General Lab Practice SOLO 3

General laboratory practice for the clinical laboratory SOLO 3

total quality management

the management philosophy and approach that focuses on processes and their improvements as the means to satisfy customer needs and requirements

Five Q framework

defines how quality is managed objectively with the scientific method or PDSA cycle

PDSA stands for..

• plan systems improvement, the 5 phrases

• do a test pilot of the change

• study the results

• act or implement the change

Quality Laboratory processes (QLP)

• include analytical processes and the general policies, practices, and procedures that define how all aspects of the work are done

• establishes standard processes for the way things are done

• new process implemented through this

Quality control (QC)

• emphasizes statistical control procedures

• includes non-statistical check procedures

  • linearity checks

  • reagent and standard checks

  • temperature monitoring

• new process measured and monitored through this

Quality assessment (QA)

• provides broader measures of laboratory performance

  • turnaround time

  • specimen identification

  • patient identification

  • test utility

• new process measured and monitored through this

Quality improvement (QI)

• provides a structured problem solving process to help identify the root cause of a problem and a remedy for that problem

• the new process is improved through this

Quality planning (QP)

• standardizes the remedy

• establish measures for performance monitoring

• ensure that the performance achieved satisfies quality requirements

• document the new QLP

• provides the planning to eliminate performance problems

• the new process is re-planned through this

total quality control measures

• a surveillance process which monitors the performance of

  • personnel

  • instrumentation

  • methods

  • materials

Quality control program

• monitor consistency of performance

• detection of nonconformity to standards

• documentation is the backbone

Why have a QC program?

• necessity

• communication

• application

Labs should perform an analysis of it’s testing process to…

identify areas of potential error

Inventory of control materials inncludes…

• adequate supply

• proper ID (lot, dates, initials)

• proper storage

• parallel or comparison testing

standard materials

• determine the concentration of an unknown quantity

• assess patient values by means of reference range

• verify measurement assignment of values

• instrument calibration

control materials

• verify the precision or reproducibility of lab procedures

• evaluate methodology and instrumentation

• closely resembles unknown test specimens

• Stable, same matrix, normal and abnormal

Lyophlized controls

reconstituted by the addition of water or a specific diluent solution

assayed controls

• come with expected values of concentration, means, and standard deviation from the manufacturer

• may be expensive

• preferable for a reference method used to measure a particular analyte

unassayed controls

• do not have assigned analyte values provided by the manufacturer and are not linked to specific assay systems by labeling or other means

frequency of internal quality control

• regulatory requirements

• manufacturer instructions

• analytical stability

• risk of harm

• event based (recalibration or maintenance)

dispersion

increased frequency of both high and low outliers

trend

a series of values that continue to increase or decrease above or below the mean over a period of several concecutive days

shift

sudden upward or downward change in values

Which Westgard rules result in a warning?

• 1-2s

Which westgard rules result in a rejections?

• 1-3s

• 2-2

• 4-1s

• 10x

• R-4s

clinical laboratory improvement act of 1967

federal goverment account for variation in pahses of testing as part of overall quality assessment and assurance requirements

clinical laboratory improvement act of 1988

mandats proficiency testing as a major part of accreditation process

six sigma process

• business management strategy that seeks to improve the quality of process outputs by identifying and removing the causes of defects and variation

• approach to TQM and the performance goal that siz standard deviation should fit with the tolerance limits for the process

lean production

• a process management philosophy derived from the toyota production system

• focused on creating more value by eliminating wasteful activities

Joint Committee for Traceability in Lab Medicine (JCTLM)

created to meet the requirement for a worldwide platform to promote and give guidance on internationally recognized equivalence of measurements in lab medicine and traceability to appropriate measurement standards

ISO 9000

• set of four standards enacted to ensure quality management and assessment in manufacturing and service industries

type 1 reagent water

• most pure

• reagent grade water

• of highest quality and is used in test methodologies where minimum interference and maximum precision and accuracy are needed

