Urine Analysis - Chemical PT PDF

URINE ANALYSIS CHEMICAL EXAMINATION OF THE URINE (1) REDUCING SUGARS IN URINE  Normally very small amounts of reducing sugars are present in urine which are not detected by reagents used However in some conditions the following reducing sugars are excreted in urine: Glucose in glyco...

URINE ANALYSIS CHEMICAL EXAMINATION OF THE URINE (1) REDUCING SUGARS IN URINE  Normally very small amounts of reducing sugars are present in urine which are not detected by reagents used However in some conditions the following reducing sugars are excreted in urine: Glucose in glycosuria Galactose in galactosemia Lactose in pregnancy and lactation. Fructose after ingestion of big amounts of fruits  Causes of Glucosuria: Diabetic glucosuria Non-diabetic glucosuria DM A- Glycosuria with B- Glycosuria without hyperglycemia: hyperglycemia: Hyperthyroidism. Renal Glycosuria. Increased ICP. Alimentary glycosuria. Emotional disturbances. Glycosuria of pregnancy. Detection of sugars in urine: Aim: test positive for reducing sugar They act in alkaline media at high temperature Steps: Put 2 ml of Benedict′s solution in test tube then add 0.5 ml urine. Boil over a flame for 2-3 minutes Result: Appearance of green, yellow, red, or brown precipitate indicates positive result (presence of a reducing sugar).  Diagnosis OF DM: 1-Measurement of fasting plasma glucose level (8-10 hr after last meal): a) 65-110 mg/dl normal blood glucose b) >126 mg/dl DM 2-Measurement of 2 hour postprandial plasma glucose level: a)65-140 mg/dl normal B)>200 mg/dl on two different occasions D.M 3- Random Plasma Glucose Test A random plasma glucose concentration of 200 mg/dl or higher in the presence of symptoms indicates diabetes 4- Glucose Tolerance Test (GTT) 5- Glycosylated HB (HB A1C)  Glucose tolerance test The ability to utilize carbohydrates can be determined by Glucose tolerance test. It is a laboratory method to check how the body breaks down (metabolizes) blood sugar , and how quickly it is cleared from the blood. Types of glucose tolerance test Standard Oral glucose tolerance test I/V Glucose tolerance test Mini Glucose tolerance test Indications of glucose tolerance test In asymptomatic persons with glucosuria. Persons with +ve family history of DM. Pregnant women at risk of DM. (Test is done at 24-28 week of gestation)  An overview of glucose tolerance test  Initially fasting blood glucose is estimated  A loading dose of glucose is given.  The blood glucose levels are estimated at regular intervals after the glucose load.  In conditions of insulin deficiency, blood glucose levels get elevated due to impaired utilization of glucose.  Procedure of oral GTT  At about 8 a.m. : the fasting blood and urine samples are collected. These are called zero samples.  A loading dose of 75 g. anhydrous glucose dissolved in 250-300 ml of water is given to the patient.  In the classical procedures: the blood and urine samples are collected at half hourly intervals of the next two and a half or three hours.  Glucose is estimated in all the blood samples.  Urine is analysed for the presence of glucose.  Glucose Tolerance Curve A curve is plotted with the blood glucose levels on the vertical axis against the time of collection on the horizontal axis. The curve so obtained is called glucose tolerance curve. Types of curves of OGTT 1. Normal curve. 2. Curve of IGT. 3. Curve of DM. Blood glucose Diabetic Curve (mg/Dl) Time in minutes  Mini or Modern GTT  As per current WHO recommendations, in the mini or modern glucose tolerance test, only two samples are collected, fasting (zero hour) and 2 hour post glucose load.  Urine samples are also collected during the same time.  The diagnosis is made from the variations observed in these results. Criteria for diagnosis of DM Fasting Blood Glucose 2 hours Postprandial > 8 hr fast blood Glucose Normal 65-110 mg/dl 65-140 mg/dl Pre- Diabetes 110 – 126 mg/dl >140 – 200 mg/dl DM > 126 mg/dl > 200 mg/dl on 2 occasions  IGT and IFT recently termed “pre-diabetic”  Glycosylated HB (HB A1C)  Hemoglobin A is the major hemoglobin in adults (97%)  Glycosylated Hb is a reaction between the Hb and glucose without enzyme  Its level in red cell is directly proportional to blood glucose concentration months (life span of R.B.Cs).  Normal Hb A1C 4-6 %  In diabetic person: above 6.5 % and may reach 12% or more of total HB A.  this test used as index of diabetic control over 2-3 months. Hence people with hemolytic anemia and sickle cell disease are not suitable for this test. THANK YOU