For clinical pathology students and those in clinical biochemistry. A great tool for your introductory class. Do's and don'ts in clinical pathology

1. LECTURES IN
CLINICAL
PATHOLOGY
PROF E. C. AZINGE

2. Introductory Lecture in Chemical
Pathology
• OUTLOOK/COMPORTMENT
• CODE OF DRESSING
• DO’S AND DON’TS OF UNIVERSITY LIFE
• STUDY PATTERNS

3. INTRODUCTION
• DEFINE CHEMICAL PATHOLOGY
• JOB OFTHE CHEMICAL PATHOLOGIST
• TEXTBOOKS IN CHEMICAL PATHOLOGY
• LABORATORY MANUAL
• ATTENDANCE AT LECTURES , PRACTICALS and SMALL GROUP
PRESENTATIONS.
• INCOURSE ASSESSMENT

4. Pathology is the study of
disease in the human body.

5. Chemical pathology, with its
synonyms, clinical chemistry,
clinical biochemistry is that
branch of pathology which uses
chemical reactions in the
laboratory, to diagnose
derangements in the metabolic
processes of the body.

6. You cannot learn Chemical Pathology
without a sound knowledge of
Physiology and Biochemistry.

7. Physiology deals with the normal
functioning of the systems of the body.

8. Biochemistry is the study of the
structure of body tissues and all the
metabolic processes going on in the
body.

9. A good knowledge of the proper
functioning of the body is essential for the
appreciation of derangement and disease
processes

10. Chemical Pathology is a clinical subject
which bridges the gap in the knowledge
of the basic medical sciences with clinical
medicine by the use of laboratory tests to
make diagnoses.

11. History taking and Clinical Examination
•A patient presents to his Clinician
with a complaint.The doctor takes
a full history of this complaint,
does a thorough physical
examination of the patient and
makes a tentative diagnosis.

12. Biochemical analysis
The clinician makes a request to the pathologist through a request form
Asking him to use the laboratory chemical analysis to scientifically prove or
disprove his tentative diagnosis.

13. On the form, details concerning the patient are filled
out.These include: -
name, age, sex, ward, hospital number, tribe, drug
history, date and time. Name of requesting clinician
and the tests he is requesting by marking the tests he
is interested in.

14. Patient preparation
Before investigations are initiated, the
patient has to undergo preparation to
ensure that the test results are
accurate and precise and will be of
benefit to the patient in the
management of his disorder.

15. The sample from which the test is going to be
performed is taken and placed in the
appropriate sample container and labelled. It
is then transported quickly to the laboratory
where appropriate action is started on it.

16. Laboratory analysis.
• In the laboratory, the sample is further given laboratory
identification numbers. Sample preparation commences when
the blood sample is centrifuged and the sample either plasma or
serum is separated from the cells.
• In the chemical pathology laboratory, most investigations are
carried out on plasma and urine.
• Lithium heparin is the anticoagulant of choice.

17. Accuracy and Precision.
It is important that the results of the
laboratory can be relied upon by the end
users who are the clinicians and of course
the patient himself.

18. METHODS
For this to be possible, the laboratory is careful in choosing
methods of analysis which will ensure that the result
obtained is accurate, that is, it is as close to the correct
value as possible. It must be precise, that means that if
repeated the same result will be got. The method must be
specific, that is, it must not analyse other constituents of
the plasma. Finally, it must be sensitive, that is, it must be
capable of picking up low levels of the substance which is
being analysed

19. Interpretation of results.
• When results have been got they must be interpreted.
• To give accurate interpretation of results, the reference ranges must
be known in the general population.
• A brief summary of the patient’s complaint must be written on the
request form.This is very important, as results in which urgent action
must be taken upon must be sent to the consulting clinician urgently.
• This is a very important role of the Chemical Pathologist who is
accountable for the quality of results the laboratory is producing.
• Strict quality control procedures are enforced to ensure that accurate
and precise results are got by the laboratory.

