Acute Kidney Injury and Glomerular Disease Flashcards
(164 cards)
1
Q
What is oliguria?
A
Less than 500ml of urine per day, or less than 20ml/hour
2
Q
What is anuria?
A
Less than 100ml of urine per day
3
Q
What does anuria indicate?
A
Blockage of urine flow
4
Q
What are the types of acute renal injury (AKI)?
A
- Pre-renal disease
- Post-renal failure
- Intrinsic renal failure
5
Q
What happens in pre-renal disease?
A
Decreased perfusion
6
Q
What happens in post-renal failure?
A
Obstruction
7
Q
What happens in intrinsic renal failure?
A
Damage to kidney
8
Q
What can cause pre-renal disease?
A
- Volume depletion
- Heart failure
- Cirrhosis
9
Q
What are the types of intrinsic renal failure?
A
- Renal artery occlusion
- Renal parenchymal
- Renal vein occlusion
10
Q
What can cause renal parenchymal failure?
A
- Intrarenal vascular
- Glomerulonephritis
- Ischaemic ATN
- Toxic ATN
- Interstitial disease
- Intrarenal obstruction
11
Q
What can cause post-renal failure?
A
Urinary tract obstruction
12
Q
What happens unless the cause of pre-renal AKI is recognised and treated promptly?
A
Acute tubular necrosis (ATN) will develop
13
Q
What can cause reduced renal perfusion?
A
- Reduced effective ECF volume
- Impaired renal autoregulation
14
Q
What can cause a reduced effective ECF volume?
A
- Hypovolaemia
- Systemic vasodilation
- Cardiac failure
15
Q
What can cause hypovolaemia?
A
- Blood loss
- Fluid loss
16
Q
What can cause systemic vasodilation?
A
- Sepsis
- Cirrhosis
- Anaphylaxis
17
Q
What can cause cardiac failure?
A
- LV dysfunction
- Valve disease
- Tamponade
18
Q
What does renal autoregulation do?
A
Maintains a normal perfusion over a range of systemic BP
19
Q
What can cause impaired renal autoregulation?
A
- Preglomerular vasoconstriction
- Postglomerular vasodilation
20
Q
What can cause preglomerular vasoconstriction?
A
- Sepsis
- Hypercalcaemia
- Hepatorenal syndrome
- Drugs
21
Q
What drugs can cause preglomerular vasoconstriction?
A
NSAIDS
22
Q
What can cause postglomerular vasodilation?
A
- ACE inhibitors
- Angiotensin II Antagonists
23
Q
What does post-renal AKI indicate?
A
An obstruction to urine flow after the urine has left the tubule
24
Q
What % of AKIs are accounted for by pre-renal AKI?
A
10%
25
Where can an obstruction to urine flow occur?
* Ureters *(bilateral)*
* Bladder
* Urethra
26
How can obstructions to urine flow be classified?
* Within the lumen
* Within the wall
* Pressure from outside
27
What can cause urine obstruction within the lumen?
* Calculi
* Clot
* Papillary necrosis
* Tumour
28
What tumours can cause urine obstruction within the lumen?
* Renal pelvis
* Ureter
* Bladder
29
Where in the lumen can stones cause obstruction of urine?
* Both renal pelves/ureters *(unless only one functioning kidney)*
* Neck of bladder
* Urethra
30
What size urinary stones do not usually pass through lumen?
\>10mm
31
What symptoms are common with urinary stones stuck within the lumen?
* Pain
* Haematuria
32
What can cause obstruction to urine flow within the wall?
* Congential
* Ureteric stricture
33
What are the congential cuases of urine flow obstruction within the wall?
* Pelviureteric neuromuscular dysfunction
* Megaureter
* Neurogenic bladder
34
Does obstruction to urine flow caused by something within the wall usually cause chronic or acute kidney injury?
Chronic
35
What can cause obstruction to urine flow due to pressure from outside?
* Prostatic hypertrophy
* Malignancy
* Aortic aneurysm
* Diverticulitis
* Accidental ligation of ureter *(during surgery*
36
What % of AKIs do instrinsic AKIs account for?
30%
37
What are intrinsic AKIs?
Direct injury to kidney
38
What are the causes of intrinsic AKIs?
