RENAL Flashcards

1
Q

Triad of HUS?

A

AKI
Microangiopathic haemolytic anaemia
Thrombocytopenia

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2
Q

What causes HUS?

A

Most causes are typical HUS which is secondary to shiga toxin producing E.Coli 0157:H7
Can also be secondary to pneumococcal infections, HIV, SLE, drugs and cancer

Primary HUS is rare and is due to complement dysregulation

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3
Q

Investigations necessary for HUS?

A

FBC to look for anaemia and thrombocytopenia
Coombs test -should be negative
Blood film - shows schistocytes and helmet cells
U&Es for AKI
Stool culture looking for evidence of STEC infection. PCR for shiga toxins

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4
Q

Tx of HUS?

A

Hospital admission!
Supportive - IV fluids, blood transfusion, dialysis
Self-limiting - most pts fully recover!

Plasma exchange if very severe HUS and not associated with diarrhoea
Eculizumab has some evidence that its greater than plasma exchange alone in treatment of adult atypical HUS

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5
Q

What increases the risk of HUS?

A

Children <5
Using antibiotics or antimotility meds if STEC is suspected (e.g. loperamide) to try to Tx the gastro

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6
Q

Pathophysiology of HUS?

A

Formation of blood clots = consumes platelets = thrombocytopenia
Thrombi & damaged RBCs = affect blood flow through kidney = AKI
Haemolysis of RBCs due to thrombi partically obstructing small blood vessels = causes churning of the RBCs and rupture

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7
Q

Management of ascites?

A
  1. Reduce dietary sodium or ff sodium is low (<125) = fluid restrict
  2. Aldosterone antagonist e.g. spironolactone (if they don’t respond add a loop diuretic)

If tense ascites - therapeutic abdominal paracentesis (if large volume >5L then albumin cover is needed

If ascetic protein is <15 = prophylactic ABx to reduce risk of SBP

TIPS can be considered

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8
Q

Outline the management of proteinuria in CKD?

A

Dietary protein restriction, tight glycaemic control & manage hypertension and hyperlipidaemia

If pt has diabetes and ACR >=3 = SGLTi

If they dont have diabetes…
ACR 30-70 and hypertension = ACEi/ARB
ACR >70 = ACEi/ARB regardless of bp

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9
Q

How do ACEi and ARBs treat proteinuria in CKD?

A

ACEi inhibits the conversion of angiotensin 1 to angiotensin 2 whilst ARBs block angiotensin 2 from binding to its receptor. This leads to dilation of the efferent arteriole, reducing intraglomerular pressure and the amount of protein leaking into the urine = decreases the hyperfiltration injury

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10
Q

How do SGLT2i treat proteinuria in CKD?

A

Blocks the sodium-glucose cotransporter in the proximal tubule, leading to increased Na+ delivery to the macula densa = triggers tubuloglomerular feedback causing afferent arteriolar construction and reducing intraglomerular pressure = minimises proteinuria

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11
Q

Pathophysiology of diabetic nephrology?

A

Causes a nephrotic syndrome!

Diabetes causes non-enzymatic glycation which damages the blood vessels = thickens capillary basement membrane by increased deposition of type 4 collagen and causes atherosclerosis of arterioles = increases permeability of vessels & tublar cells to proteins
Osmotic damage to glomerular capillary epithelium = thickening of capillary basement membrane by deposits of type 4 collagen = diffuse mesangial sclerosis +/- kimmelstiel-Wilson nodule
Affects efferent arteriole before afferent arterioles = increased GFR = hyperfiltration injury = protein loss

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12
Q

Typical causes of focal segmental glomerulosclerosis?

A

HIV - most important to remember
Drugs e.g. anabolic steroids
Heroin
Alports syndrome
Sickle cell
Secondary to other renal pathology
Idiopathic

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13
Q

Minimal change disease what age does it affect?

