renal Flashcards
causes of AKI
pre renal - infection, hypotension, hypercalcaemia, drugs, heart failure, liver failure renal artery occlusion
renal - glomerulonephritis,CKD, nephrotoxics, rhabdomyolysis, myeloma, malignant HTN, autoimmune disease, haemolytic uraemic syndrome
post renal:
obstructive: blocked catheter, BPH, prostate ca, ureter strictures, clot, renal calculi
neuro: MC, cord compression, cauda equina, post-op retention
definition of aki
a rise in serum creatinine >25mmol over 48 hours or by 50% in 5 days
or
a reduction in urine output to less than 0.5ml/kg/hour for more than 6 hours
aki stage 1 criteria
1.5-2 x rise in creatinine
<0.5ml/kg/hr over 6 hours UO
aki stage 2 criteria
2-3 x rise in creatinine
<0.5ml/kg/hr over 12 hours UO
aki stage 3 criteria
creatinine over 350
or >3 x rise in creatinine
or anuria or <0.5ml/kg/hr for over 12 hours
4 complications of AKI
- hyperkalaemia
- metabolic acidosis
- uraemia
- fluid overload
- death + multi organ failure
diagnosis of AKI
- U+E and urine output
- history! pre renal: dehydration, hypoperfusion, infection
renal: rashes, change in meds, weight loss, post-renal:urinary symptoms - examination: BP,HR, temp, abdo, assess fluid status - overloaded or dehydrated?
- check meds and stop nephrotoxics
- investigate for cause:
FBC + infection screen
calcium - raised do myeloma screen
CK for rhabdomyolysis
VBG for metabolic acidosis
CXR to look for fluid overload - fluid restrict
urinalysis (+?immunology screen)
USS KUB
ABCDE of AKI
assess meds boost bp calculate fluid balance dip urine exclude obstruction
management of hyperkalameia
protect the heart: IV calcium gluconate 30ml 10%
10 units actrapid in 10% dextrose over 15 mins
can give salbutamol
raised calcium in AKI
do myeloma screen!
when is dialysis indicated in AKI
aki stage 3
when to call the med reg for AKI
aki stage 3 hyperkalaemia resistant oedema renal transplant patient underluing CKD stage 4/5
symptoms of uraemia
nausea itching vomiting fatigue anorexia muscle cramps confusion increased thirst visual disturbance
drugs to stop in aki
nephrotoxics: acei, arb, gentamicin
renally excreted drugs: metformin, LMWH in stage 2+3
drugs that accumulate: opioids, digoxin, lithium
stop diuretics in dehydration
continue diuretics in fluid overload
CKD staging
1 egfr >90 2 60-90 3a 45-59 3b 30-44 4 15-29 5 <15 (established renal failure - dialysis)
name 7 findings on blood results in CKD
low egfr high creatinine high urea low vit D high phosphate low calcium low Hb high K+ metabolic acidosis
name 6 complications of CKD
hypertension fluid accumulation osteoporosis vitamin d deficient anaemia metabolic acidosis hyperkalaemia
indications for dialysis
stage 5 ckd
or aki with uraemia symptoms, unresponsive to tx
what are the 2 types of dialysis and how do they work
peritoneal dialysis: catheter inserted into peritoneal space and dextrose fluid inserted into peritoneum and peritoneum acts as a filter either continuously or over night
haemodialysis - either with av fistula or with tunnelled catheter in subclavian or jugular veing +into right atrium
name 3 complications of peritoneal dialysis
weight gain from absorbing dextrose
bacterial peritonitis
peritoneal sclerosis
functional failure over time
name 4 complications of an AV fistula
aneurysm
infection
thrombosis
steel syndrome
how long does an AV fistula take to be ready to use
4 months
what 3 drugs are given post renal transplant
tacrolimus
mycophenolate
prednisolone
plus immunosuppression
where is renal transplant placed and which vessels are they anastamosed to
iliac fossa
internal iliac vessels
characteristics of nephritic syndrome
low urinary protein <3g
micro or macroscopic haematuria
oliguria (reduced urine output)
oedema
characteristics of nephrotic syndrome
high proteinuria >3g
low albumin
peripheral oedema!!
