1. Acute Kidney Injury Dr Andrew Lewington
Consultant Renal Physician/Honorary Clinical Associate Professor
Leeds Teaching Hospitals

2. What is AKI?

3. Functions of the Kidney
maintenance of body composition
osmolality, electrolyte content, acidity
excretion of metabolic end products
urea, drugs
secretion of erythropoietin
maturation of erythrocytes
secretion of activated form of vitamin D3
calcium and phosphate balance
renin secretion
angiotensinogen→angiotensin I 3

4. Stages of CKD Stage 1 eGFR ≥ 90 Kidney damage, normal or increased GFR
Kidney damage, mildly reduced GFR
Stage 3A eGFR
Moderately reduced GFR ± other evidence of kidney damage
GFR < 60 ml/min for ≥ 3 months ± kidney damage
Stage 3B eGFR 30-44
Stage 4 eGFR 15-29
Severely reduced GFR ± other evidence of kidney damage
Stage 5 eGFR < 15
Established kidney failure
Kidney damage (presence of structural abnormalities and/or persistent haematuria, proteinuria or microalbuminuria) for ≥ 3 months
Stages of CKD

5. The UK eCKD Guide - Renal

7. What is Acute Kidney Injury?

8. Acute Kidney Injury Term encompasses all forms of AKI
rapid reduction in kidney function
occurs over hours to days
no specific symptoms
exception – stones
failure to regulate
fluid and electrolyte balance
acid/base balance
failure to excrete some drugs

9. Acute Kidney Injury
Most commonly associated with acute illness (hypoperfusion)
recovery usual if patient recovers from primary cause
severe AKI may progress to chronic kidney disease
Rarer forms
require rapid recognition for specific therapy

10. Increased mortality associated with changes in serum creatinine
Chertow et al: JASN 2005 10 10 10

11. New Definitions www.renal.org

12. Definition of AKI – Kidney Disease Improving Global Outcomes
Serum creatinine rise ≥26 µmol/L within 48 hours or
Serum creatinine rise ≥1.5 fold from the baseline value, which is known or presumed to have occurred within one week
Urine output is <0.5 mL/kg/hr for >6 consecutive hours

13. Serum Creatinine criteria
AKI Staging – KDIGO
AKI stage
Serum Creatinine criteria
Urine output criteria 1
­ SCr increase ≥26 µmol/L within 48 hrs or
­ SCr increase ≥1.5–2 fold from baseline
<0.5 mL/kg/hr for 6 consecutive hrs 2
­ SCr increase ≥2–3 fold from baseline
<0.5 mL/kg/hr for 12 hrs 3
­ SCr increase ≥3 fold from baseline
SCr increase ≥354 µmol/L
initiated on RRT (irrespective of stage at time of initiation)
<0.3 mL/kg/hr for 24 hr
anuria for 12 hr 13 13

14. Epidemiology

15. Epidemiology based on old definitions based on new definitions
5% of hospital admissions
30% of ICU admissions
based on new definitions
18% of hospital admissions
30-80% of ICU admissions

16. Aetiology

17. Aetiology essential to establish aetiology
aetiology determines treatment
not all AKI is secondary to ischaemia /reperfusion injury
important to identify rarer causes

18. AKI is a Syndrome Pre-renal AKI Intrinsic AKI Post-renal AKI Sepsis
Hypovolemia
Intrinsic AKI
Acute tubular injury
Tubulointerstitial injury
Glomerulonephritis
Vasculitis
Post-renal AKI
Kidney stones
Prostatic hypertrophy
Retroperitoneal fibrosis

19. Clinical Presentation of AKI

20. Clinical Presentation of AKI
Risk factors for AKI (some)
chronic kidney disease
cardiac failure
peripheral vascular disease
diabetes mellitus (with proteinuria)
liver disease
myeloma

21. Clinical Presentation
poor fluid intake
nausea, vomiting
↓ functional capacity
excessive fluid losses
fever
diuretics
diarrhoea
high stoma output
haemorrhage
burns

22. Clinical Presentation
drug history
nephrotoxic drugs
radiocontrast media
urinary tract symptoms
prostatic disease
renal calculi

23. Clinical Presentation
volume status
core temperature
heart rate
JVP
postural hypotension
cardiovascular status
peripheral perfusion BP
heart rate and rhythm

24. Clinical Presentation
palpable bladder
prostatic hypertrophy
carcinoma of cervix
bruits/absent pulses
renovascular disease
rash
vasculitis
interstitial nephritis

25. Complications

26. Complications of AKI metabolic cardiovascular gastrointestinal
hyperkalaemia
cardiovascular
pulmonary oedema, arrhythmias, pericarditis
gastrointestinal
nausea, vomiting, gastritis, ulceration, malnutrition

27. Complications of AKI neurological infectious haematological
seizures, mental status changes
infectious
haematological
anaemia, bleeding

28. Investigations

29. Investigations Full Blood Count and clotting
U&Es and bicarbonate (previous renal function)
Liver Function Tests and bone
urinalysis (prior to urinary catheter)
immunological screen – if vasculitis suspected

30. Investigations ultrasound of renal tract within 24hrs if
obstruction suspected
isoteric cause suspected requiring a kidney biopsy
consider blood film, LDH
(if ↓ Hb and ↓ Pl)
consider creatine kinase
(rhabdomyolysis)

31. Management

32. No Specific Therapy For Most Forms of AKI

33. Prevention of AKI is Essential
Risk of complications
increased length of stay
increased mortality
chronic kidney disease
Cost
£1.2 Billion

34. Prevention identify risk factors > 75 years
pre-existing chronic kidney disease
vascular disease
diabetes mellitus (with proteinuria)
cardiac failure
hypovolaemia
sepsis
nephrotoxins
drugs
contrast media