• pre-filters, activated carbon, submicron filter, UV oxidation, reverse osmosis and ion exchange all used

special reagent water

may require different preparation that reagent grade water according to intended us, such as sterility specification for tissue of organ culture, nucleic acid content for DNA testing, metal content for trace metal analysis

type II reagent water

• used in most areas of the lab

• water for lab dishwashers and autoclaves; purified to contain only low levels of organics, inorganics, and aprticulate matter so it does not leave residue on glassware or contaminate material in autoclave

type III reagent water

• used to make type I and II water

• might be used in qualitative areas such as urinalysis

standard of purity

many grades of chemicals are available, it is essential to understand which grade or type should be used for a specific chemical method

analytical reagent grade chemicals

• contains a high degree of purity in accordance to the American Chemical Society specifications

• used often in the preparation of solutions in the clinical laboratory

• recommended for quantitative or qualitative analysis

ultra pure reagents

• may be used in some clinical laboratories

• additional processing makes them suitable for special procedures

• labeled according to used: spectrograde, nanograde, or HPLC pure

Do not use chemicals labeled what?

purified, practical, technical, or commercial

primary standards

• highly purified chemicals that are weighed or measured to produce a solution with an exact concentration

• used for calibration of definitive methods

secondary standards

• solutions whose concentration cannot be prepared by weighing the solute and dissolving a known amount into a volume of solution

• its values are determines by repeated analyses, using a reference method calibrated by primary standard

National Institute of Standards and Technology

produces and provides standard reference materals for purchase

Standard reference materials and certified reference materials

• have values determined by high-quality analysis and the chemical composition is certified

• used for calibration of an instrument, verification of a measurement mehtod or assignment of values to materials

To contain pipette

• calibrated for the total volume

• must be washed out comepltely with the diluting fluid to obtain the desired amount

• holds exactly the volume indicated on its side

to deliver pipette

• calibrated from the volume delivered

• can measure and deliver the indicated volume into another container

blow-out pipette

• last drop should be dispensed

• continuous etched ring or two small rings near bulb

self-draining pipette

• allow the contents to drain freely

• tip should make contact with side of the container

transfer pipette

• designed to transfer a known volume of liquid

volumetric pipette

• calibrated to deliver accurately a fixed volume of a dillute aqueous solution

• TD

• drain by gravity

• bubble-like enlargement of stem

ostwald-folin pipette

• specific type of transfer pipette

• blow-out

• buld closer to delivery tip

• TD

• viscous fluids

measuring/graduated pipette

designed to deliver various volumes by means of multiple graduations uniformly along its length

Mohr pipette

• calibrated between two marks on the stem

• straight with multiple graduations

• capable of dispensing various volumes

• TD

• drain by gravity

serologic pipette

• graduated marks down to the tip

• TD

• etched rings: blow out

micropipettes

• used for measurements of microliter volumes

• TC

• proper use requires rinsing with final solution

gravimetric pipette calibration

a specific amount of water is pipetted, the weight of the water is determined and proportional to the volume

volumetric pipette calibration

• a specific amount of dye is pipetted into a specific volume of water

• the absorbance of the solution will determine the solume of the pipette

desiccants

• drying agents that absorb water from air or other material

• used to provide dry environment for chemical materials

• absorption of water changes color indicator from blue to pink

CLSI standard of centrifugation of blood

RCF of 1000-2000 x g for 5-15 minutes

relative centrifugal force

• the amount of force required to separate two phases of a solution

Relative centrifugal force calculation

1.118 × 10^-5 x r x rpm²

types of centrifuges

• horzontal-head or swinging bucket

• fixed-angle or angle-head

• ultracentrifuges or high-speed

centrifuge maintenance

• time check

• temeprature check

• tachometer or stroboscopic light

Henderson-Hasselbalch equation

• used in calculating the acid or base to salt ratio required to establich a desired pH in a buffer solution

• pH=pK+log([A-}(salt)/[HA](acid))

constant systematic error

• error that is always in one direction and has the same magnitude regardless of the snample concentration

• interference experiment

random error

• due to chance

• 1 in every 20 tests falls out of ±2SD

• replication experiment

proportional systematic error

• has the same percentage of the concentration being measured so the absolute mangitude increases as the concentration increases

• recovery experiment

ethical issues in the lab

• confidentiality

• allocation of resources

• code of conduct

• conflict of interest

• publishing

specificity

sensitivity

positive predictive prevalence

negative predictive prevalence

standard deviation

coefficient of variation

molarity

number of mols/numbers of liters

mols

mass/GMW

normality

Molarity x Valence

Equivalence

GMW/valence