PMLSP-2-LEC_REVIEWER_2ND-SEM.-PRELIMS

Principles of Medical Laboratory Practice 2

Coverage

  • Understanding Phlebotomy

  • Circulatory System

Phlebotomy

Definition & History

  • Phlebotomy: "Phleb" (vein) + "Otomy" (incision) = cutting a vein.

  • Historical practice of bloodletting.

Methods

  • Venesection: Cutting vein to reduce blood volume.

  • Cupping: Using suction to draw blood to the skin, followed by incisions.

Evolution of Phlebotomy

  • Leeches: Used for blood removal and pain relief.

  • Therapeutic Phlebotomy: Treats conditions like polycythemia and hereditary hemochromatosis (removes ~500 mL blood).

  • Diagnostic Phlebotomy: Blood collection for laboratory testing.

Techniques

  • Venipuncture: Collection from a vein.

  • Capillary Collection: Small samples via fingerstick or heelstick.

Role of a Phlebotomist

  1. Primary Duty: Blood collection.

  2. Other Duties:

    • Patient care

    • Sample processing

    • Receptionist tasks

    • Computer work

    • Laboratory representation

  3. Pre-analytical Phase: Proper collection for accurate diagnosis.

Types of Laboratories

Features

  • Centralized Lab: Longer turnaround, lower cost, high volume, advanced equipment.

  • Decentralized Lab: Faster turnaround, higher cost, lower volume, limited equipment.

  • Hybrid Lab: Balanced characteristics.

Traits of a Professional Phlebotomist

Education & Certification

  • ASCP Certification required in some states.

  • License Categories:

    • Limited Phlebotomy Technician: 25 skin punctures.

    • Phlebotomy Tech I: 50 venipunctures, 10 skin punctures, certification + exam.

    • Phlebotomy Tech II: Technician I + 20 arterial punctures.

Professionalism

  • Neat appearance, calm demeanor, no rushing.

Dress Code

  • No visible tattoos/piercings, fingernails ≤ ¼ inch, scrub suits only.

Healthcare Professionals in the Lab

  1. Phlebotomist → Lab Assistant → Medical Laboratory Technician (MLT)

  2. Histologic Technician: Degree + 1 year training → Certification Exam.

  3. Cytotechnologist: Degree + 12 months training → Certification Exam.

  4. Medical Laboratory Scientist (MLS/CLS): Degree + clinical training → Certification.

  5. Pathologist: Physician specialized in pathology.

Common Certifications

Medical Technologists

  • MLS (ASCP)– Medical Laboratory Scientist.

  • MT (AMT)– Medical Technologist.

Medical Laboratory Technicians

  • MLT (ASCP)– Medical Laboratory Technician.

  • MLT (AMT)– Medical Laboratory Technician.

Phlebotomists

  • PBT (ASCP) – Phlebotomy Technician.

  • RPT (AMT) – Registered Phlebotomy Technician.

  • CPT (ASPT) – Certified Phlebotomy Technician.

  • CPT (NPA) – Certified Phlebotomy Technician.

Communication in Healthcare

Effective Communication

  1. Verbal & Non-verbal communication.

  2. Respect for diversity.

  3. Professional behavior.

  4. Patient-centered approach.

Patient's Bill of Rights

  1. Show concern for patients, even irritable ones.

  2. Explain tests are physician-ordered.

  3. Inform patients about procedures.

  4. Respect the right to refuse blood collection.

  5. Keep patient information confidential.

  6. Provide access to medical records.

  7. Expedite sample processing for timely results.

Types of Healthcare Settings

  • General Departments: Administration, Laboratory, Pharmacy, etc.

  • Specialty Units: ICU, Emergency Department, Oncology, Obstetrics, Geriatric.

Clinical Laboratory Areas

Phases of Sample Testing

  1. Pre-examination: Collection, identification, transport, preparation.

  2. Examination: Performing tests using machines/manual methods.

  3. Post-examination: Delivering results, ensuring accuracy.

Common Sample Issues

  • Lipemic Sample: Milky appearance, high cholesterol.

  • Hemolyzed Sample: Reddish due to RBC rupture.

  • Normal Serum Sample: Clear without contamination.

