Ictotest-place 10 drops of the urine sample onto the filter paper provided, transfer one tablet onto the centre of the moistened area using forceps. The tablet must not be handled at all. Using a pipette place one drop of water onto the tablet, wait five seconds and then place another second drop. Look at the colour on the tablet and compare this with the colour chart supplied. Record the result for each sample down.
It must be noted that any colour changes with each test seen after the time allocated are of no diagnostic value and must be discarded. It is important to follow the timing precisely for each test in order to obtain an accurate result as possible.
Results
Discussion
After obtaining the results shown in table 1 the significance of them with respect to the likely condition the patient has will be discussed.
Albustix were used on sample pair one, sample A gave a negative result (see table 1) which is normally expected for this test because there should not be any protein present in the urine, this is because the glomerulus generally prevents the large protein molecules from entering the renal filtrate. Sample B however gave a reading of 0.3mg/dL (see table 1). The presence of protein in the urine usually indicates kidney disease. The major mechanisms in producing the presence of proteins in the urine are:
- Elevated concentration of normal and abnormal proteins in the blood such as in the case of leukaemia and certain types of cancer.
- Increased secretion of proteins by the tubules in the kidney.
- Increase in the filtration of proteins by the glomeruli in the kidney.
- Bacterial pyelonephritis.
The presence of proteins in the urine may sometimes be due to exertion. This is also known as exercise proteinuria and is sometimes seen in joggers, marathon runners etc.
There are certain interfering factors which must be considered when using albustix including; severe emotional stress, strenuous exercise and urine contaminated with vaginal secretions.
Drugs, which may give false positive results, include acetazolamide, aminoglycosides, salicylates and viomycin.the reagent area is more sensitive to albumins than any of the other proteins which may be present such as, globulins, haemoglobin, bence-jones protein and mucoproteins. Therefore a negative result does not necessarily mean that the urine contains no protein. A minute amount of protein is normally excreted by the kidney, although the sensitivity level of the albustix is above this amount, sometimes false positive results may be given for normal protein concentrations. This is especially apparent if the urine has high specifc gravity.
In highly buffered or alkaline urines false positive results may be obtained. If the urine sample is contaminated with quatemary ammonium compounds or with chlorhexidine false positive results may be observed. The colour chart for the albustix represents a range of values; therefore the colour obtained on the test strip falls within a range of values and may indicate values at both extremes of the range. Due to this the result recorded down is unreliable. If protein is detected in the urine further testing needs to be carried out in order to confirm the diagnosis. Further blood tests may be carried out to detect how much protein is excreted and the urine sample may be tested for other abnormalities such as the presence of glucose and blood etc. this is done by a machine called a biochemical analyser which measures the range of substances present in the urine.
Alternatively a quick dipstick test can be used in the doctor’s offices although the first option is the preferred. If these urine tests suggest a problem with the kidneys then the patient may need to undergo further imaging procedures, such as ultrasound scanning or MRI to look for kidney abnormalities.
Diastix were used on sample pair two. Diastix test for the presence of glucose in urine. Sample A gave a negative result (see table 1), which is normal as there is not normally any glucose present in urine, however there may be very small trace amounts present. Sample B gave a significant measurement of glucose in the urine (see table 1). Abnormal results, which are greater than normal levels, may indicate any of the following;
- Benign low renal glucose threshold (this means that the kidneys excrete glucose in the urine at relatively low blood glucose levels).
- Cushing’s syndrome
- Diabetes mellitus
- Severe stress, which may arise after trauma or surgery.
There are no risks associated with the presence of glucose in urine. There are some drugs, which may increase urine glucose measurements including aminosalicyclic acid, chloral hydrate, diazoxide, diuretics, estrogens and nicotinic acid. This test is most commonly performed as a screening test for possible diabetes mellitus or to monitor the control of blood glucose in diabetes.
Drugs that may give false positive results include acetylsalcyclic acid. Ascorbic acid and sulfonamides. Drugs which may give false negative results include ascorbic acid, levodopa and phenothiazines. If ketone bodies were also present in the urine sample this can cause the reagent area to have a decreased sensitivity to glucose therefore affecting the reaction. If ketone bodies are present in significant amounts (greater than 4.0mmol/L) then they can cause false negative results for specimens containing small amounts of glucose.
