Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 3 - Met3b > Acute Kidney Injury > Flashcards

Acute Kidney Injury Flashcards

1
Q

Define acute Kidney injury

A

Acute kidney injury is a syndrome of decreased renal function, it is measured by serum creatine or urine output over hours-days.

  • rise in creatine of >26umol/L within 48 hours
  • rise in creatine > 1.5 x baseline within 7 days
  • urine output <0.5mL/kg/h for >6 consecutive hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What factors make up acute kidney injury (RIFLE)

A

RIFLE

  • Risk of renal dysfunction;
  • Injury to the kidney
  • Failure of kidney function,
  • Loss of kidney function
  • End-stage kidney disease
  • 3 levels of dysfunction
  • 2 outcomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many stages does acute kidney injury have

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Who came up with the stages of acute kidney injury

A

The acute kidney injury network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define stage 1, 2 and 3 of acute kidney injury (RIFLE)

A

Stage 1
• Rise in serum creatinine of ≥ 26 μmol/L within 48 hours or
• 1.5-1.9 x increase in serum creatinine known or presumed to have occurred within in the last 7 days or
• 6 -12 hours oliguria (urine output < 0.5ml/kg/hour)

Stage 2

  • Serum creatine = 2-2.9 x baseline
  • Urine output <0.5ml/kg/hour for >12 hours

Stage 3

  • Serum creatine = >353.6umol/L or > 3 x baseline or having renal replacement therapy
  • Urine output = anuria for >12 hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the minimum GFR rate for solute removal

A

• 6 hours oliguria (urine output < 0.5ml/kg/hour) - minimum GFR for solute removal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Who gets AKI

A
  • Elderly
  • CKD (eGFR < 60 ml/min/1.73 m2)
  • Cardiac failure
  • Liver disease
  • Diabetes
  • Vascular disease
  • Potentially nephrotoxic medications - NSAID, ACE inhibitors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What things can cause an AKI

A

STOP

  • Sepsis and hypo perfusion
  • Toxicity (drugs and contrast)
  • Obstruction - ureters, prostate or beyond bladder
  • Parenchymal disease -disease of the kidneys itself
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do you prevent AKI

A

4Ms
Monitoring: observations (BP, pulse), fluid input/output charts, blood tests

Maintain circulation: well hydrated, adequately resuscitation, oxygenation

Minimise renal insults: reducing nephrotoxic medications, iodinated contrast if CT scan, hospital acquired infections

Manage acute illnesses appropriately

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do you manage AKI

A

Fluids

Monitoring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do you assess volume status in fluid management of AKI

A

Most important thing to do is to assess volume status
- Do this by doing the Blood pressure lying or staining, measure heart rate, JVP, capillary refill, conscious level, lactate and weight ( important in patients with dialysis and using fluid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What should you do if the patient is hypovalaemic in fluid management of AKI

A

If hypovolaemic renal perfusion will improve with volume replacement
• give bolus fluids (250 – 500 mls) with regular review until volume replete
- give further boluses of 250-500mL crystalloid with clinical review after each
• If you have given ≥ 2 L Stop + remains hypoperfused consider further circulatory support e.g. something to increase CO such as isotonic compounds or something to cause vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens if you give too much fluid in fluid management of AKI

A

• Too much fluid is harmful (pulmonary oedema, delayed recovery)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

once there euvolaemic and passing urine what should you do - fluid management of AKI

A

• If euvolaemic + passing urine give maintenance fluids (estimated daily output + 500 ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which type of fluid should you give in fluid management of AKI

A
  • Isotonic crystalloid fluids - E.G. plasmalyte, Hartmann’s) - these contain potassium (5mmol/L) - if your giving a low concentration of potassium to someone who has a high concentration of potassium you reduce the plasma potassium but risk of hypokalaemia is low yet you are increasing there whole body potassium if they are not passing urine
  1. 9% saline
    - safe
    - can worsen metabolic acidosis if large volumes are infused rapidly
    - as the chloride can cause a hypercholermic acidosis

Colloids

  • high molecular weight states
  • dextran can worsen AKI
  • therefore they are not used anymore
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the downside of using isotonic fluids for AKI fluid management

A

these contain potassium (5mmol/L) - if your giving a low concentration of potassium to someone who has a high concentration of potassium you reduce the plasma potassium but risk of hypokalaemia is low yet you are increasing there whole body potassium if they are not passing urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the downside of using 0.9% saline for AKI fluid management

