Chronic kidney disease (CKD)

• CKD is defined as abnormalities of kidney structure or function, present for more than 3 months
• Very common in Aboriginal people. Often with other chronic conditions (eg diabetes, high BP)
• Finding kidney disease early and treating high BP can slow progress of CKD and give person a better life
• Usually no symptoms — diagnosed by blood or urine tests
• Tests can be abnormal for short periods for other reasons
• Classified based on cause, glomerular filtration rate (GFR) category (G1-G5), and Albuminuria category (A1–A3), abbreviated as CGA

Green — low risk (if no markers of kidney disease, no CKD
Yellow — moderately increased risk
Orange — high risk
Red — very high risk
GFR — glomerular filtration rate

Testing for kidney disease

Diagnosis of chronic kidney disease needs 2 abnormal urine ACR at least 3 months apart OR 2 reduced eGFR at least 3 months apart

Urine testing for kidney disease

• At annual Adult Health Check
• U/A
• AND if Aboriginal adult 30 years or over — ACR
• If positive protein (1+ or more) on U/A 
• Send urine for ACR
• Collect urine for MC&S
• Standard STI check to exclude active infection — man, woman
• If ACR 2.5 or more for males or 3.5 or more for females
• AND no UTI or STI — repeat urine ACR in 3 months to confirm chronic kidney disease
• AND active UTI or STI — treat infection, repeat U/A in 3 months. If positive protein — repeat ACR
• At least one ACR should be first morning void urine (first time to toilet that day)
• If raised urine ACR results — medical follow up
• ACR useful for diagnosis, but once treatment started use eGFR to check progress of kidney disease

At diagnosis

Check

• Head-to-toe exam
• U/A, pregnancy test

Do

• Blood for UEC, FBC, BGL, lipids, CRP — UEC must be taken on the same day the bloods are sent to the lab or Se K will be elevated
• Calculate estimated glomerular filtration rate (eGFR)
• eGFR worked out using age, gender, serum creatinine level — useful estimate of true kidney function for everyday use
• If using POC Test to measure electrolytes, creatinine — calculate eGFR
• Work out CKD risk level using eGFR and urine ACR — see Table 4.10
• Estimates risk of kidney failure or cardiovascular death
• Cardiovascular risk assessment
• Promote healthy lifestyle measures — diet, weight control, physical activity, stop smoking, moderate alcohol intake
• Advise to reduce dietary daily salt intake to less than 2g of sodium (or less than 90mmol sodium or less than 5g sodium chloride per day)  in patients with high BP and CKD — refer to dietitian
• Medical consult, including medicines review
• Renal ultrasound (not essential to diagnose CKD) — essential to exclude specific problems if person has
• Recurrent UTIs
• OR symptoms of urinary tract obstruction — frequency, incontinence
• OR family history of polycystic kidney disease
• If female of childbearing age — talk about contraception. Pregnancy increases stress on kidneys

Medicines for CKD

• ACE inhibitor or ARB is mainstay of treatment
• Maximise dose to get best effect. BP target — less than 130/80
• Do not use ACE inhibitor and ARB together. Increased risk of side effects 
• Do not use in pregnancy — both contraindicated
• Advise all women of childbearing age on ACE inhibitor or ARB of risks AND
• To use reliable contraception
• To come to clinic if planning pregnancy, may need to change medicines. See pre-pregnancy counselling
• To come to clinic to stop medicine as soon as they think they are pregnant — medical consult

Step 1

• ACE inhibitor (eg ramipril, perindopril)
• If can't take ACE inhibitor (cough, angioedema) — give ARB (eg irbesartan)
• If elderly or heart failure — start with lower dose
• Check UEC 2 weeks after starting ACE inhibitor or ARB
• If eGFR decreases by more than 25% OR potassium is more than 5.5mmol/L —
• Stop ACE inhibitor or ARB
• Kidney specialist consult
• ​If no side effects — increase dose until target BP reached (less than 130/80mmHg)

Step 2

• If BP still above target after 3 months — add
• Calcium channel blocker (eg diltiazem slow-release, amlodipine). If pregnant — medical consult 
• OR beta-blocker (eg atenolol). If pregnant — medical consult 

Step 3

• If BP still above target after 3 months — change to combination medicine
• ACE inhibitor + thiazide diuretic (eg perindopril-indapamide)
• OR ARB + thiazide diuretic (eg irbesartan-hydrochlorothiazide)

• If BP not controlled with 3 drugs at maximum dose — physician/kidney specialist consult

Kidney specialist referral

Kidney specialist consult straight away for anyone with

• High potassium level — more than 6mmol/L on pathology test
• Recheck with POC Test. If still more than 6mmol/L — ECG and consult
• Unwell with signs of acute kidney injury — oliguria (low urine output), blood in urine, acute high BP, peripheral swelling
• 25% reduction in eGFR at any risk level

Consider referral to kidney specialist if

• More than 20% reduction in eGFR 
• Ongoing protein and blood in urine

Refer for shared care with kidney specialist if 

• eGFR less than 15 for first time
• Urine ACR more than 300mg/mmol (or 3+ protein on U/A) AND swollen legs — may be nephrotic syndrome
• High CKD risk level — routine referrals for planned care
• eGFR less than 45 for first time
• Check if further tests or results needed before appointment
• Renal biopsy rarely needed
• Follow-up appointments can be telehealth case conference

Common problems — high CKD risk level

Anaemia

Causes fatigue, shortness of breath, difficulty thinking

• Target Hb — 100–115g/L
• If less than 100 or more than 115g/L — follow kidney specialist team management plan or talk with kidney specialist team at case conference
• Often need iron — IV infusion or oral
• May need regular subcut erythropoietin (eg epoetin, darbepoetin). Prescribed by kidney specialist

Medicines

• Do not use NSAIDs (eg ibuprofen)
• Do not use metformin if eGFR less than 30
• Check all medicines with doctor or pharmacist — a lot of medicines cleared by kidneys can’t be given or need smaller doses
• Be careful with radiology needing contrast injection

Patients on renal replacement therapy (RRT)

Peritoneal dialysis, community based haemodialysis, with kidney transplant

Do

• Develop care plan with shared care between primary care and kidney specialist team
• Develop action plan for acute illness or an emergency

Missed dialysis

Ask

• When was last dialysis treatment
• Shortness of breath, weakness, confusion
• Nausea, vomiting, chest pain

Check

• Coma scale score
• ECG — check for signs of high serum potassium level Table 4.11
• Normal ECG does not exclude high potassium levels

Do

• Medical consult — send to dialysis unit in major centre not regional satellite
• If stable (no high potassium levels and no severe shortness of breath) — could use commercial transport rather than medical retrieval
• POC Test for electrolyte (potassium) level
•  Give
• Calcium polystyrene sulfonate (eg Resonium) oral — adult 30g, twice a day (bd)  — check indications
• AND lactulose oral — adult 30mL, twice a day (bd)  (reduces constipation)

If serum potassium level high — above 6mmol/L OR tall T wave on ECG or Lead II monitoring

• Urgent medical consult
• Give
• Calcium gluconate 10% IV bolus — 10–20mL. Give slowly over 3–10 minutes, can repeat every 5 minutes until improved
• OR if person has used digoxin — calcium gluconate 10% IV — 10mL in 100mL glucose 5% over 20 minutes
• Continuous nebulised salbutamol. Nebulisers have high risk of transmitting infection — wear full PPE

Supporting resources

GFR calculator - Kidney foundation Australia