high cholesterol
management of igA nephropathy
acei and steroids
what is henoch schonlein purpura
systemic variant of IgA nephropathy where IgA deposits in kidneys, skin, GI tract and joints causing... nephritic glomerulonephritis intermittent polyarthritis GI bleeding non blanching petechial rash on legs
presentation of henoch schonlein purpura
glomerulonephritis = haematuria, oedema, reduced urine output
intermittent joint pains
non blanching petechial rash
presentation of henoch schonlein purpura
glomerulonephritis = haematuria, oedema, reduced urine output
intermittent joint pains
non blanching petechial rash
abdo pain/ anaemia (GI bleeding)
how do you diagnose HSP
positive IgA and C3 in skin
IgA deposits on renal biopsy
usually just a clinical diagnosis
how do you manage HSP
Ace inhibitors and steroids
causes of nephritic syndrome
IgA nephropathy
HSP
post strep glomerulonephritis
goodpastures disease
presentation of post strep glomerulonephritis
2 weeks after sore throat or skin infection with a group a beta haemolytic strep
strep deposits in glomerulus = inflammation = nephritis
mg = supportive and abx if active infection
presentation of goodpastures disease
antibodies against type 4 collagen found in alveoli and glomerular membrane means you get a nephritis and aki and also pulmonary haemorrhage
so pt might present with haematuria, low urine output, high blood pressure, sob haemoptysis
how do you manage goodpastures disease
renal: often need dialysis at presentation due to severe reduction in egfr, plasma exchange, steroids and cyclophosphamide
pulm: o2
name the causes of nephrotic syndrome
primary renal:
minimal change disease (kids)
focal segmental glomerulosclerosis (adults)
membranous nephropathy
systemic: diabetic nephropathy, SLE, myeloma, amyloidosis, pre eclampsia
pathophysiology of nephrotic syndrome
damaged or abnormal podocytes = larger membrane gaps = protein leakage
management of nephrotic syndrome
- reduce oedema!!
fluid and salt restriction, po/iv furosemide, daily weights with aim of 0.5-1kg weight loss daily, - treat underlying cause:
- lower proteinurea with acei/arb
- VTE prophylaxis
- give pneumococcal vaccine bc increased infection risk due to immunoglobulins lost in urine
why should you only lower weight loss (fluid) by 0.5-1kg per day in nephrotic syndrome
because a rapid decrease in extravascular volume could cause AKI
how do you determine the cause of nephrotic syndrome
renal biopsy
how do you treat minimal change disease
po prednisolone to induce remission at 1mg/kg for 4-16 weeks
if has a relapse give immunosuppression with cyclophosphamide
how do you manage focal segmental glomerulosclerosis
reduce bp
steroids
how does lupus nephritis present
lupus plus nephrotic sydrome
get autoantibodies deposited in kidneys
tests: ANA, anti-dsDNA, C3 and C4
how do you manage diabetic nephropathy
aim Hba1c <53
reduce BP and give acei renal protection
statins
annual albumin:creatinine ratio screen
how is lupus nephritis managed
high dose pred
cyclophosphamide / rituximab
pathophysiology behind myeloma glomerulonephritis
light chains deposit in renal tubules causing obstruction and damage to glomerulus
pathophysiology behind myeloma glomerulonephritis
light chains deposit in renal tubules causing obstruction and damage to glomerulus
causes proteinuria and hypercalcaemia
what is haemolytic uraemic syndrome
haemolysis of red cells in the small vessels causes an AKI, glomerulonephritis with proteinuria or haematuria, and low platelets
what are the 3 pillars of haemolytic uraemic syndrome
microangiographic haemolytic anaemia
aki with haematuria/proteinuria
low platelets
name 2 causes of haemolytic uraemic syndrome
e.coli infection
pregnancy
how do you manage haemolytic uraemic syndrome
supportive
plasma exchange
manage AKI
never give antibiotics as makes it worse
how does haemolytic uraemic syndrome present
anaemia symptoms
aki symptoms
how do you diagnose haemolytic uraemic syndrome
fbc: Hb<100, low platelets, may be raised WCC
u+e: AKI
blood film: schistocytes (fragmented cells from haemolysis)