A
  • can worsen metabolic acidosis if large volumes are infused rapidly
  • as the chloride can cause a hypercholermic acidosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the downside of using colloids for AKI fluid management

A
  • high molecular weight states
  • dextran can worsen AKI
  • therefore they are not used anymore
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do you monitor AKI

A
  • Consider urinary catheter + hourly input/output
  • U&Es, bone profile, venous bicarbonate ≥ daily whilst creatinine rising
  • Blood gases + lactate if septic/hypoperfused
  • Daily weights
  • Regular fluid assessment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do you investigate AKI

A
  • Urinalysis - urine microscopy
  • urine dip = protein creatine ratio
    • Ultrasound scan ≤ 24 hours (≤ 6 hours if pyonephrosis (sepsis) suspected)
    • Inflammatory markers, CK, Liver Function Tests (LFTs)
    • If platelets low blood film/LDH/reticulocyte count (HUS/TTP/accelerated HTN with MAHA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What further should you investigate AKI

A
  • Consider serum protein electrophoresis/free light chains + urine Bence Jones protein
  • If blood and protein +++ on dip or acute glomerulonephritis suspected:
  • HIV, HCV IgG, Hep B surface antigen (also if going to be filtered/dialysed)
  • ANCAs
  • Anti-GBM
  • Complements (C3, C4)
  • Rheumatoid factor
  • ANA/ENAs (dsDNA)
22
Q

How should you support recovery from AKI

A

• Treat sepsis
• Maintain perfusion - make sure they are hydrated
• Stop NSAIDs, ACE, ARB, metformin, potassium-sparing diuretics, adjust drug doses (Renal Drug Database/Renal Drug Handbook)
• If hypotensive = stop antihypertensives, if underfilled = diuretics
- try to minimise iodinated contrast = if a scan is required they should get contrast but make sure they are well perfused and try to minimise it

23
Q

Name some nephrotic drugs

A 
NSAIDs
ACE
ARB
metformin
potassium-sparing diuretics
24
Q

Name the complications of acute kidney injury

A 
Hyperkalemia 
Pulmonary oedema 
Acidosis 
severe uraemia 
insufficient urine output
25
Q

What does an ECG of hyperkaelmia look like

A
  • small or absent p waves
  • tented T waves
    progresses
  • sine wave
  • increase PR interval
  • widened QRS complex
  • Sinusoidal rhtyhm
  • MI
26
Q

How do you manage hyperkalemia

A
  • If the ECG changes you should give calcium gluconate - 10mls and 10% over 10 minutes

• If K > 6.5 mmol/L or ECG changes insulin dextrose
(effective for lowering the potassium for about ≤ 4 hrs) - 10 units in 50mls of 50% dextrose
- Monitor for blood glucose for hypoglycaemia

• If bicarbonate < 22 mmol/L + not overloaded give 1.26% bicarbonate IV 500 ml 1-4 hrs (N.B. hypocalcaemia)

  • this will rise the pH and lower the level of potassium
  • calcium binds to albumin when pH goes up so can lead to hypocalcamia

To remove potassium from the body

  • calcium resonium
  • loop diuretics
  • renal replacement therapy
27
Q

What is the only thing that can lower whole body potassium

A

• Lowering whole body potassium ultimately requires recovery of function or renal replacement therapy (haemodialysis or filtration)

28
Q

How is pulmonary oedema caused by AKI

A
  • fluid overload due to salt and water infusion

- goes into the lung

29
Q

How do you manage fluid overload in AKI

A
  • oxygen supplementation if required
  • fluid restriction - consider oral and IV volumes
  • diuretics = only in symptomatic fluid overload
  • renal replacement therapy
30
Q

What does an X ray of pulmonary odeam look like

A
  • Backwing pulmonary oedema
  • pleural effusion
  • starts in the central
  • Kerley B lines
  • cardiomegaly
31
Q

what is the only way to fully resolve pulmonary oedema

A

• Resolution will require recovery of renal function or RRT

32
Q

How do you manage acidosis in AKI

A

• Ensure acidosis renal in origin (raised anion gap, gases, lactate, ketones etc.)

