Renal Flashcards
1
Q
what is an acute kidney injury (AKI)? how is it measured?
A
- an acute drop in kidney function
- serum creatinine
2
Q
NICE criteria to diagnose an AKI?
A
- rise in creatinine of 20 micromol/L or more in 2 days (48 hours)
- rise in creatinine of 50% or more in 7 days
- urine output of less than 0.5ml/kg/h for over 6 hours
3
Q
what is normal urine output?
A
0.5ml per kg per hour
4
Q
risk factors for developing an AKI?
A
- chronic disease: CKD, HF, DM, liver disease
- old age (>65)
- cognitive impairment
- drugs (NSAIDs, ACE-i)
- contrast used in CT scans
5
Q
how can the causes of AKI be classified? which is most common?
A
- pre-renal (most common)
- renal
- post-renal
6
Q
examples of pre-renal causes of AKI?
A
- dehydration
- hypotension (shock)
- HF
7
Q
describe the pathophysiology of pre-renal AKI
A
- pathology causing reduced blood flow to the kidneys
- less blood gets filtered through them
8
Q
describe the pathophysiology of renal AKI
A
- intrinsic disease of the kidney
- makes it less able to filter blood
9
Q
examples of renal causes of AKI?
A
- glomerulonephritis
- interstitial nephritis
- acute tubular necrosis
10
Q
describe the pathophysiology of post-renal AKI
A
an obstruction to outflow causes urine to build up in the kidney and reduce kidney function
11
Q
examples of post-renal causes of AKI?
A
- kidney stones
- Ca of abdomen / pelvis
- ureter / urethral strictures
- enlarged prostate (BPE)
- Ca of prostate
12
Q
investigations in AKI?
A
- urinalysis
- USS of urinary tract (?obstruction)
13
Q
what might urinalysis show in AKI?
A
depends on underlying cause:
- leukocytes and nitrites (infection)
- protein and blood (acute tubular necrosis, infection)
- glucose (diabetes)
14
Q
how can AKI be prevented?
A
- avoid nephrotoxic meds where possible
- ensure adequate fluids are given
15
Q
management of AKI?
A
treat underlying cause:
- fluid rehydration (IV)
- stop NSAIDs / antihypertensives
- relieve obstruction (e.g. catheter to get past an enlarged prostate)
if severe without clear cause, refer to renal
16
Q
complications of AKI?
A
- hyperkalaemia
- fluid overload, HF, pulmonary oedema
- metabolic acidosis
- uraemia
17
Q
which 2 complications could uraemia (secondary to AKI) cause?
A
- pericarditis
- encephalopathy
18
Q
what is CKD?
A
permanent and progressive reduction in kidney function
19
Q
causes / risk factors of CKD?
A
- DM
- HTN
- age-related decline
- glomerulonephritis
- polycystic kidney disease
- drugs
20
Q
drug causes of CKD?
A
- NSAIDs
- PPIs
- lithium
21
Q
presentation of CKD?
A
- may be asymptomatic
- pruritus
- reduced appetite, nausea
- oedema
- muscle cramps
- peripheral neuropathy
- pallor
- HTN
22
Q
investigations for CKD?
A
- eGFR
- urine albumin : creatinine ratio (ACR)
- urine dipstick
- renal USS
23
Q
how must eGFR be done in order to diagnose CKD?
A
2 tests done 3m apart
24
Q
what is a significant urine ACR reading in CKD? what does this mean?
A
- 3mg/mmol or more
- indicates proteinuria
25
what might urine dipstick show in CKD? why is this important?
- haematuria
| - could be bladder Ca, investigate!!!!
26
which CKD patients should be offered renal USS?
- accelerated disease
- haematuria
- FHx of polycystic kidney disease
- evidence of obstruction
27
how is CKD staged?
G score for each eGFR:
- G1 = >90
- G2 = 60-89
- G3a = 45-59
- G3b = 30-44
- G4 = 15-29
- G5 = <15 (end-stage renal failure)
28
what is A score in CKD?
score based on the albumin : creatinine ratio
29
how is CKD diagnosed?
at LEAST eGFR <60, OR proteinuria
30
complications of CKD?
- anaemia
- bone disease
- CVD
- peripheral neuropathy
- dialysis-related problems
31
when does a CKD patient need a renal referral?
- eGFR <30
- ACR 70mg/mmol or more
- accelerated disease
- uncontrolled HTN despite 4 or more any-hypertensives
32
in CKD, what is classed as "accelerated disease"?