If the specific gravity of the urine increases the reactivity of the glucose test will decrease therefore this will affect the result measured. The reactivity also varies with temperature. Normally small amounts of glucose are excreted by the kidney and may be found in the urine sample but this is below the sensitivity level of the test however on occasions the test will produce a colour change between negative and the 5.5mmol/L concentration giving a false positive result.
If glucose is found in the urine then the patient must undergo further investigation including testing for ketone bodies in the urine in case the patient has diabetes. Other techniques such as x-ray and a complete urinalysis may complement this in order to come to a diagnosis.
Sample pair three was tested using ketostix. Sample A gave a measurement of 4 (see table 1) which shows that ketones are present in moderate levels. Sample B gave a negative result (see table 1), which is normal for this test. Results showing the presence of ketones may be listed as small, moderate or large. In a normal subject there should be no ketones in the urine sample. The presence of ketones in the urine as in sample A are a result of rapid or excessive breakdown of fatty acids. The presence of ketone bodies in urine may be as a result of:
- Metabolic abnormalities, including uncontrolled diabetes or glycogen storage disease.
- Abnormal nutritional conditions including starvation, fasting, anorexia, increased protein intake and low carbohydrate diet.
- Protracted vomiting including hyperemesis gravidarum.
- Disorders of increased metabolism, including hyperthyroidism, fever, acute or sever illness, burns, pregnancy, lactation or following surgery.
There are no risks involved if ketones are present in urine. There are drugs such as glucocorticoids, which may cause false positive results. Fatty acid release from adipose tissue is stimulated by a number of hormones including glucagon, epinephrine, and growth hormone. The levels of these hormones are increased in starvation (may be related to excess alcohol use or not), uncontrolled diabetes mellitus and a number of other conditions.
False positive results may be obtained from urine samples containing levodopa metabolites or highly pigmented urine specimens.in some high specific gravity urine samples or low pH samples reactions may give results up to and including trace amounts. Additionaly compounds such as mesana92-mercoptoethane sulfonic acid) which contain sulfhydryl groups may cause false positive results or atypical colour change. Further tests need to be done to confirm diagnosis such as testing for other blood constituents and also x-ray imaging may be taken to try and see what the proble is.
Sample pair four was tested using hemastix. This tests for the presence of blood in the urine. Sample A gave a positive reading of 200 ery/microlitre (see table 1). ve a negative result, which is normal. The presence of blood in the urine is abnormal and it must come from one of the organs involved in making or transporting urine therefore the evaluation of hematuria needs to consider the entire urinary tract including the kidneys, ureter, bladder, prostrate or urethra. There are multiple causes of hematuria;
- Cancers
- Trauma or surgery
- Infectious obstructions of the urinary tract
- Inflammation of the kidney
- Medications which thin the bloods clotting ability
- Acute post infectious glomerulonephritis
- Renal stones
When the patient is tested for haematuria using hemastix, development of green spots (indicating intact erythrocytes) or green colour (free hemaglobin) on the reagent area within 60 seconds indicates the need for further investuigation. If the urine sample comes from a woman who is mensurating at the time then it is not uncommon for the urine to have blood present in it. Sensitivity of the test may be reduced in urine samples with a high specific gravity. The test is equally sensitive to myoglobin as it is to haemoglobin therefore will give a positive result if myoglobin is present also. Captopril may cause decreased sensitivity of the reagent area therefore affects the results. If oxidizing contaminants such as hypochlorate are present then this will give rise to false positive results. If the urine sample is obtained from someone who has a urinary tract infection, microbial peroxidase present can give rise to a false positive reaction.When hematuria is present a thorough history needs to be taken including whether the patient smokes, kidney stones, injuries to urinary tract, trouble urinating. This is needed to rule out a serious underlying disease such as cancer. Further diagnostic tests are needed when hematuria is present, three diagnostic tests usually performed are intravenous pyelogram(IVP), cytoscopy and a urine cytology. The intravenous pyelogram is a form of x-ray evaluation of the entire urinary tract. The procedure uses a dye, which is injected into the veins. The dye is then filtered by the urinary tract. A series of x-rays can then be taken in order to look for abnormalities. This method has proved useful in studying the kidneys and ureter. In order to examine the bladder, prostrate or urethra cytoscopy is used, this uses a small viewing tube called a cytoscope, which can be used to visually inspect the bladder and urethra. Another form of testing which can be used to help in the diagnosis is cytology, which involves voiding urine to be examined by a pathologist for cancer cells. In acute post infectious glomerulonephritis, the treatment is the complication bed rest, antihypertensives to lower the B.P and antibiotics. Acute pyelonephritis may require intravenous antibiotics.
