LABORATORY SAFETY, INSTRUMENTATION AND QUALITY MANAGEMENT SYSTEM IN HISTOPATHOLOGIC LABORATORY Flashcards
art of analyzing and interpreting the shapes, sizes and architectural patterns of cells and tissues within a given specific clinical background
Histopathology
art and science performed by the histotechnologist to produce a tissue section of good quality
Histotechnology
basic concepts about the principles and technicalities involved in histopathologic procedures
Histopathologic techniques
Provide skills in tissue preparation from fresh to properly mounted specimen
Histopathologic techniques
comprised of a number of glass beakers for filling different processing chemicals
Automatic Tissue Processor
a timing disc which rotates after specific intervals, and a specimen container holding assembly
Autotechnicon or Automatic Tissue Processor
Microtome is an instrument with the help of which sections of tissues are cut and the process of cutting thin sections is known
Microtomy
one of the important machines required in histopathology for processing organ and tissues before being embedded in paraffin wax
Automatic Tissue Processor
a refrigerated apparatus used in fresh tissue microtomy, for freezing the tissue into the block holder to correct degree of hardness to facilitate easier and faster sectioning
Cryostat
consist of a microotome, kept inside the cold chamber which has been maintained at a temp bet ____
Cryostat
-5°C to -30°C. (average -20°C)
used to float paraffin ribbons, to stretch sections and remove wrinkle
Tissue water bath
water temperature should be about _____ degrees below the melting point of paraffin
TISSUE WATER BATH
10°C
Drying or Dehydrating tissue samples
Laboratory oven
Used for removing moisture from samples
Laboratory Oven
optimizes times during stain process to maximize efficiency in obtention of results for a timely diagnosis
Automated Tissue Stainer
one piece of equipment that is used by both the pathologist and the histotechnologist
Microscope
examines the slide under the microscope to identify a disease process or an abnormality that will directly affect the patient’s treatment
Pathologist
examines the same slide microscopically for quality control to determine whether all technical processes are done properly and if a slide of diagnostic quality has been achieved
Histotechnologist
microscope must accomplish
three things
1) magnify the object
2) resolve the details of the object
3) make these details visible
microscope with more than
one lens and its own light
source
Compound microscope
there are ocular lenses in the
binocular eyepieces and objective lenses in a rotating nosepiece closer to the specimen
Compound Microscope
3 kinds of viewing heads of compound microscope
Monocular heads
Binocular heads
Trinocular heads
are light weight and are inexpensive
Monocular microscope
most common choice for microscope with two eyepieces and are more convenient and comfortable to use
Binocular heads
more expensive with third eyepiece tube that can be used by another person simultaneously or by an LCD camera
Trinocular heads
more expensive with third eyepiece tube that can be used by another person simultaneously or by an LCD camera
Trinocular heads
(5) main framework of compound microscope:
Base
Arm
Stage
Substage
Mechanical Stage
provides support for the microscope
Base
large and solid enough to allow the microscope to stand by itself
Base
supports and holds the magnifying and adjustment system. It can be used as a handle for carrying the microscope
Arm
flatplatformwherethe slide is placed for examination
Stage
located directly under the stage and holds the condenser and diaphragm.
Substage
permits movement of the stage while holding the slide in the phase of focus
Mechanical stage
parts of the LENS SYSTEM
Nosepiece
Objectives
Focal length
located at the end of the body
tube for holding the objectives
Nosepiece
consist of a system of lenses located at the end of the body tube that is held in place by the nosepiece and is closer to the slide under examination
Objectives
to increase or decrease magnification
Objectives
to increase or decrease magnification
Objectives
mounted on a revolving turret allowing for the change of objectives
Objectives
When one objective is focused on the turret, all lenses will be approximately in focus
PARFOCAL
distance between outer lens of objective and the cover glass of the slide under examination
Focal length
Magnification is achieved by the use of
Microscope’s lens system
product of the magnifying power of the objective and eyepiece, with a normal tube length of 160 mm
Total magnification of microscope
process of ensuring and maintaining personal as
well as environmental health and safety in the
laboratory
Risk Management
must be detailed to include control of hazardous substances, risk assessments, and other health and safety information relevant to handling of specimens
Standard operating procedures
First step for risk management is to _______ that can potentially cause harm in the laboratory.
identify hazards
Types of hazards
Chemical hazards
Physical hazards
Biological hazards
Potential exposures to chemical hazards can occur both _____ and with _____
During use
Poor storage
The “lab standard” applies to the laboratory use of chemicals and mandates written in
SOPs / STANDARD OPERATING PROCEDURES
address the particular hazards and precautions required for safe use
SOPs
terms used to define the maximum allowable airborne concentration of a chemical (vapor, fume or dust) to which a worker may be exposed
Permissible Exposure Limits (PELs)
Threshold Limit Values (TLVs)
Occupational Exposure Limits (OELs)
a regulatory limit on the amount or concentration of a substance in the air
Permissible Exposure limits
usually based on an eight-hour time weighted average (TWA)
Permissible Exposure Limits
represents the maximum level of an airborne substance that a worker can be safely subjected to without being susceptible to harm or injury
Threshold Limit Values
indicates the level of admissible exposure, for a length of time (usually 8 hours), to a chemical or physical hazard that is not likely to affect the health of a worker.