Laboratory Functions

  • Hematology: Blood cell counts, disorders.

  • Coagulation: Blood clotting studies.

  • Urinalysis: Urine analysis for infections.

  • Chemistry: Tests for glucose, cholesterol.

  • Microbiology: Detect bacteria, viruses.

  • Immunology: Antibody testing.

  • Immunohematology: Blood typing.

  • Cytogenetics: Chromosome analysis.

  • Molecular Diagnostics: DNA-based testing.

  • STAT Lab: Immediate testing for emergencies.

Handling Patient Situations

  1. For test result requests: Only physician can discuss results.

  2. If a patient refuses blood extraction: Explain necessity, notify nurse.

  3. If patient doubts a doctor’s request: Confirm orders with physician if needed.

Quick Review: Heart and Circulation

  • Heart: Pumps blood, muscular organ.

  • Blood Vessels: Transport structures.

  • Septum: Divides heart into sides.

Heart Chambers

  • Right Atrium (RA): Receives deoxygenated blood.

  • Right Ventricle (RV): Pumps blood to lungs.

  • Left Atrium (LA): Receives oxygenated blood.

  • Left Ventricle (LV): Pumps to the body.

Heart Layers

  • Endocardium: Smooth inner lining.

  • Myocardium: Muscular layer.

  • Epicardium: Outermost layer.

Heart Valves

  • AV Valves: Prevent backflow, includes Tricuspid and Bicuspid.

  • Semilunar Valves: Control flow to arteries, includes Pulmonary and Aortic.

Heart Functions

  • Cardiac Cycle: Systole and diastole.

  • Electrical Conduction System: Heart rhythm control.

  • ECG: Heart's electrical activity recording.

  • Heart Rate: ~72 beats/min.

  • Cardiac Output: Blood pumped per minute.

  • Blood Pressure: Force on vessel walls.

Heart Disorders

Key Disorders

  • Angina Pectoris: Chest pain from reduced blood flow.

  • Aortic Stenosis: Narrowing of aortic valve.

  • Congestive Heart Failure: Weak heart pumping.

  • Myocardial Infarction: Heart attack from artery blockage.

  • Pericarditis: Inflammation of the pericardial sac.

Blood Circulation Types

  • Coronary Circulation: Oxygenates heart muscle.

  • Pulmonary Circulation: Transfers blood to lungs.

  • Systemic Circulation: Distributes blood to body.

Blood Vessels

Structure

  • Tunica Intima: Smooth inner layer.

  • Tunica Media: Thick middle layer.

  • Tunica Adventitia: Protective outer layer.

Common Veins for Phlebotomy

  • Median Cubital Vein: Best for venipuncture.

  • Cephalic Vein: Second best choice.

  • Basilic Vein: Least preferred.

Composition of Blood

  • Plasma (55%): Transports nutrients, hormones.

  • Red Blood Cells (RBCs): Carry oxygen.

Blood Cells & Functions

  • RBCs: Most numerous, 120-day lifespan.

  • WBCs: Defend against infection, various types.

  • Platelets: Smallest component, promote clotting.

Blood Disorders

Common Disorders

  • Anemia: Low RBC/hemoglobin, fatigue symptoms.

  • Leukemia: Cancer of WBCs, abnormal cell production.

  • Polycythemia: Excessive RBC production.

  • Leukopenia: Low WBC count, increased infection risk.

Blood Pressure & Measurement

Blood Pressure Categories

  • Normal: <120/80 mmHg

  • Elevated: 120-129/<80 mmHg

  • Hypertension Stage 1: 130-139/80-89 mmHg

  • Hypertension Stage 2: 140+/90+ mmHg

  • Hypertensive Crisis: 180+/120+ mmHg

ABO Blood Group System

  • Type A: A antigen, anti-B antibody.

  • Type B: B antigen, anti-A antibody.

  • Type AB: A & B antigens, none (universal recipient).

  • Type O: None, anti-A & anti-B (universal donor).

Lymphatic System

Functions

  • Lymph Nodes: Filter harmful substances.

  • Tonsils: Prevent throat infections.

  • Spleen: Removes old RBCs.

  • Thymus: Produces T-cells.