Chronic Kidney Disease Flashcards
Define chronic kidney disease
Abnormalities in kidney function/structure present for >3/12, with implications for health.
Define stage 1 CKD
- eGFR (ml/min/1.73m2)
- 90+ (G1)
- Requires markers of kidney damage
- eg. ACR >3; sediment; U+Es; histology; imaging
- Urinary ACR (mg/mmol)
- A2: 3-30
- A3 >30
Define stage 2 CKD
- eGFR (ml/min/1.73m2)
- 60-89 (G2)
- Requires markers of kidney damage
- eg. ACR >3; sediment; U+Es; histology; imaging
- Urinary ACR (mg/mmol)
- A2: 3-30
- A3 >30
Define stage 3a CKD
- eGFR (ml/min/1.73m2)
- 45-59
- Urinary ACR (mg/mmol)
- A1: <3
- A2: 3-30
- A3: >30
Define stage 3b CKD
- eGFR (ml/min/1.73m2)
- 30-44
- Urinary ACR (mg/mmol)
- A1: <3
- A2: 3-30
- A3: >30
Define stage 4 CKD
- eGFR (ml/min/1.73m2)
- 15-29
- Urinary ACR (mg/mmol)
- A1: <3
- A2: 3-30
- A3: >30
Define stage 5 CKD
- eGFR (ml/min/1.73m2)
- <15
- ACR (mg/mmol)
- A1: <3
- A2: 3-30
- A3: >30
Define ‘accelerated progression’ of CKD
Either:
- Both:
- Persistent decrease in GFR of 25+%
- Change in CKD category within 12 months
- A persistent decrease in GFR of 15ml/min/1.73m2 per year
What variables are used to estimate GFR using the MDRD equation?
- Serum creatinine
- Age
- Gender
- Ethnicity: Caution in Asian or Chinese origin; if Black x1.159
What factors can affect the estimation of eGFR?
- Pregnancy; oedema
- Muscle mass: eg. amputees, body-builders
- Eating red meat 1h prior to the sample being taken
List five risk factors for CKD progression
- Cardiovascular disease
- Proteinuria
- AKI: monitor potential/worsening CKD for at 2-3+y after AKI
- HTN
- Diabetes
- Smoking
- African, Afro-Caribbean, or Asian
- Chronic use of NSAIDs
- Untreated urinary outflow tract obstruction
Categorise the aetiology of chronic kidney disease
- 70% of CKD is due to
- Diabetes mellitus: non-enzymatic glycation
- HTN: glomerulosclerosis
- Renovascular disease: Atherosclerosis
- Congenital and inherited disease
- Glomerular disease
- Vascular disease
- Tubulointerstitial disease
- Urinary tract obstruction
Name one congenital/inherited cause of CKD
- Polycystic kidney disease: adult and infantile forms
- Medullary cystic disease
- Tuberous sclerosis: benign tumour development
- Oxalosis; cystinosis
- Congenital obstructive uropathy
Name two glomerular causes of CKD
- Primary glomerulonephritides:
- FSGS; membranous nephropathy
- Secondary glomerular disease:
- Diabetic glomerulosclerosis
- SLE
- GPA
- Amyloidosis
- Sickle cell disease
- Thrombotic thrombocytopenic purpura
Name two vascular causes of CKD
- Renovascular disease: atherosclerosis
- Small-vessel vasculitis: GPA; EGPA; Goodpasture’s
- Medium-vessel vasculitis: Polyarteritis nodosa; Kawasaki’s
- HTN nephrosclerosis: common in black Africans
Name two tubulointerstitial causes of CKD
- Idiopathic
- Nephrotoxic drugs
- Reflux nephropathy
- TB; schistosomiasis
- Nephrocalcinosis: renal calcium deposition
- Multiple myeloma
- Diabetes
- Sickle cell disease
- Chinese herb nephropathy
Name three urinary tract obstructive causes of CKD
- Renal stones
- Prostatic disease
- Pelvic tumours
- Retroperitoneal fibrosis
- Schistosomiasis
Explain the mechanisms by which angiotensin II causes progression of chronic kidney disease
- Local ATII causes vasoconstriction of efferent arterioles
- Increasing glomerular filtration fraction and pore size of basement membrane ➔ proteinuria
- Increases collagen synthesis and excessive matrix formation ➔ scarring within the glomerular and interstitium
RAAS antagonists slow CKD progressionin both diabetic and non-diabetic renal disease
Name five complications of CKD
- HTN: inappropriate RAAS activation
- Anaemia: low EPO
- Hyperkalaemia
- CKD mineral and bone disorder
- Cardiovascular calcification; pericarditis
- Uraemia
- Impaired glucose tolerence
- Gout; hypercholesterolaemia
- hyperPRL; decreased testosterone; menstrual irregularities
List three clinical features of uraemia
- Anorexia; intractable NaV
- Uraemic polyneuropathy; restless legs
- Pruritus
- Pericarditis
- Encephalopathy
- Intellectual clouding; drowsiness
- Seizures
- Coma
- Haemorrhage: abnormal platelet adhesion
- ‘Uraemic frost’: acummulation in skin
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What are CKD mineral and bone disorders
CKD results in:
- Impaired 1-a-hydroxylation
- Low vit D, low Ca2+, 2o hyper-PTH
- Impaired phosphate excretion: High PO4-
- Osteomalacia
- Due to high PO4- binding to Ca2+, activates PTH
Give three indications for CKD testing
Offer CKD testing if any of following risk factors:
- Diabetes
- HTN
- AKI
- Cardiovascular: IHD; HF; PVD; stroke/TIA
- Structural renal tract disease; recurrent renal calculi; BPH
- Multisystem disease with possible renal involvement: eg. SLE
- FHx of Stage 5 CKD
- Opportunistic detection of haematuria
Request four investigations for suspected CKD
- Urinalysis: haematuria, proteinuria
- Urine ACR
- U+Es; Serum creatinine
- CBG; HbA1c
- Renal ultrasound scan if indicated
Give three indications for renal USS in CKD
- Accelerated progression of CKD
- Visible or persistent invisible haematuria
- Symptoms of urinary tract obstruction
- FHx of polycystic kidney disease and are aged >20
- CKD Stage 4 or 5
- Considered to required renal biopsy
Describe the lifestyle advice and dietary management of CKD
- Encourage exercise, healthy weight
- Smoking cessation
- Diet
- Careful potassium intake
- Reduce phosphate if CKD-MBD
- Calorie and salt intake
Outline the medical management of CKD
Treat any underlying reversible causes; stop nephrotoxins
- BP: <140/90 or 130/80 if diabetic or ACR >70
- ACEi: CKD with either diabetes; HTN; ACR >70
- Atorvastatin 20mg
- Apixaban or Warfarin: secondary prevention of CVD
- Consider and contact nephrology:
- Bisphosphonates: osteoporosis
- Vitamin D: CKD mineral and bone disease
- EPO: CKD-associated anaemia
- Sodium bicarbonate: metabolic acidosis
What monitoring should be done prior to starting a RAAS antagonist for CKD?
Serum K+ and eGFR
Do not offer RAAS antagonists if K+ >5.0 mmol/L
Stop if K+ increases to 6.0
What are acceptable changes in eGFR and creatinine after starting ACEi for CKD?
Either:
- Decrease in eGFR of up to 25%
- Rise in creatinine of up to 30% is acceptable
- Greater than this may indicate renovascular disease