A

75% of cases are in children
25% in adults

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14
Q

Cause of minimal change disease?

A

90% of cases are idiopathic

Other causes:
Drugs - NSAIDs and rifampicin
Hodgkin lymphoma
Thymoma
Infectious mononucleosis

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15
Q

Management of minimal change disease?

A

Low salt diet to stop body retaining any more fluid
80% of cases respond to oral corticosteroids
Cyclophosphamide is second line

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16
Q

Prognosis of minimal change disease?

A

1/3 have just one episode
1/3 have infrequent relapses
1/3 have frequent relapses which stop before adulthood

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17
Q

What is the difference between primary and secondary hyperaldosteronism?

A

Primary - adrenal glands directly responsible for producing too much aldosteronism so serum renin will be low as hypertension suppresses it
Secondary - there is a disproportionately lower bp in the kidneys = excessive renin stimulates the release of excessive aldosteronism

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18
Q

Causes of primary hyperaldosteronism?

A

B/L adrenal hyperplasia - most common
Conns syndrome - an adrenal adenoma secreting aldosterone

Rarely can be familial

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19
Q

Causes of secondary hyperaldosteronism?

A

Renal artery stenosis
HF
Liver cirrhosis and ascites

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20
Q

Investigations for hyperaldosteronism?

A

BP
Bloods - U&Es look for low K+. Blood gas look for alkalosis
Aldosterone-to-renin ratio (ARR)
CT or MRI to look for adrenal hyperplasia or tumour
If ?RAS - Renal artery Doppler/CT angio or MR angio
Adrenal vein sampling can be done from both adrenal veins to locate which gland is producing more aldosterone

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21
Q

Management of hyperaldosteronism?

A

Aldosterone antagonists e.g. eplerenone and spironolactone

Treat undelryign cause e.g. surgical removal of adrenal adenoma or a percutaneous renal artery angioplasty for RAS

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22
Q

Most common cause of secondary hypertension?

A

Hyperaldosteronism

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23
Q

What is anti-GBM disease?

A

A rare type of small-vessel vasculitis associated with pulmonary haemorrhage and rapidly progressive glomerulonephritis
Caused by anti-GBM antibodies against type 4 collagen
Associated with HLA DR2 and more common in men

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24
Q

Investigations when considering anti-GBM disease?

A

Bloods - U&Es, measure antiGBM antibody level, ANCA, complement 3&4 levels, ANA, anti-streptomycin O titre to rule out PSGN, clotting screening necessary before renal biopsy
Renal biopsy with immunofluorescence will show linear IgG deposits along the basement membrane
Raised transfer factors secondary to pulmonary haemorrhage

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25
Q

Management of anti-GBM disease?

A

Oral corticosteroids & Plasma exchange
Consider cyclophosphamide

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26
Q

What is the most impprtant complication of anti-GBm disease?
What makes this more likely to occur?

A

Pulmonary haemorrhage

Smoking, LRTI, pulmonary oedema, inhalation of hydrocarbons, young males

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27
Q

Pathophysiology of anti-GBM disease?

A

Auto-antibodies that attack the GBM and alveoli due to the presence of the type 4 collagen in both of these structures = rapidly progressive glomerulonephritis & pulmonary haemorrhage = haemoptysis and haematuria

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28
Q

Risk factors for bladder cancer

A

Males aged between 50-80
Smokers
Exposed to hydrocarbons
Pelvic radiation
Cyclophosphamide
Chronic bladder inflammation from a schistosomiasis infection, log term catheters or recurrent UTIs

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29
Q

Whats the most common type of bladder cancer?

A

Transitional cell carcinoma (90%)

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30
Q

Most common cause of squamous cell carcinoma bladder cancer?

A

Prolonged inflammation within the bladder e.g. schistosomiasis but also occasionally recurrent UTIs/long term catheters
This is why its more commonly seen in Africa and Asia

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31
Q

Referral criteria for ?bladder cancer?

