renal investigations Flashcards
AKI stage 1
mild: creatinine 1.5-1.9x baseline creatinine or urine output <0.5 ml/kg/hour for 6 hours.
AKI stage 2
moderate: 2-2.9 x baseline creatinine or urine output <0.5 ml/kg/hour for >12 hours.
AKI stage 3
4 points
severe: 3/>3 x baseline creatinine
or urine output <0.3 ml/kg/hour for 24 hours
or anuria for 12 hours
or serum creatinine >354umol/dl
what does the creatinine KINASE have to be to diagnose rhabdomyolosis
5x normal limit
what would the urea:creatinine ratio of a pre renal cause of AKI be
> 100
what would the urea:creatinine ratio of an intrinisc renal aki be
<100
diagnostic criteria for AKI
(3 )
increase creatinine >26micromol/L in 48 hrs
or
increase in creatinine by >50% in 7 days
or
decrease in urine output <0.5ml/kg/hr for more than 6 hours
Alport syndrom diagnostic test
Biopsy of kidneys showing thickenig and thinning of the GBM, splitting of the lamina densa
“basket weave appearance”
Myeloma diagnosis
1st line Ix
1st line Ix: serum protein electrophoresis (tests for globulins in blood) and BJP from urine
How to classify lupus nephritis
ISN classification
1-6
Based on the severity of mesangial proliferation> glomerular sclerosis
gold standard test for bladder cancer
cytoscopy
Ixs and their results for minimcal change disease
electron microscopy shows fusion of podocytes and effacement of foot processes
urinalysis: highly selective proteinuria is also a sign
when is renal biopsy carried out for minimal change disease
after failure to respond to steroids
screening test for CKD in diabetics
urinary Albumin/creatinine ratio (ACR) on a spot urine sample.
If abnormal, repeat with a first pass morning urine specimen
first indicator of diabetic nephropathy
microalbumineria
Ix for membranous glomerulonephritis and the results of it
renal biopsy:
electron microscopy shows basement membrane is thickened with subepithelial electron dense deposits.
this creates a “spike and dome” appearance
what is used to confirm diagnosis of recent streptococcal infection (in PSGN)
bloods: raised anti-streptolysin 0 tire
what must be monitored for HSP patients
blood pressure and urinalysis monitoring
what investigation is used to screen for ADPKD
and what is the diagnostic criteria for patients with a positive family history
ultrasound
<30yrs: 2 cysts unilateral or bilateral
30-59yrs: 2 cysts in both kidneys
> 60yrs: 4 cysts in both kidneys
initial screening test
and
gold standard test for CKD caused by hypertension/renal artery stenosis
initial: abdominal duplex ultrasound
Renal MRA (magnetic resonance angiogram)
Prostate cancer intial investigation
Issues with this ix
Most useful for
Psa
High grade cancers may not produce PSA
Useful for monitoring post treatment
What is the gleason grading system for
Predicts the prognosis of the prostatic tumour
3 is the lowest - well differentiated
5 is the highest- least differentiated
you get 2 scores but so lowest is acc 6 and highest is 10
the lower the score the better
(the higher the score the more abnormal the cancer therefore the prognosis is worse)
normal range of protein in the urine
<150mg/24 hrs
how much protein in the urine is classed as nephrotic
> 450mg/25hrs 3+ on dipstick reading
stage 1 CKD:
eGFR> 90ml/min/1.73m2 w/ demonstratble kidney damage eg haemuturia/proteinuria
has to be for 3 months or greater !
stage 2 CKD
60-89ml/min/1.73m with demonstratable kidney damage eg proteinuria/heamaturia/inc ACR
stage 3 ckd
30-59ml/min/1.73m
can be split into 3a and 3b
stage 4 ckd
eGFR is 15-30 ml/min/1.73m2.
stage 5 ckd
eGFR is <15 ml/min/1.73m2
Gold stanfard test for renal colic
low dose non contrast CT scan of kidneys, ureters and bladder
indications for treating obstructed kidney immedietley
pain persisting, pyrexia, persistent nausea/vomiting, impaired renal function
frank haemuturia type of referral and Ixs
2 week wait referral
cytoscopy and uss
twisted testicle ix
surgical exploration as it is an emergency
renal trauma injury Ix
triple face CT scan
gold standard investigation for Anti-GBM disease/goodpastures
renal biopsy: light microscopy- can show rpgn
immunoflouresence will also show linear deposits of IgG at GBM
1st line Ix for suspected prostate cancer
MRI
what does a positive phrens sign indicate
+ phrens= relief on lifting the testicle. differentiates between epidydmitis and torsion (torsion would result in a negative phrens sign)
Ix for renal tb
urinary auramine staining and microscopy
Ix for an infection in a kidney cyst
blood culture
diagnostic test for pyelonephritis
mid stream urine microscopy and culture
(this is done to guide the antibiotic treatment)
