Renal Flashcards
Describe polycystic kidney disease.
Autosomal dominant
Unilateral or bilateral renal mass(es)
~10% have asymptomatic intracranial aneurysm (therefore screen patients with FHx and ask about subarachnoid haemorrhage symptoms)
What is hepatorenal syndrome?
Rapid deterioration in kidney function in individuals with cirrhosis or fulminant liver failure i.e. kidney failure following liver failure due to reduced perfusion
What are the differentials for unilateral renal masses?
PRIMARY:
- cancer (paeds = Wilm’s tumour)
- haematoma
- renal abscess (liquefactive necrosis in setting of acute pyelonephritis)
- xanthogranulomatosis
- pyelonephritis
- hydronephrosis
- renal cyst
- PCKD (usually bilateral)
What are the differentials for bilateral renal masses?
- renal metastases
- lymphoproliferative disease
- renal infarcts
- primary cancer
- renal abscesses
- leukaemia
- adult PCKD
- hydronephrosis
What are the investigations in hepatorenal syndrome?
BEDSIDE:
- urine dip. = ?infection, proteinuria, ACR
- mental status
BLOODS:
- FBC = ?infection, ?anaemia, ?spontaneous bacterial peritonitis, bilirubin, albumin, clotting, hep. B & C, antibodies
- LFTs = monitoring
- U&Es = monitoring
- clotting
- complement
- alpha-fetoprotein = ?hepatocellular carcinoma
IMAGING:
- liver US
FUNCTIONAL:
- ascitic drain and tap = transudative or exudative
- OGD = ?varices
What is acute kidney injury?
Decrease in renal function which occurs over weeks or months
What are some of the pre-renal causes of acute kidney injury?
Systemic:
- shock
- dehydration
- burns
- crush injury
Local:
- thrombus
- atheroma
- stenosis
- trauma
What are some of the intrinsic causes of acute kidney injury?
Acute tubular necrosis/septic/toxic renal failure (severe acute ischaemia, nephrotoxins)
Interstitial disease (NSAIDs, aminoglycosides, ACE inhibitors, infection)
Glomerular disease:
PRIMARY: IgA nephropathy, minimal change glomerulonephritis, membranous glomerulonephritis, post-infectious glomerulonephritis, focal segmental glomerulosclerosis
SYSTEMIC: vasculitides, SLE, Goodpasture’s, RA, IBD, drugs, neoplastic
Give some examples of small vessel vasculitides.
Behcet's Henoch-Schonlein purpura Microscopic polyangitis Granulomatosis with polyangitis Cryglobulinaemia
Give some examples of medium vessel vasculitides.
Buerger’s disease
Cutaneous vasculitis
Kawasaki disease
Polyarteritis nodosa
Give some examples of large vessel vasculitides.
Polymyalgia rheumatica
Takayasu’s arteritis
Temporal arteritis
What is the management of renal calculi?
US: ?hydronephrosis due to obstruction –> nephrostomy
?CT: ?hydropnephosis, location of calculus
Outline the staging of chronic kidney disease.
Stage GFR
1. >90 Kidney damage with normal or increased GFR
2. 60-89 Kidney damage with mild decrease in GFR
3A. 45-59 Mild/moderate fall in GFR (but asymptomatic)
3B. 30-44 Moderate fall in GFR and symptomatic
4. 15-29 Severe fall in GFR
5. <15 or on RRT Established renal failure
Use suffix p to denote presence of proteinuria
Stage 1 and 2 need other evidence of kidney damage e.g. urinalysis, USS
How is chronic kidney disease staged according to albumin:creatinine?
Stage ACR
A1. <3 Normal
A2. 3-30 Moderate increase
A3. >30 Severely increased
note: albumin makes up 70% of total protein in urine, creatinine is a measure of proteinuria
Outline the screening criteria for CKD.