```
one of the following:
- eGFR drops by 15
- eGFR drops by 20%
- eGFR drops by 15ml/min
all within 1 year
```
33
how can the progression of CKD be slowed?
- optimise DM and HTN control
| - treat glomerulonephritis
34
how can complications be reduced in CKD?
- exercise to maintain healthy weight
- stop smoking
- special dietary advice on phosphate, sodium, potassium and water intake
- atorvastatin 20mg for CVD prevention
35
how are complications in CKD treated?
- PO sodium bicarbonate (metabolic acidosis)
- iron and erythropoietin (anaemia)
- vit D (bone disease)
- dialysis / transplant for ESRF
36
first line drug for HTN in CKD? target BP?
- ACE-i
| - <140/90
37
which electrolyte needs to be monitored closely in someone with CKD and on an ACE-i?
- serum K+
| - hyperkalaemia can result from both of these
38
how does CKD cause anaemia?
healthy kidney cells should produce erythropoietin but they don't in CKD
39
How should the iron deficiency in CKD be treated?
- erythropoietin
| - IV iron used in dialysis patients
40
which bone diseases can arise from CKD?
- osteomalacia (softening)
- osteoporosis (brittle)
- ostesclerosis (hardening)
41
X-ray changes seen in CKD bone disease?
- "rugger jersey"
- sclerosis on both ends of vertebra
- osteomalacia in the middle
42
how does CKD cause secondary hyperparathyroidism?
the parathyroid glands respond to the low Ca by secreting more PTH
43
management of renal bone disease in CKD?
- active forms of vit D (alfacalcidol, calcitriol)
- low phosphate diet
- bisphosphates if osteoporotic
44
AEIOU: indications for acute dialysis in AKI patients
- Acidosis (severe, refractory)
- Electrolytes (severe hyperkalaemia)
- Intoxication (drug OD)
- Oedema (severe, pulmonary)
- Uraemic symptoms
45
features of uraemia indicating dialysis?
- seizures
| - reduced consciousness
46
2 indications for long-term dialysis?
- ESRF (CKD stage 5)
| - any acute indications continuing long-term
47
what are the 3 main types of dialysis?
- continuous ambulatory peritoneal dialysis
- automated peritoneal dialysis
- haemodialysis
48
which factors are taken into account when choosing a method for dialysis?
- patient preference
- comorbidities
- individual risks of each type
49
which factors are taken into account when choosing a method for dialysis?
- patient preference
- comorbidities
- individual risks of each type
50
complications of peritoneal dialysis?
- bacterial peritonitis
- peritoneal sclerosis
- ultrafiltration failure
- weight gain
- psychosocial effects
51
which 2 methods are there to access blood flow in order to carry out haemodialysis?
- tunnelled cuff catheter
| - AV fistula
52
complications of an AV fistula?
- aneurysm
- infection
- thrombosis
- stenosis
- STEAL syndrome
- high output heart failure
53
what is STEAL syndrome?
inadequate blood flow to limb distal to AV fistula (it literally STEALS the blood rip)
54
describe the scar left by a renal transplant
hockey stick scar over ipsilateral iliac fossa
55
describe the scar left by a renal transplant
hockey stick scar over ipsilateral iliac fossa
56
what is the immunosuppressant regime used after a kidney transplant? hint: there are 3
- tacrolimus
- mycophenolate
- prednisolone
57
how long is the immunosuppressant regime continued for after a renal transplant?
lifelong
58
complications of a renal transplant?
- transplant rejection
- transplant failure
- electrolyte imbalances
- any complications relating to immunosuppressant therapy
59
features of nephritic syndrome?
- haematuria
- oliguria
- proteinuria
- fluid retention
60
features of nephrotic syndrome?
- peripheral oedema
- proteinuria (>3g/day)
- frothy urine
- low serum albumin
- hypercholesterolaemia
61
define glomerulonephritis
an umbrella term used to describe any condition which causes inflammation of the glomerulus
62
define interstitial nephritis. what are the 2 main diagnoses?
- inflammation between the cells and tubules of the nephron
- acute interstitial nephritis
- chronic tubulointerstitial nephritis
63
define glomerulosclerosis
- scarring of the glomerulus tissue
64
list 3 causes of glomerulosclerosis
- glomerulonephritis
- obstructive uropathy
- focal segmental glomerulosclerosis
65
management of glomerulonephritis?
- steroids
| - ACE-i / ARB
66
complications of untreated nephrotic syndrome?