* Acute tubular necrosis (ATN)
* Glomerular and arteriolar disease
* Acute tubule-interstitial nephritis
39
What are the causes of acute tubular necrosis?
* Severe acute ischaemia
* Toxic acute tubular necrosis
40
What are the causes of severe acute tubular ischaemia?
Pre-renal causes
41
What happens if the fall in renal perfusion is not treated promptly in severe acute ischaemia?
Tubular necrosis results
42
What happens in acute tubular necrosis?
Nephrotoxins damage epithelail cells lining the tubules, and cause cell death and shedding into lumen
43
Are nephrotoxins endogenous or exogenous?
Can be either
44
When is acute tubular necrosis much more likely?
If there is reduced perfusion and a nephrotoxin
45
How is acute tubular necrosis identified?
* Muddy brown casts (idk wat this is)
* Fractional excretion of Na _\>_ 3%
46
Give 3 endogenous nephrotoxins
* Myoglobin
* Urate
* Bilirubin
47
Give 4 exogenous nephrotoxins
* Endotoxin
* X-ray contrast
* Drugs
* Other poisions
48
What other poisons can act as nephrotoxins?
* Weedkillers
* Antifreeze
*
49
What drugs can act as nephrotoxins?
* ACE inhibitors
* Aminoglycosides
* NSAIDs
* Gentamicin
* Angiotensin receptor blockers
50
Why can NSAIDs act as nephrotoxins?
* Prostaglandins normally cause vasodilation of afferent arterioles in renal autoregulation
* NSAIDs inhibit prostaglandin production *(inhibit COX enzyme)*
* Unopposed vasoconstriction of afferent arteriole -\> reduced glomerular perfusion pressure -\> AKI
51
How is fractional excretion calculated?
52
What glomerular and arteriolar disease can cause intrinsic AKI?
Acute glomerulonephritis
53
What is acute glomerulonephritis?
Immune disease affecting the glomerulus
54
What are the types of acute glomerulonephritis?
* Primary
* Secondary
55
What does primary acute glomerulonephritis affect?
Only the kidneys
56
What happens in secondary acute glomerulonephritis?
Kidneys are involved as part of systemic process
57
What conditions are associated with acute glomerulonephritis?
* SLE
* Vasculitis
58
What is acute tubulo-interstitial nephritis?
Inflammation of kidney intersticium
59
What are the causes of acute tubulo-interstitial nephritis?
* Infection
* Toxin induced
60
What infection can cause acute tubulo-interstitial nephritis?
Acute pyelonephritis
61
What is acute pyelonephritis?
Ascending bacterial infection
62
What can cause toxin induced acute tubulo-interstitial nephritis?
Drugs
63
When is an AKI pre-renal?
When the kidneys are underperfused
64
What can cause the kidneys to be underperfused?
* Shock
* Severe vascular disease
65
What types of shock can cause the kidneys to be underperfused?
* Hypovolaemic
* Septic
* Cardiac
66
What can cause the kidneys to be underperfused in severe vascular disease?
Emboli
67
When is an AKI renal?
* When nephrotoxins are implicated
* Parenchymal disease
* Multisystem disease
68
When are nephrotoxins implicated?
* Drugs
* Sepsis
* Myoglobin
69
What multisystem disease can cause renal AKI?
UTI
70
When is an AKI post-renal?
When there is a renal tract obstruction
71
What is investigated in pre-renal AKI?
Cardiac failure
72
How can cardiac failure cause AKI?
Overloading kidney
73
What will be found on investigation with AKI caused by cardiac failure?
* Gallop rhythm
* Raised BP
* Raised JVP
* Pulmonary oedema
* Peripheral oedema
74
What are the features of pulmonary oedema on investigation?
* Basal crackles
* Dyspnoea
75
Where is peripheral oedema found in cardiac failure causing AKI?
* Sacral
* Ankle
76
What will be found on investigation with sepsis causing renal AKI?
* Pyrexia and rigors
* Vasodilation
* Warm peripheries
* Bounding pulse
* Rapid capillary fill
* Hypotension
77
What will be found on investigation with urinary tract obstruction causing post-renal AKI?
* Anuria
* Single functioning kidney
* History of renal stones, prostatism, or previous pelvic/abdominal surgery
* Palpable bladder
* Pelvic/abdominal masses
* Enlarged prostate (DRE)
78
What methods are used to investigate patients with AKI?
