MM renal tutorial Flashcards
What is AKI
Decreased renal function
How is AKI measured?
Serum creatinine or urine output
How can you differentiate AKI from chronic kidney disease?
It occurs over days or hours
How many stages of AKI are there?
3
How should you measure creatinine?
Compare it to a patients baseline- younger patients will have different levels to older
What will AKI progress to?
Chronic kidney disease
What are the causes of AKI?
Pre renal
Renal
Post renal
What are pre renal causes of AKI? Why do they cause AKI?
All of them cause hypoperfusion of the kidneys:
Hypovolemia
Renal artery stenosis
Hypotension eg sepsis, heart failure, NSAIDs
What are post renal causes of AKI?
They can be internal eg renal calculi, urethral, stricture or external eg pelvic, malignancy and BPTT
What are renal causes of AKI?
Glomerular= glomerulonephritis, haemalytic, uraemic syndrom
Vascular= vasculitis
Tubular= acute tubular necrosis, multiple myeloma
Interstitial disease= acute interstitial nephritis
What is the most common cause of renal AKI?
Acute tubular necrosis
What is acute tubular necrosis?
Death of the epithelial cells that line the tubules in the kidney
How does AKI present?
Different symptoms depending on the cause but they may have symptoms of: Malaise Anorexia Vomiting Pruritis Drowsiness Oligouria Coma
What should you always ask if you suspect AKI?
Ask about medication (have they been started on any nephrotoxic drugs recently?)
Have they had any recent burns or surgery (can cause hypovolemia)
What is the usual cause of hypervolemia?
Iatrogenic
What are the complications of AKI and how do you remember them?
Remember them by thinking about the function of the kidneys and what would go wrong if these functions weren’t carried out. Use the pneumonic A WET BED:
A- maintaining ACID balance (if this isn’t done there will accumulation of acid)
W- maintaining WATER balance (if this isn’t done there is usually hypovolemia but can be hypervolemia too)
E- maintaining ELECTROLYTE balance (if this isn’t done you get hyperkalemia and high phosphates)
T- toxin removal (if this isn’t done you get uremia)
B- maintain BLOOD pressure (if this isn’t done you get hypertension because the kidney secretes renin)
What are complications of AKI?
Excess acid Hyper or hypovolemia Hyperkalemia High phosphates Uraemia
Progression to CKD
What investigations should you do if you suspect AKI?
Bloods= U+Es, LFTs, FBC (if you suspect an autoimmune cause you could test for those specific antibodies too)
Urinalysis
ECG
CXR
USS (if you think AKI is obstructive/ unsure of the cause)
Renal biopsy
How will hyperkalemia show up on an ECG
?
High T waves
How do you treat AKI?
Depending on the cause
How do you treat AKI that has arisen from nephrotoxic drugs?
Stop the drug treatment
How do you treat pre renal AKI?
Manage volume depletion
How do you treat renal AKI?
Refer to a specialist, likely do a renal biopsy
How do you treat post renal AKI?
Catheter, urological intervention
What should you monitor when treating someone with AKI?
Urea and electrolytes ABG Potassium levels Blood pressure Urea levels
What happens if you can’t control hyperkalemia or pulmonary oedema in an AKI pateint?
Use renal replacement therapy
What is given to treat hyperkalemia in AKI?
Calcium
IV dextrose and insulin
Salbutamol
Why is calcium given to treat hyperkalemia in AKI?
To prevent risk of cardiac arrythmia
Why is IV dextrose and insulin given to treat hyperkalemia in AKI?
To drive potassium into cells
Why is salbutamol given to treat hyperkalemia in AKI?
To increase the effects of the IV potassium and insulin
How would a metabolic acidosis from AKI be treated?
IV sodium bicarbonate
How is pulmonary oedema treated?
Oxygen
IV diamorphine
IV GTN
Frusemide
Why is IV diamorphine given to treat pulmonary oedema in AKI?
It relieves anxiety and breathlessness
What is the main investigation for chronic kidney disease?
