Urine acetone

Urine acetone by Mr.Manoj kumar Mehta

1. URINE ACETONE Mr.Manoj kumar Mehata

2. KETOSIS Whenever there is a defect in carbohydrate metabolism or absorption or an inadequate amount of carbohydrate in the diet, the body compensates by metabolizing increasing amounts of fatty acids. When this is increase is large, ketone bodies the products of incomplete fat metabolism , begin to appear in the blood known as ketonemia and is followed by kenonuria and kussmaul respiration (acetone breath).these all are collectively known as ketosis .

3. KETONE BODIES Ketones bodies are water soluble molecules produced by liver, intermediate product of fat metabolism, they are acetone, acetoacetic acid and beta hydroxybutyric acid. Ketone is found when there is excessive fat metabolism. excessive fat metabolism occurs in various situation Impaired ability to metabolize carbohydrate Inadequate carbohydrate intake Excessive carbohydrate loss Increased metabolic demand.

4. KETOGENESIS Acetyl coA + Acetyl coA acetoacetyl coA synthase Acetoacetyl coA HMG coA synthase b- hydroxy b-methyl glutaryl coA HMG coA lyase Acetoacetate decarboxylaton dehydrogenase acetone b- hydroxy butyrate

5. KETONURIA In ketonuria , the three ketone bodies present in the urine are Acetoacetic ( diaacetic ) acid (20%) Acetone (2%) 3-hydroxybutarate(about 78%) According to killander (1962) up to 2mg acetoacetic acid per deciliter is normal. Ketonemia and ketonuria are commonly seen in uncontrolled diabetes mellites , as well as several other conditions .

6. DIABETIC KETONURIA Ketonuria implies the presence of ketoacidosis (ketosis) and may provide a warning of impending coma. Upto 50mg of acetoacetic acid per deciliter may be present without clinical evidence of ketosis. Type 1 diabetic patients are prone to episodes of ketosis, often associated with infection ,stress or other problems in management. Whereas there are large amounts of ketones and glucose in urine in diabetic ketoacidosis, ketonuria is not found with the hyperosmolar hyperglycemic coma sometimes occuring in type 2 diabetics .

7. NON DIABETIC KETONURIA In infants and children, ketonuria commonly occurs in a variety of condition, such as acute febrile diseases and toxic states accompained by vomiting or diarrhoea . Inherited metabolic disease should be suspected when there is severe persistent neonatal ketosis. Ketonuria may be present in hyperemesis of pregnancy, in cachexia , and following anesthesia. In these case, ketoneuria is likely related to increased tissue (especially fat) catabolism in the face of limited food intake. In pregnancy, a normal patient may have a low fasting blood glucose level and mild ketonuria .

8. LACTIC ACIDOSIS Lactic acidosis may coexist with many conditions including shock diabetes mellitus, renal failure, liver disease , infections and in response to certain drugs, especially phenformin and salicylate poisoning. Acetoacetate and 3-hydroxybutyrate may both be highly elevated, although usually the butyrate is high and acetoacetate low. Under these circumstances, ketonuria may not be detected by usual nitroprusside test.

9. METHODS Rothera's test for acetone. Reagent strip test Nitroprusside tablet test Gerhard's test for diacetic acid Lindeman's test for diacetic acid Han’s method for beta- hydroxybutyric acid. Enzymatic method Flourometric technique and automatic colorimetric method

10. ROTHERA’S TEST Principle : Nitroprusside used in this test reacts with both acetone and acetoacetic acid in presence of alkali to produce purple ring at the junction. Requirements Test tubes dropper Rothera’s powder mixture Sodium nitroprusside:1gm Ammonium sulphate:20gm Sodium carbonate:20gm

11. Procedure Weigh out require amount of sodium nitropruside , ammonium sulphate and anhydrous sodium carbonate. Mix completely, but do not grind together. keep dry and it will keep for at least a year. Place a small pinch of powder on a white surface tile or in test tube and add 1 drop of urine. Acetone and acetoacetic acid give an immediate violet colour . Report as trace, (+) , (2+), (3+) as the intensity of purple colour . ROTHERA’S TEST

12. REAGENT STRIP TEST This method is based on a nitroprusside (sodium nitroferricyanide ) reaction for ketones. Different formulations are available. Reagent strips without alkali react to acetoacetic acid and not to acetone. With large (3+) results, urine may be diluted and remeasured , reporting a ‘moderate’ result and dilution factor.

13. Chemstrip reagent strip contains sodium nitroferricyanide and glycine, which react with acetoacetic acid and acetone in an alkaline medium to form a violet dye. A positive result is indicated by a colour change from beige to violet, which is read at 60 seconds. The method detects about 10mg/dl of acetoacetic acid and 70mg/dl of acetone, and the sensitivity and reaction of the reagent strip are similar to those of the tablet. Multistrip contains buffer and sodium nitroferricyanide , which react with acetoacetic acid ,producing a pink maroon color in 15 seconds. T he reagent area detects 5-10 mg acetoacetic acid per deciliter of urine. It does not react with acetone . REAGENT STRIP TEST

14. Disadvantages of reagent strip test False positive occurs : A fter use of phthaleins (BSP or PSP dyes) or in the presence of extremely large amounts of phenylketones and the preservatives 8-hydroxyquinoline or 1-dopa metabolites. Acetylcysteine (aerosol ) produces a strong red color. Antihypertensive drugs methyldopa and captopril give positive results. False negative results occur : loss of reagent reactivity Presence of salicylates REAGENT STRIP TEST

15. NITROPRUSSIDE TABLET TEST A tablet test method may be useful if the urine has interfering color. These are very sensitive to humidity and will deteriorate if not stored properly. The acetest tablet contains sodium nitroprusside , glycine, and a strongly alkaline buffer. It can be used to assay whole blood, plasma, serum or urine. Acetest will detect 5-10 mg of acetoacetic acid per deciliter of urine and 20-25mg acetone per deciliter of urine. Like the reagent strip, it does not react with 3-hydroxybutyrate. It will give positive results with 1-dopa and large amount of phenylketones and with BSP and PSP dyes, which react with the alkali in tablets .

16. Procedure for tablet test Place the tablet on a clean surface, preferbly a piece of white paper. Place one drop of urine, serum, plasma or whole blood on the tablet For urine measurement, compare the color of the tablet with a color chart at 30 seconds. For serum or plasma measurement, compare color of tablet with color chart at 2 minutes. For whole blood measurements, remove clotted blood from tablet and compare color of tablet with color chart, 10 minutes after application of the specimen.

17. If acetone and acetoacetic acid are present , the tablet will show a color varying from lavender to deep purple. Report the result as negative, small , moderate, or large. If large , a dilution may be made. Report these analyses in a form such as this undiluted “large” 1:2 dilution “large” 1:4 dilution “ moderate” etc.

18. Clinical Significance Increased In Diabetes mellitus Propanol poisoning Severe starvation. Severe carbohydrate restriction Anorexia Fasting Fever Prolonged vomiting Lactic acidosis Salicyclate toxicity .