relevance of lab.diagnosis

1. CHEMICAL PATHOLOGY
INVESTIGATIONS FOR PRIMARY
HEALTH CARE LEVEL
BY
Bot Yakubu Sunday
Chairman, AMLSN Plateau State Branch

2. Neglect of laboratory services
Osita-Oleribe
Princess
2

4. OUTLINE
Introduction
Basic Physiology
Importance of Biochemical tests
Disease State (Pathology)
Types/Classes of Biochemical tests
Basic Primary Care tests
Conclusion

5. INTRODUCTION
 The human body is an incredible machine which
needs fuel to run
 It can coordinate various biochemical processes
 Eliminate waste products and has the ability to
reproduce
 The food we consume acts as the fuel, which
supplies the energy (Carbohydrates) and help in
building/repairing structures (proteins)

6.  The food can be classified basically into 2
 Organic and Inorganic (salts, water, acids,
bases etc)
 The inorganic food have no carbon atom and
no relationship with living matter
 The organic compounds have carbon atoms in
them
 Carbon is an essential constituent and related
to living matter
.
INTRODUCTION (Contd)

7.  The inorganic salts control several body functions
 Osmotic pressure, pH and water balance
 Basic physiological functions are carried out by
few organs in the body include:
• The digestive system
• Circulatory system
• regulatory system
• Excretory system
• The reproductive system
INTRODUCTION (Contd)

8.  The digestive system breaks down the
complex organic food molecules into simpler
molecules which are absorbed into the
circulatory system
 The excretory system helps to eliminate
materials that cannot be absorbed and other
waste products after being utilized by the
body
INTRODUCTION (Contd)

9.  Two major organs involved in the regulation of
metabolism in the body are the liver and pancreas
 In disease state, the normal functions
(physiology) of these body organs is affected
 Since these internal organs are not visible to the
physical eyes, the only way to assess them is
through ‘Biochemical tests’
DISEASE STATE (PATHOLOGY)

10.  This brings to the fore, the importance of
‘Chemical Pathology’
• The study, analyses or assays carried out in the Lab
• Using biochemical means
• To elucidate the cause of disease
• And the depth or extend of the disease
 We use a variety of body fluids to achieve this
IMPORTANCE OF BIOCHEMICAL TESTS

11. Clinical Chemistry is also known as Chemical Pathology,
clinical Biochemistry or Diagnostic Chemistry
Known to involve the investigation of biochemical
changes in human body
The detection and measurements of the biochemical
constituents of body fluids and excretions

12.  These include:
• Serum or plasma
• Whole blood
• Urine
• Saliva
• Cerebrospinal fluid
• Stool
• Aspirates
• Gastric juice
SAMPLES FOR BIOCHEMICAL TESTS

13.  The biochemical tests used in diagnosis are
many
 They can be classified based on the area and
facilities available for such diagnosis basically
as:
1. Primary health care delivery
2. Secondary Care
3. Tertiary Care
CLASSES OF BIOCHEMICAL TESTS

14.  In the developed world, almost all tests are carried
out even when it is primary health care delivery
 But in the developing countries, most diagnosis
stop at the primary and secondary care with just a
few tertiary health institutions providing tertiary
(complex) laboratory services
CLASSES OF BIOCHEMICAL TESTS (Contd)

15.  These include basic screening or qualitative
tests that can be done with little or no much
machines or equipment
 Urinalysis (Dipstix Combur 4, 6, 7, 8, 9 or 10)
 Pregnancy Test (PT)
 Glucose test (Clinistix and glucose test
strips),
 Occult blood test (Okokit tablet)
CLASSES OF BIOCHEMICAL TESTS (Contd)
PRIMARY CARE TESTS

