Renal medicine Flashcards
(147 cards)
1
Q
What are the 2 most common causes of CKD?
A
- HTN
2. DM
2
Q
How much urine is produced by the kidneys each day?
A
1-1.5L
3
Q
What are the 4 main functions of the kidneys?
A
- excretion (drugs and waste products)
- Homeostasis (inc acid-base balance)
- endocrine (renin, erythropoietin and prostoglandins)
- metabolism (vit D)
4
Q
Where in the abdomen are the kidneys positioned?
A
retroperitoneal
5
Q
What are the 2 types of nephrons?
A
This depends on the size of the nephron:
- cortical nephrons (85%)
- renal corpuscle in outer part of cortex
- short loop of henle - juxtamedullary nephrons (15%)
- larger renal corpuscle in inner 3rd of cortex
- long loop of henle extending into medulla
6
Q
What % of CO do the kidneys receive?
A
20-25%
7
Q
How much of total erthyropoietin is produced by the kidneys?
A
85%
8
Q
What is the half life of EPO?
A
5hrs
9
Q
What stimulates the production of EPO?
A
- hypoxia
- anaemia
- renal ischaemia
10
Q
What is the active metabolite of vitamin D ?
A
1,25-dihydroxycholecalciferol
11
Q
List some congenital abnormalities of the kidneys.
A
- agenesis of the kidney
- hypoplasia
- ectopic
4 horseshoe
12
Q
What is potter’s syndrome?
A
- bilateral renal agenesis
- oligohydramnios
- pulmonary hypoplasia
it is incompatible with life
13
Q
what is a horseshoe kidney?
A
fusion of the 2 kidneys at the lower poles
more common in boys than girls
prone to reflux, obstruction, infection and stone formation
14
Q
What are mesangial cells?
A
specialised smooth muscle cells that support the glomerulus and regulate blood flow and GFR
15
Q
What causes renin release from the macula densa (DCT)?
A
low BP (detected by baroreceptors) low NaCl
16
Q
What is the function of PCT?
A
- 70% total Na reabsorption
- reabsorption of aa, glucose, cations
- bicarbonate reabsorbed (using carbonic anhydrase)
17
Q
What electrolyte channel is found in the thick ascending limb of the loop of Henle?
A
NKCC2 (Na/K/2Cl triple symporter)
18
Q
What electrolyte channel is found in the DCT?
A
NCC (NaCl co-transporter)
19
Q
What is the function of the thick ascending loop of henle?
A
creation of osmolality gradient
20
Q
Where is calcium reabsorbed in the nephron?
A
DCT
calcium reabsorption is under the control of PTH
21
Q
What electrolyte channels are found in the medullary collecting ducts?
A
ENaC (basolateral aldosterone-sensitive Na/K pump)
22
Q
What is the function of the cortical collecting duct?
A
regulation of water reabsorption
controlled by AQP2 channels
23
Q
List the 5 classes of diuretics.
A
- carbonic anhydrase inhibitors
- loop diuretics
- thiazide diuretics
- potassium-sparing diuretics
- osmotic diuretics
24
Q
What is the MOA of loop diuretics?
A
inhibit NKCC2 symporter in thick ascending limb
causes massive NaCl, K and Ca excretion
SEs: hypokalaemia, ototoxic, metabolic alkalosis
25
What is the MOA of thiazide diuretics?
inhibit NCC co-transporter in DCT
moderate NaCl excretion, increased calcium reabs.
SEs: hypokalaemia, hyperglycaemia, inc. urate
CI in gout
26
What are the side effects of potassium sparing diuretics?
1. hyperkalaemia
| 2. gynecomastia (anti-androgenic)
27
What drugs cause haematuria?
1. NSAIDs
2. ciprofloxacin
3. furosemide
4. cephalosporins
28
What are the renal causes of haematuria?
1. infection (pyelonephritis)
2. inflammation/trauma
2. neoplasm
4. immune (glomerulonephritis)
5. congenital (PCK)
29
What is the triad of nephrotic syndrome?
1. proteinuria (>3.5g/24hr)
2. hypoalbuminaemia
3. oedema
NB hyperlipidaemia is often present
30
What are the 4 histological patterns of nephrotic syndrome?
