Renal Flashcards
In CKD what replaces the normal glomeruli and tubules?
Fibrosis
What is the prevalence of CKD in adults?
3 to 7 percent
Which races are prone to CKD?
Blacks and Asians (2-3x)
What is the biggest cause of CKD in the UK?
Diabetes
What is the second biggest cause of CKD in the UK?
Glomerular nephritis
What is the third biggest cause of CKD?
Hypertension
What the common causes of CKD?
DM GN HTN Pyelonephritis Vascular disease
In which age group is CKD most common?
The elderly
Describe the natural history of CKD?
Hyperfiltration > microalbuminuria > macroalbuminura > nephrotic syndrome and proteinuria > CKD
What mode of inheritance is polycystic kidney disease?
Autosomal dominant
Explain the genetics behind polycystic kidney disease?
Single mutation of either one of two interacting genes
In polycystic kidney disease, is the patient predisposed to CKD?
Yes
What complications may arise in polycystic kidney disease?
Subarachnoid haemorrhage
Where are cysts found in polycystic kidney disease?
Liver
Kidneys
Ovaries
How is polycystic kidney disease diagnosed?
USS
How is polycystic kidney disease managed?
Treat hypertension
Deal with complications such as infected cysts
Tolvaptan slows progression
Transplant
When is a patient with polycystic kidneys likely to reach CKD stage 5?
Middle age
What other considerations, outside of treatment, must be made in CKD?
Screen family
Organise a pre emptive transplant
What is a normal GFR?
100ml/min
What can naturally influence GFR?
Age, sex, race and muscle mass
Which stages of CKD are normal and do not require treatment?
1 and 2
What is CKD stage 1?
eGFR
What is CKD stage 2?
eGFR 60-90 with a kidney problem
What is CKD stage 3?
eGFR 30-60
What is CKD stage 4?
eGFR 15-30
What is CKD stage 5?
eGFR less than 12
What is the most common reason for mortality in stages 3 and 4?
Another cause
What is the PCR?
The ratio of protein to creatine in the urine - divided by 100 gives the rough 24h urine protein
When is PCR inaccurate?
Extremes of muscle mass
Which value of PCR is significant?
over 100
What PCR will put you in the nephrotic range?
over 250
What stage of CKD needs urgent renal replacement therapy?
5
What are the primary targets in CKD treatment?
Reducing BP
Reducing proteinuria
In CKD which drugs are used to lower protein and adjust BP?
ACE-I e.g. ramipril
What factors must be considered when managing CKD?
BP Reducing proteinuria Diabetic control Cholesterol Prophylactic aspirin Healthy living
Why may anaemia be present in CKD?
Lack of EPO production
Why is calcium often high with osteoporosis in CKD?
Kidneys cannot activate vitamin D so PTH is elevated to release calcium from bones
Why else might PTH be high in CKD?
High phosphate as not lost in urine can cause PTH to rise
How is metabolic acidosis treated in CKD?
Bicarbonate tablets
What is a major side effect of bicarbonate tablets?
Raised BP
What stages of CKD should be referred onto nephrology?
4 and 5
Define an AKI?
Acute, usually reversible decline in kidney function
How is AKI defined?
Pre renal
Intrinsic renal
Post renal
What may cause pre renal AKI?
Hypovolaemia
Renal artery stenosis
What is the UK prevalence of AKI?
38000/year
What is the mortality rate of those with AKI?
15.2 percent
What is a stage 1 AKI?
Creatinine over 250mmol or 150-200 percent from baseline
What is a stage 2 AKI?
200-300 percent rise in creatinine from baseline
What is a stage 3 AKI?
Over 300 percent rise in creatinine from baseline or creatinine over 350mmol
OR
Creatinine over 45 on RRT
What is a stage 3 AKI if on RRT?
Creatinine over 45
Which artery enters the kidney?
Afferent renal artery
Which artery exits the kidney?
Efferent renal artery
What is the normal glomerular filtration pressure?
10mmHg
What factors normally maintain renal perfusion?
