Chronic Kidney Disease. Janak de Zoysa

Transcription

1 Chronic Kidney Disease. Janak de Zoysa

2 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).

3 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

4 Patient Problems with S Cr: Variability Population ref. range Cr (mmol/l)

5 Serum creatinine (mmol/l) Problems with Serum Creatinine: Insensitive Up to 50% loss of GFR can occur with serum creatinine remaining within population reference range Creatinine- blind region C inulin (ml/min/1.73m 2 ) Population ref. range

6 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) Age [if female] 1.16 [if Black] 1.05 [if Asian] 1.01 [if Hispanic and Native American]

7 CKD - Staging Divided into 5 stages: CKD 1 GFR > 90 ml/min CKD 2 GFR ml/min CKD 3a GFR ml/min CKD 3b GFR ml/min CKD 4 GFR ml/min CKD 5 GFR < 15 ml/min

8 Albuminuria Is a marker of renal disease and prognosis. Addition of albuminuria to staging: A1 < 30 mg/mmol A mg/mmol A3 >300mg/mmol

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10 Renal prognosis.

11 Other implications.

12 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

13 Sociodemographic risk factors. Age more common in the elderly Sex more common in men Ethnicity more common in Asians, Pacific Island peoples and Māori.

14 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?

15 Case 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

16 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

17 Case 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

18 Renal Biopsy Histology.

19 Renal Biopsy Immuno (IgA)

20 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)

21 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

22 Imaging.

23 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.

24 Case 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

25 Discussion. Probably HT nephrosclerosis Do bloods and US renal tract Try to optimise BP 140/80mmHg or lower

26 Case 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

27 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

28 Case 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

29 Discussion. Probably not abnormal for his age. Could do a urinalysis and 24 hour creatinine clearance to check.

30 Creatinine and egfr. Serum Cr 140 mmol/l GFR = 120 ml/min GFR = 20 ml/min

31 egfr (ml/min/1.73m2) Renal Function changes with age Low Limit Median High Limit 60 ml/min %<60 ml/min 0 0 Age (years) Based on 200,000 routine pathology results, courtesy Dr Ken Sikaris

32 Causes of CKD. The most common causes of CKD are: Diabetic nephropathy 40% Glomerulonephritis 30% Hypertensive nephrosclerosis 10% Polycystic kidney disease 10%

33 Slowing progression. Intervention into the primary renal disease Intervention into secondary factors

34 Diabetes

35 Renal survival (%) Hypertension. Progression of CRF has been linked to HT. Lowering BP alters speed of progression. Renal survival and hypertension. 90 < 107mmHg Months > 107mmhg Locatelli et al. NDT 1996

36 Hypertension. Target 140/80 mmhg or better Weight loss Salt restriction Exercise Moderation of alcohol Stop smoking

37 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

38 HT drugs Naturesis (diuretics) Renin : angiotensin system Sympathetic nervous system

39 Complementary Drugs. (RAAS +/- SNS blockade) (Natriuretic +/-vasodilator) Beta blockers ACE inhibitors ARB s Clonidine Methyldopa Diuretics CCB Alpha-blocker Minoxidil

40 Good and bad combinations Good Bad Thiazide and ACEI ACE and CCB B-blocker and α-blocker Thiazide and CCB ACEI and B-blocker ARB and B-blocker ACEI and ARB

41 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.

42 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

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44 Interesting Links. ndards--policy/consultations/ckd-consensusstatement-25-sept-2013.pdf /pdf/ckd/kdigo_2012_ckd_gl.pdf d=