1. minimal change
2. membranous nephropathy
3. mesangiocapillary glomerulonephritis
4. focal segmental glomerulosclerosis (FSGS)
31
What is the commonest type of nephrotic syndrome in children?
minimal change
90% undergo remission with steroids
if frequently relapsing or steroid-dependent give ciclosporin/tacrolimus
32
How is urea produced?
from ammonia by the liver in ornithine cycle
increased in dehydration as decreased flow increases urea
33
What happens to urea and creatinine in renal failure?
increase
34
What factors are considered when calculating eGFR?
serum creatinine
sex
age
race
35
Name some nephrotoxic drugs.
1. NSAIDs
2. ACEi
3. gentamicin
4. amphotericin (anti-fungal)
36
What ECG changes would you be worried about in AKI?
hyperkalaemia:
- tall tented T waves
- flattened P waves
- increased PR interval
- widened QRS
37
What are the risk factors for AKI?
```
>75y/o
CKD
HF
PVD
diabetes
sepsis
history of urinary symptoms
```
38
What will you see on blood film with haemolytic uraemic syndrome?
red cell fragmentation
39
What is the triad for haemolytic uraemic syndrome?
1. microangiopathic haemolytic anaemia (Coomb's negative)
2. AKI
3. thrombocytopenia
40
What is the most common cause of AKI in children?
haemolytic uraemic syndrome
41
What are patients at risk of if taking metformin with a rising creatinine?
lactic acidosis
stop metformin if creatinine >150mM
42
What are the complications of uraemia?
encephalopathy
pericarditis
treat with dialysis
43
What is the management of hyperkalaemia?
K>6-7mmol/L requires urgent treatment
1. 10ml of 10% calcium gluconate over 2 mins
- repeat as necessary until ECG improves
- cardioprotective
2. insulin and glucose
- 10units actrapid in 50ml 20% glucose
- drives potassium into cells
- aim to low serum K by 1-2mmol/L over 60mins
3. salbutamol nebuliser (10-20mg)
44
What is the complication of hyperkalaemia?
ventricular fibrillation
45
What staging system is used for AKI?
KDIGO
kidney disease improving global outcomes
46
What is the criteria for diagnosing AKI?
KDIGO:
1. >26micromol/L rise in creatinine in 48hrs
2. >1.5x rise in creatinine from baseline
3. urine output <0.5ml/kg/hr for >6 consecutive hrs
47
What are the life-threatening complications of AKI?
hyperkalaemia
| pulmonary oedema
48
How do you treat pulmonary oedema?
1. oxygen - consider CPAP
2. IV GTN
3. IV furosemide 80-250mg
4. IV diamorphine 2.5mg (venous vasodilator) + 10mg metoclopramide
49
Define AKI.
A significant decline in renal function over hours to days manifesting as an abrupt and sustained increase in creatinine and urea
50
What are the indications for acute dialysis?
1. refractory pulmonary oedema
2. persistent hyperkalaemia (>7mmol/L [3.5-5])
3. symptomatic uraemia
4. severe metabolic acidosis (pH<7.2)
5. poisoning (aspirin - salicylate level >700mg/L)
51
What is the most likely cause of nephrotic syndrome is adults?
membranous nephropathy
52
What is Goodpasture's?
anti-GBM antibodies against type IV collagen found in glomerular and alveolar basement membranes
haematuria + haemoptysis
53
What are the Sx of acute nephritis syndrome?
1. oliguria
2. haematuria
3. proteinuria
4. uraemia
5. fluid retention
6. HTN
54
What is an early indicator of glomerulosclerosis in diabetic patients?
microalbuminuria
55
Where does the majority of bicarbonate reabsorption occur?
90% in PCT
56
How do the convoluted tubules regulate body pH?
the reabsorption of bicarbonate
57
How does PTH affect kidneys handling of phosphate?
decreases phosphate reabsorption in the PCT
58
What treatment of hyperkalaemia actually removes potassium from the body?
calcium resonium
59
List some drugs that cause tubulointerstital nephritis.
