I. Introduction
If you've ever passed a kidney stone, you're not likely to forget the experience — it can be excruciatingly painful. Kidney stones (renal lithiasis) are an ancient affliction dating back to the age of the Egyptian pyramids, yet they are still a common disorder today. The incidence of kidney stones has been increasing in recent decades. Although the reasons for this are still unclear, many experts believe that diet choices and lack of fluids are important factors that have contributed to this increase.
Your kidneys are two bean-shaped organs, each about the size of your fist. They're located in back of your abdomen on each side of your spine, and their main function is to remove excess fluid, unneeded electrolytes and waste from your blood in the form of urine. The ureters carry urine from your kidneys to your bladder, where it's stored until you eliminate it from your body.
Kidney stones usually form when your urine becomes too concentrated. This causes minerals and other substances in urine to form crystals on the inner surfaces of your kidneys. Over time, these crystals may combine to form a small, hard mass, or stone.
What a rock! Yup, its a kidney stone.
II. Signs and symptoms
A patient is not likely to have signs and symptoms unless a kidney stone is large, causes a blockage, is associated with an infection or is being passed. Then the most common symptom is an intense, colicky pain that may fluctuate in intensity over periods of five to 15 minutes. The pain usually starts in the patient’s back or side just under or below the edge of his ribs. As the stone moves down the ureter toward the patient’s bladder, the pain may radiate to his lower abdomen, groin and genital structures on that side. If the stone stops moving, the pain may stop too. Other signs and symptoms may include:
- Bloody, cloudy or foul-smelling urine
- Nausea and vomiting
- Persistent urge to urinate
- Fever and chills if an infection is present
The patient must try to catch the stone in a strainer during urination.
III. Causes
The crystals that lead to kidney stones are likely to form when the patient’s urine contains a high concentration of certain substances — especially calcium, oxalate, uric acid and rarely, cystine — or low levels of substances that help prevent crystal formation, such as citrate and magnesium. Crystals also may form if the patient’s urine becomes too concentrated or is too acidic or too alkaline.
A number of factors can cause changes in the patient’s urine, including the effects of heredity, diet, drugs, climate, lifestyle factors and certain medical conditions. Each of the four main types of kidney stones has a different cause:
Roughly four out of five kidney stones are calcium stones. These stones are usually a combination of calcium and oxalate. Oxalate is a compound that occurs naturally in some fruits and vegetables. A number of factors can cause high concentrations of these substances in urine. Excess calcium, for instance, may result from ingesting large amounts of vitamin D, from treatment with thyroid hormones or certain diuretics, and from some cancers and kidney conditions. You may also have high levels of calcium if your parathyroid glands, which regulate calcium metabolism, are overactive (hyperparathyroidism). On the other hand, certain genetic factors, intestinal bypass surgery and a diet high in oxalic acid may cause excess amounts of oxalate in your body.
Found more often in women than in men, struvite stones are almost always the result of chronic urinary tract infections caused by bacteria that produce specific enzymes. These enzymes increase the amount of ammonia in the urine, which is incorporated in the crystals of struvite stones. These stones are often large, may have a characteristic stag's-horn shape and can seriously damage the patient’s kidneys.
These stones are formed of uric acid, a byproduct of protein metabolism. A patient is more likely to develop uric acid stones if he has undergone chemotherapy, consumes a high-protein diet or has certain genetic factors that predispose him to the condition.
These stones represent only a small percentage of kidney stones. They form in people with a hereditary disorder that causes the kidneys to excrete excessive amounts of certain amino acids (cystinuria).
Kidney stones vary in size and shape.
Golf-ball sized and round
Small and smooth
Jagged and yellow
IV. Material & Methods
Sample Preparation
Dissolve a sample as homogenously as possible of the urinary calculus to be analysed. From this solution the various components of the calculus are determined semi-quantitatively, the titrimetric method being used for calcium and a colorimetric method (ie. visual colour comparison) being used for oxalate, phosphate, magnesium, ammonium, uric acid and cysteine. The composition of the urinary calculus is obtained form the results of these determinations with the help of the test kit’s calculation aid.
1. 1. Finely triturate the calculus to be analysed in a motar.
2. 2. Mix the resultant powder thoroughly and using a spatula, transfer a tipful to a plastic boat.
3. 3. Add 5 drops of Sulfuric acid. Stir with spatula to ensure complete dissociation.
4. (Evolution of gas during dissolution indicates carbonate.)
5. 4. Transfer the solution into a 100ml graduate filed to one-third with distilled water.
6. 5. Make up to the 50ml mark with distilled water and mix well with the plastic boat.
7. 6. Transfer 5ml of the sample solution into each of several test tubes for other calculi composition testing, with the exception of Magnesium.
