Chronic Kidney Disease Flashcards
CKD is defined as __ (eGFR __) for (duration)
kidney damage or reduced kidney function (eGFR <60) for 3 or more months
What are the markers of CKD?
- Albuminuria woth ACR > 30mg/g
- Urine sediment abnormalities
- Electrolyte imbalance due to tubular disorders
- Histologic abnormalities
- Structural abnormalities on imaging
- History of kidney transplantation
KDIGO Classification of CKD:
CKD secondary to (Cause), stage (GFR stage) - (ACR stage)
Prognosis of CKD by GFR-ACR categories
Comparative albuminuria staging for proteinuria
A1: uPCR < 15 mg/mmol or protein strip trace
- Protein excretion rate < 150 mg/1.73m2/day
A2: uPCR 15-50 mg/mmol or protein stip trace to 1+
- Protein excretion rate 150 - 500 mg/1.73m2/day
A3: uPCR > 50 mg/mmol or protein strip 2+
- Protein excretion rate > 500 mg/1.73m2/day
Importance of early identification of CKD
- Definitive diagnosis
- Treatment to prevent progression
- Managment of CKD complications
- Anaemia, mineral bone disease, acidosis, cardiovascular diseases - Prevent and detect further AKI
- Plan for RRT or transplant
What are the factors that influence serum creatinine levels?
Increased production
1. Muscle mass
2. Protein intake (myotein intake)
Reduced excretion
3. CKD
4. Drugs
- trimethoprim, fenofibrate
- NSAIDs (unapposed renal afferent arteriole vasoconstriction)
- SGLT2 inhibitors
Why is it important to evaluate urinary albumin excretion in CKD?
Albuminuria as risk factor for development of ESRF
(Nephrotic range proteinuria higher risk)
Reduction in proteinuria is associated with improved kidney outcomes
What are the causes of CKD?
(Bolded are commonest)
Glomerular
- FSGS - primary or secondary
> Secondary FSGS: DM, HTN
- IgAN
- Membranous nephropathy
- Diffuse proliferative GN
- MCD
Tubulointerstitial
- UTI
- Autoimmune
- Stones
- Obstruction
Vascular
- ANCA associated vasculitis
- Fibromuscular dysplasia
Cystic and congenital
- Kidney dysplasia
- Medullary cystic disease
- Polycystic kidney disease
Do all diabetic patients develop CKD?
How to diagnose CKD-DKD?
When is it indicated for renal biopsy?
Only 30-40% type 1 or type 2 DM develop CKD
Presumed DM nephropathy in patients with:
DM + albuminuria + DM complications
Indications for renal biopsy in DM patients:
- RBC cast
- Nephropathy early in course of DM
- Rapid progression of CKD
(Caution: some studies have shown that half of type 2 DM patient actually has CKD from other diseases instead of DM nephropathy)
African patients have higher incidence of CKD due to __.
__ gene on chromosome 22q13 greatly increases CKD risk,
Advantage: confers ability to kill __ to provide survival advantage in endemic areas.
Disadvantages: associated CKD diseases (3)
Familial aggregation of ESRF
APOL1 gene
Ability to kill trypanosoma brucei rhodesiense
Associated with:
1. Idiopathic FSGS
2. HIV associated nephropathy
3. Hypertensive nephropathy
What are the risk factors for developing CKD?
Non-modifiable
- Age (natural eGFR reduction of 1 point per year)
- Family history of kidney disease
- Low birth weight
- Ethnicity (African)
- Reduction in kidney drugs
Modifiable
- Diabetes mellitus
- Hypertension
- Smoking
- Obesity and metabolic syndrome
- Cardiovascular disease
- Autoimmune disease - SLE
- AKI and its recovery
- UTI with reflux nephropathy
- Kidney stones
- LUT obstruction
- Nephrotoxic drugs
How does kidney disease progress?
- Initial adaptive changes to loss of nephrons
- Glomerular hyperfiltration
- Increased residual nephrons filtration rate - Pathologic changes
- Glomerular sclerosis
- Kidney fibrosis
- Podocytes loss
- RAS activation
- Proteinuria
What are the common symptoms of CKD
- Fatigue
- Weakness
- Anorexia
- Nausea, vomiting
- Volume overload with pulmonary oedema
- Pericarditis
- Peripheral neuropathy
- Seizures, coma, death
Describe the pathology of diabetic nephropathy
- Glomerular and tubular basement membrane thickening
- Mesangial expansion forming nodules (Kimmelstiel-Wilson lesion)
- Arteriolar hyalinosis
- Tubulointerstitial fibrosis
Glucose toxicity
Glomerular hypertension
Oxidative stress
Toxic effects of metabolites, cytokines
Advanced glycation end products
What are the complications of CKD?
- Volume overload
- Hyperkalaemia
- Metabolic acidosis
- Hyperphosphataemia
- Hypertension
- Anaemia
- Malnutrition
- Mineral bone disease
- Dyslipidaemia
- Sexual dysfunction
- Uraemic bleeding
- Recurrent infection
- Pericarditis
- Uraemic encephalopathy
- Thyroid dysfunction
- Cardiovascular disease
Slowing down progression of CKD
- BP control
- RAS inhibition
- Dietary protein restriction
- Good glycaemic control
- Bicarbonate supplementation if Bicarb < 22
- Avoid nephrotoxic drugs - NSAIDs, aminoglycosides, contrast
- Treat reversible causes