Acute Kidney Injury

Question 1

Definition of Acute renal failure

Answer 1

increase in SCr by ≥ 0.3 mg/dl within 48 hours
OR
increase in SCr to ≥ 1.5 times baseline, which occurred within the prior 7 days;
OR
Urine volume <0.5 ml/kg/h for 6 hours

Question 2

Steps of Acute Kidney Injury (AKI)

Answer 2

Initiation - Exposure to toxic/ischaemic insult causing injury
Maintenance - Established parenchymal injury, Worst Oliguria, Typical duration 1-2 weeks
Recovery - Gradual increase in urine output, fall in serum creatinine

Question 3

What is RCN and how long does it usually last for

Answer 3

Radiocontrast Nephropathy

Usually resolves after 72 hours (may cause permanent damage)

Question 4

RCN risk factors

Answer 4

Diabetes mellitus
Renovascular disease
Impaired renal function
High volume of Radiocontrast

Question 5

What is Myeloma

Answer 5

A monoclonal proliferation of plasma cells producing an excess of immunoglobulins and light chains
2nd most common haematological malignancy
Median survival 5 years

Question 6

Multiple Myeloma presentation (8)

Answer 6

Anaemia
Back pain
Cord compression
Weight loss
Markedly elevated ESR
Fractures
Infections
Hypercalcaemia

Question 7

Causes of AKI

Answer 7

Sepsis
Cardiac failure
Myeloma 
Glomerulonephritis 
Vasculitis 
Stones
Radiocontrast, NSAID's and Gentamicin

Question 8

Consequences of AKI’s

Answer 8

Acidosis
Fluid and electrolyte imblance/disturbance
Intoxication
Uraemic complications

Question 9

What does the STOP-AKI management acronym mean

Answer 9

S - Sepsis
T - Toxins (stop/avoid nephrotoxins)
O - Optimise BP
P - Prevent harm (treat complications)

{Fluid balance - Volume resuscitation if volume deficit
Fluid restriction if volume overload}

Question 10

ECG changes in hyperkalaemia

Answer 10

1. Peaked T waves (usually earliest sign of hyperkalaemia)
"Tall-Tented T waves"
2. P waves Widen and flatten
3. PR segments lengthen
4. P waves eventually disappear 
5. Prolonged QRS interval
6. Sinus bradycardia or slow A-Fib

(There are more)

Question 11

Steps in hyperkalaemia treatment

Answer 11

STABILISE (myocardium) - Calcium Gluconate

SHIFT (K+ intracellularly) - Insulin-dextrose
Salbutamol

REMOVE - Diuresis, Dialysis and Anion exchange resins

Question 12

Steps in Intoxication treatment

Answer 12

Use antidote if available
Morphine (Naloxone)
Digoxin (Digibind)

May require RRT

Question 13

Summary of AKI

Answer 13

1. AKI is very common in hospital
2. AKI >=1.5 x baseline in 7days)
3. Outcomes are very poor with high mortality
4. There are many causes of AKI
   a) pre-renal (v. common)
   b) renal (less common but v. important)
   c) post renal (v. common and usually v. curable)