20. Turnaround time.
•The time it takes for the result after request,
to get back to the requesting clinician is
called the turnaround time. (TAT)
•The shorter the turnaround time the more
efficient the laboratory, and the more useful
the result for patient management.

21. TAT
Tests are divided into stat tests, those required for quick decision making.
The turnaround time for such tests must be as short as possible.
Routine tests are those done within the day’s work and the usual turnaround time
for routine tests is about eight hours.
Any time greater than this renders the test ineffective towards quick medical
decision making.

22. CHEMICAL PATHOLOGY LABORATORIES ARE
STAFFED BYTHE FOLLOWING:-
• CHEMICAL PATHOLOGISTS (MEDICALGRADUATES) MBBS, with clinical qualifications
FWACP, FMCPATH, MRCP ,MRCPATH.They must undergo training in all aspects of
Pathology.
• MEDICAL LABORATORY SCIENTIFIC OFFICERS.Technical staff or science graduates
who are qualified with BSc, diplomas,OND or HND from departments or schools of
Medical LaboratoryTechnology. Highly skilled analysts and experts in instrumentation.
• Clinical Scientists Science graduates trained alongside medical graduates in a teaching
hospital in all the aspects of the subject but with emphasis on the analytical aspect. In the
UK they hold an MRCPath of the Royal College of Pathologists.

23. CHEMICAL PATHOLOGY LABORATORY REQUEST FORM
• Surname
• Patient’s
• Patient’s
• First Name
• Hospital
• Number
• Ward/
• Clinic
• Lab
• Number
• Clinician
• Age
• Sex
• Relevant Clinical Data/Clinical Summary
• Name of lab staff who did the test(s):
• Sample:Venous Blood □ Arterial Blood □ Capillary Blood □ Urine □ CSF □

24. CHEMICAL PATHOLOGY REQUEST FORM
• □ Sodium (serum)………mmol/l (135 - 145)
•
• □ Potassium (serum)………mmol/l (3.5 - 5.0)
• □ Bicarbonate (serum)………mmol/l (18 – 31)
•
• □ Chloride (serum)………mmol/l (95 – 105)
•
• □ Urea (serum)………mmol/l (2.5 – 6.4)
•
• □ Urea [BUN] (serum)………mmol/l (1.7 – 9.1)
•
• □ Creatinine (serum)………µmol/l (53 – 115)
•
• □ Total Bilirubin (serum)……… µmol/l (1.7–17.1)
•
• □ Direct Bilirubin (serum)……… µmol/l (< 3.4)
•
• □ Indirect Bilirubin (serum)……… µmol/l
•

25. CHEMICAL PATHOLOGY REQUEST FORM
• □ Fasting Plasma Glucose…….. mmol/l (3.5 – 5.8)
•
• □ Random Plasma Glucose (RBG)…..... mmol/l (< 7.8)
•
• □ 2HPP Glucose …......... mmol/l (< 7.8)
•
• □ OGTT (5 Samples)…............
•
• □ CSF Glucose………mmol/l (2.5 – 4.5 or < 60%RBG)
•
• □ CSF Protein………g/l (0.15 – 0.45:Adults)
•
• □ CSF Protein………g/l (0.3 – 1.0:Children)
•
• □ Other Tests (Please Specify)….............

26. Job of a Chemical Pathologist
• CLINICAL AND SCIENTIFIC LIAISON
• PATIENT PREPARATION AND SAMPLE HANDLING
• QUALITY ASSURANCE ANDTROUBLE SHOOTING
• INTERPRETATION OF ANALYTICAL DATA FOR DIAGNOSIS AND
MANAGEMENT OFTHE PATIENT
• DEVELOPMENT OF PROTOCOLS

27. Job of a Chemical Pathologist
• ACTING AS A SCIENTIFIC RESOURCE FORTHE HOSPITAL
• TEACHING
• RESEARCH

28. TEXTBOOKS
• TEXTBOOK OF CLINICAL CHEMISTRY byTIETZ.
• CLINICAL CHEMISTRY byWILLIAM MARSHAL