1. NSAIDs
2. penicillin
3. gold
4. rifampicin
60
Which part of the nephron is impermeable to water?
thin and thick ascending limbs
61
Where is body fluid osmolality detected?
hypothalamus
triggers release of ADH
62
Why might a psych patient taking lithium develop an abnormality in their serum osmolality ?
nephrogenic diabetes insipidus
63
What is Conn's syndrome?
primary hyperaldosteronism
overproduction of aldosterone causes fluid retention and hypertension
64
Which fluid compartment contains the greatest volume of water?
intracellular fluid
65
What does aldosterone do to electrolyte levels
causes reabsorption of sodium (increases sodium therefore increases ECF volume) and increases the excretion of potassium (lowers serum potassium)
66
What process takes place in the kidneys when the baroreceptors detect hypotensive state?
increased sympathetic tone triggers the release of renin from the macula densa
67
List some causes of secondary HTN.
1. Cushing's
2. Conn's
3. oestrogen
4. phaeochromocytoma
68
How would adrenal insufficiency affect BP?
hypotension
69
Why do you get a dry cough with ACEi?
inhibition of the breakdown of bradykinin
70
Which diuretics cause hypokalaemia?
thiazide diuretics
| loop diuretics
71
What is the most common type of renal stone?
calcium oxalate (alkaline urine)
72
What is adult PCK disease associated with? And what does this put these patients at risk of?
associated with berry aneurysms
| at risk of SAH (PC: thunderclap headache)
73
What can patients develop after a long time on dialysis?
acquired cystic disease
74
What symptom triad do you get with renal cell carcinoma?
1. frank haematuria
2. flank pain
3. loin mass
75
What is the most common malignant renal tumour in children?
Wilm's tumour
Most commonly occurs aged 1-4
76
Describe the synthesis and storage of ADH.
- ADH is a peptide hormone
- it is synthesised in the supraoptic nucleus of the hypothalamus as a large precursor molecule
- it is transported to the posterior pituitary gland
77
What drugs affect ADH release?
increase ADH release:
- nicotine
- ether
- morphine
- barbiturates
inhibit ADH release:
- alcohol
78
What are the CKD stages and their respective eGFRs?
```
stage 1 >90
stage 2 60-89
stage 3a 45-59
stage 3b 30-44
stage 4 15-29
stage 5 <15
```
79
How does HTN affect the size of the kidney?
makes it smaller
80
What conditions result in an enlarged kidney?
diabetes
PKD
RCC
renal mets
81
What is a sign of renal artery stenosis?
renal bruit
82
What is the management of nocturnal enuresis?
desmopressin nasal spray
--> can be caused by a reduction in circulating ADH at night time
83
What is the normal plasma osmolality (Posm)?
285-295mOsmol/kg H2O
84
What is the maximum urine osmolality?
1400mOsm/kg H20
85
define hyponatraemia.
plasma sodium <130mmol/L
86
What are the causes of SIADH?
1. CNS: abscess, stroke, SLE
2. malignancy: small cell carcinoma of lungs
3. lung disease: TB, pneumonia, aspergillosis
4. drugs: opiates, chlorpropamide, oxytocin
5. metabolic disease: porphyria, hypothyroidism
6. other: pain, GBS, trauma
87
What is diabetes insipidus?
the inability to reabsorb water from the distal part of the nephron due to failure of secretion/action of ADH
88
What are the symptoms of diabetes insipidus?
1. polyuria
2. polydipsia
3. low urine osmolality (dilute urine)
89
What are the 2 types of diabetes insipidus?
1. neurogenic
| 2. nephrogenic
90
What is the cause of thrombotic thrombocytopenia purpura (TTP)
?
genetic/acquired deficiency of ADAMTS13
91
What is rhabdomyolysis and how does it affect the kidneys?
- muscle breakdown leading to the release of myoglobin into the blood
- myoglobin is freely filtered by the kidneys
- if the filtrate is acidic the myoglobin precipitate forming casts which block the normal flow of urine through tubules
- causes v high creatine kinase and hyperkalaemia
92
What is acute tubular necrosis?
the result of acute tubular cell damage by ischaemia of toxins
hyperkalaemia can develop
93
What is Fanconi syndrome?
disturbance of PCT function leading to generalised impaired absorption
94
List some complications of acute pyelonephritis.