Occupational Exposure Limits
Cause destruction or irreversible alterations when exposed to living tissue
Corrosive chemicals
Chemicals that cause reversible
inflammatory effects at the site of contact with living tissue, especially the skin, eyes and respiratory passages
Irritans
Every chemical should be labeled with certain basic information, including:
• Chemical name
• if a mixture
• names of all ingredients
• Manufacturer’s name
• address if purchased commercially
• name of person making the reagent;
• Date purchased or made;
• Expiration date
• Hazard warnings
• safety procedures.
Capable of causing death by ingestion,
skin contact, or inhalation at certain
specified concentrations
Toxic materials
Example of toxic materials
methanol
chromic acid
osmium tetroxide
uranyl nitrate
Substances that induce tumors in
animals and humans
Carcinogens
Carcinogens examples
chloroform
chromic acid
formaldeyhyde
auramine
basic fuchsin
Carcinogenic dyes
Auramine
Basic fuschin
Any dye derived from BENZIDINE (Congo red and Diamino-benzidine)
Cause allergic reactions in a substantial proportion
Sensitizers
slips and falls from working in wet locations and the ergonomic hazards of lifting, pushing, pulling, and repetitive tasks
Physical hazards
Other physical hazards often unnoticed
Electrical hazards
Mechanical hazards
Acoustic hazards
Thermal hazards
Substances that ignite a certain temperature
Combustibles
substances whose vapors will ignite at or above a certain temperature (or flash point) or in the presence of an ignition source
Combustibles
OSHA defines “flash point” as
100°F (38°C)
Department of Transportation defines it as
141°F = 60.5°C
initiate or promote combustion and
present a serious fire risk when in contact with certain substances
Oxidizers
Oxidizers
Sodium iodate
Mercuric oxide
Chromic acid
Picric acid
refer to anything that can cause disease in humans, regardless of their source
Biological hazards
one of the most important health hazards
Allergens
Common Histological Chemicals (8)
Hydrogen peroxide
Methanol
Nitric acid
Xylene
Cryogens
Osmium tetroxide
Sodium hypochlorite
Sulfuric acid
Essentially harmless if used in
concentrations less than 5%
Hydrogen peroxide
Essentially harmless if used in
concentrations less than 5%
Hydrogen peroxide
Moderate skin and eye irritant but toxic by ingestion and inhalation
Methanol
Corrosive to skin, mucous
membranes
Nitric acid
Skin and eye irritant, and is toxic
by ingestion, inhalation or skin contact
Xylene
temperatures below -153°C (-243°F), such as liquid nitrogen and a boiling point of -196°C (-321°F)
Cryogens
temperatures below -153°C (-243°F), such as liquid nitrogen and a boiling point of -196°C (-321°F)
Cryogens
Corrosive to EYES and mucous
membranes
Osmium tetroxide
A strong oxidant, eye irritant and
corrosive to most metals
Sodium hypochlorite
Strong irritant to skin, eyes and respiratory system
Sulfuric acid
degree to which healthcare services strive to provide accurate desired outcomes for patients and are consistent with current professional knowledge
Quality
system of routine technical activities
Quality control
provides routine and consistent checks to identify, address errors and omissions, ensures data integrity, correctness and completeness and also records all quality control activities
Quality control
“freedom from accidental injury” and safety consciousness & safety practices
Safety
planned system of review procedures conducted by personnel not directly involved in the laboratory process
Quality assurance
Quality assessment programs
College of American Pathologists / CAP
United Kingdom National External Quality Assessment Service (UK NEQAS)
correlation of errors, complaints, failures or other unexpected results
data of QC provides the data for QA
Quality Assurance (2) two distinct systems:
Selective system
Distributive system
participating laboratories are asked to stain sections that have been submitted by the scheme organizer
Distributive system
stained preparations from departmental archival records are used to assess the quality of staining
Selective system
means that the report generated by the lab are accurate
Quality Management System
QMS functions
• concerns with good sampling
• Tissue processing with quality reagents
• Providing supplies and equipment
• Receiving
• Documenting
• Validating results
used to approach, evaluate and identify opportunities to improve quality before problems occur through evaluation of all systems/processes in the laboratory
Continuing quality improvement system
Goal of Continuing quality improvement system
improve potential care and safety through
recognition of potential errors before they occur
Effective QMS
• Skilled histotechnologist/nicians
• Properspecimencollection
• Proper processing of specimen
• Efficient processing of results
• High quality of reagents and equipment
• Preventive Maintenance of equipment
• Continuous professional education of staff
• Documentation and control
• Proper coordination
• Timely customer’s
feedback
Can endanger quality of histopathology report
Pre-analytical phase
(4) Pre-analytical phase
• Collection of the right specimen
• The proper fixation of the specimen
• The correct identification of the spec
• The timely transportation of the specimen.
slide reading along with relevant data and preparation of report
Analytical phase
• Grossing
• Processing
• Procedure reliability using technical manual
• Reagent integrity and efficiency
• Cutting of paraffin sections
• Staining
• Slide labeling
Analytical phase
• Diagnosis (hard copy) free of clerical errors.
• Reports reaches the appropriate
clinicians/surgeons.
• Filing of paraffin blocks
• Slides storage
Post-analytical phase
Getting the right test at the right time on the right specimen from the right patient with right diagnosis and the right price.
Data of QC provides data for QA
Getting the right test at the right time on the right specimen from the right patient with right diagnosis and the right price.
Data of QC provides data for QA
system of routine technical activities
QC
