Revision - CKD & AKI Flashcards
What ACR is defined as clinically important proteinuria?
≥3 mg/mmol
What ACR is:
a) Normal to mildly increased
b) Moderately increased
c) Severely increased
a) <3
b) 3-30
c) >30
When can a diagnosis of CKD be made?
(2)
When there are consistent results of 3 months of either:
1) eGFR <60
or
2) ACE >3 mg/mmol
How long must features be present for for CKD diagnosis?
At least 3m
What is accelerated progression in CKD?
A sustained decline in eGFR within 1 year of either >25% or 15 ml/min
Complications of CKD?
1) anaemia
2) renal bone disease
3) CVD
4) peripheral neuropathy
5) end-stage kidney disease
6) dialysis related complications
At what eGFR does anaemia typically become apparent in CKD?
when the GFR is less than 35 ml/min (other causes of anaemia should be considered if the GFR is > 60 ml/min).
What does anaemia in CKD predispose to?
To the development of LV hypertrophy (increase in mortality)
Bone profile results in renal bone disease?
1) low vit D
2) high phosphate
3) low calcium
4) 2ary hyperparathyroidism
Cause of increased phosphate in CKD?
Reduced phosphate excretion by kidneys
Characteristic xray finding in renal bone disease?
Rugger jersey spine
This involves sclerosis of both ends of each vertebral body (denser white) and osteomalacia in the centre of the vertebral body (less white).
How can ACEi affect creatinine?
What rise is acceptable?
As these drugs tend to reduce filtration pressure a small fall in glomerular filtration pressure (GFR) and rise in creatinine can be expected.
NICE suggest a rise in creatinine of up to 30% is acceptable.
When are ACEi offered to:
a) patients with diabetes
b) patients with HTN
c) anyone
a) ACR >3
b) ACR >30
c) ACR >70
2 drugs used for proteinuria in CKD?
1) ACEi (or ARBs)
2) SLGT-2 inhibitors
What is the SGLT-2 inhibitor licensed for CKD?
Dapagliflozin
Criteria for diagnosing an AKI?
a) Rise in creatinine
b) Urine output
a) 50% in 7 days or 25micromol/L in 48h
or
b) urine output <0.5ml/kg/hr for 6 hours
Pre-renal causes of AKI?
1) Dehydration
2) Shock e.g. sepsis
3) Hypovolaemia e.g. D&V
4) Renal artery stenosis
5) HF
Renal causes of AKI?
1) Rhabdomyolysis
2) ATN
3) AIN
4) Glomerulonephritis
5) Tumour lysis syndrome
6) HUS
Dose of calcium gluconate given to stabilise the cardiac membrane in hyperkalaemia?
IV 10ml 10% calcium gluconate
What is used for the removal of potassium from the body in hyperkalaemia?
Calcium resonium
(or dialysis)
Management of all patients with suspected AKI secondary to urinary obstruction?
Prompt review by urologist
What is the most common intrinsic cause of AKI?
ATN
Via what 2 ways can damage to kidney cells occur in ATN?
1) Ischaemia due to hypoperfusion (e.g., dehydration, shock or heart failure)
2) Nephrotoxins (e.g. gentamicin, radiocontrast agents or cisplatin)
What confirms ATN on urinalysis?
Muddy brown casts (renal tubular epithelial cells)
Indications for dialysis?
AEIOU
A - Acidosis
E - Electrolyte imbalance e.g. treatment resistant hyperkalaemia
I - Intoxication e.g. lithium, ethylene glycol
O - Oedema (e.g. pulmonary)
U - Uraemia
What 2 complications can uraemia cause?
1) Encephalopathy
2) Pericarditis
Define azotemia
Elevation, or buildup of, nitrogenous products (BUN-usually ranging 7 to 21 mg/dL), creatinine in the blood, and other secondary waste products within the body.
Urine sodium in pre-renal uraemia vs ATN?
Pre-renal uraemia: <20 mmol/L i.e. low (kidneys hold on to sodium to preserve volume)
ATN: >40 mmol/L i.e high
Urine osmolality in pre-renal uraemia vs ATN?
Pre-renal uraemia: >500 (high i.e. very conc)
ATN: <350 (low)
Response to fluid challenge in pre-renal uraemia vs ATN?
Pre-renal uraemia: Good
ATN: Poor
Serum urea:creatinine ratio in pre-renal uraemia vs ATN?
Pre-renal uraemia: Raised
ATN: Normal
Why are potassium sparing diuretics contraindicated in AKI?
Due to risk of hyperkalaemia
What is TURP syndrome?
A rare and life-threatening complication of transurethral resection of the prostate surgery.
Cause of TURP syndrome?
Irrigation with large volumes of glycine (hypo-osmolar) –> systemically absorbed when prostatic venous sinuses are opened up during prostate resection.
Key feature of TURP syndrome?
Hyponatraemia
What surgery time is a risk factor for TURP syndrome?
> 1 hour
Is warfarin safe to continue in an AKI?
Yes
What is the most common cause of death in CKD patients on haemodialysis?
IHD
Which NSAID can be continued in AKI?
Aspirin at cardioprotective dose
Give 7 causes of hyperkalaemia
1) AKI
2) CKD
3) Rhabdomyolysis
4) Massive blood transfusion
5) Tumour lysis syndrome
6) Adrenal insufficiency (Addison’s)
7) Drugs e.g. potassium sparing diuretics, ARBs/ACEi
What can cause pseudohyperkalaemia during sampling?
Haemolysis (rupture of blood cells) during sampling –> recommend a repeat sample.
Give 4 ECG changes in hyperkalaemia
1) Tall tented T waves
2) Broad QRS
3) Prolonged QT
4) Flattened/absent P waves
Is hyperkalaemia associated with acidosis or alkalosis?
Acidosis
Beta blockers vs beta agonists (e.g. salbutamol) in hyperkalaemia?
Beta blockers –> interfere with potassium transport into cells (can cause hyperkalaemia in patients with renal failure)
Beta agonists –> cause intracellular shift of K+ (fall in potassium) hence used in hyperkalaemia treatment
In hyponatraemia causes, what 3 tests should be ordered?
1) urine osmolality
2) plasma osmolality
3) urinary sodium
Give some causes of hyponatraemia if the patient is hypovolaemic w/ urinary sodium >20 mmol/l?
This is due to renal losses:
- Addison’s
- Renal failure
- Diuretics
Give some causes of hyponatraemia if the patient is hypovolaemic w/ urinary sodium <20 mmol/l?
This is due to loss NOT by kidneys:
1) D/V
2) SBO
3) Burns
4) Excessive sweating
5) Fistulae
Give some causes of hyponatraemia if the patient is euvolaemic
If raised urine osmolality –> SIADH (most common)
If not raised urine osmolality:
1) water intoxication
2) severe hypothyroidism
3) Glucocorticoid insufficiency
Give some causes of hyponatraemia if the patient is hypervolaemic
1) HF
2) Renal failure
3) Cirrhosis
4) Neprotic syndrome
Give 4 causes of hypernatraemia
1) Dehydration
2) Diabetes insipidus
3) Excess IV saline
4) Osmotic diuresis e.g. HHS
Hypokalaemia can be associated with alkalosis or acidosis.
Give some causes of hypokalaemia with alkalosis
1) Vomiting
2) Thiazide diuretics
3) Cushing’s
4) Conn’s (primary hyperaldosteronism)
Give some causes of hypokalaemia with acidosis
1) diarrhoea
2) renal tubular acidosis
3) acetazolamide
4) partially treated diabetic ketoacidosis