do stool culture and PCR looking for evidence of shiga toxin producing e.coli
how does thrombotic thrombocytopenic purpura present
fever microemboli in cerebral circulation = fluctuating neuro signs headache palsy AKI from emboli in renal tract low platelets haemolytic anaemia
how do you manage TTP
haematological emergency so contact on call reg
plasma exchange / infusion
steroids and rituximab for relapses
name causes of TTP
pregnancy
post viral
SLE
drugs eg ciclosporin, COCP, anti virals
what organism is associated with haemolytic uraemic syndrome
shiga toxin producing e.coli triggers an autoimmune response = HUS
how is TTP different to HUS
both have aki, low platelets due to clumping and clotting, and a haemolytic anaemia but TTP has additional fever with fluctuating neuro signs due to emboli in cerebral circulation obstructing and then passing so may have headaches and palsys
how does aldosterone work in the kidney
causes net reabsorption of sodium and excretion of potassium
hypokalaemia
metabolic acidosis
high urinary pH
what is the cause
either type 1 or type 2 renal tubular acidosis
both genetic so generally present in younger kids
what causes type 1 renal tubular acidosis and what do you find on investigation
genetic problem with H+ ATPase pump or H/K ATPase
caused by: SLE, sjorens, lithium, hyperthyroid, primary billiary sclerosis
inv: high urinary pH (bc not excreting acid) hypokalaemia, metabolic acidosis
what causes type 2 renal tubular acidosis and what is found on investigation
genetic problem in proximal tubules meaning bicarb is unable to be re absorbed so high amounts of bicarb is excreted so cant neutralise H+ so get metabolic acidosis, hypokalaemia and high urinary pH
what causes type 4 renal tubular acidosis and what would you find on investigation
caused by low aldosterone (ie adrenal insufficiency (addisons), spironolactone, SLE, diabetes
aldosterone normally causes reabsorption of water and sodium and excretion of potassium and hydrogen ions
so if aldosterone is low then potassium and hydrogen ions will be reabsorbed and sodium and water excreted
so therefore would get a hyperkalaemic metabolic acidosis, dehydration and a low (acidotic) urinary pH due to reduced ammonia production
how do you manage type 4 renal tubular acidosis
fludrocortisone - to boost BP
sodium bicarb to correct acidosis
manage hyperkalaemia!!
name 2 complications of UTI in pregnancy
preterm delivery
intrauterine growth restriction
what is the first line management of pyelonephritis in pregnancy
cefalexin
which antibiotics are first line in pyelonephritis
co-amox TDS for 7 days or ciprofloxacin BD 7 days
cp of pyelonephritis
fever rigors back pain dysuris or recent cystitis vomiting white cell casts in urine
what is the cause of pyelonephritis
ascending infection with e.coli
what investigation should you do in pyelonephritis and when should you do it
MSU culture and sensitivity, do before giving abx
what makes a UTI ‘complicated’
recurring pregnant being male non responsive to tx atypical organism on culture persistent haematuria
difference in management of UTI in men and women
women 3 days
men 7 days
causes of hydronephrosis
vesicoureteric reflux
urethral strictures
renal calculi
any form of obstruction eg bph
what is vesicoureteric reflux and who is it more common in
more common in kids
when there is a structural abnormality that causes backflow of urine from the bladder to the kidneys
complications of vesicoureteric reflux
recurrent uti
pyelonephritis
hydronephrosis
renal scarring –> HTN
how do you diagnose vesicoureteric reflux
micturiating cystourethrogram
DMSA scan to look for renal scarring
how do you investigate recurrent UTI
USS renal tract to look for abnormalities
how does prostatitis present
pain in rectum, pelvis, perineum, scrotum, penis, lower back fever nausea and vomiting dysuria, frequency, anuria swollen tender prostate on PR
how do you manage prostatitis
4 week course of po ciprofloxacin (better than trimethoprim or nitro bc penetrates seminal fluid better)