* Serum biochemistry
* ECG
* Urine testing
* Soluble immunological tests
* Imaging
* Histology
79
What will be found on serum biochemistry with AKI?
* **Increased urea**
* **Increased creatinine**
* Hyperkalaemia
* Hyponatraemia
* Hypocalcaemia
* Hyperphophataemia
80
What causes ECG changes in AKI?
Hyperkalaemia
81
What will be seen on ECG with hyperkalaemia?
* Tall T waves
* Small/absent P waves
* Increase in PR interval
* Wide QRS complex
* 'Sine wave' pattern
* Asystole
82
What urine testing is conducted when investigating AKI?
* Dipstick testing
* Microscopy
83
What is being looked for with dipstick testing for AKI?
* Blood
* Protein
* Leucocytes
84
Is proteinuria present with pre-renal AKI?
No
85
Is haematuria seen with pre-renal AKI?
No
86
Is proteinuria seen with ATN?
No
87
Is haematuria seen with ATN?
No
88
Is proteinuria seen with glomerulonephritis?
Yes, lots
89
Is haematuria seen with glomerulonephritis?
Yes, lots
90
What will be seen on microscopy with pre-renal AKI?
Hyaline cast
91
What is hyaline cast?
Aggregations of protein seen in concentrated urine
92
Is hyaline cast normal?
Yes
93
What will be seen on microscopy with acute tubular necrosis?
Muddy brown cast
94
What will be seen on microscopy with rapidly progressing glomerulonephritis?
Red blood cell cast
95
What is detected by soluble immunological tests with AKI?
Circulating antibodies
96
What ciculating antibodies may be found with AKI?
* Anti-nucleur antibodies
* Anti-neutrophil cytoplasmic antibody
* Anti-glomerular basement membrane antibodies
97
In what condition would anti-nucleur antibody be found circulating?
SLE
98
In what condition would anti-neutrophil cytoplasmic antibody be found circulating?
Systemic vasculitis
99
In what condition would anti-glomerular basement membrane antibodies be found circulating?
Goodpasture's disease
100
What imaging is conducted when investigating AKI?
* Ultrasound
* CXR
101
What is being looked for on ultrasound with AKI?
* Renal size
* Hydronephrosis
* Presence of obstruction
102
What is being looked for on CXR with AKI?
Pulmonary oedema
103
What is required for histology when investigating AKI?
Biopsy
104
When is a biopsy obtained in AKI?
* When pre-renal and post-renal AKI have been ruled out
* A confident diagnosis of ATN cannot be made
* Systemic inflammatory symptoms or signs are present
105
Here come dat boi
O shit waddup
106
What is treatment of AKI dictated by?
Its cause
107
What is the treatment for pre-renal failure?
Volume correction
108
How is hypovolaemia treated?
Fluid administration
109
How is heart failure treated?
Diuretic
110
How is post-renal failure treated?
Urological intervention to re-establish urine flow
111
How is acute tubular necrosis treated?
*Treament is supportive,* maintaing good kidney perfusion and avoiding nephrotoxins
112
When is dialysis initiated in AKI?
If the kidneys can no longer adequately excrete salt, water, and potassium
113
How is asymptomatic glomerular disease detected?
Incidentally, by dipstick analysis
114
When may asymptomatic glomerular disease be detected incidentally?
At a health check or life insurance medical
115
How can asymptomatic glomerular disease be detected in dipstick analysis?
Microscopy haematuria, proteinuria, or both
116
What is sometimes detected at the same time as asymtomatic glomerular disease?
Hypertension
117
What is the first investigation carried out following urine dipstick in asymptomatic glomerular disease?
Cystoscopy
118
Is a renal biopsy mandatory in asymptomatic glomerular disease?
No
119
What can cause microscopic haemtauria?
* Renal stones/tumours
* Arteriovenous malformations
* Glomerular disease
120
What is considered to be non-nephrotic proteinuria?
\<3.5g/24hrs protein in urine
121
Can microscopic proteinuria be associated with conditions other than glomerulonephritis?
Yes
122
Who is the cutest g pig in the world?
Gypsy
123
What is often true of episodic macroscopic haematuria associated with glomerular disease?