A

> =45 with either unexplained visible haematuria or visible haematuria that persists/recurs after successful Tx of UTI
=60 with unexplained non-visible haematuria + either dysuria or raised WCC

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32
Q

Investigations for bladder cancer?

A

Urinalysis ans culture to exclude infection
FBC, U&Es
Urgent flexible cystoscopy
Consider CT or MRI staging scan

For complete diagnosis a transurethral resection of bladder tumour (TURBT) must be done to get a histological analysis

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33
Q

Management of bladder cancer?

A

If non-muscle invasive - may only need TURBT, may need some intra-vesicle chemotherapy

If muscle-invesive - neoadjuvant chemo & radical surgery e.g. radical cystectomy. More modern approaches now recommend TURBT & chemo & radiotherapy and suggest a similar prognosis to radical cystectomy

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34
Q

How does contrast cause an AKI?

A

Contrast agents are directly nephrotoxic to renal tubular cells but they can also alter the vasoactive substances such as renin, angiotensin etc -? Reduces glomerular blood flow

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35
Q

Definition of contrast media nephrotoxicity?

A

25% increase in Cr occurring within 3 days of IV administration of contrast media

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36
Q

How to prevent contrast media nephrotoxicity?

A

IV 0.9% sodium chloride at a rate of 1ml/kg/hour for 12 hours pre- and post-procedure

Also remember if pt is high risk hold metformin for 48 hours and then until renal function has normalised to prevent lactic acidosis

37
Q

What is the most common type of glomerulonephritis in adults?

A

Membranous glomerulonephritis

38
Q

Renal biopsy findings in membranous glomerulonephritis?

A

On electron microscope you can see a thickened BM with subepithelial electron dense deposits = spike and dome appearance

39
Q

Causes of membranous glomerulonephritis?

A

Malignancy - commonly asked in exam Qs so remmeber M for malignancy
Idiopathic e.g. due to anti-phospholipase A2 antibodies
Infections - malaria, hep B, syphilis
Drugs - gold, penicillamine, NSAIDs
Autoimmune diseases

40
Q

Management of membranous glomerulonephritis?

A

ACEi or ARB to reduce proteinuria and improve prognosis
Immunosuppression e.g. corticosteroid & cyclophosphamide
Consider anticoagulant for high risk pt

41
Q

Prognosis of membranous glomerulonephritis?

A

Prognosis - rule of thirds
one-third: spontaneous remission
one-third: remain proteinuric
one-third: develop ESRF

42
Q

Types of renal calculi?

A

Calcium oxalate - most common ~60%!!
Calcium phosphate uric acid ~20%
Uric acid ~15%
Struvite (magnesium ammonium phosphate) ~1-5%
Cystine ~1%
Drug induced stones ~1%

43
Q

Where do renal stones usually obstruct?

A

The vesicoureteric junction
The mid ureter where the ureter crosses the iliac vessels
The pelvic ureteric junction

44
Q

What are calcium oxalate stones associated with?

A

Low urine volume
Hypercalciuria
Hyperuricosuria
Hyperoxaluria
Hypocitraturia

45
Q

What are calcium phosphate stones associated with?

A

Low urine volume
Hypercalciuria
Hypoctraturia
High urine pH
Primary hyperparathyroidism
RTA

46
Q

What are uric acid renal stones associated with?

A

Hyperuricosuria
Low urinary pH (<5.5)

47
Q

What causes struvite stones?

A

Bacterial infections which hydrolyze urea to ammonia and raises the urine pH to >7.2
Consist of a mixture of magnesium, ammonium and phosphate

48
Q

What are cystine stones associated with?

A

Cystinuria - a genetic condition causing cystine to leak through kidneys (different to homocystinuria)

49
Q

Risk factors for renal stones?