Serum electrolytes, urea and creatinine
What is CKD?
Kidney damage (manifesting as proteinuria or hematuria) GFR <60 mL/min For 3 months (longer than AKI)
How many stages are there of CKD and how are they catagorised?
5
they are based on GFR
What is stage 1 of CKD?
Kidney damage with normal GFR
What are causes of CKD?
Glomerular= glomerulonephritis, diabetes, SLE
Vascular= hypertension, heart failure
Tubular/interstitial= interstitial nephritis, pyelonephritis, medication
Obstruction= kidney stones, BPH, multiple myeloma
Medication use= NSAIDs
Congenital= PCKD, alport syndrome
What are the 2 biggest causes of CKD?
Diabetes
Hypertension
How does CKD present?
It is cause specific, general symptoms of renal deterioration:
Pruritis Nausea and vomitting Anorexia Oedema Polyuria/ oligouria Shortness of breath (due to fluid) Bruising
What investigations should you do if you suspect CKD?
Bloods (creatinine is used to estimate GFR, check glucose to check for underlying diabetes, FBC, LFTs, calcium and phosphate)
Urinalysis (hematuria/proteinuria/ tubular cells)
CXR (to check for fluid overload)
Renal biopsy
Renal ultrasound is not usually done but can be
What is are the best initial investigations for renal patients?
Serum electrolytes, urea, creatinine (you want to check their GFR and this is the way to do it)
What is glomerulonephritis?
The inflammation of the glomeruli
What does glomerulonephritis lead to?
Nephritic or nephrotic syndrome
What are the 2 main symptoms of glomerulonephritis?
Haematuria
Proteinuria
What is the main symptom of nephritic syndrome?
Haematuria
How might patients describe haematuria?
Coca-cola coloured urine/ dark urine/ brown urine
What is the main symptom of nephrotic syndrome? Whats a good way to remember it?
Proteinuria
Remember nephrOtic syndrome= prOteinuria whereas as nephritic is more haematuria
Is oedema more associated with nephrotic or nephritic syndrome?
Nephrotic
What are the symptoms of nephritic syndrome?
Haematuria
Oligouria
Hypertension
Oedema
What are the symptoms of nephrotic syndrome?
Proteinuria (severe, PCR> 300mg/mol) Hypoalbuminaemia Oedema Hyperlipidaemia Intravascular volume depletion
What symptom of glomerulonephritis is IgA nephropathy more associated with?
Haematuria
What renal conditions cause haematuria?
IgA nephropathy Post-strep glomerulonephritis Small vessel vasculitis Anti-GBM disease SLE
What renal conditions cause proteinuria?
Minimal change nephropathy FSGS Membranous nephropathy Amyloid Diabetic nephropathy SLE
What will urine casts look like in nephrotic vs nephritic syndrome?
Nephritic= RBC casts and cola/smoky urine Nephrotic= fatty casts
What will proteinuria levels be like in nephrotic vs nephritic syndrome?
Nephrotic= higher (>3.5g/day) Nephritic= lower (<3.5g/day)
Why do you get fatty casts in nephritic syndrome?
Due to hyperlipidaemia
How does haematuria vary between nephritic vs nephrotic syndrome?
Nephrotic= may or may not be present Nephritic= will be present
How do clinical features vary between nephrotic and nephritic syndrome?
Nephrotic= generalised oedema (periorbital) and hypertension Nephritic= less oedema more hypertension
What are the main signs of nephritic syndrome?
Haematuria (coca cola coloured urine) Proteinuria Oligouria Uraemia Hypertension Oedema RBC casts in urine Sterile pyuria (pus in urine)
What are the 4 main causes of nephritic syndrome? Which is most common?
IgA nephropathy= most common
Post strep glomerulonephritis
Rapidly progressive glomerulonephritis
Alport syndrome
What is post step glomerulonephritis associated with?
Infection, usually a child, presents weeks after infection
How will someone with nephritic syndrome from IgA nephropathy present?
