Acute Kidney Injury

Question 0

Define Oliguria

Answer 0

< 500mls urine output /24hours or < 20mls/ hour

Question 1

Define Anuria

Answer 1

No urine output or < 100mls/24 hours

Question 2

Define polyuria

Answer 2

> 2.5L urine output / 24hours

Question 3

Define Acute Kidney Injury (AKI)

Answer 3

Inability of kidney to maintain homeostasis leading to a buildup of nitrogenous wastes

Question 4

What are the 3 types of acute renal failure (ARF)?

Answer 4

Pre-renal (functional), renal-intrinsic (structural) and post-renal (obstruction)

Question 5

Discuss pre-renal kidney injury

Answer 5

Decreased renal perfusion w/o cellular injury
Often reversible upon restoration of renal blood flow and glomerular perfusion pressure
KIDNEYS ARE NORMAL
Causes: hypovolaemia, low CO, systemic dilation or selective nitrate all vasoconstriction
Results in: decreased renal blood flow and GFR, increase Na and H2O reabsorption, Oliguria, high Uosm, low Una, elevated BUN/Cr ratio

Question 6

Discuss intrinsic AKI

Answer 6

Structural injury in the kidney
Causes: acute tubular necrosis (ischaemia, toxin, tubular factors), acute interstitial necrosis (inflammation, oedema), glomerulonephritis (damage to filtering mechanisms), drugs

Question 7

What is contrast-induced AKI?

Answer 7

Risk factors: renal insufficiency, diabetes, multiple myeloma and high osmolar contrast media
Clinical characteristics: onset 24-48hrs after exposure, duration 5-7 days, non-Oliguric (majority), urinary sediment (variable), low fractional excretion of Na

Question 8

Discuss post-renal AKI

Answer 8

Causes: intra-renal obstruction (drugs, acute runic acid nephropathy), extra-renal obstruction (renal, pelvis or ureter, bladder, urethra)

Question 9

What are the common signs of AKI? Rationale these..

Answer 9

Weight gain, peripheral oedema, hypertension, hyperkalaemia, pulmonary oedema, ascites, asterixis encephalopathy, rise in BUN and serum creatinine, acidosis, increase in phosphate levels, low serum calcium levels, anaemic (from blood loss)

Question 10

What diagnostic tests would you perform for AKI and what will the results show?

Answer 10

Tests: FBC, ABGs, Radiography, urinary sediments (U&Es, creatinine), urine volume, aortorenal angiography,
Findings: increased creatinine and urea, increased potassium, decreased Hb, Acidosis, hyponaturaemia, hupocalcaemia

Question 11

What are the indications for acute dialysis (AEIOU)?

Answer 11

Acidosis, Electrolytes, Ingestion of drugs/ischaemia, Overload (fluid), Uraemia

Question 12

Discuss the treatment of AKI

Answer 12

Immediate treatment if pulmonary oedema and hyperkalaemia
Treat cause
Dialysis as required
Adjustment if drug regimen
Usually restriction of water, Na, and K intake; provision of adequate protein
Possibly phosphate binders and Na polystyrene sulfonate

Question 13

What type of patient is at risk for a reduced renal reserve?

Answer 13

Pre-existing chronic renal failure, age > 60, hypertension, diabetes

Question 14

What type of patient is at risk for a reduced intra-vascular volume?

Answer 14

Diuretics, sepsis, cirrhosis, nephrosis

Question 15

Describe in brief the pathophysiology of AKI

Answer 15

Abrupt loss of kidney function, resulting in:
retention of urea and nitrogenous waste products
dysregulation of extracellular volume and electrolytes

Question 16

Define Azotemia

Answer 16

A rise in BUN concentration

Question 17

What are the manifestations of AKI? Rationale these..

Answer 17

Lethargy w/ persistence nausea and diarrhoea, DMM and skin, CNS manifestations (drowsiness, headache, muscle twitching, seizures), low urine output

Question 18

What might you find upon skin examination of a pt w/ AKI?

Answer 18

Digital ischaemia, butterfly rash, palpable purpura (rash), systemic vasculitis, maculopapular rash, allergic interstitial nephritis, track marks (IV drug abusers)

Question 19

What might you find upon eye examination of a pt w/ AKI?

Answer 19

Dry conjunctivae, autoimmune vasculitis, jaundice, liver disease, hypercalcaemia, retinopathy

Question 20

What might you find upon ear examination of a pt w/ AKI?

Answer 20

Hearing loss, aminoglycoside toxicity, mucosal or cartilaginous ulcerations

Question 21

What might you find upon CVS examination of a pt w/ AKI?

Answer 21

Irregular rhythms (AF), thromboemboli, murmurs, endocarditis, pericardial friction rub, uraemic pericarditis, inc jugulovenous distension, rales (crackles), S3 heart failure

Question 22

What might you find upon abdominal examination of a pt w/ AKI?

Answer 22

Pulsatile mass or bruit (artheroemboli), abdominal or costovertebral angle tenderness, nephrolithiasis, papillary necrosis, renal artery thrombosis, renal vein thrombosis, pelvic/rectal masses, prostatic hypertrophy, distended bladder, urinary obstruction, oedema, rhabdomyolysis (breakdown of muscle tissue)

Question 23

What might you find upon pulmonary examination of a pt w/ AKI?

Answer 23

Rales, haemoptysis (coughing blood)

Question 24

Discuss the routine nursing care for a pt w/ AKI

Answer 24

FBC (input and output), monitor urine SG, daily weights, vitals, auscultation of heart and lung sounds, GCS, oral fluid replacement w/ restrictions, correct reversible causes of AKI, skin integrity, infection control, psychological support, mouth care, comfort, medications, catheter care, dialysis as indicated

Question 25

What are the complications of AKI?

Answer 25

Fluid buildup (pulmonary oedema), chest pain (endocarditis), muscle weakness (hypercalcaemia), permanent kidney damage, death

Question 26

What are the 3 different types of dialysis and give a brief explanation of each

Answer 26

Haemodialysis: Pts blood pumped through blood compartment of dialyzer (water/wastes removed) and blood returned to the body
Peritoneal dialysis: sterile solution containing glucose (dialysate) run through tube into peritoneal cavity, diffusion and osmosis drive waste products and excess fluid through peritoneum into dialysate, dialysate drained, discarded and replaced w/ fresh dialysate
Heamofiltration: same process as haemodialysis but no dialysate used, works by applying pressure gradient