renal Flashcards
eGFR is based on serum Cr, age, gender and ethnicity. What 3 things may affect the result?
Pregnancy
Muscle mass
Eating red meat 12 hours before
NICE guidelines suggest referring to a nephrologist from primary care if within 1 year, the eGFR falls by…
Sustained decrease in eGFR by >15 or >25%
Or falls below <30
Within 1 year
Pruritis can occur in chronic kidney disease secondary to…
uraemia
Referral to nephrology from primary care if the urinary albumin:creatinine ratio (ACR) is what level
> 70mg/mmol
or >30mg/mmol with haematuria
eGFR is worked out by which 4 variables
Serum Cr
Age
Gender
Ethnicity
CKD stages + ranges
CKD 1 = >90
CKD 2 = 60-90
CKD 3 = 30-45 (3a = 45-60, 3b = 30-45)
CKD 4 = 15-30
CKD 5 = <15 or ESRF
In a patient with ACR > 30, and high blood pressure or CKD, what is the first line anti-hypertensive medication
ACE inhibitor
Patients with hypertension have different treatment guidelines depending on ACR level. What is the cut-off ACR for these guidelines?
ACR <30 - treat as usual HTN guidelines
ACR >30 - start on ACE inhibitor
ACE inhibitors are useful in chronic kidney disease when ACR >30 - what is their mechanism of action
Reduces proteinuria
Reduces filtration pressure by causing efferent dilation (therefore can increase Cr, decrease eGFR)
What is an acceptable decrease in eGFR or rise in Cr for ACE inhibitors in HTN for CKD patients (ACR >30)
eGFR of up to 25% decrease
Cr of up to 30% increase
any higher suggests renal artery stenosis
What loop diuretic is useful as an anti-hypertensive in patients with CKD?
Furosemide
Furosemide is useful as anti-HTN in CKD patients particularly when eGFR falls to below…
<45
Also lowers K+
In non-diabetics if ACR >/= 70
what is the antihypertensive that should be started regardless of BP
Start ACE inhibitor/ARBs
AND refer to nephrology
In Type 2 Diabetics if ACR > 3
what is the anti-hypertensive
Start ACE inhibitors/ARBs
Make sure it is titrated to max dose
And then offer SGLT-2 inhibitor (-gliflozin) if ACR >70 (consider if ACR 3-30)
Type 1 diabetes, and ACR >3
what anti-hypertensive should be started
ACE inhibitors/ARBs
For all patients with CKD what statin should be started
atorvastatin 20mg if no cardiovascular Hx
ACR to PCT to urinary protein excretion (g/24 hours) equivalent values:
ACR 30
ACR 70
ACR 30 = PCR 50 = 0.5g/24hrs urinary protein excretion
ACR 70 = PCR 100 = 1g/24hrs urinary protein excretion
ACR sample should be what kind of urine sample
First-pass morning
Spot sample
If the initial ACR is between 3-70, how should this be confirmed
Subsequent early morning sample
If initial ACR >70, repeat sample does not need to be repeated
NICE guidelines regard a confirmed ACR of what as clinically important proteinuria
ACR >3
Other than ACE inhibitors, what other medication may be useful for patients who have proteinuric CKD (with or without diabetes)
SGLT-2 inhibitors
e.g. dapagliflozin, empagliflozin
SGLT2 inhibitors can be used for proteinuric CKD patients. What is their mechanism of action
Block reabsorption of glucose at the proximal tubule
Increase glycosuria
Reduces sodium reabsorption
Reduces intravascular volume, BP, and intraglomerular pressure
In order to diagnose CKD, you need eGFR below what and over what timeframe
eGFR <60 on at least 2 occasions separated by at least 90 days
If the initial ACR test is between 3-70, what should be done in terms of repeat samples/referral?
Repeat another ACR early morning sample
If >30 and haemturia - refer
If >70 - refer
If the initial ACR test result is >70, what should be done in terms of repeat samples/referral?
Repeat sample does not need to be done
Refer to nephrology!
When should ACR urine sample be done
Early morning sample
minimal change disease (usually presents as a nephrotic syndrome) is usually idiopathic in most causes. in 10-20% causes can be found including what three things?
- drugs - NSAIDs, rifampicin
- Hodgkin’s lymphoma, thymoma
- infectious mononucleosis
Minimal change disease renal biopsy usually shows what
Normal glomeruli on light microscopy
Electron microscopy shows fusion of podocytes, effacement of foot processes
Nephrotic syndrome triad
Oedema
Proteinuria
Hypoalbuminaemia
Nephritic syndrome triad
Hypertension
Haematuria
Oliguria
Treatment of minimal change disease
Oral corticosteroids - 80% are steroid-responsive
Cyclophosmide for steroid-resistant cases
Prognosis of minimal change disease
1/3 have one episode
1/3 have infrequent relapses
1/3 have frequent relapses that stop before adulthood
painless, visible haematuria indicates what cancer
Transitional cell carcinoma of the bladder
n.b. renal cell carcinoma typically has mass + abdo pain!
what 2 drugs can cause red/orange urine (where blood is not present)
rifampicin
doxorubicin
persistent haematuria is defined as
blood on 2 out of 3 samples at least 2-3 weeks apart
urgent 2 week referral criteria for haematuria (young - goes to renal, older - goes to urology)
> 45 years and:
- unexplained visible haematuria without UTI; or
- visible haematuria that persists/recurs after UTI treatment
> 60 years and:
- unexplained non-visible haematuria and either dysuria/high WCC on bloods
NON-URGENT REFERRAL: >60 years with persistent/resistant UTI
what is a useful medication to lower uric acid and phosphate levels
sevelamer
what is the mechanism of action of Sevelamer
Non-calcium based phosphate binder
Prevents absorption by binding to dietary phosphate
Reduces uric acid
1-alpha hydroxylation usually occurs where and what does it do
In the kidneys
produces active vitamin D
chronic kidney disease leads to lower 1-alpha hydroxylation occurring. what does this do to vitamin D and phosphate levels?