Sample pair five was tested using the Ictotest. Sample A gave a negative result, which is expected of this test, as no bilirubin should be present in the urine. Sample B gave a positive result with the Ictotest. Bilirubin is not normally found in the urine and its presence may indicate liver or gallbladder problems. Normally if bile ducts are obstructed then bilirubin will build up to a high level and some of it will appear in the blood and urine. If direct bilirubin is found in the urine then this means that the biliary ducts are obstructed. Increased levels of bilirubin may indicate;
- Biliary strictures
- Liver cirrhosis
- Gallstones in the biliary tract
- Hepatitis associated with biliary obstruction
- Surgical trauma which can affect the biliary tract
- Tumors in the liver or gall bladder.
Some of the drugs, which can give false positive results with urine, include allopurinol, some antibiotics, barbiturates, chlorpromazine, diuretics, ethoxazene, oral contraceptives and steroids. Drugs that can produce false negative results include indomethacin and ascorbic acid. The container with the reagent tablets must remain unopened before the test and must not be tampered with as this can cause reactivity and unstableness before the reaction. Failure to guard the tables against exposure to light, heat and ambient moisture may lead to altered reagent activity. If sample is in the presence of light or heat then bilirubin is rapidly decomposed once excreted. The addition of urine preservatives will not prevent this decomposition; therefore negative results can be obtained from sample, which have not been used immediately after excretion. Care must have been taken to handle the tables, by avoiding manual contact and using forceps at all times. This is to avoid transferring moisture to the tablet and therefore making it unstable. Metabolites of pyridium may give a brick red- orange colour with the test, which masks the reaction of small amounts of bilirubin. If the urine sample contains elevated concentrations of urobillinogen this does not mask the reaction of small amounts of billirubin but atypical orange colours can be produced which affect the colours produced by the billirubin. If chlorpromazine is present in the urine sample in relatively large amounts then a false positive result may be observed. Metabolites of lodine may also cause false positive or atypical colour results. Further blood tests may be carried out to test for the presence of other blood constituents, which may also be present in the urine. Imaging techniques can be used to examine suspected malfunctioning parts of the body, using x-ray scans, ultrasound and MRI scans. These techniques accompanied with injecting coloured dyes to produce contrast may reveal the underlying problem such as gallstones.
There are some limitations and errors may have affected all of the dipstick tests carried out. If any of the test strips where tampered with before use this may have caused a reaction with the reagent area and therefore cannot be entirely accurate if accidentally used again. In all the tests there where specific timing instruction given for when to observe the colour on the reagent area, if the timing was inaccurate due to a delay in starting/stopping the stop clock then this can lead to a reaction proceeding for longer than it should and the colour observed will be incorrect. If the reagent test kits where not thoroughly checked before use some of the bottles may have passed their expiry date therefore will not be of any use and give unreliable results. Specifically dipsticks should not have been used from a bottle, which was opened more than 6 months ago, it should be discarded and a fresh set used. If the urine samples used where left uncovered for a period of time before tested then cross contamination may have occurs therefore the urine sample will give inaccurate results. The reagent area on the dipstick or the Ictotest tablet must not be touched because moisture can affect the out come of the results. When attempting to read the result of the dipsticks lighting conditions may influence the colour observed. Heat and light may hve caused the reagent areas of dipsticks to become unstable and therefore cannot give an accurate result. In all tests exact agreement between visual results and instrumental results might not be found because of the inherent differences between perception of the human eye and the optical system of the instruments. Finally as with all laboratory testing, a definitive diagnostic decision should not be made on a single method or result. The tests should be repeated a minimum of three times and further diagnostic tests carried out to confirm diagnosis.
References