A

Males (3:1)
40-60 year olds
White people
Diet intake high in oxalate, urate, sodium and animal protein
Chronic dehydration
Obesity
High ambient temperatures (affect fluid status)
FHx
Anatomical abnormalities of urinary tract
Genetic conditions e.g. cystinuria, RTA, CF
Some GI conditions
Conditions which alter urinary volume, pH or concentrations of certain ions e.g. hyperparathyroidism, diabetes, gout
Some drugs

50
Q

How common are kidney stones?

A

It is estimated that 12% of men and 6% of women will have one episode of renal colic at some stage in their life

51
Q

Complications of renal stones?

A

Obstruction of urinary flow - can decrease GFR of aefcted kidney. If obstruction >48 hours it may lead to reduced renal blood flow and irreversible kidney damage
Obstructive pyelonephritis or pyonephrosis (build up of high pressure pus behind the obstruction) - very high risk of sepsis!!

Less commonly:
- renal carcinoma
- CKD
- coronary heart disease
- spontaneous rupture of renal calyx -> urinoma

52
Q

Features of renal stones?

A

Colic - abrupt onset of severe unilateral abdominal pain originating in the loin or flank and radiating to the labia in women or to the groin or testicle in men. Spasms which last mins-hours
N&V
Haematuria
Dysuria, urinary frequency and straining when the stone reaches the vesicoureteric junction and irritates the detrusor muscle

53
Q

Investigations for renal stones?

A

Urine dipstick and culture
U&Es, FBC, CRP, calcium and urate plasma levels, clotting if intervention planend
Stone analysis once stone has passed
Urgent low-dose non-contrast CT KUB within 24 hours of presentation… USS KUB is less preferred but an alternative e.g. in pregnancy or children (but not a negative result does not exclude renal stone)

54
Q

Which renal stones are opaque on radiograph?

A

Calcium oxalate
Calcium phosphate stones
Struvite stones

Cystine stones may be semi-opaque with a ground glass appearance

55
Q

What are stag-horn calculi?

A

Stones which involve the renal pelvis and extend into at least 2 calyces
Caused by struvite stones

56
Q

Why does hypocitraturia increase the risk of calcium renal stones?

A

citrate forms complexes with calcium making it more soluble so when its low we get Hypercalciuria

57
Q

Why does hyperuricosuria increase the risk of calcium renal stones?

A

May cause uric acid stones which calcium oxalate can bind to!

58
Q

Which renal stones have urine pH <5.5?

A

Uric acid stones

59
Q

Which renal stones have urine pH >7.2?

A

Struvite stones

60
Q

Which drugs can cause calcium-based renal stones?

A

loop diuretics, steroids, acetazolamide, theophylline

61
Q

Which drugs can prevent calcium-based renal stones?

A

Thiazide diuretics as they increase distal tubular calcium reabsorption

62
Q

Management of renal stones generally?

A

Analgesia - NSAIDs by any route (IM Diclofenac is the most common)
Antiemetics for N&V
If infection present pt may need ABx

63
Q

Management of renal stones <5mm and asymptomatic?

A

Watchful waiting

64
Q

Management of distal ureteric stones <10mm?

A

Medical expulsive therapy with an alpha blocker to facilitate spontaneous stone passage

65
Q

When is surgical treatment considered for renal stones?

A

If pain is ongoing and stone unlikely to pass i..e >5mm

66
Q

Surgical options for renal stones?

A

5-10mm -> shockwave lithotripsy
10-20mm shockwave lithotripsy OR ureteroscopy
>20mm percutaneous nephrolithotomy

67
Q

Management of ureteric stones that are 10-20mm?

A

Ureteroscopy

68
Q

How to prevent calcium renal stones?

A

High fluids, add lemon to drinking water, avoid carbonated drinks, limit salt intake, potassium citrate (to bind to Ca) or thiazide diuretics

69
Q

How to prevent oxalate renal stones?

A

cholestyramine & pyridoxine both reduces urinary oxalate secretion

70
Q

How to prevent uric acid stones?

