AKI

Question 1

Accelerated HT

Answer 1

Diastolic Over 120
Medical emergency
Papilloedema, HF, fits, AKI

Question 2

Extra-renal manifestations

Answer 2

Leukonychia (hypoalbuminaemia)

Question 3

Mb in urine

Answer 3

Rhabdomyolysis - nephritic syndrome
Protein breakdwon
Excess exercise, trauma, dehydrated
CK raised

Question 4

ECG in hyperkalaemia

Answer 4

Tall tented T waves
No/flat P waves
Long ST segment
Sin waves
VT -> VF -> asystole
Can mean rhabdomyolysis

Question 5

What is AKI?

Answer 5

Abrupt reduction in kidney function (less than 48 hours)
Increase in serum creatinine by 26.4
Increase in creatinine by 50%
Reduction in UO

Question 6

Pre-renal causes of AKI

Answer 6

Hypovolaemia (haemorrhage)
Hypotension (shock)
Renal hypoperfusion (NSAID/ACEI/ARB)

Question 7

What is pre-renal AKI?

Answer 7

Reversible volume depletion leading to oliguria and increased creatinine

Question 8

Normal urine output

Answer 8

0.5ml/kg/hour

Question 9

Oliguria

Answer 9

Less than 0.5ml/kg/hour

Question 10

Effect of AT on efferent arteriole

Answer 10

Vasoconstricts = increased GFR

Question 11

Effect of ACEI/ARB/diuretic/NSAID on efferent arteriole

Answer 11

Vasodilates = decreased GFR

Warn patients about sick day rules (diarrhoea/vomiting = stop taking meds)

Question 12

Untreated pre-renal AKI leads to:

Answer 12

Acute tubular necrosis

Question 13

What is acute tubular necrosis?

Answer 13

Commonest form of AKI in hospital

Decreased renal perfusion due to low BP/sepsis/dehydration/rhabdomyolysis/drug toxicity

Question 14

Treatment of pre-renal AKI

Answer 14

Supportive: reverse cause (stop drugs, rehydrate, antibiotics), dialysis
Asses hydration
0.9% NaCl, NOT dextrose

Question 15

What is renal AKI?

Answer 15

Diseases causing inflammation or damage to cells causing AKI

Question 16

Causes of renal AKI

Answer 16

Vascular: vasculitis, renovascular disease
Glomerular: GN
Interstitial nephritis: drugs (NSAIDs, PPIs, antibiotics), infection (TB, sarcoid)
Tubular injury: ischaemia (prolonged hypoperfusion), drugs (gentamicin), contrast, rhabdomyolysis

Question 17

Symptoms of renal AKI

Answer 17

Anorexia, weight loss, fatigue
N+V
Itch
Oedema, SOB (fluid overload)

Question 18

Signs of renal AKI

Answer 18

Fluid overload (HT, oedema, pulmonary oedema, effusions)
Uraemia (itch, pericarditis - rub)
Oliguria

Question 19

Sore throat

Answer 19

Post-Strep GN

Question 20

Rash, joint pains

Answer 20

SLE, vasculitis

Question 21

D+V

Answer 21

ACEI

Question 22

Haemoptysis

Answer 22

Goodpastures

Question 23

Ca low, phosphate high

Answer 23

Vit D deficient (CKD)

Question 24

Eosinophilia

Answer 24

Interstitial nephritis

Question 25

High CK, dark urine (Mb)

Answer 25

Rhabdomyolysis - IVDU

Question 26

Vascular bruit

Answer 26

Renal artery stenosis

Question 27

Investigations for renal AKI

Answer 27

``` U&Es - K, Na, creatinine, urea FBC and coag screen (anaemia, CKD, MM) Urinalysis (protein, blood) US (obstruction) Immunology (ANA, ANCA, GBM) Protein electrophoresis and BJP (MM) ```

Question 28

Urgent indications for renal biopsy

Answer 28

Rapidly progressive GN | Positive immunology and AKI

Question 29

Semi-urgent indications for renal biopsy

Answer 29

Unexplained AKI | To rule out obstruction, volume depletion and ATN

Question 30

What do you have to ensure before biopsy?

Answer 30

Normal clotting Not on warfarin/aspirin Normotensive No hydronephrosis

Question 31

Treatment of renal AKI

Answer 31

Good perfusion pressure: fluid resus, inotrope/vasopressor Underlying cause: antibiotics Stop nephrotoxics (ACEI/NSAID/diuretic/Gen) Dialysis if anuric and uraemia

Question 32

Life threatening complications of renal AKI and indications for dialysis

Answer 32

Hyperkalaemia (life threatening) Fluid overload (oliguric/anuric, not responding to diuretics) Severe metabolic acidosis pH less than 7.15 Uraemia - pericardial rub, over 40

Question 33

What is post-renal AKI?

Answer 33

Obstruction of urine flow leading to back pressure (hydronephrosis) and loss of concentrating ability

Question 34

Causes of post-renal AKI

Answer 34

Stones, cancers, strictures, extrinsic pressure

Question 35

Treatment of post-renal AKI

Answer 35

Relieve obstruction: catheter, nephrostomy | Stent

Question 36

Hyperkalaemia

Answer 36

Life threatening complication of AKI | Over 5.5

Question 37

Life threatening hyperkalaemia

Answer 37

Over 6.5

Question 38

Treatment of hyperkalaemia

Answer 38

Cardiac monitor and IV access 10ml 10% Ca gluconate over 10 mins Insulin (actrapid 10 units) with 50ml 50% dextrose Salbutamol neb 2.5mg Na bicarbonate if acidotic Ca resonium (NOT in acute setting, prevents GI absorption)

Question 39

Urgent indications for emergency dialysis

Answer 39

Hyperkalaemia over 7 or over 6.5 unresponsive to therapy Severe acidosis pH less than 7.35 Uraemia over 40 and pericardial rub Fluid retention unresponsive (pulmonary oedema)

Question 40

Risk factors for AKI

Answer 40

Age Diabetes Comorbidity CKD

Question 41

Nephrotoxic drugs

Answer 41

``` ACEI ARB NSAID Contrast (CT) Gentamicin ```