- diabetes
- hypertension
- CVD: IHD, chronic heart failure, PVD, cerebral vascular disease
- structural renal tract disease
- renal calculi
- prostatic hypertrophy
- multisystem disease with potential for renal involvement e.g. SLE
- FHx of stage 5 CKD or hereditary kidney disease
- opportunistic detection of haematuria or proteinuria
What are the factors in calculating eGFR?
Serum creatinine
Age
?female
?Black
Define chronic kidney failure.
Progressive and irreversible loss of renal function over a period of months or years
Renal tissue replaced by extracellular matrix in response to tissue damage
How can the risk of CKD be reduced?
- patient education
- relevant medications: ACE inhibitors/Angiotensin II blockers indicated in diabetes when ACR>3 or established CKD with hypertension and ACR>30
- lifestyle advice
- treat hypertension: threshold for treatment is 140/90, target BP is 120-139/<90 (if ACR>70 then target BP is 120-129/<80)
- assess CVD risk: treat hyperlipidaemia, aspirin if indicated
- influenza/pneumococcal vaccination
What are the risk factors for renal replacement therapy?
Diabetes - 25% (~5% incidence in total UK population)
21% unknown
12% glomerulonephritis
7% chronic pyelonephritis
7% hypertension
7% adult polycystic kidney disease
6% renovascular
Outline the factors of pre-dialysis planning.
Dialysis: home or unit (QoL, survival time)
Access:
- AV fistula = creates large vein which can have a wide bore cannula inserted
- AV graft
- (un)tunnelled cuffed catheter
- implantable titanium port
What are the advantages of dialysis?
- large evidence base, long-term survivors
- dose can be varied or individualised
- available
- may be done at home/overnight
- daily treatment possible
- can have up to 4 days off from treatment
What are the disadvantages of dialysis?
- 30% experience intra- and post-dialysis symptoms
- intermittent treatment leads to large shifts in fluid balance and biochemical changes
- diet may be sodium/potassium/phosphate/protein/water restricted
- patient may require transport to haemodialysis centres
- vascular access may be difficult/limiting
What are some of the complications of dialysis?
- CVD: effects on LV, haemodynamic instability, vascular/valvular calcification
- sepsis: catheter-related blood infection (1-2/1000 days)
- degenerative: dialysis-related amyloidosis (gradual accumulation of beta-2 microglobulin in blood, as it cannot cross filter)
What are the contraindications of peritoneal dialysis?
ABSOLUTE:
- GI/urinary stoma
- known peritoneal sclerosis
- diaphragmatic fluid leak
RELATIVE:
- hernia
- severe back pain
- nephrotic syndrome
- lack of manual dexterity
- severe organomegaly
- multiple operations
- severe respiratory disease
- ascites
- morbid obesity
- body image
- cognitive problems
- unsuitable home environment
What are the advantages of peritoneal dialysis?
- easy to learn with visual/manual disability
- independence (home-based therapy)
- mobility (patient can travel more easily)
- continuous therapy allows more gentle control of uraemia/fluid balance
What are the disadvantages of peritoneal dialysis?
- limited technique survival (50% at 3yrs)
- infections may be life-threatening
- weight gain and metabolic problems (glucose in dialysate)
- daily therapy time-consuming
- long-term rise of sclerosing peritonitis
What are the complications of peritoneal dialysis?
Peritonitis (1/18-24months)
Fluid leaks
Encapsulating peritoneal sclerosis
What are the causes of treatment failure in peritoneal dialysis?
40%-47% peritonitis
15%-19% loss of peritoneal function
9%-15% catheter malfunction
4%-15% patient preference
<2% malnutrition
When is renal transplantation offered?
All patients with progressive renal impairment/end-stage renal failure
25% of patients on haemodialysis on list
What are the contraindications for renal transplant?
Extensive PVD
Mental incapacity
Active viral hepatitis
AIDS with opportunistic infections
Cancer
Active infection
Uncontrolled IHD
What are some of the medications given to renal transplant recipients?
