Nephrology Flashcards
What are the prerenal causes of AKI?
dehydration
shock - sepsis, blood loss
renal artery stenosis - often triggered by ACEi/NSAIDS
What are the intrinsic renal causes of AKI?
INTRINSIC Ischaemia Nephrotoxic Abx Tablets ( NSAIDS, ACEi) Radiological contrast Injury (rhabdomyolysis) Negatively birefringent crystals Syndromes (glomerulonephritis) Inflammation (vasculitis) Cholesterol emboli
What are some postrenal causes of AKI?
Lumen: sloughed papilla or stone
In wall: tumour (renal cell, transitional cell), fibrosis
External pressure: BPH, prostate ca, aneurysm, lymphadenopathy
Indications for dialysis?
MUH FC metabolic acidosis [pH<7.1] uraemic symptoms [encephalopathy, nausea, pruritic, malaise, pericarditis] hyperkalaemia fluid overload CKD stage 5 [GFR <15]
what are the types of peritoneal dialysis?
CAPD - continuous ambulatory peritoneal dialysis
APD - automated peritoneal dialysis
what sort of catheter is used for peritoneal dialysis
Tenckhoff catheter
what are the complications of an AV fistula?
thrombosis, stenosis, infection, bleeding, aneurysm, steal syndrome
what are the complications of a tesio line?
sepsis, peritonitis, DIC, fluid overload, DDS
Dialysis disequilibrium syndrome = cerebral oedema
what is a tesio line?
central line to internal jugular and right atrium, tunnelled under skin with two lumens entering skin
what is a swan gantz line and where is the entry point?
3 lumen line into subclavian vein
what technique is used to insert lines?
seldinger
LA + US guidance
CXR
which drugs can be used for immunosuppression in transplant?
calcineurin inhibitors
anti-proliferative (MMF, azathioprine)
steroids
Which HLAs are most important to match before transplant?
DR>B>A
Complications of transplant?
surgical
anaesthetic
transplant (failure or rejection)
immunosuppression (GvHD, SCC)
What are the types of rejection?
Hyper acute (<24h)
Acute (<6m)
Chronic (>6m)
RFs for hyper acute rejection?
previous blood transfusion, previous transplant, multiple pregnancies
Mx acute rejection?
antibody mediated: IVIG plasmapheresis anti-CD20 anti-c5
T cell mediated: (more common)
steroids
OKT3
ATG
Intrinsic causes of ARF?
vasculitis: small vessel - HUS, TTP, DIC, GPA, eGPA/ large vessel - renal artery/vein thrombosis
glomerulonephritis: minimal change (children), membranous
ATN
AIN/interstitial nephritis: drugs (75%)/ rash, fever, eosinophilia, sterile pyuria, nephrotic syndrome
how to differentiate between pre-renal and intrinsic renal AKI?
URINARY SODIUM
pre-renal:<20 (low as kidneys hold on to sodium)
intrisinc [ATN]: >40 (ischaemia of tubules means loss of sodium)
Which drugs may precipitate AKI?
DAMN Diurtics ACEi/ARB Metformin NSAIDs
what are the CKD stages?
eGFR stage 1: >90 + other signs damage stage 2: 60-90 + other signs damange stage 3a: 45-60 stage 3b: 30-45 stage 4: 15-30 stage 5: <15
In CKD when should routine referral to nephrology be made?
eGFR <30mL/min/1.73m^2
eGFR decrease >25% or >15ml/min in 12m
Management of CKD?
Diet: reduce phosphate, Na, K, fluid restrict. AvoidETOH, tea, coffee, chocolate and banana
PO binders- sevelamar (binds and prevents absorption)
Vit D
Parathyroidectomy (rarely)
Mx CKD
ACEi
Ix CKD?
ACR
>3mg/mmol + diabetes
>30mg/mmol + HTN
>70mg/mmol
Consequences of CKD?
- failure of homeostatic function: acidosis, hyperkalaemia
- failure of hormonal function: anaemia, renal bone disease
- cardiovascular disease: vascular calcification, renal osteodystrophy
- uraemic cardiomyopathy
Screening for PCKD?
