CKD, AKI, Transplantation Flashcards
Low GFR < 60 ml/ min for 70 days, CKD or AKI?
- Defined as GFR of < 60ml/min for > 90 days/3 months
- If < 90 days may be AKI
How is CKD classified
Classification includes both eGFR and urinary albumin: creatine ratio (ACR) eg. G3a A3
As raised serum creatinine reflects compromised renal function with reduced GFR
Non-renal cause of CKD
Diabetes, hypertension
what is measured to test for proteinuria, how is it quantified
Albumin, quantify using albumin/creatine ratio
first line investigation in patients with albumin in dipstick
ACR, (then test kidney renal function)
Treatment for proteinuria
ACE inhibitors and corticosteroids
Should treatment be given if ACR is <30
No, may occur transiently. but need to prevent diabetic nehropathy
What does presence of proteinuria WITH BLOOD imply
What does proteinuria in HTN imply
Glomerular disease (problems with filtering)
Albuminuria suggest a primary renal cause in Hypertension → SEC Hypertension
What is nephrotic syndrome
- Clinical syndrome comprising oedema, heavy proteinuria, hypoalbuminemia (low levels of albumin IN BLOOD)
- May not have blood in urine
(MAINLY GLOMERULAR PROBLEMS)
- May not have blood in urine
is GFR normal or abnormal in nephrotic syndrome
Depends on whether there is impairment of excretory function
One sign of nephrotic syndrome, dominant symptoms
stretch marks in legs during protein leaking. severe lethargy, reduced exercise tolerance, nausea and loss of appetite
What causes congenital Nephrotic syndrome
Mutations in nephrin in podocyte
How are the test results in systemic vasculitis
Tends to have more blood than protein - indicates inflammation
what antibody us systemic vasculitits associated with , what other symptoms
ANCA, May have painful lesions over joints (in both hands and feet) and rashes
Are CKD patients more likely to be hypo or hyperkalaemic
What other drugs or diseases can exacerbate this?
- Hyperkalaemia common as GFR declines to less than 25
- May occur at GFR > 25
- Diabetes and type 4 RTA
- ACE inhibitors → should consider reducing ACE inhibitors
- High K Diet→ reduce consumption of high K food, increase low na food
- High K diet will affect Na delivery to DCT
Related to distal sodium delivery, decreased DND with decreased GFR
- High K diet will affect Na delivery to DCT
- May occur at GFR > 25
Is acidosis or alkalaemia more likely in CKD
- Most Acidosis in CRF is due to animal protein in food → phosphates and sulfates generated as they break down
- Inability to acidify urine in CKD
Bone disease as complication of CKD => What types??
Renal osteodystrophy
- High turnover bone disease
- Secondary hyperparathyroidism (Osteitis Fibrosa)
- Low turnover bone disease
- Osteomalacia
- Due to low calcium
- Adynamic bone disease
- Aluminium bone disease
- Osteomalacia
Treatment of renal osteodystrophy
phosphate restriction- meat and dairy , take calcium or non-calcium binders with meals, vitamin d therapy directly to override hydroxylation (alfacalcidiol), may require parthyriodectomy ??
What risk does CKD increase?
CVD
What is renal clearance? Diff vs GFR
VOLUME of plasma completely cleared of a substance per unit time
GFR = clearance if substance is completely lost to urine = C urine x UO / C plasma
MDRD vs Cockcroft gault equation for estimating GFR
What are the equations
MDRD does not require weight, only requires plasma creatinine
Cockcroft= eGFR = (140-age) * (weight)* 1.22 or 1.04 / Cr
What is AKI characterized by
Acute oliguria and increases in plasma urea and creatinine
Normal response to water deprivation test
- plasma osmolality static but urine osmolality rises ( conc. of urine)
- DI→ plasma osmolality rises as urine remains dilute
- CDI→ responsive to DDAVP
What does RTA type 1 result in and how to test
- Renal Tubular Acidosis Type 1 (exclusively affects tubules) can lead to pH of urine being more than 5.5 (usually less than 5.5)
- Due to distal tubular cells being unable to secrete H+(Abnormally permeable to H+)
- an be tested through Ammonium Chloride loading test
- Used to confirm suspected RTA type I
- NH4Cl administration leads to metabolic acidosis
- If pH of urine> 5.5 persists then RTA type 1 confirmed
What is pre-renal AKI
- Reduced real or “effective blood volume”
- Kidneys are working fine but do not get sufficient blood supply
Glomerular causes of renal AKI
- Rapidly progressive glomerulonephritis
- Immune aetiology characterised by “glomerular crescents”
allergic cause of tubulointerstitial damage and treatment
Non allergic cause?
