clinical chemistry

1. PRINCIPLES OF CLINICAL
CHEMISTRY AUTOMATION

2. 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.

3. 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.

4. 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

5. 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

6. 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.

7. 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

8. 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.

9. 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.

10. 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.

11. 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.

13. HITACHI 902 ANALYZER

14. 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 Assurance
 Quality Control

15. TOTAL LABORATORY AUTOMATION

17. SELECTION PROCESS
What is your lab’s workload like?
 Discrete or large batch testing?
 Single instrument or multiples?
Storage of reagents
 Need refrigeration or freezing? expense
 Kept at room temperature until
reconstituted

18. POINT OF CARE
TESTING

19. 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.”

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

22. 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

23. 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

24. 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.

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