Renal medicine Flashcards
what is bacteriuria
bacteria in the urine - may be asymptomatic or symptomatic
what is lower UTI
uretheritis
cystitis
prostatitis
what is upper UTI
renal pelvis - pyelonephritis
what are risk factors for UTI
female
sexual intercourse
exposure to spermicide in females (by diaphragms or condoms)
pregnancy
menopause
reduced defence host -
immunosuppression, DM
urinary tract - obstruction, stones, catheter, malformation
UTI in catheterised patients - tx?
no treatment unless symptomatic.
main organism(s) causing UTI
E.coli
proteus mirabilis
klebsiella pneumonia
staphylococcus saprophyticus
symptoms of cystitis
frequency dysuria urgency haematuria suprapubic pain
symptoms of acute pyelonpehritis
high fevers rigors vomiting loin pain tenderness oliguria
symptoms of prostatitis
flu-like symptoms
low backache
few urinary symptoms
swollen or tender prostate on PR
signs of UTI
fever
abdo pain or loin tenderness
foul-smelling urine
occasionally distended bladder, enlarged prostate
investigations for a UTI
DIPSTICK THE URINE
if dipstick negative but patient symptomatic -> send a MSU sample for lab MC&S to confirm this.
Send a lab MC&S anyway if
- child (do USS)
- MALE
- pregnant
- immunosuppressed
- ill
MC&S - pure growth of >10 organisms/ml is diagnostic.
causes of a sterile pyuria
TB treated UTI <2 weeks prior inadequately treated UTI appendicitis calculi; prostatitis bladder tumour polycystic kidney
bloods for UTI
FBC
U+E
CRP
blood cultures
imaging for UTI
consider ultrasound referral to urology for assessment (CTKUB, cystoscopy, urodynamics) for UTI: - in children - men - if failure to respond to treatment - recurrent UTI (>2/year) - pyelonephritis - unusual organisms - persistent haematuria
prevention of UTI
drink more water
antibiotic prophylaxis, continuously or post-coital
drinking 200-750ml of cranberry or lingo berry juice a day - reduces risk of symptomatic recurrent infection in women by 10-20%. (Avoid if on warfarin)
management of UTI - non-pregnant women ≥16 years old
drink plenty of fluids; urinate often
Trimethoprim or nitrofurantoin (eGFR ≥45) for 3 days.
2nd line
- nitrofurantoin if not used first line
- fosfomycin
- pivmecillinam
management of UTI - pregnant women
nitrofurantoin (eGFR ≥45) for 7 days (AVOID AT TERM).
2nd line
- Amoxicillin for 7 days
- Cefalexin for 7 days
management of UTI - men ≥16y
trimethoprim or nitrofurantoin (eGFR ≥45) for 7 days.
2nd line
- consider pyelonephritis or prostatitis
management of prostatitis
1st line
- ciprofloxacin
or ofloxacin
(alt if unable to take fluoroquinolone - trimethoprim)
2nd line (on specialist advice) - levofloxacin or co-trimoxazole
management of pyelonephritis
ORAL cefalexin or ciprofloxacin
(if sensitivity known - co-amoxiclav or trimethoprim)
IV first line if severely unwell or unable to take oral treatment: ceftriaxone cefuroxime ciprofloxacin gentamicin
management of pyelonephritis - pregnant women
oral first line - cefalexin
IV first line - cefuroxime
features of genitourinary TB
have a high suspicion in sterile pyuria and those with risk factors (esp HIV +ve), look for high ESR/CRP, ask about past lung TB
dysuria flank pain perineal pain scrotal fistula sterile pyuria - leucocytes in urine haematuria
criteria for diagnosing AKI - stage 1
rise in creatinine >26 in 48h or increase in creatinine >1.5x baseline
urine output <0.5ml/kg/h for >6 consecutive hours
criteria for diagnosing AKI - stage 2
increase in creatinine 2-2.9x baseline
<0.5ml/kg/h for >12h consecutive hours UO
criteria for diagnosing AKI - stage 3
increase in creatinine >3x baseline or >354 or commenced on RRT irrespective of stage
<0.3ml/kg/h for >24h or anuria for 12h
risk factors for developing AKI
age >75 CKD HF peripheral vascular disease chronic liver disease DM drugs sepsis poor fluid intake/increased losses history of urinary sx
pre-renal causes of AKI
renal hypoperfusion - hypotension (any cause, inc hypovolaemia, sepsis), renal artery stenosis ± ACEi
renal causes of AKI
acute tubular necrosis - commonest intrinsic renal cause of AKI - due to drugs e.g. ahminoglycosides, radiological contrast or myoglobinuria in rhabdomyolysis.
