renal 11-13 (s + p + t) Flashcards
Why is urinalysis used as a basic clinical test and what for?
- many drugs and their metabolites eliminated via the kidneys
- for initial diagnosis of common conditions i.e. various types of renal disease
How do we use urine test strips for urinalysis?
- dip strip completely in fresh urine
- gently tap to remove excess urine
- dab back of strip on paper towel
- hold strip in horizontal position to prevent mixing of chemicals
- read at (timed) 30 seconds (bilirubin + glucose) by holding it over matchingcolour charton bottle
- read all tests at times specified by chart to find relevant values
How can we qualitatively assess urine?
colour and appearance e.g. may appear cloudy due to protein/blood
What is the normal range for osmotic pressure of urine?
Hint - digits of 300
300-600 mOsmol/l
State the normal expected results of urinalysis for:
a) glucose (mmol/L)
b) bilirubin (not a number)
c) ketones (s-m)
d) specific gravity (no units lots of zeroes)
e) blood (m-l)
f) pH (two whole numbers range)
g) protein (g/L)
h) urobilinogen (not a number but atypical indicator)
i) nitrite (not a number)
j) leukocytes (not a number)
a) 5.5mmol/L
b) positive
c) small-moderate
d) 1.000-1.015
e) moderate-large
f) 7-8.0
g) 0.3-1.0g/L
h) positive colours may be atypical
i) positive
j) positive
Which disease may be indicated by a urinalysis with a high glucose concentration?
(Hint - seen in juveniles)
type 1 diabetes
Which disease may be indicated by a urinalysis with a high protein concentration?
glomerulonephritis
Which disease may be indicated by high volumes of abnormally diluteurine?
(Hint - ‘insipidus’ is Latin for plain or tasteless)
diabetes insipidus
Which disease may be indicated by urine of a low pH?
Hint - to do with microorganisms and acid-producing flora
urinary tract infection (UTI)
ammonia-forming organisms can lead to a low pH
Which disease may be indicated by a urinalysis with a positive urobilinogen value?
(Hint - urobilinogen is produced in the liver)
hepatitis
indicates excess conjugated bilirubin in blood plasma which can only link to the liver
How does clean-catch MSU collection work?
(lean-catch midstream urine collection)
- washarea around urinary opening and start urination into the toilet
- stopmidstream
- let 1-2 ounces (30-60ml) flow into container
- finish urinating into toilet
- hand over sample to HCPs
What are the main causes of blood in the urine (haematuria)?
Hint - KILT G → hepatic, renal, general
- kidney stones
- infection
- leakage from bladder area (harmless)
- tumours in bladder/kidney
- glomerulonephritis
What are the most common abnormal microscopic and microbiological constituents of urine which can indicate disease?
(Hint - RWcb)
- RBC’s
- WBC’s
- casts (mucoprotein matrix structures)
- bacteria
State some limitations of urinalysis.
Hint - +VE → n, -VE → p + g + k + b, S → pre pKa poly, quality vs quantity
- potential of false positives forthe nitrite
- potential of false negatives forthe protein, glucose, ketone (reacts with acetoacetic acid but not react with acetone), bilirubin (patients on large doses of chlorpromazine makes urine red)
- SGTs (specific gravity tests) require a pKa change of certain pre-treated polyelectrolytes
- qualitative analysis is subjective (i.e cloudiness and RBC’s can’t be seen with naked eye)
Define:
a) proteinuria
b) glucosuria
c) ketonuria
d) haematuria
e) hypersthenuria (Hint - water)
f) urobilinogenuria
g) hyposthenuria (Hint - SG)
h) bilirubinuria
i) nitrituria
j) pyuria
presence of abnormal quantities of... a) protein b) glucose c) ketone d) blood e) hypersthenuria → osmolality f) urobilins g) hyposthenuria → (low) specific gravity h) conjugated bilirubin i) nitrites j) pus ... in the urine
Define nephrotic syndrome and where it often occurs.
(Hint - the said syndrome ‘itis’ and in the part inside the bowman’s capsule)
- syndromecomprising signs of nephritis → kidney disease involving inflammation
- often occurs in glomerulus (glomerulonephritis)
Define nephrotic syndrome.
(Hint - caused by damage to which blood vessels?)
- kidneydisorder causing protein to pass into urine
- caused by damage to small clusters of blood vessels in kidneys which filter waste from blood
Define acellular casts.
clumping of substances which are not cells (hyalinecasts are solidified mucoproteins secreted from tubular cells of nephrons)
What are kidney stones, what are the different types and why may they form?
• 75% are calcium stones and remainder are struvite, urate or cysteine
• very common and form due to:
- genetic factors (metabolic abnormality) e.g. cysteinuria
- environmental factors - heat, dehydration, medications e.g. calcium
What is cysteinuria?
- inherited abnormality where there is a defect in cysteine transport from tubular lumen to tubular cells
- leads to increased urinary cysteine
- cysteine not very soluble, most often found in young people
What is proteinuria a marker of and what can affect its detection by dip-stix screening tests?
- a marker and cause of kidney damage → >300mg/24 hrs is abnormal (spot Protein Creatinine Ratio, PCR)
- can be reduced by certain BP drugs
What is the guidance for BP thresholds in renal patients?
Hint - normal limit “less than,” protein/diabetic limit, agents available for
- should be <140/90
- <130/80 if proteinuria/diabetes
- many agents available to lower BP
In which four ways can renal function be assessed and which is the best method?
(Hint - the usual G, CI clearance and then plasma c levels)
- plasma creatinine - but this a flawed marker
- creatinine clearance - involves 24-hour urine collection
- inulin clearance (gold standard)
- glomerular filtration rate (GFR)
Which two treatments can offered for renal problems to control BP?
(Hint - pye and peri)
- pyelolithotomy → lengthy procedure clamping of renal artery where thousands of cysteine stones removed
- peritoneal dialysis → used to manage post-op developed renal failure
How can cystinuria be treated and managed so more stones won’t form?
(Hint - treatment: have 5L altogether, sodium bicarb to reduce acid and penicillin with amines + management: low protein, low NaCl, capto meds, pH dipper to keep urine high)
• treatment: - 4L fluid/day - wake up overnight to drink 1L water - sodium bicarbonate to alkalinise urine - penicillamine • management: - low protein, low salt diet - captopril (ACE inhibitor) - pH dispstix at home to keep urine alkaline
Which other surgical treatments can be offered for stones?
Hint - scopy and stent, nephro blocking, the most common using igh frequency waves lithotr
• ureteroscopy + ureteric stent
• nephrostomy (opening between kidney and skin to drain blocked urine)
• lithotripsy (high frequency waves to break stone down)
- not useful for cysteine stones
- some stones large and can’t be extracted via ureter
- so, nephrostomy + crushing of stones
- some stones → episodes of renal obstruction
- ongoing hypertension