Laboratory Activity 2 – Concepts of Quality Control and Safety in Serologic Testing Flashcards
1
Q
The [?] of serologic test results are important in the correct diagnosis of diseases.
A
accuracy and reliability
2
Q
There are various factors in the laboratory function that affect the outcome of serologic testing; these include
A
specimen collection and processing, methodology, test reagents/kits, instrumentation, technologist’s skills, and others.
3
Q
To ensure the reliability of results, these factors must subscribe to the
A
standards of quality.
4
Q
The exposure of the technologist to disease causing agents in the laboratory is of [?] concern.
A
primary health and safety
4
Q
Possible [?] must, therefore, be known and well understood
A
risk factors
5
Q
Refers to the overall process of guaranteeing quality patient care and is regulated throughout the total testing system
A
QUALITY ASSESSMENT or QUALITY ASSURANCE (QA)
5
Q
are the variables that occur before the actual testing of the specimen
A
Pre-analytical factors
6
Q
are the processes that directly affect the testing of specimens.
A
Analytical factors
7
Q
Pre-analytical factors
A
• Test request
• Patient preparation
• Specimen collection, handling, and storage
8
Q
Analytical factors
A
• Reagents
• Instrumentation and equipment: instrument calibration and maintenance
• Testing procedure
• Preventive maintenance
• Access to procedure manuals
• Competency of personnel performing the tests
9
Q
Refers to the materials, procedures, and techniques that monitor the accuracy, precision, and reliability of a laboratory test
A
Quality Control (QC)
10
Q
are performed to ensure that acceptable standards are met during the process of patient testing
A
QC procedures
11
Q
Used to verify the accuracy and precision of a test and are exposed to the same conditions as the patient samples.
A
. External quality controls
12
Q
(ability to obtain the expected result)
A
accuracy
13
Q
(ability to obtain the same result on the same specimen)
A
precision
14
Q
is the ability to maintain both precision and accuracy.
A
Reliability
15
Q
consists of internal monitoring systems built into the test system
A
Internal quality control
16
Q
monitor the correct addition of a patient specimen or reagent, the instruments/reagents interaction, and test completion
A
Internal or procedural controls
17
Q
monitor a test system’s electronic or electric components
A
Electronic controls
18
Q
• The testing of unknown samples received from an outside agency
• It provides unbiased validation of the quality of patient test results
A
Proficiency testing
19
Q
are processes that affect the reporting of results and correct interpretation of data.
A
Post-analytical factors
20
Q
How close measurement is to the true value
A
Accuracy
21
Q
How close results are when the same sample is tested multiple times
A
Precision
22
Q
Range of values over which laboratory can verify accuracy of a test system
A
Reportable range
23
Formerly called a normal value
Reference interval
24
Lowest concentration of a substance that can be detected by a test method
Analytical sensitivity
25
Ability of method to measure the only analyte it is supposed to measure and not other related substances
Analytical specificity
26
Process of testing and adjusting analyzer’s readout to establish a correlation between measured and actual concentrations
Calibration
27
Reference material with a known concentration of analyte
Calibrator
28
Testing materials of known concentrations (calibrators, controls, proficiency testing samples, patient specimens with known values) to ensure accuracy of results throughout reportable range
Calibration verification
29
Calibration verification
• Test three (3) levels:
high, midpoint, and low
30
Calibration verification
• Required every [?], when a lot number of reagents changes, following preventive maintenance or repair, and when controls are out of range
six months
31
Positive result in a patient who has the disease
o True Positive (TP)
32
Positive result in a patient who does not have the disease
o False Positive (FP)
33
Negative result in a patient who does not have
the disease
o True Negative (TN)
34
Negative result in a patient who has the disease
o False Negative (FN)
35
% of the population with the disease that tests positive
o Diagnostic sensitivity
36
% of the population without the disease that tests negative
o Diagnostic specificity
37
% of the time that a positive result is correct
o Positive predictive value (PPV)
38
% of the time that a negative result is correct
o Negative predictive value (NPV)
39
Other Components of the QA Program
o Correlation study
o Preventive maintenance
o Function checks
o Delta checks
39
Study to verify the accuracy of a new method
o Correlation study:
40
Schedule of maintenance to keep equipment in peak operating condition
o Preventive maintenance:
41
Procedures specified by the manufacturer to evaluate critical operating characteristics of a test system
o Function checks:
42
Comparison of patient data with previous results
o Delta checks:
43
Source: Infectious agents
Biological
44
Source: Needles, lancets, and broken glass
Sharp
45
Source: Preservatives and reagents
Chemical
46
Source: Equipment and radioisotopes
Radioactive
47
Source: Ungrounded or wet equipment and frayed cords
Electrical
48
Source: Bunsen burners and organic chemicals
Fire/explosive
49
Source: Slippery floors, heavy boxes, and patients
Physical
50
Possible Injury: Bacterial, fungal, viral or parasitic infections
Biological
51
Possible Injury: Cuts, punctures, or bloodborne pathogen exposure
Sharp
52
Possible Injury: Exposure to toxic carcinogenic or caustic agents
Chemical
53
Possible Injury: Radiation exposure
Radioactive
54
Possible Injury: Burns or shock
Electrical
55
Possible Injury: Burns or dismemberment
Fire/explosive
56
Possible Injury: Falls, sprains, and strains
Physical
57
Denotes infectious materials or agents that present a potential health risk
BIOHAZARD/Biological Health Hazard
58
Chain of infection and safety practices related to the biohazard symbol
BIOHAZARD/Biological Health Hazard
59
Concern over exposure to blood-borne pathogens resulted in the drafting of guidelines and regulations by the [?] and the [?] to prevent exposure.
