الرئيسية
INTRODUCTION TO PRACTICAL HAEMATOLOGY
Introduction:-
In the past humankind know about presence of blood, but a few centuries back science discovered that this blood circulates in our body. In Greek, Roman, and Unani medicine describe some disease due to blood abnormalities into: traumatic, inflammatory, infective, and neoplastic.
DEFINATION OF BLOOD:
Blood is highly specialized (sterile) connective tissues, which circulate in a closed system of vessels as a liquid with red coluor, but in out this system a solid phase will perform, which we called plug or blood clot.
Haematology: is the science that study the blood, and it's structure, function, disease, and the convenience between structure and the function.
BLOOD COMPONENT
Mainly we can divide blood into two parts:
1) Plasma 2) Blood cells.
The total amount of blood approximately 1/14 of the total body weight or 60-70 ml/ each kilogram of body weight.
Blood flows through every organ of the body providing effective communication between tissues.
PLASMA:
Plasma is a pale yellow fluid in which blood cells are suspended in.
Plasma forms about 55% of blood volume and composed of 95%or more water, and many solutes including proteins, minerals, ions, organic materials, hormones, enzymes, products of digestion, and waste products.
BLOOD CELLS:
1) Red blood cells (RBC).
2) White blood cells (WBC).
3) Platelets.
FUNCTION OF BLOOD:
□ Transportation and distribution:
- Oxygen transportation by haemoglobin from lungs to the tissues.
- Blood also can transport the nutrients absorbed by the digestive system to the tissues for use or storage.
- Hormones are carried from endocrine glands to the organs.
- Wastes are transported from tissues for excretion e.g.: carbon , dioxide, urea, createnine,…
□ Regulatory:
- Plasma maintain the PH. of blood (7.35-7.45), and in the tissues .
- Osmotic pressure in plasma is regulate by proteins and salts (sodium, chloride) to prevent excessive loss of fluids from the blood into tissues.
- Regulation of the body temperature.
□ Protective:
- Platelets and coagulation factors control the blood loss by thrombous formation.
- Leukocytes defend and produce antibodies and toxin against infection and tumor cells.
HAEMATOPOIESIS:
In normal healthy person there is a constant break down and new formation of cells, and the procedure of blood cells formation called Haematopoiesis.
NORMAL SITES OF BLOOD FORMATION:
- Fetus:
* Less than 2 months: in Yolk sac.
* 2-7 months: in the liver and a few in the spleen.
* Full term: in bone marrow for RBC, PLTs, and granulocytes, but lymphocytes and monocytes occures in spleen, lymph nodes and lymphoid tissues (liver and bone marrow with less numbers).
- After birth:
Mainly from bone marrow even monocytes, except lymphocytes still from spleen and lymph tissues.
- In adult:
Main sites of haematopoiesis are the vertebrae, ribs, sternum, skull bones, pelvis, sacrum, and proximal ends of femur and humerus.
Haematopoiesis can be sub-divided into 3 stages:
1) Mesoblastic period.
2) Hepatic period.
3) Myeloid period.
ABNORMAL SITES OF HAEMATOPOIESIS:
In certain disorders the fetal haematopoitic organs revert to their old function supported by the reticulum cells, this occurs when bone marrow can not fulfill the requirements or demand for new cells, this called EXTRA-MEDALLARY haematopoiesis, (Myeloid metaplasia).
In some rare cases adrenal glands, cartilages, adipose tissues, intra thoracic areas, kidneys, and endo-sternum can produce blood cells.
PRE-ANALYSIS MANAGEMENT
The clinical laboratory is useful to assist in diagnosis, and management of patient.
A test request is a request for consultative services, to generate a laboratory report using to make clinical judgments.
- Understanding of the test process and procedures, collection, and handling enables the laboratory staff to achieve more nearly optimal conditions and consequently to improve the accuracy and precision of each measurement.
REASONS FOR ORDERING LAB. REQUEST:
1) To confirm a clinical impression or diagnosis.
2) To rule out a diagnosis.
3) To monitor therapy.
4) To establish prognosis.
5) To screen for or detect disease.
TEST REQUESTATION:
The physician initiates the test request by writing an order for lab. examinations in the patient medical chart/record.
- The orders are carry out to an appropriate lab. request form by the nursing station or secretary unit.
- Each laboratory form has a list of test with reference intervals and a space for the result.
- Patient data (demographics) include, patient name, sex, age, date of admission, date of test ordering, room number,……..must be clearly writing on the request, or patient's addressograph plate or computerized label are stamped onto the request.
- The requests are given to the collect unit or to the phlebotomist /nurse to draw the specimen, specimen tube must be labeled be for the specimen is drawn.
