Objectives

Understand why AKI matters

Natural history

Associated risk

Be able to recognise AKI

Do small changes in creatinine/eGFR really matter?

Be confident about what to do

Be confident about when to refer

KIDNEYS

Understand why AKI matters

NICE Guidance 28th August 2013

The National Confidential Enquiry into Patient Outcome and Death found that only half of patients with AKI had received 'good' care

Up to 30 per cent of cases of AKI can be prevented - that equates to at least 12,000 unnecessary deaths per year

Inadequate assessment of risk factors in 24% of patients admitted with AKI

Commonest risk factors not assessed were medication, co-morbidity and hypovolaemia

Understand why AKI matters: Natural history

Acute kidney injury results most often from ‘external’ insults threatening glomerular perfusion

Exacerbated by ‘toxic’ insults

Often in setting of ‘damaged’ kidneys

Significant biochemical changes have no ‘immediate’ clinical correlate but are ‘red flags’ for potentially significant ongoing insult/s to kidneys

If the insult is not corrected kidney injury will progress and reversible injury may become irreversible

Understand why AKI matters: Associated risk

AKI is associated with increased mortality

Degree of change directly proportional to increased risk

CKD≥3 is associated with increased mortality

AKI may be irreversible or only partially reversible resulting in CKD

‘Angina of the kidneys’

Need to stop becoming MI

(N=1,120,295)

1.0

1.4

2.0

2.8

3.4

Ha

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tio fo

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V e

ven

t

0

1

2

3

4

Reduced kidney function is associated with a higher risk of CV events

≥60 45-59 30-44 15-29 <15

eGFR (mL/min/1.73 m2)

Go et al. N Engl J Med 2004 351: 1296–1305 Tonelli et al. J Am Soc Nephrol 2006 17: 2034–2047Eeg-Olofsson et al. J Internal Medicine 2010 268: 471–482 Khaw Nature Reviews Endocrinology 2009 5: 130-131

8.0-8.9

9.0-9.9

CKD3

Be able to recognise AKI: Classification

A rise in serum creatinine of ≥26.5 μmol/L in 48 hoursA rise in serum creatinine of ≥50% in 7 days

AKI stage 1: a rise in creatinine of ≥26.5 μmol/L or 1.5-1.9 × baseline

AKI stage 2: a rise in creatinine of 2.0-2.9 × baseline

AKI stage 3: a rise in creatinine of ≥3 × baseline or increase in creatinine to ≥353 μmol/L

Be able to recognise AKI: Small changes

A rise in serum creatinine of ≥26.5 μmol/L in 48 hoursA rise in serum creatinine of ≥50% in 7 days

AKI stage 1: a rise in creatinine of ≥26.5 μmol/L or 1.5-1.9 × baseline

AKI stage 2: a rise in creatinine of 2.0-2.9 × baseline

AKI stage 3: a rise in creatinine of ≥3 × baseline or increase in creatinine to ≥353 μmol/L

Be able to recognise AKI: Change from baseline

140

120

100

140

120

100

Hemmelgarn BR. Kidney International 2006: 29: 2155

10,184 community-dwelling subjects aged 66 or over

Decline in eGFR greatest in diabetics (2.1 and 2.7 ml/min/1.73m2/year in F and M respectively)

Decline in eGFR in non-diabetics: 0.8 and 1.4 ml/min/1.73m2/year in F and M respectively

Decline more likely if baseline eGFR <30

Decline of GFR in elderly people

RRT

60

50

40

30

20

10

eGFR

CKD3

CKD4

X

Be able to recognise AKI: Is it really CKD?

Do not ignore eGFR 30-59ml/min until know

direction of travel and significant causes ruled

out

Direction of travel is everything

Haematuria and proteinuria are flags for further investigation

Risk factors for AKI include age >65, diabetes, CVD and ACEI/ ARB

Infection is a trigger for AKI in at risk patients even if not involving urinary tract

Summary

What to do

Recognise at risk patient

Identify and treat reversible insults irrespective of kidney function

Document kidney function

What to do: Medications

ACEI/ARB StopLoop Diuretics StopMetformin StopSUs ReviewMetiglinides No changeGliptins No changeStatins No changeAspirin No changeNSAIDs Stop/AvoidTrimethoprim Avoid

When to refer

AKI 1: Can be managed in primary care if cause treatable and kidney function stabilises

AKI 2: Refer general medicine

AKI 3: Refer nephrology

NB Obstruction and rapidly progressive glomerulonephritis should be referred to specialist unit directly whatever level of kidney function

Challenges: A lot of work for no return?