1-2 days after an upper resp tract infection with high IgA
Also maybe with Hencoh purpura (affects older children more, they’ll have a rash, arthritis etc)
What is rapidly progressive glomerulonephritis associated with?
Vasculitis
Lupus nephritis
Goodpastures/ anti GBM disease
What antibody will be found in someone with vasculitis?
pNCA
What is anti GBM disease also known as?
Goodpastures
What antibody is found in goodpastures disease?
anti GBM
What will you see in a patient with goodpastures that is key to look for in exam qs?
Pulmonary haemorrhage
What part of the body will goodpastures affect asides from the kidneys?
Lungs
How does one get goodpastures disease?
Genetic
What will be the cause of nephritic syndrome if someone has an infection a few days ago vs a few weeks ago?
A few days ago= IgA nephropathy
A few weeks ago= post strep glomerulonephritis
What are the 5 causes of nephrotic syndrome?
Minimal change disease Focal segmental glomerulosclerosis Membranous nephropathy Amyloidosis Diabetic glomerulonephropathy
What is the pathophysiology of minimal change disease? What major effect does it have?
T cell/cytokine mediated GBM damage, it results in protein easily slipping through the GBM
Who is likely to present with nephrotic syndrome caused by minimal change disease?
Children/ young people
How long does it take to present with nephrotic syndrome caused by minimal change disease?
A long time- it takes a while to progress
What does nephrotic syndrome caused by minimal change disease respond to?
Steroids
What is nephrotic syndrome caused by focal segmental glomerulosclerosis associated with?
HIV +ve patients
What is nephrotic syndrome caused by membranous nephropathy associated with?
Malignancy
Who is likely to present with nephrotic syndrome caused by membranous nephropathy?
An adult with a malignancy
What antigen is membranous nephropathy associated with?
PLAR2
How is nephrotic syndrome caused by amyloidosis diagnosed? What will you see when you investigate?
Diagnosed by rectal biopsy
Congo staining will show apple green birefrigence
What is the most common cause of nephrotic syndrome?
Diabetic nephropathy
How is nephrotic syndrome caused by diabetic nephropathy diagnosed? What will you see when you investigate?
Ultrasound KUB
Will show large kidneys
How is nephrotic syndrome caused by diabetic nephropathy treated?
Ace inhibitors
What is Alport syndrome?
A genetic condition that leads to nephritic syndrome
Who will commonly present with Alport syndrome? How?
A child, they present with kidney damage and will also have sensorineural hearing loss
Why may someone with nephritic syndrome present with polyphonic wheeze as a sign?
They may have oedema in the lungs
How does one get polycystic kidney disease?
Inherited- autosomal recessive PKD1 gene on chromosome 16
What is polycycstic kidney disease?
Multiple cysts with renal parenchyma
What are symptoms of polycystic kidney disease?
Abdominal or loin pain
Symptoms of chronic renal failure (nausea and vomiting, oedema, pruritis)
Heart murmur
What heart murmur is observed in polycystic kidney disease? What does it sound like?
Mitral valve prolapse, its a mid systolic click
What murmur is a mid systolic click?
Mitral prolapse
Mid systolic= left side of heart
click= valve prolapsing
How might someone suddenly die of polycystic kidney disease? Why?
Via subarachnoid haemorrhage
Small berry aneurysms form in the brain which are at risk of bursting
What should you always ask about if you suspect polycystic kidney disease and why?
Family history, its genetic so if someone in their family suddenly died of a subarachnoid haemorrhage it makes it likely they might have PCKD
What investigations should you do if you suspect PCKD?
Blood pressure Urine dip U+Es Abdo US CT head ECG
What is the gold standard investigation for PCKD?
Abdominal ultrasound
What will you expect to see on U+Es in someone with PCKD?
High creatinine and urea
What is renal artery stenosis?
Narrowing of the renal arteries resulting in hypoperfusion
What effect would renal artery stenosis have on blood pressure and why?