Centers for Disease Control and Prevention (CDC)
Occupational Safety and Health Administration (OSHA)
60
The [?] describe four levels of biosafety depending upon the biological agents isolated or studied.
National Institutes of Health guidelines
61
The Biosafety levels are based on the [?] of the agents and the availability of effective [?]
virulence
treatments and vaccines
62
laboratories handle agents that have no known potential for infecting healthy people.
Biosafety Level 1
63
laboratories are those laboratories that work with microorganisms associated with human diseases that are rarely serious and for which preventive or therapeutic interventions are often available.
Biosafety Level 2
64
is recommended for materials that may contain viruses not normally encountered in a clinical laboratory and for the cultivation of mycobacteria. Working with mycobacteria requires the use of N95 HEPA filter respirators.
Biosafety Level 3
65
is required for work with dangerous and exotic agents that pose a high risk of aerosol-transmitted laboratory infections and life threatening disease for which effective treatments are limited.
Biosafety Level 4
66
Exposure risks
• Accidental punctures with needles
• Spraying (aerosols) or spilling infectious materials onto desktop or floor
• Cuts or scratches from a contaminated object
• Centrifuge accidents: aerosols, broken tubes, etc
67
all patients are considered to be possible carriers of blood-borne pathogens
Universal Precautions (UP)
68
The Universal Precautions (UP) recommends wearing [?] when collecting or handling blood and body fluids contaminated with blood and wearing [?] when there is a danger of blood splashing on mucous membranes and when disposing of all needles and sharp objects in puncture-resistant containers
gloves
face shields
69
The CDC excluded [?] not visibly contaminated by blood from UP, although many specimens can contain a considerable amount of blood before it becomes visible
urine and body fluids
70
guidelines are not limited to bloodborne pathogens; they consider all body fluids and moist body substances to be potentially infectious
Body Substance Isolation (BSI)
71
According to BSI guidelines, personnel should wear gloves at all times when encountering
moist body substances.
72
A significant disadvantage of BSI guidelines is that they do not recommend [?] following [?] unless visual contamination is present
handwashing
removal of gloves
73
Assume that everyone is potentially infected or colonized with an organism that can be transmitted in the healthcare setting
Standard Precaution
74
Includes guidelines describing personnel protective practices
Standard Precaution
75
1. Requiring all employees to practice [?]
1. UP/Standard Precautions
76
2. Providing laboratory coats, gowns, face and respiratory protection, and gloves to employees and laundry facilities for[?]
2. non-disposable protective clothing
77
3. Providing sharps disposal containers and prohibiting [?] of needles
recapping
78
4. Prohibiting eating, drinking, smoking, and applying cosmetics, lip balm, and contact lens in the
work area
79
5. Labeling all [?] material and containers
biohazardous
80
6. Providing free immunization for
HBV
81
7. Establishing a [?] for work surfaces; an appropriate disinfectant for bloodborne pathogens is ____________________
daily disinfection protocol
82
8. Providing [?] for employees who have been accidentally exposed to bloodborne pathogens
medical follow-up
83
9. Documenting [?] in safety standards for employees
regular training
84
Any [?] to a possible blood-borne pathogen must be immediately reported
accidental exposure
85
Evaluation of the incident must begin right away to ensure appropriate
post-exposure prophylaxis (PEP)
86
Preventive measures are taken when a person is exposed to infectious disease
Post-exposure prophylaxis
87
Post-exposure prophylaxis Procedure:
1. Draw a baseline blood sample from the employee and test it for [?]
2. If possible, identify the source patient, collect a blood sample, and test it for HBV, HCV, and HIV. Patients must usually, give [?] for these tests, and they do not become part of the patient’s record.
3. Testing must be completed within [?] for maximum benefit from PEP.
1. HBV, HCV, and HIV.
2. informed consent
3. 24 hours
88
General procedures/ policies that mandate measures to reduce or eliminate exposure to hazard
Work practice controls
89
Safety features built into the overall design of a product
Engineering controls
90
Work practice controls
o Hand washing after each patient contact
o Cleaning surfaces with disinfectants
o Avoiding unnecessary use of needles and sharps and not recapping
o Red bag waste disposal
o Immunization for hepatitis
o Job rotation to minimize repetitive tasks
o Orientation, training, and continuing education
o No eating, drinking, or smoking in the laboratory
o Warning signage
91
Engineering controls
o Puncture-resistant containers for disposal and transport of needles and sharps
o Safety needles that automatically retract after removal
o Biohazard bags
o Splash guards
o Volatile liquid carriers
o Centrifuge safety buckets
o Biological safety cabinets and fume hoods
o Mechanical pipetting devices
o Computer wrist/arm pads
o Sensor-controlled sinks or foot/knee/elbow-controlled faucets
92
Barriers that physically separate the user from a hazard
Personal protective equipment (PPE)
93
Personal protective equipment (PPE)
o Non-latex gloves
o Gowns and laboratory coats
o Masks, including particulate respirators
o Face shields
o Protective eyewear (goggles, safety glasses)
o Eyewash station
o Chemical-resistant gloves; subzero (freezer) gloves; thermal gloves
94
All biological waste, except urine, must be placed in appropriate containers labeled with the
biohazard symbol.
95
This includes both specimens and the materials with which the specimens come in contact
biological waste
96
The waste is then decontaminated following institutional policy:
incineration, autoclaving, or pickup by a certified hazardous waste company.
97
Disinfection of the countertops and sink using a [?] of sodium hypochlorite should be performed daily.
1:5 or 1:10 dilution
98
can be divided into three phases (i.e., pre-analytical, analytical, and post-analytical). These phases of the total testing process can be targeted individually for improving quality.
Laboratory practice
99
However, presence of [?] adversely affects the quality of the testing process.
laboratory errors
100
• Guideline describing personnel protective practices
Standard Precaution
101
o Present a serious biological hazard, particularly for the transmission of blood-borne pathogens
SHARP HAZARDS
102
Specimens that are POTENTIALLY infectious
o Blood
o Pus and purulent fluids
o Semen
o Vaginal secretions
o Cerebrospinal fluid
o Pleural fluid
o Peritoneal fluid
o Pericardial fluid
o Amniotic fluid
o Breast milk
103
Specimens that are usually NOT infectious (unless visibly bloody)
o Feces
o Nasal secretions
o Sputum
o Sweat
o Tears
o Urine
o Vomitus
104
is a law monitored and enforced by OSHA.
Occupational Exposure to Blood-Borne Pathogens Standard
105
Focus: Process; Defect Prevention
Quality Assessment
106
A pro-active process – avoiding errors before the actual process; prevention
Quality Assessment
107
o Should be appropriate and error free
o Job for the management
Quality Assessment
108
ALL THINGS ABOUT SAMPLE
PREPARATION
Pre-analytical factors
109
Test request
Patient preparation
Specimen collection, handling, and storage
Pre-analytical factors
110
indicating the days of testing for markers after exposure
Test kits with specifications
111
o Folded papers inside test kits; instructions
112
o Primary reference – from manufacturers
Package inserts
113
o Contains calibrating procedures
Package inserts
114
indicates a certain time before the detection of ABs and AGs
Package inserts
115
Reagents
Instrumentation and equipment: instrument calibration and maintenance
Testing procedure
Preventive maintenance
Access to procedure manuals
Competency of personnel performing the tests
Analytical factors
116
– detection of presence or absence of marker
Qualitative Tests
117
– determining concentrations of unknown; positive or reactive patients
Quantitative Tests
118
– Test for Analytical Sensitivity
Screening Tests
119
– Test for Analytical Specificity
Confirmatory Tests
120
Focus: Product or Results; Defect identification
Quality Control (QC)
121
A reactive process – defects identified are corrected
Quality Control (QC)
122
Should be high in order to avoid false negative reactions
Analytical sensitivity
123
Should be high in order to avoid false positive reactions
Analytical specificity
124
Formerly known as the STANDARD
Calibrator
125
– techniques or tests
Analytical
126
– results
Diagnostic
127
Delta checks are used for checking:
1. Mixed up samples – wrong sample tested
2. Technical errors – human or machine error; duplication of test to rule out problem
3. Patient response to therapy – expected response is not achieved; may be due to changes on patient condition
128
most common biological agent among lab workers
Hepa B virus
129
viruses can survive in blood spills for
10 to 14 days
130
Establishing a daily disinfection protocol for work surfaces; an appropriate disinfectant for blood-borne pathogens is
5.25% NaCl in H2O (1:10)
131
10% common household bleach inactivates
o HBV for
o HIV for
o HBV for
o HIV for
131
10% common household bleach inactivates
o HBV for
o HIV for
o HBV for
o HIV for
131
10% common household bleach inactivates
o HBV for
o HIV for
o HBV for 10 mins
o HIV for 2 mins
