Professor Suetonia Palmer

Transcription

1 Professor Suetonia Palmer Department of Medicine Nephrologist Christchurch Hospital Christchurch 14:00-14:55 WS #108: The Kidney Test - When To Test and When to Refer ( and When Not To) 15:05-16:00 WS #118: The Kidney Test - When To Test and When to Refer (and When Not To) (Repeated)

2 Chronic kidney disease in adults Suetonia Palmer Nephrologist, Christchurch Hospital

3 Reasons for a nephrology referral Identify and make a diagnosis in people with undiagnosed kidney disease including hereditary diseases Identify (or rule out) kidney disease that requires specialist investigation (biopsy) and therapy (immunosuppression) Treat life-threatening complications of acute kidney injury or stage 5 CKD (hyperkalaemia, uremia, acidemia, fluid overload) Prepare patients with progressive kidney disease for dialysis and transplantation (or supportive care) Decision-making about whether to start or stop dialysis

4 About chronic kidney disease Structural abnormality, urine abnormality (cells, casts, protein), or decreased kidney function >3 months >90% of kidney function lost before symptoms (usually fatigue) CKD is a cardiovascular risk factor Patients with CKD are 20 times more likely to die from cardiovascular disease that start dialysis/transplant Only a small number of patients need specialist input due to progressive kidney failure or specific treatment

5 Differentiating stable and progressive CKD Need to distinguish between the majority of patients who have stable CKD and the minority with or at high risk of progressive CKD who need collaborative management Difference between CKD as a consequence of multimorbidity and CKD as primary disease or key determinant of patient well-being/prognosis

6 Step 1 who to screen for CKD Diabetes Hypertension Raised BMI >35 Established cardiovascular disease (known coronary artery disease, cerebrovascular disease, PVD) Family history of renal disease Urological disease Māori/Pacific/Indo-Asian ethnicity (CKD occurs at 10 years earlier in context of risk factors)

7 Step 2 Screen for CKD Urine and blood test Urine albumin to creatinine ratio (first void, confirm) Urine cells (white blood cells if no bugs, red cells, casts) Dipstick is not recommended as only indicator (confirm) Serum creatinine (egfr) Blood pressure If all normal, then risk of CKD is low (unless pre-clinical hereditary disorder)

8 Step 3 Interpret results: Urine ACR Urine ACR (PCR) Persistent for 3 months or longer PCR is alternative but less sensitive than ACR in very early phases of CKD In patients without diabetes, ACR > 30 or PCR >50 indicates significant risk of progression In patients with diabetes, ACR > 3.6 indicates kidney disease

9 Step 3 Interpret results: cells If (absence of infection) Pyuria (white cells >100) Haematuria (RCC >100) Red cell casts* Dysmorphic cells* Consider glomerular disease, especially if high BP, decreasing GFR, proteinuria

10 Step 3 -- Interpret GFR Consider if GFR normal for age Patient age (years) Normal GFR Expected range 20 to to to to to to to to to to to to 96

11 Step 4 decide if CKD is present and stable or progressive If GFR <60, consider AKI (drop of 25% from previous known value) If uncertain, and urine has no red or white cells, patient is well, repeat tests in a few days Make a diagnosis of CKD if ACR >30 or decreased GFR <60 for > 3 months Determine if progressive If GFR <60 and GFR decreased >15 in previous 12 months* High risk of progression if ACR >250 If stable GFR and mild-moderate proteinuria, lower risk of progression

12 Additional tests Blood pressure CBC Glucose, HbA1C Myeloma screen Serum calcium and phosphate Ultrasound if: GFR <30 GFR <45 with diabetes GFR dropped >15 in 12 months or ACR >250

13 Management Red flags AKI, biochemical complications, fluid overload, rapidly progressive kidney failure (referral to service with specialist experience in underlying condition) Consider reversible causes (obstruction, medicines, sepsis, hypovolaemia) Decide if referral is needed

14 Referral to nephrology if: Progressive CKD (GFR decreased by >15 in 12 months and <60 ml/min) Low GFR (<30 ml/min), although may not be needed if stable, ACR <70, CV risk reduction achieved, and/or severe comorbidity Proteinuria (ACR >70) unless known cause and appropriately treated Proteinuria with glomerular haematuria Intrinsic renal disease (active urinary sediment, nephrotic syndrome) Discussion needed about disease management issues even if patient doesn t need to be physically seen

15 Ongoing care: Patient may be best managed in primary care after: Diagnosis secured No indication for further specialist interventions or treatment (e.g. Immunosuppression) No indication to prepare for dialysis/transplant [yet], would not benefit [due to comorbidity] Plan generated for frequency of monitoring and criteria for rereferral made Generally if GFR >30, CV risk factors okay, kidney disease not progressive, controlled BP

16 Anaemia If GFR <30 If Hb <100 No active bleeding No other cause Replaced B12 and folate Replace iron (IV) if iron saturation <20% and ferritin <200 (community health pathway) after specialist approval Epoetin if patient would benefit (comorbidity, okay with slow rise in Hb, if Hb <90 and symptomatic), nephrology dept coordinates treatment Consider blood transfusion if more rapid increase needed, non-renal cause etc

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18 Thank you.