- thrombosis
- HTN
- high cholesterol
67
most common cause of nephrotic syndrome in children?
minimal change disease
68
most common cause of nephrotic syndrome in adults?
focal segmental glomerulosclerosis
69
what is IgA nephropathy?
- Berger's disease
| - most common cause of primary glomerulonephritis
70
when does IgA nephropathy typically present?
in 20s
71
what is seen on histology in IgA nephropathy?
- IgA deposits
| - glomerular mesangial proliferation
72
what is the most common type of glomerulonephritis overall?
membranous glomerulonephritis
73
how does post-strep GN present?
- patient <30 years old
- weeks after a strep infection
- nephritic syndrome presentation
- full recovery
74
which streptococcal infections could be followed by post-strep GN?
- tonsillitis
| - impetigo
75
key feature of diabetic nephropathy?
proteinuria
76
how is diabetic nephropathy prevented?
it is screened for using albumin:creatinine ratio (ACR) and UEs
77
management of diabetic nephropathy?
- optimise BMs and BP
- ACE-i is antihypertensive of choice
- start even if they have a normal BP
78
how does acute interstitial nephritis present?
delayed onset, 2-40 days after drug trigger:
- AKI
- HTN
- rash
- fever
- eosinophilia
- transient arthralgia in some
79
causes of acute interstitial nephritis?
infection but mostly drugs:
- ABx
- NSAIDs
- diuretics
- rifampicin
- allopurinol
- PPIs
80
management of acute interstitial nephritis?
- remove underlying cause
| - steroids
81
pathophysiology of acute tubular necrosis?
ischaemia / toxins causing death of epithelial cells of the renal tubules
82
causes of acute tubular necrosis? (hint: split into ischaemic and nephrotoxic)
ischaemic:
- shock
- sepsis
- dehydration
nephrotoxic:
- radiology contrast dye
- gentamicin
- NSAIDs
- lithium
- statins
- ACE-i, ARBs
- heroin
83
investigation and findings in acute tubular necrosis?
urinalysis shows "muddy brown casts"
84
management of acute tubular necrosis? hint: same as other AKIs
- supportive
- IV fluid resus
- stop / remove any nephrotoxins
- haemofiltration / haemodialysis if severe
85
pathophysiology of type 1 renal tubular acidosis?
- pathology of distal tubule making it unable to excrete hydrogen ions
- results in acidosis
86
causes of type 1 renal tubular acidosis?
- genetic
- SLE
- sjogren's syndrome
- PBC
- hyperthyroidism
- sickle cell anaemia
- marfan syndrome
87
how does type 1 renal tubular acidosis present?
- FTT in children
- hyperventilation (compensatory)
- CKD
- osteomalacia
88
investigation findings in renal tubular acidosis (type 1 and type 2)?
- low K+
- metabolic acidosis
- urinary pH >6 (high)
89
management of renal tubular acidosis (types 1 and 2)?
PO bicarbonate
90
pathophysiology of type 2 renal tubular acidosis?
pathology of proximal tubule making it unable to reabsorb bicarbonate
91
main cause of type 2 renal tubular acidosis?
fanconi syndrome
92
which group of people is fanconi syndrome most associated with?
Ashkenazi Jews
93
features of fanconi syndrome?
- cafe au lait spots
- triangular face
- microcephaly
- absent radii bones
94
what causes type 4 renal tubular acidosis?
low aldosterone
95
investigation findings in type 4 renal tubular acidosis?
- high K+
- high Cl-
- metabolic acidosis
- low urinary pH (due to low ammonia production)
96
most common type of renal tubular acidosis?
type 4
97
causes of type 4 renal tubular acidosis? hint: these all lower aldosterone levels
- adrenal insufficiency
- ACE-i
- spironolactone
- SLE
- DM
- HIV
98
management of type 4 renal tubular acidosis?
- fludrocortisone (mineralocorticoid, so mimics aldosterone)
- sodium bicarbonate
- treat hyperkalaemia (IV insulin w/ glucose + calcium gluconate)
99
what is haemolytic uraemic syndrome (HUS)? what causes this?
- thrombosis in all the small vessels around the body
| - caused by shiga toxin
100
features of HUS? hint: classic triad
- haemolytic anaemia
- AKI
- thrombocytopenia
101
where does the shiga toxin come from?
either E. coli or shigella infection
102
presentation of HUS?
- E. coli gastroenteritis (bloody diarrhoea)
- reduced UO
- haematuria (dark brown)
- abdo pain
- lethargy, irritability
- confusion
- HTN
- bruising
103
management of HUS?
- medical emergency!
- anti-hypertensives
- blood transfusions
- dialysis
104
prognosis of HUS?
- 10% mortality rate
| - approx 75% make a full recovery
105
what do muscle cells release when they die? (features of rhabdomyolysis)
- myoglobin (myoglobinurea)
- potassium
- phosphate
- creatinine kinase (raised CK)
106
complication of potassium release from rhabdomylosis?
- high K+
- increased risk of arrhythmias
- cardiac arrest
107
causes of rhabdomyolysis?
- prolonged immobility
- extremely rigorous exercise
- crush injuries
- seizures
108
presentation of rhabdomyolysis?
- muscle aches / pains
- oedema
- fatigue
- confusion (esp in elderly)
- red-brown urine
109
investigations and findings in rhabdomyolysis?
- CK (raised, remains high for 1-3 days)
- urine dipstick (positive for blood due to myoglobin)
- UEs (AKI, hyperkalaemia)
- ECG (hyperkalemia changes)
110
management of rhabdomyolysis?
- IV fluids
- IV sodium bicarbonate
- IV mannitol (raises GFR)
- treat hyperkalaemia
111
main complication of hyperkalaemia?
- arrhythmias
| - particularly VF
112
causes of hyperkalaemia?
- AKI
- CKD
- rhabdomyolysis
- adrenal insufficiency
- tumour lysis syndrome
- drugs
113
drug causes of hyperkalaemia?
- spironolactone
- ACE-i, ARBs
- NSAIDs
- potassium supplements
114
what can cause a falsely raised potassium in a blood test?
haemolysis of the sample
115
ECG signs in hyperkalaemia?
- tall tented T waves
- flat / absent P waves
- broad QRS complexes
116
management of acute hyperkalaemia?
- close ECG monitoring
- IV insulin and dextrose infusion
- IV calcium gluconate
117
management of less urgent hyperkalaemia?
- nebulised salbutamol
- IV fluids
- PO calcium resonium
- IV / PO sodium bicarbonate
- dialysis
118
at what level of K+ does hyperkalaemia need to be managed urgently?
- >6mmol/L with ECG changes, OR:
| - >6.5 mmol/L regardless of ECG
119
what is polycystic kidney disease (PKD)? what does it cause?
genetic condition where the kidneys develop fluid-filled cysts
120
which other organs can have cysts in them in PKD?
- liver
- spleen
- pancreas
- ovaries
- prostate
121
extrarenal findings in ADPKD?
- cysts in liver, pancreas, spleen
- cerebral aneurysms
- mitral regurg (from mitral valve prolapse)
- colonic diverticula
- aortic root dilatation
122
what is the mode of inheritance of PKD?
- there are both autosomal dominant and recessive forms
| - autosomal dominant (ADPKD) is more common
123
how is PKD diagnosed?
- USS of kidneys
| - genetic testing
124
which genes are associated with autosomal dominant PKD?
- PKD-1 (chrom 16), majority
| - PKD-2 (chrom 4)
125
complications of PKD?
- chronic loin pain
- HTN
- CVD
- gross haematuria
- renal stones
- ESRF aged 50
126
management of PKD?
- tolvaptan
- manage the complications
- genetic counselling
- avoid contact sports
- regular USS to monitor cysts
127
what is haemolytic uraemic syndrome (HUS)? what causes this?
- thrombosis in all the small vessels throughout the body
| - caused by shiga toxin
128
how does autosomal recessive PKD (ARPKD) present?
- oligohydramnios in pregnancy
- underdeveloped lungs, resp failure shortly after birth
- flat nasal bridge
- low set ears
- ESRF before reaching adulthood
129
renal features of ADPKD?
- flank pain
- renal dysfunction
- HTN
- haematuria
- microalbuminuria
130
most common complication of dialysis?
dialysis-induced hypotension
131
criteria for stage 1 AKI?
either:
- Cr >1.5x baseline
- UO <0.5ml/kg/hr for 6h
132
criteria for stage 2 AKI?
either:
- Cr >2x baseline
- UO <0.5ml/kg/hr for 12h
133
criteria for stage 3 AKI?
any of these:
- Cr >3x baseline
- Cr >354
- UO <0.3ml/kg/hr for 24h
- anuria for 12h
134
which other conditions are associated with focal segmental glomerular sclerosis?
- IgA nephropathy (berger's disease)
- HIV
- sickle cell disease
135
first line renal replacement therapy in ESRF? why is this preferred?
- peritoneal dialysis
- does not require AV fistula
- can be done at home
136
which variables are taken into account to calculate eGFR?
- age
- sex
- Cr
- weight
