Tuberculosis
Schistosomiasis
Nephrocalcinosis
Multiple myeloma
Renal papillary necrosis i.e. diabetes, sickle cell disease + trait, analgesic nephropathy
Chinese herb neuropathy
What are the most common causes of chronic kidney disease in the UK?
Diabetes
Glomerulonephritis
High BP / renovascular disease
How is chronic kidney disease staged?
- pg 1393 kumar&clarks
- pg 302 ox handbook
Patients are staged according to
=> eGFR
=> Albuminuria
Both these parameters correlate with progressive renal impairment and cardiovascular risk
Who does CKD affect?
Ethnic variation
End-stage kidney disease is much higher in:
i. Black African => hypertensive nephropathy more common in this group
ii. Asians => diabetes nephropathy more common in this group
iii. Middle eastern => schistosomiasis causing urinary tract obstruction most common in this group
iv. Elderly => CKD caused by atherosclerotic renal vascular disease
* >70% of CKD due to diabetes, hypertension and atherosclerosis
Patients with chronic glomerular disease tend to deteriorate more quickly than those with chronic tubulointerstitial nephropathies.
What does the rate of decline to end-stage renal disease depend on in CKD?
Underlying nephropathy
Control on BP
What is the underlying pathology as a result of CKD?
I. Each kidney has ~million nephrons. In CKD, many nephrons have scarred and failed => increased burden of filtration on a small number of nephrons
II. The small number of functioning nephrons undergo hyperfiltration (increased blood flow as flow hasn’t changed)
=> these nephrons adapt via glomerular hypertrophy and reduced arteriolar resistance
III. Increased flow, pressure and stress => raised intraglomerular capillary pressure => accelerates remnant nephron failure
IV. Increased flow/strain may be detected by new or increasing proteinuria
What is the role of angiotensin II in CKD?
i. Ang II produced locally modulates intraglomerular capillary pressure and GFR
=> vasoconstriction of postglomerular arterioles + increasing the glomerular hydraulic pressure
ii. Ang II indirectly upregulates TGF-b (fibrogenic cytokine)
=> increases collagen synthesis
ii. Ang II indirectly upregulates plasminogen activator inhibitor-1
=> inhibits matrix proteolysis by plasmin
=> accumulation of excessive matrix
=> scarring in glomeruli and interstitium
What does the prognosis of CKD depend on?
Reduced GFR and albuminuria independently assoc. with high risk of:
i. all cause mortality
ii. CVS mortality
iii. progressive kidney disease & kidney failure
iv. AKI
What do you need to ask the patient if suspecting CKD?
Previous UTI, lower urinary tract symptoms
PMHx of hypertension, diabetes, ischaemic heart disease, systemic disorder, renal colic
Drug Hx
Family Hx inc. renal disease and subarachnoid haemorrhage
System review i.e. rare causes
Current state: symptomatic CKD if GFR <30
i. symptoms of fluid overload i.e. peripheral oedema, shortness of breath
ii. anorexia
iii. nausea & vomiting
iv. restless legs
v. fatigue & weakness
vi. pruiritis
vii. bone pain
viii. amenorrhoea
ix. impotence
What peripheral signs might you notice on examination suggestive of CKD?
Periphery:
i. Peripheral oedema
ii. Signs of peripheral vascular disease or neuropathy
iii. Vasculitis rash
iv. Gout tophi
v. Joint disease
vi. Arteriovenous fistula
vii. Signs of immunosuppression i.e. bruising from steroids
viii. Uraemic flat / encephalopathy GFR <15
What facial signs might you notice on examination suggestive of CKD?
Face:
i. Anaemia
ii. Xanthelasma
iii. Yellow tinge (uraemia)
iv. Jaundice (hepatorenal)
v. Gum hypertrophy (ciclosporin)
vi. Cushingoid (steroids)
vii. Periorbital oedema (nephrotic syndrom)
viii. Taut skin/telangiectasia (scleroderma)
ix. Facial lipidystrophy (glomerulonephritis)
What neck signs might you notice on examination suggestive of CKD?
Neck:
i. JVP for fluid state
ii. scar from parathyroidectomy or lymphadenopathy
What cardiovascular signs might you notice on examination suggestive of CKD?
CVS:
i. BP
ii. Sternotomy
iii. Cardiomegaly
iv. Stigmata of endocarditis
* if right sided heart failure or tricuspid regurgitation, JVP doesn’t reflect fluid state
What respiratory signs might you notice on examination suggestive of CKD?
Pulmonary oedema or effusion
What abdomen signs might you notice on examination suggestive of CKD?
Abdomen:
i. Peritoneal dialysis catheter or scars from previous ones
ii. Signs of previous transplant
iii. Ballotable polycystic kidneys ± palpable liver
What general investigations are carried out for in CKD?
Bloods : => U&E (compare with previous) => Hb (normochromic, normocytic anaemia) => Glucose => Decreased Calcium ; increased phosphate & PTH (renal osteodystrophy)
=> Direct investigations of renal disease: ANA, ANCA, anti-phospholipid antibodies, paraprotein complement, cryoglobulin, anti-GBM (glomerular basement membrane)
Urine:
=> Dipstick (microscopy, culture and sensitivity),
=> Albumin/protein : creatinine ratio,
=> Bence jones
Ultrasound imaging
Histology
What imaging is carried out in CKD?
Ultrasound for size, symmetry, anatomy, corticomedullary differentiation and to exclude obstruction
=> In CKD kidneys may be small except in diabetes, infiltrative disorders (amyloid, myeloma), adult polycystic kidney disease
=> If asymmetrical, consider renovascular disease
=> Scarring may be seen on ultrasound but isotope scans more sensitive