ABDOMINAL USS
>=2 cysts age <30
>= 2 cysts in both kidneys age 30-59
>=4 cysts in both kidneys >60
Features of PCKD?
liver cysts
berry aneurysms
mitral valve prolapse
renal failure signs
Mx PCKD?
tolvaptan (slows progresion)
what are the features of ADPKD1?
85% CASES
Chr16 (PKD1 gene)
presents earlier with renal failure
what are the features of ADPKD2?
15% cases
Chr4 (PKD2 GENE)
What is the most common glomerulonephritis?
IgA nephropathy
IgA and IgG complex and deposit in organs
S/S IgA Nephropathy?
purpuric rash - urticarial, maculopapular, spares trunk
arthralgia- large joints
abdominal pain - colicky, melena, intussusception
glomerulonephritis - micro/macroscopic haematuria
Ix IgA nephropathy?
Urinalysis: RBCs, proteinuria, casts, urea, Cr, 24h protein (rule out meningococcal)
1st: FBC, clotting screen, urine dip, U&E
Increase IgA, normal coag
follow up: weekly for 1m, 2weekly for 2m, 3m, 6m, 12m with bP and urine measurements
Mx IgA nephropathy?
resolve spontaneously within 4w (most)
joint pain - NSAIDs
scrotal involvement/oedema/abdo pain - oral prednisolone
renal involvement - IV corticosteroids (nephrotic proteinuria or declining renal Fx)
When are hyaline casts seen in urine?
tamm-horsfall protein (secreted by DCT) NORMAL urine after exercise during fever with loop diuretics
When are brown granular casts seen in urine?
ATN
when are red cell casts seen in urine?
nephritic syndrome
What is the most common renal tumour?
RCC (85% of all renal malignancies)
clear cell carcinoma
S/S renal carcinoma?
loin pain frank haematuria abdominal mass may see haemoptysis if cannonball mets VHL
associated features RCC?
LEFT varicocele (obstruction of testicular vein), PUO, metastasis paraneoplastic: EPO, PTHrp, renin, ACTH
Management of bladder Ca?
in situ - trans-urethral resection
ex situ - radical cystectomy
Ix bladder cancer
CT IVU
Bladder Ca associations?
dyes
rubber chemical
smoking
schistosomiasis (SCC bladder)
Who is nephroblastoma common in?
80% of GU malignancies <15y
S/S npehroblastoma ?
flank mass (90%) HTN (50%)
Ix nephroblastoma?
USS
CT
Mx nephroblastoma?
resection + chemotherapy
Where does neuroblastoma arise from?
adrenal gland
Ix neuroblastoma?
MIBG
CT (calcified)
Mx neuroblastoma?
resection
chemotherapy
radiotherapy
Staging of Renal cell carcinoma?
T1: tumour <=7cm and confined to kidney
T2: tumour >7cm AND CONFINED TO kidney
T3: tumour extends to major veins but not into adrenal or beyond gerota’s fascia
T4: tumour invades beyond gerota’s fascia
Complications of haemodialysis?
site infection endocarditis stenosis at site hypotension arrhythmia air embolus anaphylactic reaction disequilibration syndrome
Complications of peritoneal dialysis?
peritonitis sclerosing peritonitis catheter infection catheter blockage constipation fluid retention hyperglycaemia hernia back pain malnutrition
What is contrast media nephrotoxicity?
Contrast media nephrotoxicity may be defined as a 25% increase in creatinine occurring within 3 days of the intravascular administration of contrast media.
RF contrast media nephrotoxicity?
known renal impairment (especially diabetic nephropathy)
age > 70 years
dehydration
cardiac failure
the use of nephrotoxic drugs such as NSAIDs
which procedures may cause may cause contrast-induced nephropathy?
CT with contrast
coronary angiography/percutaneous coronary intervention (PCI)
around 5% of patients who’ve undergone PCI develop a transient rise in the plasma creatinine concentration of more than 88 µmol/L
prevention of contrast media nephrotoxicity?
intravenous 0.9% sodium chloride at a rate of 1 mL/kg/hour for 12 hours pre- and post- procedure.
isotonic sodium bicarbonate
hold metformin for 48 h after until renal function normal
what does minimal change disease present as?
a nephrotic syndrome
75% of cases in children and 25% in adults
what causes minimal change disease?
