7.5 Acute Kidney Injury

Question 1

Define AKI

Answer 1

Defined by a rapid decline in glomerular filtration rate, resulting disturbance of renal physiological functions, including impairment of nitrogenous waste production excretion, loss of water and electrolyte balance and loss of acid-base regulation
ABRUPT, POTENTIALLY REVERSIBLE FALL IN GFR

Question 2

Causes of pre-renal AKI

Answer 2

• Hypovolemia
• Renal hyperperfusion (NSAIDs, ACEI, renal artery stenosis, hepatorenal syndrome)
• Hypotension: cardiogenic, sepsis
• Oedematous state: nephrotic syndrome, cardiac failure

Question 3

Causes of intrinsic AKI

Answer 3

• Glomerulonephritis
• Acute tubular necrosis
• Acute interstitial nephritis
• Small vessel disease

Question 4

Causes of post renal AKI

Answer 4

• Obstructive acute renal failure
• Intrinsic: intraluminal (stone, clot, papillary necrosis), intramural (urethral structure, prostatic hypertrophy or malignancy, blader tumour, radiation fibrosis)
• Extrinsic: pelvic malignancy or retroperitoneal fibrosis

Question 5

Symptoms and pointers of pre renal

Answer 5

vomiting, diarrhea, bleeding, decreased fluid intake, burns, medications, history of cardiac ot liver failure

Question 6

Symptoms and pointers of intra renal

Answer 6

fever, pulmonary symptoms, hemoptysis
skin lesions , pharyngitis (post infectious)
History of drug intake, contrast exposure
muscle exertion or damae - rabdomyolysis
Bone pains - myeloma

Question 7

Symptoms and pointers of post renal

Answer 7

Gross haematuria, dysuria, loin pain, lithuria

Question 8

What are the issues with the RIFLE criteria?

Answer 8

• confusion between pre renal and obstructive
• Utility at bedside less clear
• Why serum creatinine changes not baseline

Question 9

What is the RIFLE system?

Answer 9

risk 
injury
failure 
loss 
end stage renal disease

Question 10

What are the risk factors for AKI in hospital settings?

Answer 10

• post operative: haemodynamic comprimise, infection and sepsis, cardiac surgery
• Contract nephropathy: low BP, diabetes mellitus, pre-existing renal impairment, vomule of contract
• Nephrotoxic antibiotics