glomerular - autoimmune such as SLE, HSP, drugs, infections, primary glomerulonephritides
interstitial - drugs, infiltration with e..g lymphoma, infection, tumour lysis syndrome
vascular - vasculitis, malignant high BP, thrombus or emboli from angiography, HUS/TTP, dissection.
post-renal causes of AKI
caused by urinary tract obstruction
- luminal: stones, clots, sloughed papillae
- mural: malignancy (ureteric, bladder, prostate), BPH, strictures
- extrinsic compression - malignancy (e.g. pelvic), retroperitoneal fibrosis
assessment of a patient with an AKI
ABCDE
- check fluid status - check BP, JVP, skin turgor, CRT <2sec, UO (catheterise)
- check an urgent K on a venous blood specimen and an ECG to check for life-threatening hyperkalaemia
bedside tests for AKI
DIPSTICK URINE ALWAYS
- infection or glomerular disease
- microscopy for casts, crystals, cells
- culture for infection
- consider Bence Jones Proteins
bloods for AKI
U+E, FBC, LFT, CLOTTING, CK, ESR, CRP
consider ABG for acid-base assessment
blood cultures if signs of infection
consider blood film and renal immunology if systemic cause suspected
- immunoglobulins and paraprotein electrophoresis
- complement (c3/4), autoantibodies (ANA, ANCA, anti-GBM)
- ASOT
imaging for AKI
renal ultrasound
- distinguishes obstruction and hydronephrosis, and look for abnormalities such as:
- — cysts
- — small kidneys
- — masses
- — corticomedullary differentiation
- Complete anuria is unusual in AKI and suggests an obstruction
o In elderly men – prostate should be considered – often relieved by catheterisation. - If catheterization does not resolve anuria and you suspect obstruction above the prostate, get an URGENT USS TO CHECK FOR HYDRONEPHROSIS AND CONSIDER AN URGENT CTKUB (no contrast required), which can show OBSTRUCTING MASSES OR CALCULI.
parameters suggesting CKD
small kidneys
anaemia
low calcium
high phosphate
indications for dialysis
refractory pulmonary oedema
persistent hyperkalaemia
severe metabolic acidosis (ph <7.2)
uraemia complications such as encephalopathy or uraemic pericarditis
drug overdose - BLAST: barbiturates, lithium, alcohol, salicylates, theophylline
management of AKI
assess volume status
- low urine output
- non-visible JVP
- poor tissue turgor
- low BP
- high pulse
signs of fluid overload
- high BP
- high JVP
- lung crepitations
- peripheral oedema
- gallop rhythm on cardiac auscultation
STOP NEPHROTOXIC DRUGS e.g. NSAIDs, ACEi, gentamicin, amphotericin. stop metformin if creatinine >150.
monitor observations hourly.
daily u+e
daily fluid balance and daily weight
treat underlying cause
- pre-renal: iv fluids, treat sepsis with iv abx.