  • make sure your not missing something
  • look for a raised anion gap acidosis
  • Sodium bicarbonate reserved for correction of hyperkalaemia - bicarbonate can crate carbon dioxide therefore you have to make sure that you have adequate ventilation for the patient
  • pH < 7.15 should go to critical care referral if appropriate
  • May be an indication for RRT
33
Q

What requires dialysis

A 
Hyperkalemia 
Pulmonary oedema 
Acidosis 
severe uraemia 
insufficient urine output
34
Q

When should you refer to the renal time

A
  • AKI not responding to treatment
  • Complications – hyperkalaemia, acidosis, fluid overload
  • Stage 3 AKI
  • AKI with difficult fluid balance
  • AKI due to intrinsic renal disease
  • AKI with hypertension
35
Q

How many patient deaths are associated with acute kidney injury

A
  • about 100,000

- 1/3rd were thought to be preventable - dehydration

36
Q

what are the commonest causes of AKI

A
  1. sepsis
  2. Major surgery
  3. Cardiogenic shock
  4. other hypovolaemia
  5. drugs
  6. Hepatorenal syndrome
  7. Obstruction
37
Q

What are the three sites in which acute kidney injury occurs

A
  • Pre-renal = decrease perfusion to the kidney
  • Renal = intrinsic renal disease
  • Post-renal = obstruction to urine
38
Q

What is the pathology of pre renal acute kidney injury

A
  • decrease in vascular volume = due to haemorrhage, burns, pancreatitis
  • decrease cardiac output = Cardiogenic shock and MI
  • systemic vasodilation = sepsis and drugs
  • Renal Vasoconstriction = NSAIDs, ACE-i, ARB, hepatorenal syndrome
39
Q

What is the pathology of renal acute kidney injury

A
  • Glomerular damage = glomerulonephritis, ATN
  • Interstitial damage = drug reaction, infection, infiltration
  • Vessels damage = vasculitis, HUS, TTP, DIC
40
Q

What is the pathology of post-renal acute kidney injury

A
  • Within renal tract = stone, renal tract malignancy, stricture, clot
  • Extrinsic compression = pelvic malignancy, prostatic hypertrophy, retro-peritoneal fibrosis
41
Q

What is the management of AKI

A

Pre-renal

  • Give IV fluids
  • Bolus fluids 250-500mls crystalloids over 15mins with regular review
  • Give further boluses of 250-500mls crystalloid
  • Stop with euvolemic or 2L given and seek expert help

Renal

  • Biopsy
  • Refer to renal team if intrinsic renal disease

Post renal
- Catheter, nephrostomy or urological intervention

42
Q

Name 3 pathological consequences of AKI

A
  • hyperkalaemia
  • fluid overload
  • uraemia
43
Q

What are the signs of hypovolaemia

A
  • decrease in blood pressure
  • decrease in urine volume
  • non visible JVP
  • poor tissue turgor
  • increase in pulse
  • daily weight loss
44
Q

What are the signs of fluid overload

A
  • increase in blood pressure
  • increase in JVP
  • lung crepitations
  • peripheral oedeem
  • gallop rhythm
45
Q

In what situations are colloids given for acute kidney injury

A
  • hepatorenal syndrome
  • septic shock
    Under specialist advice
46
Q

What are the indications of renal replacement therapy

A
  • fluid overload and unresponsive to medical treatment
  • severe/prolonged acidosis
  • recurrent/persistent hyperkalaemia despite medical treatment
  • uraemia e.g. pericarditis, encephalopathy
47
Q

Name differential diagnosis for AKI

A

Decrease serum urea

  • low protein intake
  • liver failure
  • sodium valproate treatment

Increased serum urea

  • corticosteroid treatment
  • tetracycline treatment
  • gastrointestinal bleeding

Decreased creatine
- low muscle mass

Increased creatine

  • high muscle mass
  • red meat ingestion
  • muscle damage
  • decreased tubular secretion
48
Q

Why do you do urinalysis and urine microscopy in acute kidney injury

A
  • Look for red cell clasts - these are indicative of glomerulonephritis
  • tested for haemoglobin and myoglobin
  • urine protein: creatine ratio is helpful if parenchymal disease is possible
49
Q

in AKI how long does it take creatine to rise in the plasma

A
  • takes 48 -72 hours
50
Q

what can you measure in plasma instead of creatine that is indicated of AKI

A
  • urinary and plasma biomarkers such as kidney injury molecule 1, neutrophil gelatinise associated lipocalin rise within a few hours of AKI
51
Q

What are the symptoms and signs of an AKI

A
  • Reduced urine output
  • Pulmonary and peripheral oedema
  • Arrhythmias – secondary due to changes in potassium and acid-base balance
  • Features of uraemia
52
Q

How do you tell the difference between dehydration and AKI

A

urea is proportionally higher than the rise in creatinine in dehydration

Year 3 - Met3b (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions