What are the normal levels of the following substances in the urine? - uric acid - bicarbonate ions - creatinine - potassium ions - sodium ions - chloride ions - ureas

- uric acid = 0.6g - bicarbonate ions = 1.2g - creatinine = 3.2g - potassium ions = 3.2g - sodium ions = 4.1g - chloride ions = 6.6g - ureas = 25g

Urine as an Indicator of Disease Flashcards by laura edgar

What are the 3 aspects of urine that you can investigate?

gross appearance
microscopy
biochemistry

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What are the advantages of urine analysis?

non-invasive diagnosis
easily obtained - feasible in local GP practice
normal composition normally know
for pre-renal or renal disease
changes in levels of what should be present or appearance of material that should be ‘absent’

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What are the normal levels of the following substances in the urine?

uric acid
bicarbonate ions
creatinine
potassium ions
sodium ions
chloride ions
ureas

uric acid = 0.6g
bicarbonate ions = 1.2g
creatinine = 3.2g
potassium ions = 3.2g
sodium ions = 4.1g
chloride ions = 6.6g
ureas = 25g

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Why is a 24h urine sample the most useful?

most representative as levels of substances change over the course of a day

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Describe appropriate collection of urine

clean/sterile container
random samples, clean catch midstream specimen
timing depends on test required
test as soon as possible
24 hour specimen, with empty bladder at hour 0

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What is a typical volume of urine in 24 hours?

0.8-2L

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What should the gross appearance of urine be?

pale yellow and clear

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Blood in different sections of urine indication blood from where

early = urethra
throughout = bladder
end = prostate

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What is pseudohaematuria caused by?

free Hb, myoglobin, porphoryins, drugs

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What does red/brown urine indicate?

conjugated bilrubin

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What does black urine indicate?

melanin e..g in disseminated melanoma

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What does foamy urine indicate?

proteinuria

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What does cloudy urine indicate?

protein, oxalates, cells, phosphates, platelets

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Why does normal urine darken on standing?

completion of oxidation

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What does dramatic darkening on standing indicate?

haematuria in case of sever P.falciparum malaria

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What four things can be found on microscopic examination and how?

Centifuge urine sampel, examine sediment for:

bacteria
cells
casts
crystals

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How many RBC’s and WBC’s are normal in the urine?

RBC >1 is abnormal

WBC >10 is abnormal

What do casts indicate?

What do redcell casts indicate?

Casts e.g. hyaline. composed for primary mucoprotein secreted by tubules or fine granular

normal finding post exercise
larger coarse casts are abnormal
red cell cast = kidney damage

What 4 kinds of crystals can be present in urine?

oxalate crustals
crusting
triple phosphate
amorphous crystals

What is a normal pH range for urine?

4.5-8

What factors in diet lead to acidic urine?

What factors in diet lead to alkaline urine?

acidic = meat 
alkaline = citrus fruit and veg

What diseases cause extremely acidic urine?

uncontrolled diabetes, starvation, respiratory disorders

What diseases cause extremely alkaline urine?

UT obstruciton, some repistoraty disorders e.g. alkalosis

What can cause variation in excreted creatinine?

increased = excessive meat diet

- decrease = wasting disease, malnutrition, poor renal blood blood or function

Which two kinds of disorder cause abnormal solute excretion?

pre-renal and renal

Describe pre-renal cause of abnormally high/low solute excretion

- kidney function is normal Overspill: - increased solute filtration --> increased production in body - abnormal metabolite so no suitable transporter for reabsorption Decreased solute filtration - decreased production in body - decreased delivery e.g. cardiac failure, haemorrhage, burns

Describe renal causes of abnormal solute excretion

- kidney is abnormal Glomerular malfunction - infection, autoimmune disease, inflammation --> leakage Tubular malfunction - infection, autoimmune disease, inflammation, necrosis, drugs, toxins - defective reabsorption e.g. glucose - defective secretion e.g. H+

What is urea?

the non-toxic end-product of nitrogen metabolism

What factors increase urea excretion?

- excess protein intake - protein energy malnutrition - uncontrolled DM1 - infections, burns, wasting diseases, trauma

What factors decrease urea excretion?

- low protein diet, severe liver disease/genetic defects - glomerular nephritis, acute tubular necrosis - poor renal bloody supply or renal obstruction

What are the outcomes of decreased urea excretion?

- hyperammonaemia, NH4+ crosses BBB --> lethargy, irratibilty, finally coma

What are the casues of glycosuria? x3 categories

``` Metabolic hyperglycaemia - diabetes mellitus type 1 - anxiety, stress - phaechromocytoma Reduced renal threshold - pregnancy or renal glycosuria (genetic) Tubular malfunction - generalised tubular damage secondary to other damage - fanconi syndrome ```

``` What are the characteristics of pheochromocytoma? What is it? What are the symptoms? How is it diagnosed? What is the treatment? ```

- a pre renal disorder --> increased end-product excretion - secreting adrenal medullary tumour - ocassinoaly ectopic - excessive secretion of adrenaline causes hypertension, headaches, sweating, anxiety, palpitation, tachycardia, anorexia, hyperglycaemia, high plasma FFAs - diagnosed by excessive adrenaline breakdown products in ruine - metaneprhones and VMA - therapy by surgery and blockers

What sugars are abnormally excreted in urine? | When might they be present?

- galactose = enzyme deficieny - fructose = fructose intolerance, essential fructosuria - lactose = lactation, lactase deficient, coeliac - pentoses = essential pentosuria

When may ketones be present in the urine?

- unctornled type 1 diabetes | - starvation

When might amino acids be present in the urine?

- generalised tubular damage - specific transporter defects (e.g. cystinuria and Hartnup's) - raised plasma AA's e.g. PKU, cystinosis

When might conjugated bilibruin be present in the urine?

- liver damage | - obstructed bile ducts

What is the definiciton of proteinuria? | What does it indicate?

- >200mg/24h of proteins | - nephrotic syndrome

What is orthostatic proteinuria?

- usualyl a benign condition affecting children - protein isnot detectable in morning - delvops only after standing uprights - insignificant if proteinuria is detected only in somme of the urine samples

What are the mechanisms of proteinuria?

Pre renal problem (overflow) e.g. Bence Jones proteins Renal problem - glomerular e.g increased permeability to albumin - tubular e.g. impaired of saturated respiration - secreted e.g. due to secretion by kidneys or epithelium of urinary tract

Protein size indicates pre-renal vs renal problem. | Explain

Low MWt --> kidney is topically normal e.g. myoglobin | High MWt --> damaged kidney e.g. albumin

What is the deficiency in PKU? What does it lead to in the urine? What are the consequences

- genetic deficieny of Phe hydroxylase - excess excretion of phenylpyruvate - accumulation of hydrophobic Phe which affects the brain - build up of transmission byproducts