Steroids Azathioprine Cyclosporin A/tacrolimus Rapamycin Mycophenolate mofetil Antibodies
What are the advantages of renal transplant?
- freedom from dialysis
- can restore normal renal function
- cheap
What are the disadvantages of renal transplant?
Requires lifelong immunosuppresive drugs Operative morbidity/mortality Not suitable for all Limited supply of organs Still left with progressive CKD
What are the complications of renal transplant?
SURGICAL:
- ureteric obstruction
- lymphocoele
- urine leaks
- graft thrombosis
- renal artery stenosis
- wound infection
- bleeding
NON-SURGICAL:
- rejection
- drug nephrotoxicity
- reoccurence of primary renal disease
LONG-TERM:
- diabetes
- chronic rejection
- malignancy
- infection
What are the sources for donor kidneys?
Cadavers (donation after brain death)
Non-heart beating donor (donation after cardiac death)
Living related donor
Living emotionally related donor
Living unrelated donor
Outline withdrawal of dialysis.
2nd commonest cause of death (~15%)
Predictors: age, diabetes, White, co-morbidities, poor QoL
What are some of the causes of chronic renal failure?
- hypertension
- vascular
- diabetes
- autoimmune: glomerulonephritis, SLE
- myeloma, neoplasms
- infection: pyelonephritis
- genetic: Alport’s, PCKD
- idiopathic
- obstruction/reflux
- hypercalcaemia
What are the investigations indicated in chronic renal failure?
Bloods:
- autoantibody screen
- complement
- Ig
- CRP
Imaging:
- US: size, ?hydronephrosis
- CT
- MRI
- MR renal angiography
Renal biopsy: if kidneys are normal size and cause of CKD is not obvious
What are some of the complications of chronic renal failure?
- anaemia: reduced EPO production, resistance to EPO, reduced RBC survival, blood loss, LV hypertrophy
- renal osteodystrophy: osteitis fibrosa cystica, vascular calcificatiom, periarticular calcification, (sub)cutaneous calcification
- secondary hyperparathyroidism: bone pain, fractures, hypocalcaemia, hyperphosphataemia
- coagulopathy
- hypertension: LV hypertrophy, heart failure, stroke, CVD
- neurological: uraemic encephalopathy, peripheral neuropathy, restless legs syndrome, sleep disorders, cognitive impairment
- dialysis-related amyloidoses: bone pain, arthropathy, carpal tumnel syndrome
- fluid overload: pulmonary oedema, hypertension
- malnutrition: infections, poor wound healing
- glucose intolerance
Outline the management of complications of chronic renal failure.
- treat underlying disease: diabetes, hypertension
- modulation of maladaptive response: antihypertensives, protein restriction
- fluid balance: restriction of fluid intake in oliguria, diuretics in severe volume overload, dietary restriction of sodium and protein
- hyperkalaemia: dialysis, restrict potassium intake, prevent GI haemorrhage, acidosis or tissue necrosis
- chronic metabolic acidosis: oral HCO3- supplements
- malnutrition: folic acid and vitamin B supplements, ?NG tube feeding
- coagulopathy: oral antiplatelets/anticoagulants
- bone: bisphosphonates if GFR>30, vitamin D supplements, dietary phosphate restriction or phosphate binders
What are the characteristics of glomerulopathies?
Primarily immunologically mediated injury to glomeruli, although renal interstitial damage is a regular accompaniment
Kidneys are involve symmetrically
Secondary mechanisms of glomerular injury result following an initial immune insult such as fibrin deposition, platelet aggregation, neutrophil infiltration, and free radical-induced damage
Renal lesions may be part of a generalised disease e.g. SLE
What are the signs and symptoms of nephrotic syndrome?
- massive proteinuria (>3.5g/day)
- hypoalbuminaemia
- oedema: peri-orbital, face, arms
- lipiduria
- hyperlipidaemia
- frothy urine
- ascites
- normal JVP
What are the causes of nephrotic syndrome?
All types of glomerulonephritis
Systemic vasculitides
Amyloidoses
Drugs
Allergies
What are the general and diagnostic investigations in nephrotic syndrome?
GENERAL
- 24hr urine protein >3-5g/day
- serum albumin >30g/l
- serum urea and creatinine
- creatinine clearance
- CXR for ?pulmonary oedema
DIAGNOSTIC
- throat swab
- antistreptolysin O titre
- ANCA
- anti-GBM antibody
- cryoglobulins
- renal biopsy (contraindicated in young children with selective protein leak, long-standing diabetes, or drug-induced disease)
What is the general and specific management of nephrotic syndrome?
GENERAL
- sodium restriction
- thiazide diuretics
- ACE inhibitor
SPECIFIC e.g. minimal change glomerulonephritis –> high dose steroids and cyclophosphamide
What are the complications of nephrotic syndrome?
- DVT (req. long-term prophylactic anticoagulation)
- sepsis (give pneumococcal vaccines)
- oliguric renal failure
- lipid abnormalities
What are the primary and secondary types of nephrotic syndrome?
PRIMARY Bland urine sediments - minimal change nephropathy - focal segmental glomerulosclerosis - membranous glomerulopathy
Active urine sediments
- membranoproliferative glomerulonephritis
- IgM nephropathy
SECONDARY
Bland urine sediments
- amyloidosis
- diabetic nephropathy
Active urine sediments
- lupus glomerulonephritis
- cryoglobulinaemic renal disease
- Henoch-Schönlein purpura
What are the features of minimal change nephropathy?
Electron microscopy = fusion of podocytes (non-specific; seen in other conditions associated with proteinuria)
- most common in children
- does not lead to CKD
- high dose corticosteroids indicated
What are the features of focal segmental glomerulosclerosis?
Massive proteinuria, haematuria, hypertension, and renal impairment
Circulating permeability factor increases membrane permeability in isolated glomeruli
Segmental glomerulosclerosis seen –> global sclerosis
Focal tubular atrophy and interstitial fibrosis also present
Rx = prednisolone, ciclosporin, cyclophosphamide, azathioprine, etc.
What are the features of membranous glomerulopathy?
Asymptomatic proteinuria or frank nephrotic syndrome
May also have microscopic haematuria/hypertension/renal impairment
~40% develop CKD
75% primary (idiopathic), secondary (drugs, autoimmune, infection, neoplasia)
Immunofluorescence = uniform granular capillary wall deposits of IgG and complement C3 –> deposits encircled by basement membrane on silver staining (“spiky” appearance) –> uniform thickening of capillary basement membrane on light microscopy
Rx = cyclophosphamide, ciclosporin, rituximab, mycophenolate
What are the features of amyloidosis?
Eosinophilic deposits (insoluble protein fibrils)
Light chains (AL amyloid) or secondary amyloid A (AA)
Renal biopsy required
Rx = reduce treatment of amyloidogenic protein, treat underlying inflammation
What are the features of diabetic nephropathy?
Initial enlargement of kidneys –> glomerular hyperfiltration
Early histological changes: glomerular basement membrane thickening and mesangial expansion, progressive depletion of podocytes (due to apoptosis or detachment and resulting podocyturia)
Later changes: nodular glomerulosclerosis
Rx = lifestyle, ACE inhibitors/Angiotensin II blockers
What are the features if membranoproliferative glomerulonephritis?
Mesangial cell proliferation
Most develop end-stage kidney disease eventually
No treatment required when idiopathic and normal renal function
Rx = prednisolone trial (children), aspirin or dipyramidamole (adults)
What are the features of IgM nephropathy?
Increased mesangial cellularity of glomeruli with associated granular immune deposits (IgM and complement) in mesangial regions
Rx = cyclophosphamide, prednisolone
What are the features of lupus glomerulonephritis?
