Acute kidney injury

Question 1

Classification of AKI

Answer 1

AKIN Stage
1= 1.5-2.0x increase from baseline or oligouria
2= >2.0-3.0x increase or oligouria
3= >3x increase from baseline or Cr>355 or anuria or need for RRT

Question 2

Definition of AKI

Answer 2

Acute rise in serum Cr
Acidosis and hyperkalaemia common
Urine output variable

Features of CKD absent - Anaemia, high PO4, high PTH, Small kidneys

Question 3

Risk factors of AKI

Answer 3

Elderly
Previous AKI
CKD
DM
Vascular disease
Sepsis - HIGH MORTALITY

Question 4

Types of AKI

Answer 4

Define by cause in relation to kidney

Prerenal - most common –> reduced perfusion of the kidney
Renal - intrinsic disease
Post renal - obstruction

Question 5

Pre-renal AKI

Answer 5

Physiologic response to volume depletion
Constriction of efferent arterioles –> increased filtration and decreased hydrostatic force–> increased sodium reabsorption and H2O reabsorption –> decreased urine output

Treatment:

• Reperfuse with hydration
• ? diuretics
• RRT

Question 6

Post Renal AKI

Answer 6

Bilateral obstruction is required to cause AKI
Ultrasound –> diagnosis

Refer to surgeons - usually AKI resolves with resolution of obstruction

Question 7

Causes of renal AKI

Answer 7

ATN - most common
AIN
Acute GN
Acute vascular Syndromes - APL syndrome and cholesterol emboli
Intratubular obstruction

Question 8

Diagnosis of Cause of renal AKI

Answer 8

History of exposures
Urine output
Urinary indices and sediment

Question 9

Causes of ATN

Answer 9

Ischaemia
Sepsis
Nephrotoxins
- Radiocontrast
- Aminogylcosdies
- Cisplatin
- Pigment nephropathy

Question 10

Causes of AIN

Answer 10

PPIs
Penicillin
PD-1 Inhibitors

Question 11

Tumour lysis syndrome

Answer 11

Death of tumour cells –> mass release of K, PO4, Ca and uric acid onto the circulation

Malignancies with highly chemoTx sensitive cells - lymphproliferative and leukaemic

Prevention = Hydration, allopurinol and urinary alkanization

Treatment = hydration and rasburicase

Question 12

Hepato-renal syndrome

Answer 12

3 phases:

• Pre-ascitic = compensated Na retention
• Ascitic = Na retention secodnary to dreased renal perfusion
• HRS = PCT Na retention - either primary progressive or slow chronic form

HRS fails to improve with volume replacement, diuretic removal or albumin
Trial terlipressin
Dialysis and liver transplant

Question 13

Elderly lady
Presented with sepsis, now controlled
Now metabolic acidosis with respiratory compensation

What is diagnosis and investigation of choice?

Answer 13

Cell crisis in the elderly

Investigation is urine pyroglutamic acid screen