1. Blood collection
Sample collection is done by trained scientific officers, phlebotomists, technicians and nurses. There are two methods for blood collection for hematology tests.
Capillary method (finger prick method) - Microtainer
Blood is usually obtained by pricking a finger. In case of babies, the big toe or heel may be used. Microtainer tubes with flo-top collectors and closure plugs and with a capacity 500ul are used for blood collection by finger prick method. Anticoagulant used is (K2) EDTA. Specimen can be stored in microtainer tubes (containing EDTA) for up to four hours prior to performing hematological determinations.
The blood is withdrawn from a forearm vein by means of a prevaccumed tube. To minimize the possibility of infection of personnel, evacuated tube system is used for the collection of venous blood. Tubes may contain anticoagulants in varying concentrations dependent upon the amount of vacuum and the required additives to blood ratio for the tube. The vacuum controls the amount of blood which enters the tube ensuring an adequate specimen for the subsequent tests and the correct proportion of anticoagulant when this is present. EDTA vacutainers are used for routine hemogram testing. Similarly samples are collected in respective containers for Biochemistry, Microbiology and other tests.
The skin is cleaned with spirit and allowed to dry before being punctured. Phlebotomist wears gloves during venipuncture and when handling blood collection tubes to minimize exposure hazard, then selects site for venipuncture, applies tourniquet, prepares venipuncture site with appropriate antiseptic. Thereafter phlebotomist places patients arm in downward position, remove needle shield, and performs venipuncture. Tourniquet is removed as soon as blood appears in the tube. When first tube has filled to its stated volume and blood flow ceases, it is removed from the holder. Used needles and syringes are disposed using an appropriate disposal device. Micro tape /sticker are applied at the puncture site.
2. Bone marrow aspirate and biopsy
Bone marrow procedures are performed by doctors from medical oncology in the minor operation theatre in Room Number 197, Third Floor, Golden Jubilee Building.
What is bone marrow?
In the center of most large bones there is a soft tissue (marrow) that makes all blood cells. Different types of blood cells are red blood cells, white blood cells, and platelets. Biopsy is done using a special needle. A local anesthetic agent is given before starting the procedure to reduce pain. The bone marrow sample is sent to different labs with requisition forms for microscopic examination, histopathology, immunophenotyping, cytogenetics and molecular studies.
Why do we do it?
It is usually performed for diagnosing the disease or to know the extent of spread of disease (staging). The sample is evaluated in different laboratories for presence of any disease.
What are the common risks associated with this procedure?
As with any surgical procedure, complications can occur, however, these are usually minor and are easily managed. These could be bruising and discomfort, prolonged bleeding or infections near the biopsy site.
Points to note before the procedure:
Physician/phlebotomist will explain the procedure to patient and offer the opportunity to ask any questions about the procedure. Verbal consent is taken before the procedure. Patient must inform physician if he/she is sensitive to or allergic to any medications and anesthetic agents (local and general). Notify physician if there is any history of bleeding disorders or if taking any anticoagulant medications or aspirin. It may be necessary for patient to stop these medications prior to the procedure. Patient may receive a sedative prior to the procedure to help him/her relax. Because the sedative may have side effects like drowsiness, patient will need to arrange for a companion.
How do we do it?
It is performed both as an outpatient and on an indoor basis. A bone marrow biopsy is commonly performed on the pelvic bone (posterior superior iliac spine). In a child, a leg bone may be used.
In the minor operation theatre (and in the wards), the patient is asked to lie on his side. The skin over the biopsy site is cleansed with an antiseptic solution. As the physician injects a local anesthetic to numb the area, patient feels a needle stick and a brief stinging sensation. A small incision may be made over the biopsy site and the biopsy needle is inserted into the bone marrow. A bone marrow aspiration is usually performed first. The physician uses a syringe to pull a small liquid sample of the bone marrow through the needle. The physician may remove a small, solid piece of bone marrow, called a core biopsy, using a special hollow needle. The biopsy needle is withdrawn and firm pressure is applied to the biopsy site for a few minutes, until the bleeding stops. A sterile bandage/dressing is applied. The bone marrow sample is divided and sent to different laboratories for examination.
Care after the procedure:
Once patient is out of operation theatre, he is advised to keep the biopsy area clean and dry and leave the bandage in place for as long as instructed by his physician (usually until the next day, when it can be removed at the time of bath). The biopsy site may be tender or sore for several days after the bone marrow biopsy. A pain reliever may be taken. Aspirin or certain other pain medications may increase the chance of bleeding. Be sure to take only recommended medications. Patient must contact physician if he/she develops fever, redness, swelling, bleeding or increased pain around the biopsy site. Patient may resume usual diet and activities unless your physician advises him/her differently.
The reports are dispatched to the respective wards/OPDs within the defined turn around time. Hemogram reports are attached to the case files within 2 hours of sample collection
Flow cytometer - FACS Calibur
This instrument helps us do immunophenotyping of peripheral blood and bone marrow samples in cases of leukemia and lymphomas helping us reach a correct diagnosis.