Quality Assurance and Quality Control of LFT Flashcards
What is QA?
- Compliance with local/national/international guidelines
- Test Performance/Protocols
- > Single Breath technique
- > 2 technically acceptable measurements
- Equipment Specification
- Quality Control e.g. frequency/criteria
- SOP’s/lab manuals -> up to date/evidence based/accessible
- Staff Training/CPD/Qualifications
What does QA ensure?
All results generated are accurate and reliable over time.
What components of QA?
- Equipment
- Environment
- Education + Training
- Diagnostic Testing
What is Quality Control?
How well the equipment reproduces the same result/measurement under various conditions over a period of time.
Should equipment be used if it fails a QC?
No.
Why is QA/QC important?
- High Quality and Accurate diagnostic test results
–> Test results impact on diagnosis and QoL
–> Responsibility usually lies with the lead physiologist
How can we record QC?
–> Lab Notebook/Computer Spreadsheet
- -> Physical Calibration
- Physiological/BioQC
Examples of Preventative Equipment Maintenance?
- Performed on a schedule basis
- Recorded in a logbook
- Usually by a physiologist
- Calibration procedures/Checking Spirometer/Check tubing for tears/Electrical safety
Examples of Corrective Equipment Maintenance?
- Unscheduled and unable to correct equipment failure
- Company engineer/EBME
- Service contacts
- PPM
Physical QC? What is this?
Calibration performed against independence standards.
–> Calibration syringe (of known volume)
Performed regularly (e.g. daily/sessional) or if a problem is encountered
What sizes do calibration can come in?
(1-3L)
What does a cal syringe do?
Injects a known volume of air through the spirometer.
How often does a syringe need to be checked?
Annually for accuracy.
Flow rates for Spiro VolCal?
2-12s^-1
How often is it performed?
Daily/Start of each session (Brompton)
Where does it need to be stored?
Stored in same environment as measuring device (→ same temperature/humidity)
What must be attached?
Bacterial/Viral filter
What is an offset?
To adjust the input to a calibrated requirement
For example, if a volume (input) is 3.10 litres and the requirement is 3.00 litres, an offset of - 0.1 litres is required
What is gain?
The ability of a circuit (or amplifier) to increase the power or amplitude of a signal from the input to the output by adding energy to the signal.
Def Calibration?
Using a standard (e.g. calibration syringe) to generate and apply a gain to correct any measured deviation (offset)
Def Verification?
The process of checking the calibration using a standard (e.g. calibration syringe) to check equipment is reading correctly
What do we use normal volunteers for?
- normal volunteers as physiological control
- ideally non-smokers
- many readings in order to calculate their own mean/SD/normal ranges
Plethysmography Cal?
The box pressure (volume signal) and mouth pressure need to be calibrated prior to each session via a sinusoidal Calibration Pump
Plethysmography Cal How?
Pumps in a volume of air causing pressure change (deflection).
What does pumping of air do in box cal?
- Simulates changes in inspiratory and expiratory volumes
- Similar to volume and frequency of “panting” manoeuvres
What happens to the pressure transducer when air gets pumped in?
The pressure transducer is then adjusted to give a known signal for a known volume (e.g. ∆ box pressure → ∆ volume)
What happens during box measurements (leak)?
- the box is closed with an airtight seal, except for a small controlled leak
- leak helps to stabilise internal pressure
- Leak test performed to check there are not significant leaks
What is the polytropic process?
The relationship between the pressure and volume during the compression or expansion of an ideal gas.
What is the polytropic process equation?
PVn= K
Isothermal process?
The change of a system in which the temperature stays constant.
Inaccurate measuring equipment pathway?
Inaccurate measuring equipment leads to inaccurate test results leads to misdiagnosis and then poor patient outcomes.
What is IQIPS
Lab Accreditation promotes improvement and gives assurance to commissioners and the public.