RAAS
Sympathetic nervous system
What may cause a pre renal AKI?
Loss of blood
Loss of plasma
Loss of salt and water
Which conditions can cause reduced kidney perfusion in the absence of hypovolemia?
Cardiac nephrotic syndrome (nephrotic syndrome with CCF)
3rd Spacing - loss of intravascular volume to other parts of the body
Which type of AKI can be seen on a urine dip?
intrinsic
What are the signs of pre renal AKI?
Not visible JVP due to volume depletion
Orthostatic hypotension
When would pre renal AKI have a raised JVP?
Cardiac nephrotic syndrome or in co existing CCF
What are the first line investigation in AKI?
Urine dip
Urine sodium
Blood test shows raised creatinine
How is pre renal AKI treated?
Volume replacement ( or improve cardiac function in CCF)
What treatments are contraindicated in pre renal AKI?
Catheter
Diuretics
Does GN normally present as an AKI?
No, usually CKD
Which syndrome may cause intrinsic AKI?
Nephrotic syndrome
What musculoskeletal signs are seen in intrinsic AKI?
Myalgia
Bone pain
Joint pain
Which signs are often seen on examination with intrinsic AKI?
Depleted fluid status
Rash
Uveitis
Hearing loss or neurodeficit
What is the gold standard test for intrinsic AKI?
Renal biopsy
Which drugs are most likely to cause intrinsic AKI?
Antibiotics
Which tests should be done in intrinsic AKI?
Urine culture and microscopy GN Screen PCR Electrophoresis Blood film Creatinine
Which diseases affect the kidney interstitium?
Tubular interstitial nephritis
Acute tubular necrosis
Which drugs can cause tubular interstitial nephritis?
NSAIDs and antibiotics
Which white blood cells are present in acute tubular necrosis?
Eosinophils
What is seen on microscopy with acute tubular necrosis?
Protein casts
What is a complication of acute tubular necrosis due to protein casts?
Cast nephropathy due to obstructive casts
Which form of AKI can lead to acute tubular necrosis?
Pre renal AKI
Which drug can cause direct acute tubular necrosis?
Gentamycin
Which condition can cause acute tubular necrosis?
Rhabdomyolysis
How is acute tubular necrosis managed?
Self resolving
If acute tubular necrosis does not resolve, what is the complication?
Cortical necrosis
How is interstitial nephritis treated?
Stop offending medication
Start steroids
What SHOULD NOT be done when treating intrinsic AKI?
Catheter
How is intrinsic AKI initially treated?
IV fluids and diuretics
How can obstruction be classified in post renal AKI?
Outside
Within lumen
Within wall
Which type of AKI presents with pain?
Post renal
Which urine symptoms may be present in post renal AKI?
Anuria
Haematuria
What may be present on examination with post renal AKI?
Palpable bladder due to retention
Which lab investigations must be done in post renal AKI?
Urine and bloods
What imaging must be done on post renal AKI?
USS and CT
What signs are seen on a CT with post renal AKI?
Mickey Mouse sign
Grossly dilated renal pelvis
What is the initial management of a post renal AKI?
Catheter
After a catheter, what is the next step in the management of a post renal AKI?
anterograde or retrograde drainage
What complication can lead to ECG in AKI?
Hyperkalemia
What are the complications of AKI?
Hyperkalemia
Metabolic acidosis
Pulmonary oedema
Is hyperkalemia a medical emergency?
Yes
How is hyperkalemia treated?
IV calcium
Insulin and dextrose
IV salbutamol
Dialysis
Why does pulmonary oedema occur in AKI?
Salt and water retention
How is pulmonary oedema treated?
High dose IV diuretics
Dialysis
Vasodilation
Venesection (maybe)
What is complication of AKI resolution?
Diuresis
When might diuresis occur after AKI?
After acute tubular necrosis or obstruction
How is diuresis monitored?
Blood pressure
Pulse
Assess fluid status using daily weights
How is diuresis treated?
IV fluids
What is the diagnostic criteria for nephrotic syndrome?
