FN: Acute Kidney Injury

Question 1

Definition

Answer 1

Significant decline in renal function over hrs or days manifesting as an abrupt and sustained raise in SE U and CR

Question 2

Causes

Answer 2

Pre-renal and ATN account for 80%

Question 3

Renal causes

Answer 3

ATN:

1. ischaemia: shock, HTN, HUS, TTP
2. Direct nephrotoxins: drugs, contrast, Hb

Acute TIN: drug hypersensitivity
Nephritic syndrome

Question 4

Post-renal

Answer 4

SNIPPIN
Stone
Neoplasm
Inflammation: stricture
Prostatic hypertrophy
Posterior urethral valves
Infection: TB, schisto
Neuro: post-op, neuropathy

Question 5

Presentation

Answer 5

Uraemia/Azotaemia
Acidosis
Hyperkalaemia
Fluid overload:
1. Oedema, inc. pulmonary
2. Raised BP (or decreased)
3. S3 gallop
4. Raised JVP

Question 6

Chronic features

Answer 6

Hx of comorbidity: DM, HTN
Long duration of symptoms
Previously abnormal bloods (GP records)

Question 7

Clinical assessment

Answer 7

Acute or chronic
Volume depleted
GU tract obstruction
RAre cause

Question 8

Volume depleted? signs

Answer 8

Postural hypotension
Reduced JVP
Raised Pulse
Poor skin turgor, dry mucus membranes

Question 9

GU tract obstruction?

Answer 9

Suprapubic discomfort
Palpable bladder
Enlarge prostate
Catheter
Complete anuria (rare in ARF)

Question 10

Rare cause

Answer 10

Assoc. with proteinuria ± haematuria

Vasculitis: rash, arthralgia, nosebleed

Question 11

Investigations

Answer 11

bloods
ABG
GN screen

Urine
ECG
CXR
Renal US

Question 12

Bloods shows

Answer 12

FBC
U+E
LFT
Glucose
Clotting
Ca ESR

Question 13

ABG

Answer 13

Hypoxia (oedema), acidosis, raised K+

Question 14

GN screen

Answer 14

if cause unclear

Question 15

Urine

Answer 15

Dip
MCS
Chemistry (U+E, PCR, osmolality, BJP)

Question 16

ECG show

Answer 16

Hyperkalaemia

Question 17

CXR

Answer 17

Pulmonary oedema

Question 18

Renal US

Answer 18

Renal size

Hydronephrosis

Question 19

NB urine osmolality

Answer 19

In pre-renal failure, urine is concentrate and NA is reabsorbed - raised osmolality, Na

Question 20

Classification

Answer 20

RIFLE classification

Question 21

Treatment general

Answer 21

1. Identify and Rx pre-renal or post-renal causes
2. Urgent US
3. Rx exacerbating factors e.g. sepsis
4. Give PPis
5. Stop nephrotoxins: NSAIDS, ACEi, gent, nac
6. Stop metformin if Cr >150mM

Question 22

Monitoring

Answer 22

Catheterise and monitor UO
Consider CVP
Fluid balance
Wt.

Question 23

Hyperkalaemia features

Answer 23

Peaked T waves
Flattened P waves
Raised PR interval
Widened QRS
Sine-wave pattern  - VF

Question 24

Management of Hyperkalaemia

Answer 24

1. 10ml 10% calcium gluconate
2. 100ml 20% glucose + 10u insulin (Actrarapid)
3. Salbutamol 5mg nebuliser
4. Calcium resonium 15g PO or 30g PR
5. Haemogiltration (usually needed if anuric)

Question 25

Pulmonary Oedema

Answer 25

1. Sit up and give high flow oxygen
2. Morphine 2.5 mg IV (±metaclopramide 10mg IV)
3. Frusemide 120-250mg IV over 1h
4. GTN spray ± ISMN IVI (unless SBP

Question 26

Bleeding

Answer 26

Raised urea impairs haemostasis
FFP + Plats as needed
Transfuse to maintain HB >10

Question 27

Indications for Acute Dialysis (AEIOU)

Answer 27

1. Persistant hyperkalaemia (7mM)
2. Refractory pulmonary oedema
3. Symptomatic uraemia: encephalopathy, pericarditis
4. Severe metabolic acidosis (pH