Acute allergic interstitial nephritis,
- PPIs (omeprazole), antibiotics, diuretics, NSAIDs
- May have eosinophilia (no rash)
- Often respond well to steroids
ATN- drugs, hypoperfusion eg. ACEI
post-renal causes of AKI and first line method of exclusion
Obstruction, ultrasound
what kind of AKI does myeloma cause
Post renal=> intra renal obstruction
Treatment of multiple myeloma
- Similar to primary hyperparathyroidism, but instead of surgery:
- Reduce tumour mass by chemotherapy and/ or radiotherapy (reduces bone resorption)
- Consider autologous bone marrow transplant
what protein test for myeloma
Bence Jones
treatment for rapidly progresive glomerulonephrotis
Immunosupression
Indications for dialysis in severe AKI
- Severe “uraemia”
- No prospect of immediate improvement
- Low amount of urine passed
- Uraemic encephalopathy or seizures
- Uraemic pericarditis
- No prospect of immediate improvement
- Hyperkalaemia unrespove to medical treatment (>6.5)
- Instituted for fluid overload esp pulmonary oedema as they cannot respond to diuretics/ fluid restriction during AKI
- Severe acidosis⇒ cells cant work well in myocardium, results in myocardial depression and hypotension
What is CKD defined as
- GFR of < 60ml/min for > 90 days/3 months
- If < 90 days may be AKI
When is CKD diagnosed despite GFR being over 60
- Persistent proteinuria/microalbuminuria
- Haematuria
- Renal anatomical/genetic abnormality eg. biopsy-proven GN, or PKCD, or ultrasound or radiology
- hypertension
What drugs can cause CKD
NSAIDs, contrasts, gentamicin, phosphate enemas
when should you test for proteinuria ( 2 disease, 1 symptom)
HTN, DM, Ascites/oedema
CV complications of ESRD
LV hypertrophy, stroke
Treatment of anaemia from CKD
- EPO replacement therapy
- All patients with Hb < 105 and adequate iron stores should be on EPO
- In the form of long lasting EPO, give 3 times a week if on dialysis
- All patients with Hb < 105 and adequate iron stores should be on EPO
- f poor response to EPO
- Check iron stores/CRP/B12+folate/PTH/Aluminium/? malnutrition/?malignancy
is phosphate low or high in renal osteodystrophy and why
High, due to increased resorption of bone. Po4 not removed properly by kidneys despite being high
What problem can PTH result in wrt bone
Osteitis Fibrosa
What happens in renal osteodystrophy if too responsive to Vit D treatment
Adynamic bone disease as whole bone process is shut off
Consequences of hyperphosphataemia
Vascular calcification which worsens BP
- Non-compliant vessels
- Systolic hypertension - L Vent Hypertrophy
- Diastolic hypotension - MI
- Calciphylaxis
- Phosphate and vascular calcification
What is the relationship between plasma creatinine and GFR
Reciprocal
How can urine Na help to determine type of AKI
Urine sodium can be used to determine whether tubular function is appropriate
If low, suggests that tubules are appropriately re absorbing Na+ and water, may be pre-renal failure caused by hypotension.
If high, suggests tubular dysfunction or damage, or inadequate aldosterone action eg. established renal failure
Causes of hypotension not related to hypovolaemia that can cause pre-renal AKI
Liver failure and septic/cardiogenic shock
Tubulointersitial causes of AKI
Acute tubular Necrosis
-Tubular toxins eg. Gentamicin, cisplatinum,(nephrotoxic and used for cancers), NSAIDs ( limit blood flow and can be direct allogernic to kidneys) and radio- contrast dye
- Severe prolonged hypotension ( sepsis or MI etc.)
- Renal hypoperfusion( ACEI, ARBs, diuretics etc)
What renal cause of AKI is related to thrombosis
- Haemolytic uraemic syndrome (HUS)
- E.coli related ⇒ may get better
Post renal causes of AKI
- Obstruction - multiple levels ⇒ Bilateral obstruction of obstruction or a single kidney ( transplant only one kidney) to result in AKI
- Ureter
- Calculi, tumour, extrinsic compression ( retroperitoneal fibrosis, tumour)
- Bladder lesions- tumour
- Stones ⇒ May have no pain at all
- Prostate - hypertrophy (common), cancer
- Myeloma spread to kidney ⇒ Intrarenal obstruction
How does PTH change in mutliple Myeloma
suppressed due to hypercalcaemia