- intra-renal: refer to nephrology early
post-renal: catheterise and consider CTKUB if obstruction likely
RRT - haemodilaysis/ haemofiltration
complications of AKI
hyperkalaemia
pulmonary oedema
uraemia
acidaemia
ECG changes in hyperkalaemia
Tall Tented T waves
Widened QRS complex
Increased PR interval
small or absent P wave
immediate treatment of hyperkalaemia
Do ECG + if ECG changes:
10ml of 10% calcium gluconate
IV insulin and glucose - 10 units of act rapid in 100ml of 20% glucose over 30 mins.
salbutamol nebuliser
IV sodium bicarbonate if patient is acidotic.
treatment of pulmonary oedema
sit the patient up
give high flow oxygen
IV furosemide 40mg
diamorphine 2.5mg IV (+anti-emetic e.g. cyclizine)
if no response, haemodialysis or haemofiltration is needed.
consider CPAP
prevention of AKI (sick day rules)
review drugs withhold/avoid - diuretics - NSAIDs - ACEi - Metformin - abx - gentamicin, nitrofurantoin
use opiates with caution as they accumulate in renal failure. oxycodone is better in renal impairment.
radiological contrast
- ensure patient is well hydrated - 1L 0.9% saline over 12 hours pre and post-procedure
CKD - definition
Impaired renal function for >3 months based on abnormal structure or function,
OR GFR <60ml/min/1.73m2 for 3 months with or without evidence of kidney damage.
stages of CKD
stage 1 - >90* stage 2 - 60-89* stage 3a - 45-59 stage 3b - 30-44 stage 4 - 15-29 stage 5 - <15
*stages 1+2 (eGFR >60) - must have other evidence of renal damage e.g. proteinuria, haematuria, evidence of abnormal anatomy
causes of CKD
diabetes hypertension or renovascular disease glomerulonephritis - IgA nephropathy Unknown pyelonephritis and reflux nephropathy
risk factors for developing ESRF
deteriorating function proteinuria ≥3mg/mmol haematuria high BP young age
commonest inherited cause of CKD
adult polycystic kidney disease
rare - Alpert’s syndrome: CKD, hearing loss, minor eye problems
symptoms of uraemia
anorexia vomiting restless legs fatigue weakness pruritis bone pain
causes of rapid decline in renal function
infection dehydration uncontrolled high BP metabolic disturbance e.g. high Ca obstruction nephrotoxins
chief cause of death in renal failure
cardiovascular disease
- falling GFR is an independent risk factor for CVD
investigations for CKD
creatinine-based estimate of eGFR (eGFRcreatinine) - advise patient not to eat meat in the 12h before having this blood test.
o Interpret with caution – reduced muscle mass will give an overestimate and increased muscle mass may give an underestimate.
- Cystatin C-based estimate of GFR (eGFRcystatinC), use if:
o An eGFRcreatinine of 45-59, sustained for 90d AND
o No proteinuria (ACR <3) - early morning urine sample to test for urinary albumin:creatinine ratio (ACR)
- <3 - no proteinuria. no action.
- ≥3-70 - suggests proteinuria, REPEAT TEST WITHIN 3 MONTHS.
- if ≥70 - don’t repeat
transient increases in urine ACR may be seen with menstruation, urinary tract infection (UTI), strenuous exercise, and upright posture (‘orthostatic proteinuria’).
Make a diagnosis of CKD if there is a persistent reduction in renal function (eGFR is <60 mL/min/1.73 m2) and/or proteinuria (urinary ACR is ≥3 mg/mmol) lasting for at least three months.
Check the person’s nutritional status, body mass index (BMI), blood pressure, and serum HbA1c and lipid profile to assess for cardiovascular risk factors
for which indications should patients with CKD be referred early to a nephrologist.
CKD stage 4+5
moderate proteinuria (ACR ≥70) unless due to DM and already treated.
proteinuria (ACR ≥30) with haematuria
rapidly falling egfr (>15 in 1year or >10 in 5years)
high BP poorly controlled despite ≥4 antihypertensives
known or suspected rare or genetic cause of CKD
suspected renal artery stenosis
management of CKD
- Investigation - identify and treat reversible causes - relieve obstruction, stop nephrotoxic drugs, deal with high Ca, and cardiovascular risk (stop smoking, healthy weight), tight glucose control in DM.
