PRINCIPLES OF CLINICAL CHEMISTRY AUTOMATION

AUTOMATION IN CLINICAL CHEMISTRY

The modern clinical chemistry laboratory uses a high degree of automation.

Many steps in the analytic process that were previously performed manually can now be performed automatically.

This Permits the operator to focus on tasks that cannot be readily automated and increasing both efficiency and capacity.

AUTOMATION IN CLINICAL CHEMISTRY

The analytic process can be divided into three major phases— preanalytic, analytic, and postanalytic—corresponding to sample processing, chemical analysis, and data management, respectively.

Substantial improvements have occurred in all three areas during the past decade.

The analytic phase is the most automated, and more research and development efforts are focusing on increasing automation of the preanalytic and postanalytic processes.

WHY AUTOMATION? Increase the number of tests by one

person in a given period of time Minimize the variations in results from

one person to another Minimize errors found in manual

analyses – equipment variations – pipettes

Use less sample and reagent for each test

TYPES OF ANALYZERS Continuous Flow

Tubing flow of reagents and patients samples

Centrifugal analyzer Discrete

Separate testing cuvets for each test and sample

Random and/or irregular access

CONTINUOUS FLOW

This first “AutoAnalyzer” (AA) was a continuous-flow, single-channel, sequential batch analyzer capable of providing a single test result on approximately 40 samples per hour.

Analyzers with multiple channels (for different tests), working synchronously to produce 6 or 12 test results simultaneously at the rate of 360 or 720 tests per hour.

In continuous flow analyzers, samples were aspirated into tubing

to introduce samples into a sample holder,

bring in reagent, create a chemical reaction, and then pump the chromagen

solution into a flow-through cuvette for spectrophotometric analysis.

CONTINUOUS FLOW

CONTINUOUS FLOW

• The major drawbacks that contributed to the eventual demise of traditional continuous-flow analyzers in the marketplace were significant carry-over problems and wasteful use of continuously flowing reagents.

CONTINUOUS FLOW

Continuous flow is also used in some spectrophotometric instruments in which the chemical reaction occurs in one reaction channel and then is rinsed out and reused for the next sample, which may be an entirely different chemical reaction.

DISCRETE ANALYZERS

Discrete analysis is the separation of each sample and accompanying reagents in a separate container.

Discrete analyzers have the capability of running multiple tests on one sample at a time or multiple samples one test at a time.

They are the most popular and versatile analyzers and have almost completely replaced continuous-flow and centrifugal analyzers.

DISCRETE ANALYZERS

Sample reactions are kept discrete through the use of separate reaction cuvettes, cells, slides, or wells that are disposed of following chemical analysis.

This keeps sample and reaction carryover to a minimum but increases the cost per test due to disposable products.

HITACHI 902 ANALYZER

WITH AUTOMATION THERE IS STILL SOME VERY BASIC STEPS

Specimen preparation and Identification Labeling still critical Programming of instrument

Laboratory personnel must perform and observe:Quality AssuranceQuality Control

TOTAL LABORATORY AUTOMATION

SELECTION PROCESSWhat is your lab’s workload like?

Discrete or large batch testing?Single instrument or multiples?

Storage of reagentsNeed refrigeration or freezing?

expenseKept at room temperature until

reconstituted

POINT OF CARE TESTING

DEFINITION Point-of-care testing (POCT) has been

defined by the College of American Pathologists (CAP) as “those analytical patient-testing activities provided within the institution, but performed outside the physical facilities of the clinical laboratories.”

PLACE OF ANALYSIS Physician’s offices Operating rooms Emergency rooms Intensive Care Units Home health care Patient performed

PERSONNEL ISSUES Most often performed by non-laboratorians Physicians Nurses or nurses aides Respiratory technicians Not specifically trained in the requirements

for accurate testing and interpretation

LABORATORY SUPPORT

Laboratory still responsible for results

Therefore responsible for training and management of POCT programs

Laboratory must build a structure to support and facilitate POCT

SUPPORT STAFF Director - PhD, MD or laboratory

scientist or pathologist POC Coordinator – laboratory scientist

with high level technical & interpersonal skills

POC Trainers – designated person(s) for problem solving etc.

COMMON APPLICATIONS Glucose Testing Chemistries Electrolytes Blood gases Hematology Coagulation – ACT Hematocrit