Stimulates the renin angiotensin system
Increased angiotensin II causes increased aldosterone which increases blood pressure
What might high blood pressure from renal artery stenosis cause?
Kidney failure
Who is most likely to have renal artery stenosis and what are the risk factors?
Men over 50
Normal cardiovascular risk factors eg diabetes, overweight, hyperlipidaemia, hypertension etc
Asides from older men who have cardiovascular risk factors what is another cause of renal artery stenosis and who is it common in?
Fibromuscular dysplasia
Common in women under 45 who have high blood pressure
If a women under 45 with hypertension presents with renal artery stenosis, what is the likely cause?
Fibromuscular dysplasia
How will someone with renal artery stenosis present?
They may be asymptomatic
Patients who have a history of hypertension
May have symptoms of renal disease eg proteinuria, fluid overload eg pulmonary oedema, abdominal bruits
What drugs may someone with renal artery stenosis have recently been started on?
Ace inhibitor
Angiotensin receptor 2 antagonist
What effect will vasconstriction of the afferent arteriole of the Bowman’s capsule have on the GFR?
It will reduce it (perfusion into the bowmans capsule is redcued)
What effect will vasconstriction of the efferent arteriole of the Bowman’s capsule have on the GFR?
It will increase it (makes it harder for blood to leave the bowman’s capsule)
What effect would an angiotension II receptor blocker or an ace inhibitor have on GFR?
It would stop the efferent arteriole vasoconstricting and would therefore reduce GFR and perfusion of the kidney
What drugs should you not give someone with renal artery stenosis and why?
Ace inhibitor or angiotensin II receptor blocker because they reduce renal perfusion by stopped the efferent arteriole constricting, those with renal artery stenosis already have poor perfusion
What investigation should you do for renal artery stenosis?
Bloods (U+Es, FBC, aldosterone:renin)
Duplex ultrasound
Conventional angiography
What is duplex ultrasound? Give advantages and disadvantages
It measures the velocity of the blood flow in the renal artery so you can see how occluded it is but its not very sensitive so will only pick up occlusion if its more than 50%
What is the gold standard/ best investigation for renal artery stenosis? Give its advantages
Conventional angiography
It is more sensitive than MR/CT angiography and doesn’t require contrast whereas MR/ CT angiography does. Contrast may be nephrotoxic
What will you hear on examination that may make you think the issue could be renal artery stenosis?
Renal bruit
What are some risk factors for renal cell carcinoma?
Smoking
Male
Obese
Hypertension
What symptoms will someone with renal cell carcinoma present with?
Triad of haematuria, flank pain and flank/abdominal mass
Malignancy symptoms include malaise, appetite loss, weight loss
Shortness of breath
Why may someone with renal cell carcinoma get shortness of breath?
They may be anaemic
What is the gold standard investigation for renal cell carcinoma?
CT of the abdomen and pelvis
What investigations would you do if you suspect renal cell carcinoma?
CT abdomen/ pelvis
Bloods (FBC for anaemia, U+Es for renal function, LDH is a prognostic factor for late stage disease, calcium, LFTs for liver mets, coagulation)
Urinalysis (check for proteinuria or haematuria)
Why might someone with renal cell carcinoma get anaemia or low RBC count?
Lack of erythropoietin
What are causes of urinary tract calculi
Mostly idiopathic, sometimes due to high calcium or urea
What are risk factors for urinary tract caliculi?
Low fluid intake
Structural abnormalities of the ureter
Crystalluria
High protein and salt intake
What are the 3 most common sites of impaction/obstruction of the ureter?
Ureteropelvic junction
Crossing of the iliac artery
Uterovesical junction
What is crystalluria?
Formation of crystals in the urine
How will a patient with urinary tract calculi present?
Often asymptomatic Severe loin to groin pain Nausea and vomiting Urinary frequency/ urgency Haematuria
How do you tell apart kidney stone pain from peritonitis?
Kidney stone patients will be writhing around in pain
Peritonitis patients will be lying completely still and will experience severe pain on moving