- Limit progression
- BP (target <140/90). treat with ACEi or ARB in diabetic kidney disease even if normal BP.
- Renal bone disease: low vitamin D, high phosphate, low calcium
- Secondary hyperparathyroidism - due to low calcium, high phosphate and low vitaminD. can cause a Brown tumour in bones.
severe clinical manifestations
- osteitis fibrosa cystica (hyperparathyroid bone disease)
- osteomalacia - due to low vit D
- osteoporosis
- osteosclerosis
phosphate rises in CKD, which increases PTH further, also precipitates in the kidney and vasculature.
- restrict diet, give binders (e.g. Calcichew) to reduce gut absorption.
- vitamin D
offer colecalciferol or ergocalciferol to treat vit D deficiency first.
- if vit D deficiency has corrected but sx of CKD mineral and bone disease persist –> vitamin D analogues (e.g. calcitriol) to people with GFR ≤30.
offer bisphosphonates to prevent and treat osteoporosis in its with GFR ≥30.
cardiovascular modification - give stains and aspirin.
diet - healthy, moderate protein diet, K restriction if hyperkalaemic, avoidance of high phosphate foods (milk, cheese, eggs)
symptom control in CKD
ANAEMIA
o Most significant reason is REDUCED ERYTHROPOIETIN LEVELS.
Gives a normocytic normochromic anaemia
Becomes apparent when GFR <35ml/min
Anaemia in CKD predisposes to the development of LEFT VENTRICULAR HYPERTROPHY – associated with a three fold increase in mortality in renal patients.
o Check haematinics and replace iron/b12/folate if necessary
o if still anaemic, consider recombinant EPO
ACIDOSIS
- consider sodium bicarbonate supplements
OEDEMA
- high doses of loop diuretics may be needed (e.g. furosemide + metalozone each morning) and restriction of fluid and sodium intake.
RESTLESS LEGS/CRAMPS
- clonazepam or gabapentin
or
dopamine agonists
types of dialysis
haemodialysis
haemofiltration
peritoneal dialysis - risk of PF peritonitis (due to s. epidermidis/aureus)
indications for emergency dialysis
AEIOU
- Acidosis
- Electrolytes (refractory K)
- Intoxicants (lithium)
- Overload (fluid) when diuresis isn’t working (refractory)
- Uraemia (pericarditis, encephalitis)
absolute c/i to renal transplant
active infection
cancer
severe co-morbidity
triple therapy used to maintain immunosuppression in transplant patients
tacrolimus/ciclosporin
azathioprine/mycophenolate
prednisolone
complications of transplants
surgical - bleed, thrombosis, infection, urinary leaks, lymphocyte, hernia
delayed graft function - acute tubular necrosis in graft due to ischaemic-perfusion injury.
rejection
drug toxicity
infection - HSV, candida, pneumocystis jerovecii, CMV
malignancy
cardiovascular disease - leading cause of death in transplant patients.
important bloods to check before biopsy (renal)
FBC
CLOTTING
G+S
stop anticoagulants
- aspirin 1 week before
- warfarin 2-3d before
- LMWH - 24h before
indications for renal biopsy
- unexplained AKI/CKD
- acute nephritic syndromes
- unexplained proteinuria and haematuria
- systemic diseases associated with kidney dysfunction
- suspected transplant rejection
- to guide treatment
what is glomerulonephritis
inflammation of the glomeruli and nephrons
what are the consequences of inflammation
damage to the glomerulus restricts blood flow, leading to compensatory high BP (activation of renin-angiotensin system).
damage to the filtration mechanism allows protein and blood to enter the urine.
