Renal Disease Flashcards
What are causes of Renal Disease?
- Inflammatory: Infection, Drugs, Toxins, Autoimmune, Infiltration
- Inherited: RTA, Polycystic kidney/tubulopathies
- Metabolic Disease: Diabetes mellitus
- Obstruction: Renal calculi, Carcinoma, Renal vein thrombosis
Affects any or all parts of the kidney (glomerular, interstitial, tubular and/or vascular
What are features of chronic renal disease?
- Develops slowly (months/years)
- Irreversible and Progressive. Loss of both glomerular and tubular function.
- Leads to End Stage Renal Disease (ESRD)
- Significant morbidity and mortality
What are features of Acute Renal Disease?
- Rapid (hours/days) onset of kidney failure caused by injury or illness.
- Usually reversible
- Potentially fatal
What is the definition of Chronic Kidney Disease?
Abnormalities of kidney function or structure present for ≥3 months
- Markers of kidney damage (albuminuria/haematuria/structural abnormalities)
- and/or
- GFR <60 ml/min/1.73 m2 on at least 2 occasions separated by a period of at least 90 days
What are risk factors/causes of Chronic Kidney Disease?
- Diabetes Mellitus
- CVD
- Smoking
- Hypertension
- Obesity
- Multisystemic disease such as SLE
- Structural renal disease/ Renal stones
- Family history
- Ethnicity
- Age
How does Chronic Kidney Disease present?
Asymptomatic in early stages
- Uraemic syndrome
- Progressive weakness, fatigue, loss of appetite, nausea, vomiting, tremors, altered mental function
- Nocturia,polyuria
- Pain
- Oedema.
What are some biochemical findings for CKD?
- Increased serumurea/creatinine
- Hyponatraemia
- Hyperkalaemia
- Metabolic acidosis
- Hyperphosphataemia
- Hypocalcaemia
- Glucose metabolism (Impaired glucose tolerance, Decreased insulin)
- Lipid metabolism (Increased in triglycerides, Decreased HDL, Cardiovascular effects)
- Protein metabolism (Patients are catabolic – protein loss)
- Red cell production (Normocytic, normochromic anaemia,Decreased erythropoietin)
What are renal causes, clinical features of each Biochemical finding in CKD?
Increased serum urea/creatinine
- Renal Cause: Reduced GFR
- Clinical Feature: Uraemic syndrome
Hyponatraemia
- Renal Cause: Reduced GFR (sodium retention), Reduced tubular function (sodium loss, inability to concentrate or dilute urine)
- Clinical Features: Risk of over/under hydration, Polyuria/nocturia
Hyperkalaemia
- Renal Cause: Reduced GFR
- Clinical Features: Cardiac arrythmias, Cardiac arrest
Metabolic acidosis
- Renal Cause: Reduced H ion excretion (GFR and reduced PO4 excretion), Reduced tubular function (bicarb reabsorption)
- Clinical Features: Acidosis
Hyperphosphataemia
- Renal Cause: Reduced GFR
- Clinical Features: Renalosteodystrophy
Hypocalcaemia
- Renal Cause: Reduced 1,25 –vitamin D. (1a hydroxylase)
- Clinical Features: Renalosteodystrophy
How is Chronic Kidney Disease investigated and diagnosed?
- Non specific symptoms
- Often diagnosed when in advanced stage – increased mortality and morbidity
- Early diagnosis – slow progression / reduce number progressing to ESRD.
- Screening of at risk populations – DM, CVD, hypertension, multisystemic disease (SLE), family history, nephrotoxic drugs.
- Incidental finding – proteinuria and/or haematuria
What are investigations for CKD?
eGFR
- Use the CKD-EPIcreat equation - previously most labs reported MDRD.
- Use specific creatinine assays (enzymatic)
- Advise people not to eat meat in the 12 hours before having a blood test for creatinine/eGFR.
Proteinuria
- Use urine ACR in preference to PCR, if the ACR = 3 - 70 mg/mmol, confirm by a subsequent EMU. If the initial ACR ≥70 mg/mmol, repeat not required.
Other Markers
- Urine sediment abnormalities,
- Electrolyte and other abnormalities due to tubular disorders,
- Abnormalities detected by histology,
- Structural abnormalities detected by imaging, Ultrasound
- History of kidney transplantation.
How is the classification of Chronic Kidney disease derived?
Based on eGFR and albumin:creatinine ratio (ACR)
When is the eGFRcystatinC used?
Consider using eGFRcystatinC at initial diagnosis to confirm or rule out CKD in people with:
- eGFRcreatinine of 45–59 ml/min/1.73 m2, sustained for at least 90 days and
- no proteinuria ACR<3 mg/mmol) or other marker of kidney disease.
When should patients not be diagnosed with Chronic Kidney disease?
Do not diagnose CKD in people with:
- An eGFRcreatinine of 45–59 ml/min/1.73 m2 and
- An eGFRcystatinC of more than 60 ml/min/1.73 m2 and
- No other marker of kidney disease.
Describe the progression of Chronic Kidney Disease worsen CKD?
- Kidney has a large reserve capacity. 50-60% loss of functioning kidney before symptom/biochemical abnormalities seen.
- Adapts by hyperfiltration of remaining functioning nephrons
- Hyperfiltration causes glomerular damage.
- Initates an inflammatory response: Cellular infiltration and T-cell activation, Fibroblast activity increased leading to ECM synthesis – renal fibrosis, Disruption to renal blood flow which causes ischaemic damage
What increases risk of CKD progression?
Risk of progression:
- ↑ACR
- ↓eGFR
- CVD, ↑BP, DM, smoking, AKI, NSAIDs, ethnicity
Increased risk of progression to end stage kidney disease if they have either:
- A sustained decrease in GFR of 25% or more over 12 months or
- A sustained decrease in GFR of 15 ml/min/1.73 m2 or more over 12 months
How is Chronic Kidney Disease managed?
No cure
Primary aim to:
- Manage/treat complications
- Slow progression
- Rzeduce risk of co-morbidities – CVD