Proteinuria >3g/day
Hypoalbuminaemia
Which medications can cause nephrotic syndrome?
NSAIDs
Herbal medications
Which non specific symptoms may be seen in nephrotic syndrome?
Frothy urine
Low BP
Oedema
What would show on urine dip with nephrotic syndrome?
Protein (+/- blood)
When does PCR underestimate protein in the urine?
In muscular people
When does PCR overestimate protein in the urine?
In frail people with little muscle
What is PCR 15-30?
Trace
What is PCR 30-100?
1+
What is PCR 100-300?
2+
What does PCR 300-1000 indicate?
3+
What does PCR over 1000 indicate?
4+
When might PCR results be a false positive for nephrotic syndrome?
When albumin is not the greatest protein component in urine e.g. in multiple myeloma
Which fluid compartment expands with nephrotic syndrome?
Interstitial fluid
What complications can arise from oedema?
Pleural effusion
Ascites
Why does pulmonary oedema occur in nephrotic syndrome?
It leads to congestive cardiac failure
Why does oedema occur in nephrotic syndrome?
Primary sodium retention (overfill hypothesis)
Why does primary sodium retention occur in nephrotic syndrome?
Increase in the sodium/potassium pump activity
What can further increase water retention in oedema?
ANP
What is the underfill hypothesis?
Low serum albumin so low colloid oncotic pressure activates RAAS that causes salt and water retention
In which type of nephrotic syndrome is oedema due to the undersell hypothesis?
Sudden onset
What are the first line investigations in nephrotic syndrome?
Urine - PCR, microscopy, and dipstick
FBC, clotting, Us and Es +/- nephritic screen
USS KUB
What is the gold standard test to confirm nephrotic syndrome?
Renal biopsy
What conditions can cause nephrotic syndrome?
Minimal change disease
FSGS
Membranous nephropathy
Amyloidosis
In which group of patients with nephrotic syndrome, is a biopsy not recommended?
Young children
What is seen on light microscopy with minimal change disease?
Nothing
What is seen on electron microscopy with minimal change disease?
Fusion of podocytes
What is the main cause of minimal change disease?
Primary/idiopathic
What are secondary causes of minimal change disease?
Drugs
Cancer
Infection
Allergy
In which age group is minimal change disease most prevalent?
Children under 5
What affect does minimal change disease have on blood pressure?
Normal or low
What effect is there on renal function in minimal change disease?
None - unless in pre renal AKI
Is there microscopic haematuria in minimal change disease?
No - but possible in adults
What are the classifications of FSGS?
Primary idiopathic and secondary
How is secondary FSGS identified?
Histological lesion
In primary FSGS what symptoms are present?
Nephrotic syndrome
Microscopic haematuria
Hypertension
Renal impairment
What is the most common cause of secondary FSGS?
Hypertension
Is nephrotic syndrome present in secondary FSGS?
No
Which underlying conditions can cause secondary FSGS?
Hypertension
HIV
Obesity
Which drugs can cause secondary FSGS?
Heroin
Pamidronate
Which part of the glomerulus is affected in FSGS?
Segmental part
Why does sclerosis occur in FSGS?
Excess collagen deposition due to damage
When is membranous nephropathy the most common cause of nephrotic syndrome?
In non diabetic adults
What are the risk factors for membranous nephropathy?
Older
Male
White
What is seen on histology with minimal change disease?
Thickened capillary loops
Sub endothelial immunoglobulin deposition
Which medical conditions can cause secondary membranous nephropathy?
SLE
Malignancy
Infection
Sarcoidosis
Which drugs can cause membranous nephropathy?
Penicillamine
Gold
Anti TNF
Which infections can cause membranous nepthropathy?
Hepatitis B and C
HIV
Malaria
Syphillis
When can amyloidosis cause membranous nephropathy?
In minimal change disease
What is a major cause of membranous nephropathy in infants?
Congenital
What is the treatment for oedema?
Fluid restrict to less than 1l a day
Diuretics
What is the first line diuretic in oedema?