loss of usual filtration capacity leads to AKI
presentation of nephrotic syndrome
hypoalbuminaemia
proteinuria
oedema
hyperlipidaemia
presentation of nephritic syndrome
haematuria
proteinuria
hypertension
oliguria
causes of nephrotic syndrome
membranous nephropathy
minimal change disease
focal segmental glomerulosclerosis
mesangiocapillary GN
causes of nephritic syndrome
IgA nephropathy post-streptococcal nephropathy vasculitis SLE anti-GBM disease cryoglobulinaemia
mesangiocapillary GN
investigations for glomerulonephritis
bloods - FBC, U+E, LFT, ESR, CRP, IgA, electrophoresis, complement
autoantibodies: ANA, ANCA, anti-dsDNA, anti-GBM
blood culture
ASOT
HBsAg
anti-HCV
urine
- RBC casts
- MC&S
- bence jones protein
- ACR
imaging
- CXR
- renal ultrasound
RENAL BIOPSY - gold standard for glomerulonephritis.
general management of glomerulonephritis
early referral to a nephrologist.
keep BP <130/80 or <125/75 if proteinuria >1g/d
include an ACEi or ARB - reduce proteinuria and preserving renal function.
what is IgA nephropathy
most present with macroscopic or microscopic haematuria - occasionally nephritic syndrome.
typical patient - young man with episodic macroscopic haematuria, recovery is often rapid between attacks.
increased IgA possibly due to infection, which forms immune complexes and deposits in mesangial cells.
occurs DURING OR STRAIGHT AFTER a streptococcal infection.
what would you find on renal biopsy for IgA nephropathy
mesangial proliferation, immunofluorescence shows deposits of IgA and C3
high serum IgA
normal C3
treatment of IgA nephropathy
BP control with ACEi.
immunosuppression may slow decline of renal function.
What is Henoch-Schönlein purpura
it is similar to IgA nephropathy but has a systemic picture.
causes a small vessel vasculitis.
features of HSP
features
- Purpuric rash on extensor surfaces (legs, buttocks)
- fitting polyarthritis
- abdominal pain - GI bleeding (maleana, haematemesis)
- Nephritis
diagnosis of HSP
clinical.
confirmed with positive IF for IgA and C3 in skin or renal biopsy.
treatment of HSP
BP control with ACEi
Ibuprofen - for joint pain
Steroid treatment for bowel symptoms in children.
Skin rash - dapsone
what is Goodpasture’s disease
anti-glomerular basement membrane disease
caused by autoantibodies to type IV collagen.
type IV collagen is found in the kidneys and lungs.
presentation of good pasture’s syndrome
haematuria/nephritic syndrome pulmonary haemorrhage (haemoptysis)
treatment of good pasture’s syndrome
plasma exchange
steroids
± cytotoxics
what is post-streptococcal GN
Occurs MANY WEEKS AFTER A SORE THROAT OR SKIN INFECTION.
streptococcal antigen is deposited on the glomerulus, causing a host reaction and immune complex deposition.
presentation of post-streptococcal GN
nephritic syndrome
investigation for post-streptococcal GN
high ASOT
Low C3
treatment for streptococcal GN
supportive
what forms rapidly progressive GN
- immune complex deposition e.g. post-infectious GN, SLE, IgA/HSP
- pauci-immune disease (80-90% ANCA +ve) - granulomatosis with polyangiitis: c-ANCA +ve,
microscopic polyangiitis (p-ANCA +ve),
churg-strauss syndrome
- anti-GBM disease
presentation of patients with rapidly progressive GN
AKI
fever, myalgia, weight loss, haemoptysis.
