1.Enumerate the tests for detection of blood in urine?
Microscopic examination for RBC’s
Chemical test for blood
Physical examination – Reddish or smokey appearance of urine
Spectroscopic examination for hemoglobin
2. What is the chemical test for occult blood?
Benzidine test
Orthotoluidine test
Dipstick test
3. What is the principle of Benzidine test?
Hemoglobin has peroxidase activity which releases nascent oxygen from H2O2 . Nascent oxygen oxidizes Benzidine in acid solution to form blue dye
4. What is the procedure of Benzidine test
Take 2ml of Glacial acetic acid saturated with Benzidine and add 2ml of H2O2
To this add 4ml of urine in test tube
Development of blue color indicates the presence of occult blood or hemoglobin
5. What is the procedure for Orthotoluidine test
Pinch of Orthotoluidine is dissolved in 2ml of Glacial acetic acid in a test tube
Add 10 – 15 drops of urine and shake well
Add 4ml of 30% of H2O2
Interpretation : Development of greenish blue color indicates the presence of hemoglobin or occult blood
6. What is hematuria?
Hematuria is condition where intact RBCs of more than 10/high power field are in urine which are revealed under microscope or by naked eye examination of fresh specimen of urine
7. What is hemoglobinuria?
When hemoglobin is present in urine, condition is called as hemoglobinuria
When the hemoglobin concentration of plasma exceeds the haptoglobin binding capacity of plasma, hemoglobin is filtered out of glomeruli and appear in urine
8. What are the causes of hemoglobinuria?
Paroxysmal nocturnal hematuria
Extensive burns
Marching hemoglobinuria
Autoimmune hemolytic anemia
Black water fever
Snake venom poisoning
Mismatch blood transfusion
Gas gangrene
Drug sensitivity of Quinine , sulphonamide
9. What are the causes of hematuria?
Pre renal causes
Acute febrile illness
Subacute bacterial endocarditis
Malignant hypertension
Blood dyscrasia, hemophilia, leukemia, purpura
Anticoagulant therapy
Drug reactions with salicylates
Renal causes
Glomerulonephritis
Acute pyelonephritis
Renal calculi
TB kidney
Hydronephrosis
Renal carcinoma
Wilms tumor
Renal vein thrombosis
Post renal causes
Hemorrhagic cystitis
Carcinoma prostate
Carcinoma bladder
Salpingitis
10. What is myoglobinuria and in what are the conditions causing myoglobinuria?
Presence of myoglobin (red – brown pigment) in urine is called myoglobinuria
Occurs in acute destruction of muscle during which myoglobin is released in the blood and excreted rapidly in urine
11. How can we detect myoglobin in urine ?
Spectroscopic and electrophoretic study
By
Dr.Shanthi Vissa, Associate professor, Pathology, Sri Venkateswara Institute Of Medical Sciences, Tirupathi.
Dr. Byna Shyam Sundar Rao, Professor, Pathology, Narayana Medical College, Nellore