A

Allopurinol
Urinary alkalinization e.g. oral bicarbonate

71
Q

Why is it common for a pt to get recurrent UTIs after a kidney transplant?

A

The ureteroneocystostomy can lead to stasis or reflux of urine as its placed lower down than the original kidney so there is less of a gravity effect
Pt is on immunosuppressive Tx
Post-surgery may get strictures/colonisation

72
Q

Why is the L kidney the preferred kidney to donate for a renal transplant?

A

As it has a longer renal vein
(R side has a shorter vein and is more often associated with renal vein thrombosis)

73
Q

Where is the new kidney placed in a renal transplant?

A

In the iliac fossa & extraperitoneal

74
Q

Efefcts of missing a dialysis session?

A

Hyperkalaemia
Hyper or hyponatraemia
Metabolic acidosis
Fluid overload/oedema
Uraemia - fatigue, nausea, confusion, encephalitis at the most extreme

75
Q

Indications for dialysis?

A

Acidosis not responding to Tx
Electrolyte imbalances not responding to Tx - most importantly hyperkalaemia
Intoxication i.e. OD of a drug
Oedema not responsive to Tx
Uremia Sx

Most commonly these are caused by ESRF

76
Q

Investigations for hydronephrosis?

A

Abdominal USS to identify
IV urogram
CT KUB may be needed if ?stones
Bloods and urine investigations for infections also

77
Q

Management of acute and chronic hydronephrosis?

A

Acute - usually a nephrostomy or suprapubic catheter
Chronic - need a ureteric stent or pyeloplasty

If a prostate problem and you can get a catheter around it this may be a temporary fix

All require Tx of underlying cause

78
Q

How do you manage a pt who presents with blood clots which are blocking the catheter?

A

Use a 3 way catheter to irrigate the bladder to try to push the blood clots out - will take multiple attempts until the body can undergo haemostasis and stop the bleeding cause

Also used if debris blocking catheter e.,.g after TURP

79
Q

When do hyper acute, acute and chronic graft failures occur?

A

Hyper acute - mins/hours
Acute - weeks - <6 months
Chronic - >6months-years

80
Q

What causes a hyper acute transplant rejection?

A

It’s a T2 hypersensitivity reaction where pre-existing antibodies exist against ABO or HLA antigens of the graft, activating the complement system
This leads to widespread thrombosis of the graft vessels -> ischaemia and necrosis of transplant

81
Q

Management of hyperacute organ rejection?

A

No Tx
Graft must be removed

82
Q

Pathophysiology of acute organ rejection?

A

Primarily T4 hypersensitivity reaction but also T2 contributes
Usually due to mismatched HLA - recipient CD4+ T helper cells recognise the donor HLA on graft cells and cause CD8 T cells to destroy the graft cells. They also stimulate a B cell mediated reaction

Other causes e.g. CMV infection!!

This is acute rather than hyperacute as the antibodies are not pre-made like in hyperacute!

83
Q

Management of acute organ rejection?

A

May be reversible with steroids and immunosuppressants

84
Q

Pathophysiology of chronic organ rejection?

A

T2 and T4 hypersensitivity reaction
Recipient antigen-presenting cells recognise the graft MHCs and present them to T cells which damage the transplant. B cells are also activate and can produce donor-specific antibodies
In a renal transplant this is chronic allograft nephropathy -> progressive vascular narrowing, interstitial fibrosis and tubular atrophy

85
Q

Management of chronic organ rejection?

A

No Tx

86
Q

What is graft versus host disease?

A

T cells in the graft mount an immune response against the host cells!
This is mostly seen in allogenic bone marrow transplants but it can rarely be seen following solid organ transplantation or transfusion in immunocompromised pts

87
Q

How can graft versus host disease by prevented?

A

By using irradiated blood products to eliminate lymphocytes before transplantation

88
Q

how to confirm a kidney transplant failure

A

Biopsy!