commonest reason for death in rapidly progressive GN
pulmonary haemorrhage
treatment of rapidly progressive GN
aggressive immunosuppression with high-dose IV steroids and cyclophosphamide
± plasma exchange
which type of GN is caused by hepatitis B/C
membranous nephropathy (hep B)
mesangiocapillary GN (hep C)
which type of GN is caused by SLE
class V lupus nephritis causes membranous nephropathy
in diabetic nephropathy, which specific nodules are found on biopsy
Kimmelstein-Wilson nodules
in amyloidosis, what is found on biopsy specifically
apple green birefringence (nodular)
which drugs can cause nephrotic syndrome
NSAIDs
penicillamine
anti-TNF
gold
pathophysiology of nephrotic syndrome
injury to the podocyte - effacement of the foot processes and loss of podocytes causes heavy protein loss
presentation of nephrotic syndrome
patients present with pitting oedema (ankles, shins, periorbitally)
investigations of nephrotic syndrome
urine dip: protein ++++
albumin low on LFT
?renal biopsy
ddx of nephrotic syndrome
CCF - high JVP, pulmonary oedema, mild proteinuria
liver disease - low albumin
management of minimal change disease
STEROIDS - common in children.
complications of nephrotic syndrome
susceptibility to infection e.g. cellulitis, strep infections and SBP.
thromboembolism (40%) - hypercoagulable state due to high clotting factors and platelet abnormalities.
hyperlipidaemia - hepatic lipoprotein synthesis in response to low oncotic pressure.
treatment of nephrotic syndrome
reduce oedema - loop diuretics e.g. furosemide.
- daily weights and daily U+Es
- fluid restrict to 1L/d and salt restrict while giving diuretics.
reduce proteinuria
- ACEi/ARB
reduce risk of complications
- anticoagulate if nephrotic range proteinuria
- statin to reduce cholesterol
- treat infections promptly and vaccinate
treat underlying cause
minimal change disease biopsy
normal under light microscopy
electron microscopy - effacement of the podocyte foot processes.
rx
- 90% children and 70% adults undergo remission with steroids.
(if relapsing and steroid-dependent) - cyclophosphamide or ciclosporin/tacrolimus
associations of membranous nephropathy
malignancy
hep B
drugs (gold, pencillamine, NSAIDs)
autoimmune disease (thyroid, SLE)
biopsy of membranous nephropathy
diffusely thickened GBM with IgG and C3 sub epithelial deposits on immunofluorescence.
treatment of membranous nephropathy
secondary - treat underlying cause
idiopathic - ACEi/ARB and diuretics
associations of focal segmental glomerulosclerosis (FSGS)
primary - idiopathic secondary - vesicoureteric reflux - IgA nephropathy - Alport syndrome - Vasculitis - SCD - Heroin use - HIV
presentation of FSGS
nephrotic syndrome or proteinuria
treatment of FSGS
responds to corticosteroids in 30%
cyclophosphamide or ciclosporin - if steroid resistant
associations of mesangiocapillary GN
Immune complex mediated - hepatitis C, SLE, monoclonal gammopathies.
treatment of mesangiocapillary GN
underlying cause as priority
ACEi/ARB
where do loop diuretics act on the kidney
Na/K/2Cl co-transporter on the thick ascending loop of Henle
cause hypokalaemia, hyponatraemia, alkalosis (H+ excretion increased), hypocalcaemia.
can be ototoxic in high doses
where do thiazide diuretics act
inhibit NaCl transporter in the DISTAL CONVOLUTED TUBULE
cause
- hypokalaemia
- hyponatraemia
- hypomagnesaemia
- high uric acid (gout)
- reduce urinary calcium
k-sparing diuretics SEs
hyperkalaemia
metabolic acidosis (reduced H excretion)
gynaecomastia
where do carbonic anhydrase inhibitors act
proximal convoluted tubule
where do k-sparing diuretics act
cortical collecting tubule
another name for IgA nephropathy
Berger’s disease
presentation of granulomatosis with polyangiitis (Wegener’s )
upper respiratory tract: epistaxis, sinusitis, nasal crusting.
lower respiratory tract:
- dyspnoea
- haemoptysis
rapidly progressive GN (pauci-immune)
saddle-shaped nose deformity
also - vasculitic rash, eye involvement (e.g. proptosis), cranial nerve lesions
c-ANCA positive