☼ It is essential to follow strict quality control procedures through all stages of test request to avoid several possible errors, such as, incorrect or missing test entering, ……
- All requests should have a full, clear patient data, and correct sample labeling.
- Samples quantity and anticoagulant should be suitable, and with no haemolysis, or clot.
BLOOD SPECIMEN COLLECTION:
A. SKIN PUNCTURE:
Skin puncture is the method of choice in pediatric patients, especially infants.
- Skin puncture can be used in adults with:
* extreme obesity.
* sever burn.
* thrombotic tendencies.
Technique:
1) Select an appropriate puncture site, lateral or medial plantar heel surface for infants, in older infants the palmer surface of the last digit of the second, third, or forth fingers (big toe, and ear lobe can be used).
-The site of puncture must not be edematous or a previous puncture site.
2) Warm the puncture site with a warm moist towel, and clean the puncture site with 70%of aqueous isopropanol solution, allow the area to dray.
3) Make the puncture with a sterile lancet with blade no longer than 2.4 mm.
4) Discard the first drop of blood by wiping it away with a sterile pad.
5) Collect the specimen in a suitable container (oral aspiration of blood is discouraged for a safety reasons ).
5) Label the specimen container.
B. VENOUS PUNCTURE:
Technique:
1) Identify the patient by checking identification card against the request, ask the conscious patient his/her full name and birth date (do not draw any specimen without properly identification).
2) If fasting specimen is required , confirm that the fasting order has been followed.
3) Inform the patient, what is to be done and reassure the patient to avoid as much tension as possible.
4) Position the patient properly for easy, comfortable access to the antecubital fossa.
5) Assemble equipments and supply (tubes, tourniquet, syringes…..).
6) Ask the patient to make a fist –to make the veins more palpable – then select a suitable vein (veins of atecubital fossa , in particular the median and cephalic veins are preferred), wrist , ankle, and hands veins may also be used.
If one arm has an intravenous line , use the other arm to draw a blood sample.
7) Clean the venipuncture site with 70%isopropyl alcohol solution in a circular motion and allow the area to dray.
Apply a tourniquet above the puncture site, "never leave the tourniquet longer than 1min.
9) Use your thumb and middle finger or thumb and the index finger, to anchor the vein.
10) Enter the skin with the bevel of the needle at 15 degree angle, to the arm with the arm, with the bevel up , insert the needle smoothly, and fairly fast.
- If using a syringe pull pack on the barrel with a slow until the blood flows into the syringe (do not pull back too quickly to avoid the haemolysis or collapsing the vein).
- If using a vacutainer, as soon as the needle is in the vein ease the tube fore ward in the holder, at the same time hold the needle firmly in place.
11) At the end of the collection release the tourniquet.
12) After all blood samples have been drawn, have the patient relax his fist.
13) Place a clean, sterile, dray cotton ball over the site and withdraw the needle , and apply a pressure to the site , and bandage the arm.
14) Mix the blood with the anticoagulant.
15) Check the patient condition e.g.: whither he is faint, bleeding is under control,…..
16) Dispose the contaminated materials.
C. ARTERIAL PUNCTURE:
Arterial blood is used to measure oxygen, carbon dioxide , and measuring PH.,…
Arterial punctures are technically more difficult to perform.
Technique:
1) Select the puncture site, the radial artery is the most common site, if the ulnar artery is absent, do not puncture the radial artery (use the Allen test to make sure of collateral circulation ).
The femoral artery and the brachial artery, at the antecubital fossa provide alternative sites for puncture, scalp arteries are used in infant.
2) Anesthetized the puncture site if necessary, prepare the syringe by aspirate an anticoagulant (usually heparin).
3) Record the patient temperature and perform Allen test (for radial artery puncture) as follow:
- compress the radial and ulnar arteries at the wrist until the palm of the hand becomes blanched.
- Release the pressure from ulnar artery and observe that the hand becomes flushed, if the hand remains blanched DO NOT puncture the radial artery.
4) Clean the site, place a finger over the artery and puncture the skin 5-10mm. distal to the finger .
- Blood rushing into the needle, or pull back on the plunger and obtain the required amount of the blood.
5) Quickly withdraw the needle and syringe , place a sterile cotton ball or dry gauze over the puncture site.
6) Apply firm pressure for at least 5 min.
7) Expel any air bubble from the syringe.
Remove the needle and cap it with a tight – fitting "Luer cap" and mix the anticoagulant by gentile inversing of the syringe.
9) Label the sample and place it in an ice/ice water bath.
10) Transport the sample on ice immediately to the lab.
* Drawing problems:
Occasionally, the phlebotomists are unable to obtain blood by ordinary venipuncture.
- In some cases a skin puncture may suffice; if not, a physician draws the specimen using most commonly the femoral vain or jugular vain in children.