1. renal papillary necrosis
2. perinephric abscess
3. pyonephrosis (obstruction of pelvicalyceal system)
4. chronic pyelonephritis
5. fibrosis and scarring
95
What are the risk factors for acute pyelonephritis?
1. urinary tract obstruction
2. vesicoureteric reflux
3. instrumentation of urinary tract
4. sexual intercourse
5. DM
6. immunosuppression
96
What is the most common cause of chronic pyelonephritis?
reflux nephropathy (associated with vesicoureteric reflux which is congenital)
97
What is found on histological examination for chronic pyelonephritis?
interstitial fibrosis
dilated tubules containing eosinophilic casts
(NB USS kidney is shrunken, scarred and misshapen)
98
List the 2 hereditary nephritis syndromes.
1. Alport's syndrome
| 2. Fabry's syndrome
99
What is Alport's syndrome?
- X-linked disorder affecting basement membrane collagen IV
- they lack the Goodpasture's antigen
- KIDNEY: glomerulonephritis + haematuria
- EYES: lens dislocation, cataract, cornical cornea
- EARS: sensorineural deafness
- also associated with platelet dysfunction and hyperproteinaemia
100
What is Fabry's syndrome?
- rare X linked disorder
- deficiency of galacto-sidase A
- accumulation of ceramide trihexoside in kidneys, skin and vascular system
101
What are the secondary causes of glomerulonephritis?
1. post-strep glomerulonephritis
2. non-strep glomerulonephritis
3. SLE
4. HSP
5. bacterial endocarditis
6. diabetic glomerulosclerosis
7. amyloidosis
8. goodpasture's syndrome
102
What are the causes of asymptomatic haematuria?
1. IgA nephropathy
2. think basement membrane
3. Alport's syndrome
103
At what stage of CKD do symptoms occur?
stage 4
104
At what stage of CKD is renal replacement therapy required?
stage 5
105
What are the 2 main categories of glomerulonephritis?
1. nephrotic syndrome
| 2. nephritic syndrome
106
What immune cells are thought to be involved in damage of the glomerulus?
1. macrophages
| 2. T lymphocytes
107
What is the general management of nephrotic syndrome?
1. reduce oedema
- furosemide
- check daily weights and U&Es
- fluid and salt restrict
2. reduce proteinuria
- ACEi/ARB for all pts
- they reduce proteinuria and preserve renal function
3. decrease risk of complications
- statin to reduce cholesterol
- anticoagulant if hypercoagulable
- blood pressure control
4. treat underlying cause
108
What are the 4 primary causes of nephrotic syndrome?
1. minimal change
2. membranous nephropathy
3. focal segmental glomerulosclerosis (FSGS)
4. mesangiocapillary GN
109
What does a kidney biopsy of minimal change disease show?
- normal under light microscopy
| - electron microscopy shows effacement of podocyte foot processes
110
How do you treat minimal change disease?
1. steroids
if frequent relapsing give cyclophosphamide/ciclosporin
prognosis good only 1% go on to ESRD
111
What are the biopsy findings in membranous nephropathy?
1. diffusely thickened GBM
| 2. subepithelial deposits of immune complexes - IgG + C3
112
How do you treat membranous nephropathy?
immunosuppress pt if renal function declines
113
How do you treat FSGS?
1. steroids
| 2. OR cyclophosphamide/ciclosporin
114
What are the subtypes of mesangiocapillary glomerulonephritis?
Type 1 (more common)
- immune complex mediated
- immune complexes deposited in kidneys
- activates classical pathway
- causes inflammation and capillary thickening
Type 2 (less common)
- activation of alternative complement pathway
- thickened capillaries caused by C3 deposition
115
What is the most common type of glomerular disease worldwide?
IgA nephropathy (Berger's disease)
116
What are the renal biopsy findings for IgA nephropathy?
immune complex deposition of IgA and C3 in the mesangium
117
What would be a typical history preceeding diagnosis of IgA nephropathy?
young man presents with recurrent haematuria post URTI
118
What are the 4 primary causes of glomerulonephritis presenting with nephritic syndrome?
