Acute Kidney Injury
title: Acute Kidney Injury tags: #FFICM notebook: ð-FFICM type: inprogress
source: [[Revision Notes In Intensive Care]] category: [[Acute Kidney Injury]]
-
[[Acute Renal Failure]]
-
AKI in ICU occurs in 5-35% of adult patients
- Excess 90 Day Mortality due to AKI is ~ 10%
- You are between 3-13% likely to need RRT longterm, if you survive ICU (if you had normal renal function to start with)
| Flashcard | type:basic |
|---|---|
| How common is AKI in Adult ICU Patients? | 5-35 % |
| How likely are you to need long term RRT as an adult ICU survivor? | 3-13% |
Classifications
RIFLE - Comes from 2004
- Risk
- Injury
- Failure
- Loss
- End Stage
| Flashcard | type:basic |
|---|---|
| What does RIFLE in AKI stand for? | Risk Injury Failure Loss End-Stage |
| What factors are looked at in the RIFLE AKI scoring system? | Creatinine GFR Urine Output |
| How high does your creatinine need to be for Risk in RIFLE? | 1.5 - 2x Baseline |
| How high does your creatinine need to be for Injury in RIFLE? | 2 - 3x Baseline |
| How high does your creatinine need to be for Failure in RIFLE? | 3x Baseline + Or 350micromol/L + |
| If your creatinine is greater than 1.5x it's baseline, what RIFLE AKI stage does that put you in? | Risk |
| If your creatinine is 2-3x it's baseline, what RIFLE AKI stage does that put you in? | Injury |
| If your creatinine is 3x + it's baseline, what RIFLE AKI stage does that put you in? | Failure |
| If your creatinine is greater than 350micromol/L, what RIFLE AKI stage does that put you in? | Failure |
| How much does your GFR need to have dropped by, to be Risk in RIFLE? | 25% |
| How much does your GFR need to have dropped by, to be Injury in RIFLE? | 50% |
| How much does your GFR need to have dropped by, to be Failure in RIFLE? | 75% |
| If your GFR has dropped by 25%, what RIFLE AKI stage does that put you in? | Risk |
| If your GFR has dropped by 50%, what RIFLE AKI stage does that put you in? | Injury |
| If your GFR has dropped by 75%, what RIFLE AKI stage does that put you in? | Failure |
| How low does your urine output need to be, to be Risk in RIFLE? | Less than .5ml/kg for SIX hours |
| How low does your urine output need to be, to be Injury in RIFLE? | Less than .5ml/kg for TWELVE hours |
| How low does your urine output need to be, to be Failure in RIFLE? | Less than .5ml/kg for TWENTY-FOUR hours OR Anuric for 12 hours |
| If you have been passing less than 0.5ml/kg of urine for six hours, what RIFLE stage does that put you in? | Risk |
| If you have been passing less than 0.5ml/kg of urine for twelve hours, what RIFLE stage does that put you in? | Injury |
| If you have been passing less than 0.5ml/kg of urine for twenty-four hours, what RIFLE stage does that put you in? | Failure |
| If you have been passing no urine for 12 hours, what RIFLE stage does that put you in? | Failure |
| What counts as Loss on the RIFLE AKI Score? | Persistent Complete Renal Failure for a month |
| What counts as End-Stage on the RIFLE AKI Score? | Persistent Complete Renal Failure for three months |
| If you have persistent renal failure for more than a month, what stage does that put you in on the RIFLE scoring system? | Loss |
| If you have persistent renal failure for more than 3 months, what stage does that put you in on the RIFLE scoring system? | End Stage |
| How old is the RIFLE scoring system? | From 2004 |
Based on:
- Creatinine
- GFR
- Urine Output
Creatinine Criteria:
- Risk : Creatinine x 1.5
- Injury : Creatinine x 2
- Failure : Creatinine x 3 (Or Creat 350 micromol/L)
GFR Criteria:
- Risk : GFR < 25%
- Injury : GFR < 50%
- Failure : GFR < 75%
Urine Output Criteria:
- Risk : Urine Output < 0.5ml/kg/hr for 6 hours
- Injury: Urine Output < 0.5ml/kg/hr for 12 hours
- Failure : Urine Output < 0.5ml/kg/hr for 24 hours
- Failure : Urine Output of 0 for 12 hrs
Loss and Endstage =
- Loss : Persistent Failure (Complete Loss of Function) for 1 Month
- End Stage : Persistent Failure For 3 Months