It is often brown or smoky in colour, rather than red
124
Are clots found in macroscopic haematuria?
Very unusual
125
What does episodic macroscopic haematuria with glomerular disese need to be distinguished from?
Other causes of red or brown urine
126
Other than haematuria, what are the other causes of red or brown urine?
* Haemoglobin uria
* Myoglobinuria
* Consumption of food dyes
127
Is macroscopic haematuria painful or painless?
Usually painless
128
What is the commnest glomerular cause of macroscopic haematuria?
IgA nephropathy
129
What does macroscopic haematuria require?
Urological workup
130
What is nephrotic syndrome?
A non-specific disorder, where the kidneys are damaged, leaking large amount of protein into urine
131
What are the classical triad of findings in nephrotic syndrome?
* Proteinuria *(\>3.5g/24hrs)*
* Hypoalbuminaemia
* Oedema
132
What is variably present in nephrotic syndrome?
* Hyperlipiaemia
* Muehrcke's bands
133
What does nephrotic syndroem require for diagnosis?
Renal biopsy
134
How is the biopsy taken when investigating nephrotic syndrome?
Using an ultra-sound guided needle
135
Where is the biopsy aimed when investigating nephrotic syndrome?
At the bottom of the kidney
136
Why is the biopsy aimed at the bottom of the kidney when investigating nephrotic syndrome?
To make sure a piece of cortex is biopsied
137
Why must a piece of cortex be biopsied in nephrotic syndrome?
As there are no glomeruli in the medulla, so it would not be useful for diagnosis
138
What are the causes of nephrotic syndrome?
* Minimal change glomerulonephritis
* Focal segmental glomerulosclerosis
* Membranous glomerulonephritis
139
What is nephritic syndrome?
A collection of signs (syndrome) associated wth disorders affecting the kidneys, especially glomerular disorders, characterised by having small pores in the podocytes of glomerulus large enough to permit proteins and red blood cells
140
What are the features of nephritic syndrome
* Rapid onset
* Oliguria
* Hypertension
* Generalised oedema
* Haematuria with smoky brown urine
* Normal serum albumin
* Variable renal impairment
* Urine contains blood protein and red blood cell casts
141
Describe the onset of nephrotic syndrome
Insidious
142
Describe the onset of nephritic syndrome
Abrupt
143
Is there oedema in nephrotic syndrome?
Yes, ++++
144
Is the oedema in nephritic syndrome?
Yes, ++
145
What happens to BP in nephrotic syndrome?
No change
146
What happens to JVP in nephrotic syndrome?
Same or decreasd
147
What happens to BP in nephritic syndrome?
Increased
148
What happens to JVP in nephritic syndrome?
Increased
149
Is there proteinuria in nephrotic syndrome?
Yes, ++++
150
Is the proteinuria in nephritic syndrome?
Yes, ++
151
Is there haematuria in nephrotic syndrome?
May or may not occur
152
Is there haematuria in nephritic syndrome?
Yes, +++
153
Are there red cell casts in nephrotic syndrome?
No
154
Are there red cell casts in nephritic syndrome?
Yes
155
What happens to serum albumin in nephrotic syndrome?
Decreased
156
What happens to serum albumin in nephritic syndrome?
Same or slightly reduced
157
What does rapidly progressive glomerulonephritis describe?
A clinical situation in which glomerular injury is so severe that renal function deteriorates over days
158
How may a patient present with rapidly progressive glomerulonephritis?
As a uraemic emergency, with evidence of extrarenal disease
159
What is rapidly progressive glomerulonephritis associated with?
Crescenteric glomerulonephritis
160
What is required for diagnosis of rapidly progressive glomerulonephritis?
Renal biopsy
161
What is the natural course of many forms of glomerulonephritis?
Slowly progressive renal impairment, including;
* Hypertension
* Dipstick abnormalities
* Uraemic syndrome
162
What is chronic renal failure often associated with?
Small, smooth, shrunken kidneys
163
What is the problem with biopsies in chronic renal failure?
* They are hazardous
* Unlikely to produce diagnostic material
164
What are the symptoms of chronic renal failure?
* Tiredness and lethargy
* Breathlessness
* Aches and pains
* Sleep reversal
* Nocturia
* Restless legs
* Itching
* Chest pains
* Seizures and comas