Need baseline defined in all at risk patients and technology to allow interpretation

Rapid turn round of creatinine in at risk patient with acute illness

Urinalysis

Patient education: sick day rules for kidneys

Recognition and Prevention of AKI

Is this an at risk patient?Age >65 yearsVascular diseaseDMACEI/ARBCKD

Is glomerular perfusion threatened ?Hypotension or sepsisNSAID/COXi/COX-2i

Kidney medicine in primary care: 7 minutes

Recognising the at risk patient: ACEI

ACEI/ARB essential part of managing IHD and preventing progression of CKD

ACEI/ARB, IHD and CKD are important risk factors for AKI

48 yr old man. Routine health check. Found to have eGFR of 35ml/minReferred for investigation of his “CKD 3”

No previous eGFRProtein ++++ No haematuriaBP 122/74

Case 1

Renal biopsy demonstrated FSGS

Mrs MA 74 year old eGFR 46ml/min/1.73m2

USS demonstrated ‘normal’ size kidneys

Serum electrophoresis revealed a paraprotein with urinary BJP

Case 2

Dipstick of urine revealed + protein

Mr PS 80 year old ‘Stable’ IHD Not diabetic No ACEI

Acutely SOB with possible rigor

Few crackles L base

Clarithromycin prescribed

Case 3

24 hours later confused and hypotensive

Emergency admission

Treated as CAP according to hospitalprotocol

Rx Vancomycin 1g x 2Gentamicin 160mg x 2

Case 3 continued

48 hours later AKI diagnosedBaseline eGFR 42ml/min/1.73m2

4 week hospital admission

Probably avoidable with recognition that patient likely to have CKD and risk conferred by this CKD

Admission eGFR 22ml/min/1.73m2

‘48h’ eGFR 12ml/min/1.73m2

Case 3 continued

74 year old male with 12 year history of T2DM presents to casualty unwell with lower abdominal pain. Known to have diverticular disease

Most recent HbA1c 7.4%

First thoughts?

Case 4

Rx Ramipril 5mg daily and Metformin 500mg bd

74 year old male with 12 year history of T2DM presents to casualty unwell with lower abdominal pain. Known to have diverticular disease

Rx Ramipril 5mg daily and Metformin 500mg bd

Pyrexial. BP 130/74. Euvolaemic

WCC 10.6x109/l CRP 48ng/ml

eGFR 42ml/min with a potassium of 4.2mmol/l

Case 5

92 year old is seen in clinic having been found by GP to have ‘CKD4’

She is well with an eGFR of 26ml/min

Rest of biochemistry is safe, urine reveals neither blood nor protein

What do I do?

Case 6

USS shows echobright kidneys of 8.2cm and 8.4cm with no evidence of obstruction

eGFR was 28ml/min in 2008

Case 7

A 36 yr old woman who has been previously fit and well and who rarely attends the surgery presents complaining of increased tiredness. She is an active sportswoman who has noticed reduction in exercise tolerance over 3 weeks such that she has struggled on hills when jogging. For 3 days she has had a sore throat, ‘painful’ fingers and noticed a few ‘red spots’ on her right thigh. On examination you confirm that she has a palpable non-blanching purpuric rash on her thigh. BP is 164/90 but examination is otherwise unremarkable.

What do I do?

Case 7

A 36 yr old woman who has been previously fit and well and who rarely attends the surgery presents complaining of increased tiredness. She is an active sportswoman who has noticed reduction in exercise tolerance over 3 weeks such that she has struggled on hills when jogging. For 3 days she has had a sore throat, ‘painful’ fingers and noticed a few ‘red spots’ on her right thigh. On examination you confirm that she has a palpable non-blanching purpuric rash on her thigh. BP is 164/90 but examination is otherwise unremarkable.

What do I do

Dipstick of urine revealed blood ++ and protein ++

78 year old with stable CKD3. Rx Ramipril 5mg daily

eGFR June 2011 47ml/min April 2014 41ml/min

Cares for terminally ill husband therefore deferred R hip replacement

What pain killers would you recommend?

Case 8

Pharmacist recommended Ibuprofen 400mg daily

4th July 2014 16ml/min

Stopped ibuprofen

14th July 2014 39ml/min

Slides and more info available at www.clinimeded.co.uk

https://www.thinkkidneys.nhs.uk

Wales Deanery CPD for GP http://gpcpd.walesdeanery.org/

ClinicalAcute Kidney Injury

Quiz: http://www.doctors.net.uk

More information available at

Objectives

Understand why AKI matters

Natural history

Associated risk

Be able to recognise AKI

Do small changes in creatinine/eGFR really matter?

Be confident about what to do

Be confident about when to refer