KDIGO (Kidney Disease Improving Global Outcomes)
-
KDIGO is from 2012
-
Stage One
- Stage Two
-
Stage Three
-
Creatinine
- Urine Volume
Creatinine Criteria
- Stage One : Creatinine 1.5x baseline
- Stage Two : Creatinine 2-3x baseline
- Stage Three : Creatinine 3x+ baseline
- Stage Three : Creatinine 350+ micromol/L
Urine Output
- Stage One : < 0.5ml/kg/hr for 6-12 hrs
- Stage Two : < 0.5ml/kg/hr for 12+ hrs
- Stage Three : < 0.3ml/kg/hr for 24+ hrs
- Stage Three : Anuria for 12+ hrs
| Flashcard | type:basic |
|---|---|
| What does KDIGO stand for? | Kidney Disease Improving Global Outcomes |
| When is KDIGO from? | 2012 |
| What are the stages in KDIGO? | One, Two, Three |
| What factors are looked at in the KDIGO AKI Scoring System? | Creatinine and Urine Output |
| What is the KDIGO scoring system for? | Staging severity of AKI |
| What does your creatinine have to be, to be Stage One AKI on KDIGO? | 1.5x Baseline + |
| What does your creatinine have to be, to be Stage Two AKI on KDIGO? | 2x Baseline + |
| What does your creatinine have to be, to be Stage Three AKI on KDIGO? | 3x Baseline + Or 350+ micromol/L |
| What does your urine output have to be, to be Stage One AKI on KDIGO? | Less than 0.5ml/kg/hr for 6+ hours |
| What does your urine output have to be, to be Stage Two AKI on KDIGO? | Less than 0.5ml/kg/hr for 12+ hours |
| What does your urine output have to be, to be Stage Three AKI on KDIGO? | Less than 0.3ml/kg/hr for 24+ hours Or anuria for 12+ hours |
| If your creatinine is 1.5x baseline, what stage of the KDIGO Scoring system is that? | Stage One |
| If your creatinine is 2x baseline, what stage of the KDIGO Scoring system is that? | Stage Two |
| If your creatinine is 3x baseline, what stage of the KDIGO Scoring system is that? | Stage Three |
| If your creatinine is greater than 350mmol/L, what stage of the KDIGO Scoring system is that? | Stage Three |
| If your urine output is <0.5ml/kg/hr for more than 6 hours, what stage of the KDIGO Scoring system is that? | Stage One |
| If your urine output is <0.5ml/kg/hr for more than 12 hours, what stage of the KDIGO Scoring system is that? | Stage Two |
| If your urine output is <0.3ml/kg/hr for more than 24 hours, what stage of the KDIGO Scoring system is that? | Stage Three |
| If your urine output is nothing for more than 12 hours, what stage of the KDIGO Scoring system is that? | Stage Three |
Problems Caused By AKI
- Acidosis
- Hyperkalaemia
- Electrolyte Disturbance
- Uraemic Encephalopathy/Pericarditis
- Fluid Overload of Tissues
- Pulmonary Oedema
- Increased chance of Chronic Kidney Disease
Causes/Aetiology
-
Study looking at AKI epidemiology was the "Best Kidney" study
-
Sepsis
- Surgical Insult
- Low Cardiac Output State
- Hypovolaemia
- Drugs
- Contrast
- Systemic Illness
- Abdominal Compartment Syndrome
- Mechanical Obstruction
Less common:
- Iodinated Contrast
- Rhabdo
- HUS
- Tumour Lysis
- Glomerulonephritis
- Post Strep
- IgA Nephropathy
- Vasculitis
- Tubulointerstitial Nephritis
- Nephrotoxic Drugs
- ACEi
- ARBs
- Diuretics
- Aminoglycodsides
- NSAIDS
| Flashcard | type:basic |
|---|---|
| What are the antibiotic class that up your AKI risk? | Aminoglycosides |
Pathophysiology
- ATN (acute tubular necrosis) is histopathological description, changes seen in renal tubules
- Caused by hypoperfusion
- Realistically it's more complicated than just ATN:
- Immune mediated dysfunction
- Plus other stuff
Identifying AKI
-
Problem is by the time creatinine is rising, half of your GFR is already gone!
-
Other markers? Not used yet:
- NGAL (Neutrophil gelatinase associated lipocalin)
- KIM1 (Kidney Injury Molecule)
| Flashcard | type:basic |
|---|---|
| What are the two other bloods markers that might be used in future for AKI? | NGAL amd KIM1 |
| What are NGAL and KIM1? | Potential blood markers that could be used in AKI |
| How bad is your GFR when creatinine is starting to rise? | It'll have fallen by half! |
Renal Protection
Contrast?
