Haematology and Blood Transfusion

Haematology and Blood Transfusion

• 1939: Rhesus blood group was discovered, leading to the understanding of Haemolytic Disease of the Newborn (HDN)
• Other blood group systems are now known, highlighting the importance of studying Haematology and Blood Transfusion

Functions of the Haematology Laboratory

• Establish a diagnosis or rule out a diagnosis
• Confirm a physician's clinical impression of a possible hematological disorder
• Detect an unsuspected disorder
• Monitor the effects of therapy
• Detect minimal residual disease following therapy
• Perform functions like making a diagnosis, carrying out research, preparing safe blood products, and reporting laboratory results accurately

Safety in Haematology Laboratory

• Many conditions in the laboratory have the potential for causing injury to staff and damage to the building or community
• Managers and employees must be knowledgeable about safe work practices and incorporate these into the laboratory operation
• The key to preventing accidents and laboratory-acquired infections is a well-defined safety program

Biohazards and Chemical Hazards

• Biohazards include hepatitis B virus (HBV), hepatitis C virus, and human immunodeficiency virus (HIV)
• Chemical hazards must be handled with care to prevent accidents

Applicable Safety Practices Required by the OSHA Standard

• Handwashing is essential
• Eating, drinking, smoking, and applying cosmetics or lip balm are prohibited in the laboratory work area
• Hands, pens, and other fomites must be kept away from the worker's mouth and all mucous membranes
• Food and drink must not be kept in the same refrigerator as laboratory specimens or reagents
• Mouth pipetting is prohibited
• Needles and other sharp objects contaminated with blood and other potentially infectious materials must be handled with care
• Contaminated sharps must be placed in a puncture-resistant container with the universal biohazard symbol
• Procedures that may produce splashing, spraying, or droplets must be performed behind a barrier or with protective eyewear

Housekeeping and Disinfection

• Work surfaces must be cleaned when procedures are completed and whenever the bench area or floor becomes visibly contaminated
• An appropriate disinfectant solution is household bleach in a 1:10 volume/volume dilution (10%)
• Bleach solution must be made fresh daily and labeled properly
• Other solutions used to decontaminate include phenol-based disinfectants, tuberculocidal disinfectants, and 70% ethanol
• Documentation of the disinfection of work areas and equipment after each shift is required

Laundry and Personal Protective Equipment

• Non-disposable laboratory coats must be placed in appropriate containers for transport to the laundry
• Laboratory workers should receive the HBV vaccination series at no cost before or within 10 days after beginning work in the laboratory

Hepatitis B Virus Vaccination and Post-Exposure Evaluation

• Employees must sign a release form if they refuse the vaccination series
• Post-exposure evaluation and follow-up, including prophylaxis and medical consultation, should be made available at no cost to the employee

Training and Documentation

• Hematology staff should be properly educated in epidemiology and symptoms of bloodborne diseases, modes of transmission, use of protective equipment, and work practices
• Employees should be encouraged to report all exposure incidents, and such reporting should be enforced as standard policy

Blood Cell Counts and Their Clinical Applications

• RBC: Men: 4.5 – 5.5 x 10^12/L, Women: 3.8 – 4.8 x 10^12/L
• WBC-Total: 4.0 – 10.0 x 10^9/L
• WBC-Differential: Neutrophils: 2.0 – 7.0 x 10^9/L (40 – 80%), Lymphocytes: 1.0 – 3.0 x 10^9/L (20 – 40%)
• Blood cell counts have clinical applications in diseases such as Erythrocytosis, Leucopenia, Leucocytosis, Neutropenia, and Lymphocytosis