Introduction:-
In the past humankind know about presence of blood, but a few centuries back science discovered that this blood circulates in our body. In Greek, Roman, and Unani medicine describe some disease due to blood abnormalities into: traumatic, inflammatory, infective, and neoplastic.
DEFINATION OF BLOOD:
Blood is highly specialized (sterile) connective tissues, which circulate in a closed system of vessels as a liquid with red coluor, but in out this system a solid phase will perform, which we called plug or blood clot.
Haematology: is the science that study the blood, and it's structure, function, disease, and the convenience between structure and the function.
BLOOD COMPONENT
Mainly we can divide blood into two parts:
1) Plasma 2) Blood cells.
The total amount of blood approximately 1/14 of the total body weight or 60-70 ml/ each kilogram of body weight.
Blood flows through every organ of the body providing effective communication between tissues.
PLASMA:
Plasma is a pale yellow fluid in which blood cells are suspended in.
Plasma forms about 55% of blood volume and composed of 95%or more water, and many solutes including proteins, minerals, ions, organic materials, hormones, enzymes, products of digestion, and waste products.
BLOOD CELLS:
1) Red blood cells (RBC).
2) White blood cells (WBC).
3) Platelets.
FUNCTION OF BLOOD:
□ Transportation and distribution:
- Oxygen transportation by haemoglobin from lungs to the tissues.
- Blood also can transport the nutrients absorbed by the digestive system to the tissues for use or storage.
- Hormones are carried from endocrine glands to the organs.
- Wastes are transported from tissues for excretion e.g.: carbon , dioxide, urea, createnine,…
□ Regulatory:
- Plasma maintain the PH. of blood (7.35-7.45), and in the tissues .
- Osmotic pressure in plasma is regulate by proteins and salts (sodium, chloride) to prevent excessive loss of fluids from the blood into tissues.
- Regulation of the body temperature.
□ Protective:
- Platelets and coagulation factors control the blood loss by thrombous formation.
- Leukocytes defend and produce antibodies and toxin against infection and tumor cells.
HAEMATOPOIESIS:
In normal healthy person there is a constant break down and new formation of cells, and the procedure of blood cells formation called Haematopoiesis.
NORMAL SITES OF BLOOD FORMATION:
- Fetus:
* Less than 2 months: in Yolk sac.
* 2-7 months: in the liver and a few in the spleen.
* Full term: in bone marrow for RBC, PLTs, and granulocytes, but lymphocytes and monocytes occures in spleen, lymph nodes and lymphoid tissues (liver and bone marrow with less numbers).
- After birth:
Mainly from bone marrow even monocytes, except lymphocytes still from spleen and lymph tissues.
- In adult:
Main sites of haematopoiesis are the vertebrae, ribs, sternum, skull bones, pelvis, sacrum, and proximal ends of femur and humerus.
Haematopoiesis can be sub-divided into 3 stages:
1) Mesoblastic period.
2) Hepatic period.
3) Myeloid period.
ABNORMAL SITES OF HAEMATOPOIESIS:
In certain disorders the fetal haematopoitic organs revert to their old function supported by the reticulum cells, this occurs when bone marrow can not fulfill the requirements or demand for new cells, this called EXTRA-MEDALLARY haematopoiesis, (Myeloid metaplasia).
In some rare cases adrenal glands, cartilages, adipose tissues, intra thoracic areas, kidneys, and endo-sternum can produce blood cells.
PRE-ANALYSIS MANAGEMENT
The clinical laboratory is useful to assist in diagnosis, and management of patient.
A test request is a request for consultative services, to generate a laboratory report using to make clinical judgments.
- Understanding of the test process and procedures, collection, and handling enables the laboratory staff to achieve more nearly optimal conditions and consequently to improve the accuracy and precision of each measurement.
REASONS FOR ORDERING LAB. REQUEST:
1) To confirm a clinical impression or diagnosis.
2) To rule out a diagnosis.
3) To monitor therapy.
4) To establish prognosis.
5) To screen for or detect disease.
TEST REQUESTATION:
The physician initiates the test request by writing an order for lab. examinations in the patient medical chart/record.
- The orders are carry out to an appropriate lab. request form by the nursing station or secretary unit.
- Each laboratory form has a list of test with reference intervals and a space for the result.
- Patient data (demographics) include, patient name, sex, age, date of admission, date of test ordering, room number,……..must be clearly writing on the request, or patient's addressograph plate or computerized label are stamped onto the request.
- The requests are given to the collect unit or to the phlebotomist /nurse to draw the specimen, specimen tube must be labeled be for the specimen is drawn.
☼ It is essential to follow strict quality control procedures through all stages of test request to avoid several possible errors, such as, incorrect or missing test entering, ……
- All requests should have a full, clear patient data, and correct sample labeling.
- Samples quantity and anticoagulant should be suitable, and with no haemolysis, or clot.
BLOOD SPECIMEN COLLECTION:
A. SKIN PUNCTURE:
Skin puncture is the method of choice in pediatric patients, especially infants.
- Skin puncture can be used in adults with:
* extreme obesity.
* sever burn.
* thrombotic tendencies.
Technique:
1) Select an appropriate puncture site, lateral or medial plantar heel surface for infants, in older infants the palmer surface of the last digit of the second, third, or forth fingers (big toe, and ear lobe can be used).
-The site of puncture must not be edematous or a previous puncture site.
2) Warm the puncture site with a warm moist towel, and clean the puncture site with 70%of aqueous isopropanol solution, allow the area to dray.
3) Make the puncture with a sterile lancet with blade no longer than 2.4 mm.
4) Discard the first drop of blood by wiping it away with a sterile pad.
5) Collect the specimen in a suitable container (oral aspiration of blood is discouraged for a safety reasons ).
5) Label the specimen container.
B. VENOUS PUNCTURE:
Technique:
1) Identify the patient by checking identification card against the request, ask the conscious patient his/her full name and birth date (do not draw any specimen without properly identification).
2) If fasting specimen is required , confirm that the fasting order has been followed.
3) Inform the patient, what is to be done and reassure the patient to avoid as much tension as possible.
4) Position the patient properly for easy, comfortable access to the antecubital fossa.
5) Assemble equipments and supply (tubes, tourniquet, syringes…..).
6) Ask the patient to make a fist –to make the veins more palpable – then select a suitable vein (veins of atecubital fossa , in particular the median and cephalic veins are preferred), wrist , ankle, and hands veins may also be used.
If one arm has an intravenous line , use the other arm to draw a blood sample.
7) Clean the venipuncture site with 70%isopropyl alcohol solution in a circular motion and allow the area to dray.
Apply a tourniquet above the puncture site, "never leave the tourniquet longer than 1min.9) Use your thumb and middle finger or thumb and the index finger, to anchor the vein.
10) Enter the skin with the bevel of the needle at 15 degree angle, to the arm with the arm, with the bevel up , insert the needle smoothly, and fairly fast.
- If using a syringe pull pack on the barrel with a slow until the blood flows into the syringe (do not pull back too quickly to avoid the haemolysis or collapsing the vein).
- If using a vacutainer, as soon as the needle is in the vein ease the tube fore ward in the holder, at the same time hold the needle firmly in place.
11) At the end of the collection release the tourniquet.
12) After all blood samples have been drawn, have the patient relax his fist.
13) Place a clean, sterile, dray cotton ball over the site and withdraw the needle , and apply a pressure to the site , and bandage the arm.
14) Mix the blood with the anticoagulant.
15) Check the patient condition e.g.: whither he is faint, bleeding is under control,…..
16) Dispose the contaminated materials.
C. ARTERIAL PUNCTURE:
Arterial blood is used to measure oxygen, carbon dioxide , and measuring PH.,…
Arterial punctures are technically more difficult to perform.
Technique:
1) Select the puncture site, the radial artery is the most common site, if the ulnar artery is absent, do not puncture the radial artery (use the Allen test to make sure of collateral circulation ).
The femoral artery and the brachial artery, at the antecubital fossa provide alternative sites for puncture, scalp arteries are used in infant.
2) Anesthetized the puncture site if necessary, prepare the syringe by aspirate an anticoagulant (usually heparin).
3) Record the patient temperature and perform Allen test (for radial artery puncture) as follow:
- compress the radial and ulnar arteries at the wrist until the palm of the hand becomes blanched.
- Release the pressure from ulnar artery and observe that the hand becomes flushed, if the hand remains blanched DO NOT puncture the radial artery.
4) Clean the site, place a finger over the artery and puncture the skin 5-10mm. distal to the finger .
- Blood rushing into the needle, or pull back on the plunger and obtain the required amount of the blood.
5) Quickly withdraw the needle and syringe , place a sterile cotton ball or dry gauze over the puncture site.
6) Apply firm pressure for at least 5 min.
7) Expel any air bubble from the syringe.
Remove the needle and cap it with a tight – fitting "Luer cap" and mix the anticoagulant by gentile inversing of the syringe.9) Label the sample and place it in an ice/ice water bath.
10) Transport the sample on ice immediately to the lab.
* Drawing problems:
Occasionally, the phlebotomists are unable to obtain blood by ordinary venipuncture.
- In some cases a skin puncture may suffice; if not, a physician draws the specimen using most commonly the femoral vain or jugular vain in children.