35. Prevention treat sepsis promptly optomise volume status stop/avoid
nephrotoxic medications
minimise volume of contrast

36. Treatment

37. Treatment of AKI dependent upon the cause supportive therapy
stabilise haemodynamics
treat complications
renal replacement therapy - dialysis
avoid further renal insults
nephrotoxins
Hypotension
Hold antihypertensives/diuretics

38. Treatment of AKI specific therapy e.g. vasculitis – Immunosuppression
If suspected – refer immediately

39. How Good Are We at Caring for Patients with AKI in the UK?39

40. Royal Society of Medicine
June 11, 2009
Royal Society of Medicine
London

41. Key findings < 50% of AKI care considered good
poor assessment of risk factors
43% of post-admission AKI - unacceptable delay in recognition

42. What is the relevance of AKI to the GP?

44. Patients with c-AKI sustain more severe AKI than h-AKI
Patients with c-AKI have better short term and long term outcomes than h-AKI

45. The Context: Addressing vulnerability & Transforming Urgent Care
Provide better support for people to self-care
Self-treatment options & care plan to know what to do and who to contact when deterioration
Help people with urgent care needs get right advice in right place, first time
Highly responsive urgent care services outside hospital
People with serious and life threatening emergency care needs receive treatment in centres with facilities and expertise
Connect all urgent and emergency care services

46. Acute kidney injury: prevention, detection and management up to the point of renal replacement therapy (CG169)
Guidance from the National Institute for Health and Care Excellence
August 2013
Dr Andy Lewington
Leeds Teaching Hospitals

47. NICE AKI Guideline
stresses the importance of risk assessment and prevention, early recognition and treatment
it is primarily aimed at the non-specialist clinician, who will care for most patients with AKI in a variety of settings
in view of its frequency and mortality rate, prevention or amelioration of just 20% of cases of AKI would prevent a large number of deaths and substantially reduce complications and their associated costs

48. NICE AKI Guidelines Rajib Pal (expert adviser)
GP Principal, Hall Green Health, West Midlands

53. Demographics 25% of general population > 60yrs
>85yrs age group will double in next 20 years
37% rise in admissions over last 10 years
66% of patients admitted > 65yrs
25% of patients have dementia
Patients > 85yrs account for 22% of bed days in NHS

54. Patient Population Many patients have
multiple co-morbidities
in nursing homes
more complex management issues
decreased functional reserve
Cardiac
Respiratory
Kidney
polypharmacy – e-presribing
Need to recognise at risk population

55. NHS England - Workstreams
AKI – sits under Patient safety
Detection
Risk Assessment
Chair AJPL
Co-Chairs
Fiona Loud (Patient)
Tom Blackmore (GP)
Management
Education

56. Identifying AKI in patients with acute illness
Investigate for acute kidney injury, by measuring serum creatinine and comparing with baseline, in adults with acute illness if any of the following are likely or present:
chronic kidney disease (adults with an estimated glomerular filtration rate [eGFR] less than 60 ml/min/1.73 m2 are at particular risk)
heart failure
liver disease
diabetes
history of acute kidney injury
oliguria (urine output less than 0.5 ml/kg/hour)
neurological or cognitive impairment or disability, which may mean limited access to fluids because of reliance on a carer
hypovolaemia
use of drugs with nephrotoxic potential (such as non-steroidal anti-inflammatory drugs [NSAIDs], aminoglycosides, angiotensin-converting enzyme [ACE] inhibitors, angiotensin II receptor antagonists [ARBs] and diuretics) within the past week, especially if hypovolaemic
use of iodinated contrast agents within the past week
symptoms or history of urological obstruction, or conditions that may lead to obstruction
sepsis
deteriorating early warning scores
age 65 years or over

57. Identifying AKI in patients with no obvious acute illness
Be aware that in adults, children and young people with chronic kidney disease and no obvious acute illness, a rise in serum creatinine may indicate acute kidney injury rather than a worsening of their chronic disease. [1.1.3 ]
Ensure that acute kidney injury is considered when an adult, child or young person presents with an illness with no clear acute component and has any of the following:
chronic kidney disease, especially stage 3B, 4 or 5, or urological disease
new onset or significant worsening of urological symptoms
symptoms suggesting complications of acute kidney injury
symptoms or signs of a multi-system disease affecting the kidneys and other organ systems (for example, signs or symptoms of acute kidney injury, plus a purpuric rash). [1.1.4]

58. AKI is a Global Problem

60. 1.2 million 300,000 $7,500 12.5 days (3.5 times) $9,000,000,000/YR
(3 to 14,000)
PER ADMISSION
EXCESS HOSPITAL
COSTS
$9,000,000,000/YR
Your length of stay in the hospital increases by
12.5 days
(3.5 times)
if you get AKI 22
3.5% ADMISSIONS 5
1.2 million
People per year
get AKI during a
hospital stay
300,000
people die in the US
annually from AKI
ODDS OF
DEATH
DEATH RATE/YR
More than breast cancer, prostate cancer, heart failure and diabetes, combined
Severity of AKI 60

61. Think Functional Reserve !
50% loss of function before serum creatinine rises above the upper limit of normal

62. ISN President Giuseppe Remuzzi
0 by 25 initiative
This initiative has one clear and concise aim: that no one should die of untreated acute kidney failure in the poorest parts of Africa, Asia and South America by 2025.
“It is morally inexcusable that people - mostly young people - still die of untreated acute kidney failure. ”
Giuseppe Remuzzi

63. Discussion Points Sick Day rules – NIHR funded
Vulnerable patients – how to identify
Electronic alerts
Map of Medicine – other resources
Y&H AKI Patient Care Initiative

64. QUESTIONS?