- Consider risk-to-benefit
- Keep well hydrated
- Withold nephrotoxics
- Sodium Bicarb? NAC? No evidence despite practised by some
Liver Disease
- If you are getting large volume paracentesis for ascites, give albumin resuscitation
ARDS
- Keep low tidal volumes (<6ml/kg)
At risk of tumour lysis?
- Volume load with IV fluids
- Don't bother with sodium bicarb
- Give allopurinol or rasburicase
Rhabdo
- If you've a creat > 150 to start, or a CK > 5000 to start, you are at a higher risk of needing RRT
- Resuscitate with large volumes crystalloid
- Keep urine pH > 6.5
Treatment
- Problems with starch containing colloids is may cause harm
- Problems with 0.9% saline is increased risk of AKI/RRT
- Consider cardiac output monitoring
- Avoid overload (and the venous congestion it causes)
- No particular haemodynamic support agent shown to be superior in AKI
- No evidence for low dose dopamine reducing risk of AKI/RRT
Investigations
History
- Evidence of dehydration?
- Bloody diarrhoea? - Risk of HUS
- Urine passing difficulties - Risk of Obstruction
- Haematuria - Risk of Glomerulonephritis/Stones/Malignancy
- Haemoptysis - Risk of Systemic Vasculitides
- Joint Pain/Rash - Risk of SLE
| Flashcard | type:basic |
|---|---|
| If someone has AKI and bloody diarrhoea, what's the extra diagnosis to think of? | HUS |
| If someone has AKI and haematuria, what's the extra diagnosis to think of? | Glomerulonephritis/Stones/Malignancy |
| If someone has AKI and haemoptysis, what's the extra diagnosis to think of? | Systemic Vasculitides |
| If someone has AKI and joint pain/rash, what's the extra diagnosis to think of? | SLE |
Exam
- Look for evidence of underlying cause
- Look at muscle compartments for rhabdo
- Look at abdo for abdominal compartment
- Look for vasculitic rash
Tests
Bloods
- Add Bone Profile/Mg/CK/Vasculitic Screen
Imaging
- Renal Tract Ultrasound
CKD
Definitions
-
Needs to be more than 3 months to be CKD
-
GFR is measured in ml/min/m^2 of body surface area
-
CKD Stage One = 90+
- CKD Stage Two = 60-90
- CKD Stage Three = 30-60
- CKD Stage Four = 15-30
- CKD Stage Five = 15-
| Flashcard | type:basic |
|---|---|
| How long do you need a renal impairment to count as CKD? | More than three months! |
| If your AKI has been going on three months what is it now? | CKD! |
| What measure do you use to quantify severity of Chronic Kidney Disease? | GFR |
| What GFR counts as Stage One CKD? | Down to 90 |
| What GFR counts as Stage Two CKD? | 60-90 |
| What GFR counts as Stage Three CKD? | 30-60 |
| What GFR counts as Stage Four CKD? | 15-30 |
| What GFR counts as Stage Five CKD? | 0-15 |
Problems
- Hyperparathyroid
- Hyperphosphataemia
- Acidosis
- Easily Fluid Overloaded
- Hypertensive
- CV Disease
- Anaemic
- Uraemic
- Polyneuropathy
- Maybe dialysis dependent
Plus some questions from [[mcqs-and-sbas-in-intensive-care-medicine-oxford-higher-special-training]]
| Flashcard | type:basic |
|---|---|
| When are the most recent NICE guidelines from for diagnosing AKI? | 2013 |
| In the 2013 NICE Guidelines for AKI, how much does your creatinine has to rise by (as a number) over 48 hours to count as an AKI? | More than 26micromol/l |
| In the 2013 NICE Guidelines for AKI, your creatinine has to rise by at least 26micromol/L over what period to count as an AKI? | Within 48 hours |
| In the 2013 NICE Guidelines for AKI, your creatinine has to rise by what percentage within 7 days to count as an AKI? | At least 50% |
| In the 2013 NICE Guidelines for AKI, your creatinine has to rise by at least 50% over what period to count as an AKI? | Within 7 days |
| In the 2013 NICE Guidelines for AKI, your urine output has to fall for what and for how long to count as an AKI? | Less than 0.5ml/kg/hr for 6 hours |
[Acute Renal Failure]: