Chronic Kidney Disease. - Comprehensive Care · Janak de Zoysa . CKD. •CKD is defined as...

Chronic Kidney Disease.

Janak de Zoysa

CKD.

• CKD is defined as abnormalities of kidney

structure or function, present for > 3 months,

with implications for health.

• CKD is classified based on cause, GFR

category, and albuminuria category (CGA).

Inulin clearance.

• Inulin is a sugar which is filtered by the glomerulus and neither reabsorbed nor secreted into the tubule.

• The gold standard is to inject inulin into the blood and measure the clearance of inulin in the urine.

GFR = Vol of urine per time X Conc of inulin in urine

Conc of inulin in blood

1

3

2

4

5

6

7

8

9

10

55 65 75 85 95 105 115 125 135

.

Patient

Cr (mmol/L)

Population ref. range

Problems with S Cr: Variability

• Up to 50% loss of GFR

can occur with serum creatinine

remaining within population

reference range

C inulin (ml/min/1.73m2)

Seru

m c

reatin

ine (m

mol/L

)

Creatinine-’blind’

region

0 20 40 60 80 100 120 140 160 180

100

200

300

400

500

600

700

900

1000

Problems with Serum Creatinine: Insensitive

0 55 125

Population ref. range

Estimated GFR.

• More typically derived formula, using a single

blood test of the serum creatinine, which is used

to calculate the estimated glomerular filtration

rate (eGFR).

• Cockcroft and Gault, MDRD, CKD-EPI.

• GFR=141 × min(Scr/κ, 1)α × max(Scr/κ, 1)−1.210 ×

0.993Age × 0.993 [if female] × 1.16 [if Black] ×

1.05 [if Asian] × 1.01 [if Hispanic and Native

American]

CKD - Staging

• Divided into 5 stages:

CKD 1 GFR > 90 ml/min

CKD 2 GFR 60- 90 ml/min

CKD 3a GFR 45 - 60 ml/min

CKD 3b GFR 30 – 45 ml/min

CKD 4 GFR 15- 30 ml/min

CKD 5 GFR < 15 ml/min

Albuminuria

• Is a marker of renal disease and

prognosis.

• Addition of albuminuria to staging:

A1 < 30 mg/mmol

A2 30-300 mg/mmol

A3 >300mg/mmol

Renal prognosis.

Other implications.

RRT in NZ.

Over 4000 people on RRT in NZ.

CKD in NZ is unknown but estimated as:

CKD 5 = 3000

CKD 4 = 8000

CKD 3 = 70,000

CKD 2 = 170,000

CKD 1 = >250,000

Sociodemographic risk factors.

• Age – more common in the elderly

• Sex – more common in men

• Ethnicity – more common in Asians, Pacific

Island peoples and Māori.

Cases.

• What is the classification for the renal disease?

• What else would you like to know?

• What other investigations are needed?

• What are the key management points?

Case 1.

• 54 year old Samaon lady

DM for 12 years, HT, Dyslipidaemia

Aspirin 100mg, Metformin 500mg tds,

Cilazapril 5mg, Simvastatin 20mg

Wt 100kg, BMI 37, BP 150/90mmHg

Cr 140umol/L, Urine ACR 70, HbA1c 60

Discussion

• Diabetic nephropathy

• Major cause of CKD (>40%)

• Serial Cr and urinalysis

• Optimise HbA1c

• Lower BP 130/80mmHg (diuretic/CCB)

• No absolute need for imaging

Case 2.

• 43 year old Chinese man

Usually well.

Sore throat and macroscopic haematuria

No medications

Wt 67kg, BP 150/90mmHg, BMI 24

Cr 140umol/L, MSU RCC >1000, Urine ACR 40

Renal Biopsy – Histology.

Renal Biopsy – Immuno (IgA)

Discussion.

• Probably glomerulonephritis (30%-35% of

ESKD).

• ANA, ANCA, dsDNA, C3, C4,

streptococcal serology, hepatitis serology.

• US and renal biopsy (confirms IgA)

• Treat BP 140/90mmHg or lower

(ACEI/ARB)

Case 3.

• A 39 year old lady presents for routine

renewal of the OCP. She has a family

history of polycystic kidney disease.

She is on no other regular medications.

Wt 67kg, BP 150/90mmHg, BMI 24

Cr 80umol/L, MSU RCC 10, Urine ACR 20

Imaging.

Discussion.

• PCKD (10% ESKD).

• U/S renal tract

• Treat BP 140/90mmHg or lower

• New agents coming (Sirolimus Tolvaptan)

• Advice about family hx and screening

• Advice about stones, infections and

aneurysms.

Case 4.

• 68 year old man with hypertension, Type 2 DM.