Loop diuretics e.g. furosemide
What is the second line diuretic in oedema?
Aldosterone antagonists e.g. spironolactone
Thiazide like diuretic metolazone
How does a thiazide diuretic work?
By inhibiting the sodium/chloride symporter
What the complications of oedema?
Infection
Thromboembolism
Renal impairment
Dyslipidaemia
Which age group is more prone to infection from oedema?
Children
Why does thromboembolism occur more often in oedema?
Decrease ATIII
What is the first line treatment to reduce proteinuria?
ACE-I
What is the second line treatment to reduce proteinuria?
ARBs (e.g. losartan)
How do ACE-I and ARBs reduce proteinuria?
Reduce intraglomerular pressure
How should dyslipidaemia be managed?
Statins
Which type of kidney condition takes longer to respond to steroids?
FSGS
How is idiopathic membranous nephropathy treated?
Steroids + beta calcinin inhibitor (e.g. cyclophosphamide and nitofinab)
What would GN show on a urine dip?
Blood +/- protein
What amount of protein is seen in the urine in early GN?
1 to 1.5g
What does GN show in urine microscopy?
Renal casts
What symptoms are present in aggressive GN?
AKI
Oedema
Hypertension
What is the first line investigation in GN?
Urine dip
What is the second line investigation in GN?
Urine microscopy and culture
How may rapidly processing GN appear?
Rapidly rising creatinine
What symptoms characterise nephritic syndrome?
Blood in the urine
Hypertension
Mild oedema
What on urine microscopy is trademark of GN?
Red cell casts
What are protein casts?
Tamm-Horsfall protein matrix formed in the tubles
Which conditions can cause immune mediated GN?
Small vessel vasculitis SLE Anti GBM disease (Goodpastures) IgA nephropathy Cryroglobinaemia
Which antibodies are present in small cell vasculitis?
ANCA
What can cause GN post infection?
Hep B Hep C HIV Post - strep Subacute bacterial endocarditis
Which malignancies cause GN?
Lymphoma
Multiple myeloma
What should be your top differential with blood on urine dip?
UTI (common things are common)
Explain the pathogenesis of GN?
Ig mediated > deposition of antibodies (IgA, GBM antibodies, immunocomplexes) > activation of complement > chemokine release > leukocyte recruitment > glomerular inflammation and crescent formation
Which chemotactic factor is involved in the pathogenesis of GN?
C5a
How is a crescent formed in GN?
Glomerular necrosis and extra cells infiltrating the urinary space
Which leukocytes are recruited in GN?
Neutrophils
Macrophages
Lymphocytes
What will be seen on Us and Es with GN?
Raised urea and creatinine
Reduced bicarbonate
What is the gold standard test to diagnose GN?
Renal biopsy
Why is a nephritic screen not done on every patient with suspected GN?
High cost
What on the nephritic screen is checked using immunofluorescence?
ANCA
What is the problem with immunofluorescence of ANCA?
Many false positives
What types of ANCA may be present?
Cytoplasmic (cANCA)
Perinuclear (pANCA)
Which types of ANCA are used finding ELISA purified antigens?
Proteinase 3 (cANCA) Myeloperoxidase (pANCA)
Which GN disease is linked to pANCA?
Microscopic polyangitis (small vessel vasculitis)
Which GN is linked to cANCA?
Wegeners
What can cause false positive ANCA results?
Endocarditis
What is the first line treatment for vasculitis?
High dose glucorticoids (pred or hydro)
Cytotoxic agents such as cyclophosphamide (steroid sparing)
Consider plasma exchange to remove ANCA antibodies
What is the second line treatment for vasculitis?
Rituximab
How does vasculitis typical present in GN?
Microscopic haematuria that may progress to AKI
Other than nephritic syndrome, how may ANCA associated vasculitis present?
Pulmonary renal syndrome
What are the signs and symptoms of pulmonary renal syndrome?
Haemoptysis due to pulmonary haemorrhage
Pulmonary nodules
GN