1. IgA nephropathy
2. rapidly progressive GN
3. focal proliferative GN
4. mesangiocapillary GN
119
What are the 3 subtypes of rapidly progressive GN?
type 1
- anti-GBM
type 2
- immune complex deposition
- SLE, post=strep
type 3
- pauci immune
- cANCA = GPA
- pANCA = churg strauss
120
What is HSP and what are the systems affected?
immune-mediated (IgA) small-vessel vasculitis presenting with:
1. purpura (over buttocks and extensor surfaces)
2. glomerulonephritis
3. abdo pain +/- intussusception
4. polyarthritis
121
What factors increase the risk of having SLE?
1. female
2. Asian
3. HLA B8-, DR2-, DR3- positivity
122
How does SLE affect the kidneys?
1. immune complex deposition in glomerulus
2. basement membrane thickening
3. endothelial proliferation
123
What are the main deposit sites of renal calculi?
1. pelviureteric junction
2. pelvic brim
3. vesicoureteric junction
124
Which type of calculi are likely to form in acidic urine?
1. cystine
| 2. uric acid crystals
125
Which type of calculi are likely to form in alkaline urine?
1. calcium oxalate
2. calcium phosphate
3. magnesium ammonium phosphate
126
Why should you do early morning urine sample?
to avoid orthostatic proteinuria
127
What causes a staghorn calculus ?
struvite
128
What is pyonephrosis?
infected hydronephritis
129
What is the general management of renal stones?
1. analgesia - diclofenac
2. antibiotics if infected - cefuroxime/gentamycin
3. IV fluids
130
What is medical expulsive treatment for renal calculi?
1. CCB e.g. nifedipine
2. OR alpha-blocker e.g. Tamsulosin
they promote expulsion of the stone (<10mm), decrease pain relief requirements and reduce ureteric spasms
131
List the 2 hereditary hypokalaemic tubulopathies.
1. Bartter syndrome
- mutation in co-transporter targeted by loop diuretics
- therefore similar pattern
2. Gitelman syndrome
- mutation in co-transporter targeted by thiazide diuretics
- therefore similar pattern
132
What is the causative organism of haemolytic uraemic syndrome?
E.coli O157:H7
133
Define UTI.
presence of pure growth of >10 to the 5 organisms per ml of fresh MSU
134
List an example of an upper UTI.
pyelonephritis
135
List examples of lower UTIs.
urethritis
cystitis
prostatitis
136
List some common organisms causing UTI.
1. E.coli (75-95% community)
2. proteus mirabilis
3. klebsiella pneumonia
4. staph saprophyticus
137
What is the treatment for cystitis?
nitrofurantoin
138
What is the treatment of pyelonephritis?
cefotaxime
if no response: augmentin/gent
139
Why are thiazide diuretics CI in pts with gout?
there action reduced uric acid excretion
140
Give examples of loop diuretics.
1. furosemide
| 2. bumetanide
141
Give examples of thiazide diuretics.
1. bendroflumethiazide
2. indapamide
3. metolazone
142
Give examples of potassium sparing diuretics.
1. spironolactone
| 2. eplerenone
143
Give an example of an osmotic diuretic.
mannitol
144
What are the indications for using an osmotic diuretic?
1. raised ICP
2. rhabdomyolisis
3. haemolysis
145
Give an example of a carbonic anhydrase inhibitor.
acetazolamide
- -> acts on the PCT to increase excretion of bicarbonate
- -> causes alkalinisation of urine and a subsequent mild metabolic acidosis
146
What are the causes of Fanconi syndrome?
CONGENITAL:
- idiopathic
- cysteinosis
- Wilson's disease
ACQUIRED:
- heavy metal poisoning
- drugs (gentamicin, cisplatin)
- light chains (myeloma, amyloid)
147
What are the indications for dialysis?
pneumonic: AEIOU
```
A - acidosis
E - electrolyte disturbance
I - intoxication
O - overload (fluid)
U - uraemia
```