Majority idiopathic
drugs: NSAIDs, rifampicin
Hodgkin’s lymphoma, thymoma
infectious mononucleosis
Features of minimal change?
nephrotic syndrome
normotension - hypertension is rare
highly selective proteinuria
only intermediate-sized proteins such as albumin and transferrin leak through the glomerulus
renal biopsy
normal glomeruli on light microscopy
electron microscopy shows fusion of podocytes and effacement of foot processes
Management of minimal change?
majority of cases (80%) are steroid-responsive
cyclophosphamide is the next step for steroid-resistant cases
Prognosis of minimal change?
1/3 have just one episode
1/3 have infrequent relapses
1/3 have frequent relapses which stop before adulthood
Types of peritoneal dialysis?
APD (automated peritoneal dialysis)
CAPD (continuous ambulatory peritoneal dialysis)
Complications of peritoneal dialysis?
peritonitis (s.epidermidis > S.aureus > gram -ve)
the BNF recommends vancomycin (or teicoplanin) + ceftazidime added to dialysis fluid OR vancomycin added to dialysis fluid + ciprofloxacin by mouth
Management of nephrogenic diabetes insipidus?
nephrogenic diabetes insipidus: thiazides (chlorothiazide), low salt/protein diet
- central diabetes insipidus can be treated with desmopressin
Causes of nephrogenic diabetes inspidus?
genetic: the more common form affects the vasopression (ADH) receptor, the less common form results from a mutation in the gene that encodes the aquaporin 2 channel
electrolytes: hypercalcaemia, hypokalaemia
lithium
lithium desensitizes the kidney’s ability to respond to ADH in the collecting ducts
demeclocycline
tubulo-interstitial disease: obstruction, sickle-cell, pyelonephritis
What is the screening for diabetic retinopathy?
all patients should be screened annually using urinary albumin:creatinine ratio (ACR)
should be an early morning specimen
ACR > 2.5 = microalbuminuria
what is the management of diabetic retinopathy?
dietary protein restriction
tight glycaemic control
BP control: aim for < 130/80 mmHg
ACE inhibitor or angiotensin-II receptor antagonist
should be start if urinary ACR of 3 mg/mmol or more
dual therapy with ACE inhibitors and angiotensin-II receptor antagonist should not be started
control dyslipidaemia e.g. Statins
what are some causes of hyperkalaemia?
acute kidney injury drugs*: potassium sparing diuretics, ACE inhibitors, angiotensin 2 receptor blockers, spironolactone, ciclosporin, heparin** metabolic acidosis Addison's disease rhabdomyolysis massive blood transfusion
What changes in patients with nephrotic syndrome predispose to the development of venous thromboembolism?
Loss of antithrombin-III, proteins C and S and an associated rise in fibrinogen levels predispose to thrombosis
what is the difference between AKI and CKD on ultrasound?
Most patients with CKD have bilateral small kidneys. Exceptions to this rule include:
autosomal dominant polycystic kidney disease
diabetic nephropathy (early stages)
amyloidosis
HIV-associated nephropathy
Other features suggesting CKD rather than AKI
hypocalcaemia (due to lack of vitamin D)
what are the causes of acute interstitial nephritis?
drugs: the most common cause, particularly antibiotics penicillin rifampicin NSAIDs allopurinol furosemide systemic disease: SLE, sarcoidosis, and Sjögren's syndrome infection: Hanta virus , staphylococci
What are the features of acute interstitial nephritis?
fever, rash, arthralgia
eosinophilia
mild renal impairment
hypertension
what are the investigations for acute interstitial nephritis?
sterile pyuria
white cell casts
What is Tubulointerstitial nephritis with uveitis?
occurs in young females. Symptoms include fever, weight loss and painful, red eyes. Urinalysis is positive for leukocytes and protein.
Side effects of EPO?
accelerated hypertension potentially leading to encephalopathy and seizures (blood pressure increases in 25% of patients)
bone aches
flu-like symptoms
skin rashes, urticaria
pure red cell aplasia* (due to antibodies against erythropoietin)
raised PCV increases risk of thrombosis (e.g. Fistula)
iron deficiency 2nd to increased erythropoiesis
Why might EPO therapy be ineffective?
iron deficiency inadequate dose concurrent infection/inflammation hyperparathyroid bone disease aluminium toxicity