Overt renal disease occurs in 1/3 of SLE patients, of these 25% reach end-stage CKD within 10yrs
Autoantigen driven, T-cell dependent, B-cell mediated autoimmune disorder
What are the features of cryoglobulinaemic renal disease?
Cryoglobulins are Igs and complement that precipitate reversibly in the cold.
What are the features of Henoch-Schönlein purpura?
Characteristic skin rash, abdominal colic, joint pain, glomerulonephritis
Focal segmental proliferative glomerulonephritis
Mainly IgA deposits
Steroids ineffective
What are the signs and symptoms of acute nephritic syndrome?
- haematuria
- proteinuria
- hypertension
- oedema
- oliguria
- uraemia
What are the causes of acute nephritic syndrome?
Streptococcal throat infection
Otitis media
Systemic vasculitis
Cryoglobulinaemia
What are the complications of acute nephritic syndrome?
Hypertensive encephalopathy
Pulmonary oedema
Severe uraemia
What are the general and diagnostic investigations in acute nephritic syndrome?
GENERAL
- urine microscopy (red cell casts)
- serum urea and creatinine
- creatinine clearance
- 24hr urine protein
- C3 and C4
- CXR for ?pulmonary oedema
- renal imaging (usually normal)
DIAGNOSTIC
- throat swab
- antistreptolysin O titre
- ANCA
- anti-GBM antibody
- cryoglobulins
What is the management of acute nephritic syndrome?
- daily weight checks
- fluid balance chart
- antihypertensives
- BP monitoring
- sodium restriction
- fluid restriction
- dialysis if required
- Abx for post-streptococcal infections
What are some of the acute nephritic syndromes?
Post-streptococcal glomerulonephritis Non-streptococcal post-infectious glomerulonephritis Infective endocarditis Shunt nephritis SLE Henoch-Schönlein purpura Cryoglobulinaemia
What are the features of post-streptococcal glomerulonephritis?
Patient (usually a child) suffers streptococcal infection 1-3wks previously
Renal biopsy: diffuse, acute, florid inflammation in the glomerulus with neutrophils and IgG deposition
Small no. develop CKD in later life
Give some examples of causes of non-streptococcal post-infectious glomerulonephritis.
Staph Pneumococcus Legionella Syphilis Mumps Varicella Hepatitis B and C Echovirus Epstein-Barr virus Toxoplasmosis Malaria Schistosomiasis
What are some of the different types of rapidly progressive glomerulonephritis?
Goodpasture’s syndrome
ANCA-positive vasculitides
What are the features of Goodpasture’s syndrome?
IgG and C3 deposits with extensive crescent formation
Associated with pulmonary haemorrhages
Rx = plasma exchange (remove circulating antibodies), steroids, cyclophosphamide
What are the features of ANCA-positive vasculitides?
Includes polyangitis granulomatosis, microscopic polyangitis, Churg-Strauss syndrome
Features focal necrotising lesions of organs e.g. pulmonary haemorrhage, crescenteric glomerulonephritis, purpuric/vasculitis rash
Rx = corticosteroids, cyclophosphamide
What are the causes of asymptomatic haematuria/proteinuria?
IgA nephropathy
Alport’s syndrome
What are the features of IgA nephropathy?
Commonest form of glomerulonephritis
Focal segmental proliferative glomerulonephritis with mesangial deposits of IgA
Common in children
Asymptomatic microscopic haematuria OR recurrent haematuria, sometimes following upper resp. tract/GI infection
Can go on to develop end-stage kidney disease
What are the features of Alport’s syndrome?
Hereditary nephritis with haematuria, proteinuria (<1-2g/day), progressive kidney disease, and high frequency nerve deafness
15% have ocular abnormalities
85% have X-linked mutation
Glomerular sclerosis
Causes 5% of end-stage kidney disease in children