On Aspirin 100mg, Metoprolol 47.5mg daily,

Pravastatin 10mg daily, Metformon 850mg tds

• Examination:

HR 72/min, BP 160/90mmHg, JVP 2cm, Wt 98kg

• Investigations:

Na 140, K 5.0, Cr 150µmol/L, urine ACR 10, HbA1c 49

Discussion.

• Probably HT nephrosclerosis

• Do bloods and US renal tract

• Try to optimise BP 140/80mmHg or lower

Case 5.

• 82 year old man with hypertension, osteoarthritis,

GOR, gout and COAD. Has recently completed

antibiotics (Augmentin). On Cilazapril 5mg,

Bendrofluazide 5mg, omeprazole 20mg daily,

allopurinol 100mg, serevent and flixotide. Takes

diclofenac SR 75g mgs 1-2/week.

• Examination:

HR 72/min, BP 150/90mmHg, JVP 1cm, No oedema

RR 18/min, wheeze, PEFR 300l/min

• Investigations:

Na 140, K 5.0, Urea 10, Cr 140µmol/L, urine ACR 10

Discussion.

• Multiple potential causes for renal

impairments HT, drugs.

• Probably not significantly abnormal for his

age.

• Try stopping diuretic and starting CCB

• Consider stopping PPI and NSAID

Case 6.

• 35 year old Samoan man. Usually fit and well.

Presents for a well man check.

• Examination:

Wt 100kg, HR = 70/min, BP 112/60mmHg, no oedema

• Investigations:

Na 140mmol/L, K 4.5mmol/L, urea 6.0mmol/L, Cr

125µmol/L, urine ACR 3

Discussion.

• Probably not abnormal for his age.

• Could do a urinalysis and 24 hour

creatinine clearance to check.

Creatinine and eGFR.

Serum Cr 140 mmol/L

GFR = 120 ml/min GFR = 20 ml/min

Renal Function changes with age.

0

20

40

60

80

100

120

140

160

1801

6-2

9

30

-39

40

-49

50

-59

60

-69

70

-79

80

-89

90

-99

Age (years)

eG

FR

(m

L/m

in/1

.73

m2

)

0

10

20

30

40

50

60

Low Limit

Median

High Limit

60 mL/min

%<60 mL/min

Based on 200,000 routine pathology results, courtesy Dr Ken Sikaris

Causes of CKD.

• The most common causes of CKD are:

Diabetic nephropathy 40%

Glomerulonephritis 30%

Hypertensive nephrosclerosis 10%

Polycystic kidney disease 10%

Slowing progression.

• Intervention into the primary renal disease

• Intervention into secondary factors

Diabetes

Hypertension.

• Progression of CRF has been linked to HT.

• Lowering BP alters speed of progression.

Renal survival and hypertension.

50

70

90

0 6 12 18 24 30

Months

Ren

al s

urvi

val (

%)

< 107mmHg

> 107mmhg

Locatelli et al. NDT 1996

Hypertension.

• Target 140/80 mmHg or better

• Weight loss

• Salt restriction

• Exercise

• Moderation of alcohol

• Stop smoking

Drugs and hypertension.

MDRD ABCD HOT UKPDS

Goal BP MAP < 92

mmHg DBP < 75

mmHg DBP < 80

mmHg DBP < 85

mmHg

Achieved BP 93 mmHg 75 mmHg 81 mmHg 82 mmHg

Average number

of drugs 3.6 2.7 3.3 2.8

HT drugs

• Naturesis (diuretics)

• Renin : angiotensin system

• Sympathetic nervous system

Complementary Drugs.

(RAAS +/- SNS blockade) (Natriuretic +/-vasodilator)

Beta blockers Diuretics

ACE inhibitors CCB

ARB’s Alpha-blocker

Clonidine Minoxidil

Methyldopa

Good and bad combinations

• Good

Thiazide and ACEI

ACE and CCB

B-blocker and α-blocker

Thiazide and CCB

• Bad

ACEI and B-blocker

ARB and B-blocker

ACEI and ARB

Screening – as part of CV risk.

• Hypertension

• Diabetes

• BMI > 35

• Cardiovascular disease

• Family history of kidney disease

• Prostatic syndrome/urologic disease

• Nephrotoxic drugs

• Māori, Pacific Island People or Indo- Asians

• Age over 60 years.

Who to refer.

• Intrinsic kidney disease

• Drug-resistant hypertension

• Progressive Stage 3B and 4 CKD

• CKD 5

• Where uncertainty about management or

referral exists, use of telephone consultations

and/or ‘virtual’ referrals is highly recommended

Interesting Links.

• http://www.rnzcgp.org.nz/assets/documents/Sta

ndards--Policy/Consultations/CKD-consensus-

statement-25-Sept-2013.pdf

• http://www.kdigo.org/clinical_practice_guidelines

/pdf/CKD/KDIGO_2012_CKD_GL.pdf

• http://jama.jamanetwork.com/article.aspx?articlei

d=1791497