8. 7. For Magnesium testing, transfer 1 ml of the sample solution into another test tube with 4 ml DI water.
Individual calculi composition analysis
- Calcium
Reagents
Reagent 2: Sodium hydroxide solution 27%
Reagent 3: Calconcarboxylic acid tituration
Reagent 4: Titriplex III solution
Procedure
To the sample solution, add 2 drops of reagent 2 and one spatulaful of Reagent 3 and shake.
Continue shaking, and while doing so add reagent 4 drop by drop until the colour of the solution changes from red to blue. Count the drops required for the colour change to occur.
The number of drops required multiplied by 5 gives the percentage calcium content of the calculus.
- Oxalate
Reagents
Reagent 5: Borate buffer solution
Reagent 6: Iron (III) chloride solution
Reagent 7: Sulfosalicylic acid solution
Procedure
To the sample solution, add subsequently while shaking
2 drops of Reagent 5,
2 drops of Reagent 6,
3 drops of Reagent 7; allow to stand for 2 minutes.
Compare the colour of the solution with the appropriate colour scale and determine which of the reference colours most closely matches the colour of the solution, looking through the solution from the above process.
Read off the percentage oxalate content of the calculus.
- Ammonium
Reagents
Reagent 8: Potassium tetraiodomercurate (II)
Reagent 2: Sodium hydroxide solution 27%
Procedure
Add subsequently to the sample solution, while shaking,
3 drops of Reagent 8 and
3 drops of Reagent 2.
Compare the colour of the solution with the appropriate colour scale and determine which of the reference colours most closely matches the colour of the solution, looking through the solution from the above process.
Read off the percentage ammonium content of the calculus.
- Phosphate
Reagents
Reagent 9: Ammonium molybdate solution
Reagent 10: Reducing solution 4: methylaminophenol sulfayte soldium disulfite)
Procedure
Add subsequently to the sample solution, while shaking
5 drops of Reagent 9 and
5 drops of Reagent 10; Allow to stand for 5 minutes
Compare the colour of the solution with the appropriate colour scale and determine which of the reference colours most closely matches the colour of the solution, looking through the solution from the above process.
Read off the percentage phosphate content of the calculus.
- Magnesium
Reagents
Reagent 11: Buffer solution (borate buffer)
Reagent 12: Colour reagent (1-azo-2-hydroxy-3-(2, 4-dimethyl-carboxanilido)-napthalene-1’-2-hydroxylbenzene-5-sodium sulfonate) solution
Procedure
Pipette 1 ml of sample solution into a reaction vessel and make up to the calibration mark with distilled water. Add 10 drops of Reagent 11 and 10 drops of Reagent 12 while shaking.
After 1 minute, compare the colour of the solution with the appropriate colour scale and determine which of the reference colours most closely matches the colour of the solution, looking through the solution from the above process. Read off the percentage magnesium content of the calculus.
- Uric Acid
Reagents
Reagent 13: Molybdatophosphoric acid solution
Reagent 5 Borate buffer solution
Procedure
Add 3 drops of Reagent 13 to the sample solution, shake, and allow to stand for 2 minutes. Then add 2 drops of Reagent 5 and shake. Immediately compare the colour of the solution with the appropriate colour scale and determine which of the reference colours most closely matches the colour of the solution, looking through the solution from the above process. The colour comparison should be performed within 10 seconds after the addition of Reagent 5 to the sample solution because the colour is not stable and liable to change to blue.
Read off the percentage uric acid content of the calculus.
- Cystine
Reagents
Reagent 14: Ammonia solution
Reagent 15: Reducing agent (sodium sulphite)
Reagent 16: Sodium nitroprusside titruation
Procedure
To the sample solution, add 10 drops of Reagent 14 and a red dosing spoonful of Reagent 15, and swirl until dissolution is obtained. 1 minute after the addition of Reagent 15, add a black dosing-spoonful of Reagent 16, and again shake until dissolution is obtained. Compare the colour of the solution in the reaction vessel with the appropriate colour scale 30 seconds after the addition of reagent 16, and determine which of the reference colours most closely matches the colour of the solution, looking through the solution from the above process.
Read off the percentage cystine content of the calculus.
Result Reporting
Record down the percentage values for each of the calculi components on a result slip.
V. Conclusion
Urinary calculi analysis may sound tedious, but its actually very fun to perform....if there isn't much samples. Its like O'Level Chemistry practical..Qualitative Analysis. Hope it rings a bell.
I'm sure u got lotsa questions to ask. Just show some mercy ok? This topic is really vast. This message goes out especially to those from my workplace. . =P
Will upload more exciting photos soon. Stay tuned!
Kent LieowTG 010503261J