Low vitamin D
High phosphate
High phosphate levels due to chronic kidney disease has what effect on the bones
osteomalacia
What parathyroid issue results from chronic kidney disease
Secondary hyperparathyroidism
Low vitamin D
Low calcium
High phosphate
management of mineral bone disease (high phosphate, low vit D, low calcium, osteomalacia) in chronic kidney disease patients
- Low phosphate diet
- Phosphate binders - calcium based binders; or non-calcium based binders e.g. sevelamer, binds to dietary phosphate and prevents absorption. Reduces phosphate and uric acid)
- Vitamin D: alfacalcidol, calcitriol
- Parathyroidectomy
Calcium based phosphate binders have what 2 side effects
Hypercalcaemia
Vascular calcification
Referral to nephrologist if:
ACR >70
ACR >30 and haematuria
eGFR drop >25% or >15 in 12 months or <30 overall
CKD stage 5
in a patient with eGFR <60, the next step is to
send early morning sample urine for ACR
and dipstick urine for haematuria
Henoch schonlein purpura is also known as
IgA vasculitis
small vessel vasculitis
Palpable purpura
Arthralgia/arthritis
Abdominal pain
Renal involvement
Follows URTI
Common in children
What is the diagnosis?
Henoch schonlein purpura (IgA vasculitis)
Treatment of Henoch schonlein purpura
- analgesia for arthralgia
- generally supportive
- not much evidence for steroids or immunosuppressants - Monitor BP and urinalysis to detect progressive renal involvement
Prognosis of Henoch schonlein purpura
- Self-limiting, usually resolves especially if no renal involvement
- 1/3 patients have relapse
Anaemia in CKD4 - what level of Hb do they aim for?
10-12g/dl
Anaemia in CKD predisposes to the development of what…
Left ventricular hypertrophy
associated with 3x increased mortality in renal patients
Management of anaemia in CKD patients
- Target Hb levels 10-12g/dl
- Optimise iron levels - give oral iron if not on ESAs or dialysis. If not at target Hb levels by 3 months, switch to IV iron.
- Erythropoeisis stimulating agents (ESAs) e.g. erythropoeitin, darbepoetin
What 2 drugs are associated with proteinuria
Gold
Penicillamine
Main cause of nephrotic syndrome
Primary glomerulonephritis (80%)
- minimal change
- membranous
- focal segmental
- membranoproliferative
Primary glomerulonephritis is the main (80%) cause of nephrotic syndrome. What 3 systemic diseases can also lead to nephrotic syndrome?
Diabetes
SLE
Amyloidosis
What are the 3 diuretics indicated for ascites
Spironolactone
Amiloride
Chortalidone
5 indications for spironolactone use
- Ascites - cirrhosis ascites can develop secondary hyperaldosteronism
- Hypertension
- Heart failure
- Nephrotic syndrome
- Conn’s syndrome
Two side effects from spironolactone
Hyperkalaemia
Gynaecomastia
Patients with CKD, HTN and urinary ACR or >70 should aim for what BP
<130/80
What diuretic can be useful as an anti-hypertensive in CKD patients with eGFR <45?
Furosemide
What inheritance is polycystic kidney disease
autosomal dominants
what is the screening investigation for relatives with polycystic kidney disease
abdominal ultrasound
what is the ultrasound diagnostic criteria for polycystic kidney disease (if patients have positive family history)
- <30 years - two cysts uni or bilateral
- 30-59 years - two cysts in both kidneys
- <60 years - four cysts in both kidneys
What is the medication treatment of polycystic kidney disease and the 3 criteria to start it
Tolvaptan (vasopressin receptor 2 antagonist)
- if CKD 2 or 3
- evidence of rapidly progressing disease
- company discount with patient access scheme
What genes/Chr are involved with polycystic kidney disease
Type 1 (85%) = PKD1, Chr 16
Type 2 = PKD2, Chr 4
Triad of renal cell carcinoma
Haematuria
Loin pain
Abdominal mass
Endocrine effects of renal cell carcinoma - i.e. what hormones does it secrete
Polycthaemia (secretes EPO)
Hypercalcaemia (secretes PTH)
Rein
ACTH
diabetes insipidius is caused by which hormone abnormality
Cranial DI - decreased secretion of anti-diuretic hormone (ADH)
Nephrogenic DI - insensitivity to ADH
What 2 medications can cause nephrogenic DI
Lithium
Demeclocycline
What two electrolyte disturbances can induce nephrogenic DI
Hypokalaemia
Hypercalacaemia
What will diabetes insipidus show on:
plasma osmolality
urine osmolality
High plasma osm
Low urine osm
Management of diabetes insipidus
Nephrogenic - thiazides and low salt/protein diet
Central - desmopressin
Patients with CKD on haemodialysis - what is the most likely cause of death
ischaemic heart disease
