renal

Question 1

what is AKI?

Answer 1

Rapid drop in kidney function

Question 2

What are the NICE criteria for AKI?

Answer 2

Rise in creatinine of >25 micro mol/L in 48 hours
Rise in creatinine of >50% in 7 days
Urine output of <0.5ml/kg/hour over at least 6 hours

Question 3

Risk factors for AKI?

Answer 3

Older age (>65)
Sepsis
CKD
heart failure
Diabetes
Liver disease
Cognitive impairment (therefore reduced fluid intake)
Medications (e.g. NSAIDs, gentamicin, diuretics, ACEi)
Radiocontrast

Question 4

What are the 3 types of causes of AKI?

Answer 4

Pre-renal - insufficient blood supply to kidneys
Intrinsic (renal) - damage to the kidneys themselves
Post-renal (obstructive) - obstruction to the outflow of urine away drone the kidney, causing backpressure to the kidneys and reduced kidney function

Question 5

Pre-renal causes of AKI?

Answer 5

Shock (sepsis, acute blood loss)
Dehydration
Heart failure

Question 6

Intrinsic causes of AKI?

Answer 6

Glomerulonephritis
Acute tubular necrosis
Acute interstitial nephritis
Haemolytic uraemia syndrome
Rhabdomyelitis
Tumour lysis syndrome

Question 7

What is creatinine and why is it used for renal monitoring?

Answer 7

Formed as byproduct of muscle contraction
Muscle mass tests to remain constant so creatinine production varies little
Creatinine is excreted by kidneys so serum levels are a marker of kidney function

Question 8

Post-renal causes of AKI?

Answer 8

Kidney stones
Tumours (retroperitoneal, bladder, prostate)
Strictures of ureter or urethra
BPH
Neurogenic bladder

Question 9

Symptoms and signs of AKI?

Answer 9

Can be asymptomatic early on
Arrhythmia (secondary to potassium and acid-base balance changes)
Reduced urine output
Pulmonary and peripheral oedema
Uraemia - pericarditis, encephalopathy

Question 10

Investigations for AKI?

Answer 10

U&Es - sodium, raised potassium, urea, creatinine
Urinalysis
Ultrasound

Question 11

What findings on urinalysis indicate different causes of AKI?

Answer 11

Leucocytes and nitrates - infection
Protein and blood - acute nephritis, can be positive in infection
Glucose - diabetes
Muddy brown casts, renal tubular epithelial cells - acute tubular necrosis

Question 12

What causes of AKI would a renal ultrasound show?

Answer 12

Obstructive causes

Question 13

What is the supportive management for AKI?

Answer 13

Careful fluid balance - enough perfusion but not overload
Stop nephrotoxic drugs
Loop diuretics in fluid overload

Question 14

What is the treatment for hyperkalaemia, and what is the purpose of each treatment?

Answer 14

IV calcium gluconate - stabilise cardiac membrane
Combined insulin/dextrose infusion, nebulised salbutamol - short-term shift of potassium from extracellular to intracellular compartment
Calcium resonium, loop diuretics, dialysis - to remove potassium from the body

Question 15

When is renal replacement therapy indicated?

Answer 15

If not responding to supportive treatment
Acidosis
Hyperkalaemia
Oedema
Uraemia pericarditis

Question 16

What are the forms of renal replacement therapy?

Answer 16

Haemodialysis
Haemofiltration
Peritoneal dialysis
Renal treansplantation