16. Redeemer’s
University,
Nigeria

17. Osita-Oleribe
Princess
17

18.  These may include
 Glucose test
 Urea and Electrolytes (RFT)
 Liver Function Tests (LFT)
 Cerebrospinal Fluid (CSF) analysis
 Simple equipment such as the Colorimeter can
be used to run most of these assays
CLASSES OF BIOCHEMICAL TESTS (Contd)
SECONDARY CARE TESTS

20. TERTIARY CARE:State of the Art
Laboratory
20

21.  These include more Advanced/Specialized
tests such as:
• Enzymes analyses
• Hormonal tests (infertility, thyroid
dysfunctions etc.
• Toxicological investigations, DNA
CLASSES OF BIOCHEMICAL TESTS (Contd)
TERTIARY CARE TESTS

22.  Using Special Techniques/Equipment as:
o Spectrophotometry
o Fluorescence
o Immunofluorescence
o Radio-immunoassays (RIAs)
o ELISA
o HPLC
o PCR
o Electrophoresis
o DNA sequencing machine
CLASSES OF BIOCHEMICAL TESTS (Contd)
TERTIARY CARE TESTS

23.  Our concern in this workshop is to
dwell on the Chemical Pathology
(Biochemical) tests that will enable you
carry out your role as a Medical
Laboratory Assistant or Technician at
the ‘Primary Health Care level’
PRIMARY CARE BIOCHEMICAL TESTS

24. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
 In a developing country like Nigeria, at the
Primary health care level, most Health Centres
are in the rural community where electricity
supply is not available and you have to make
do with materials and tests that do not require
electricity to do diagnosis of diseases
 Despite the challenges, you are required to
deliver accurate results of tests done by you
to enable the Physician or Community Health
Officer prescribe drugs for the patient(s)

25. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
 These tests as mentioned earlier are simple
screening tests
 They include: Urine analysis (Urinalysis)
 Pregnancy test (PT)
 Test for Glucose
 For all of these tests, strips are available in
the market and could be purchased and used
 Except for PT, the various tests give us an
indication of what takes place in the body
when it is diseased or as a result of the break
down of the food ingested and digested by

26. In primary health care setting, Diabetes can
be monitored by use of the Glucometer that
uses a drop of finger prick blood and within
seconds the result is read on the device

27. BLS Glucometer Use
Diabetes mellitus is a disease
state characterized by a
deranged relationship of
insulin and glucose
In diabetes, there is
insufficient insulin to get
glucose into the cells, and
thus the cells start to
malfunction and produce
characteristic findings
Emergencies from diabetes
are usually from
hyperglycemia or
hypoglycemia

28.  Checking the Blood Glucose Level (BGL)
Multiple Brands of Glucometers are commonly
found on EMS units
Glucometer determines the amount of glucose in
the blood, the sample usually coming from a
finger stick
A normal range is 80–120 mg/dl
Hypoglycemia is a BGL <60 mg/dl
Hyperglycemia is a BGL >120 mg/dl
Blood Glucose Monitoring
BLS Glucometer Use
You must read manufacturer's instructions for your particular
glucometer

29. PREGNANCY TEST

30. Fertilization

31. Results

32. Another Example of Results

33. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
 This is a very simple but very important
screening test that helps give direction to the
Clinician/Laboratorian in Diagnosis of diseases
 It is a guide on the physiological/pathological
state of organs such as:
• Liver
• Kidneys
• Pancreas
URINALYSI
S

34. why Urinalysis?
It provides information about:
The state of the kidney and urinary tract.
Metabolic or systemic (non-kidney)
disorders.
Urinalysis can reveal diseases that have
gone unnoticed because they do not
produce striking signs or symptoms.
Examples include diabetes mellitus,
various forms of kidney failure, and
chronic urinary tract infections.

35. Review of Kidney Function
Urine is composed of approximately 96% water
and 4% dissolved substances derived from food
or waste products of metabolism.
The actual composition of urine varies,
depending on diet, metabolism, general health of
the body, and health of the kidney.
Urinalysis is performed to assess the urine’s
composition as well as kidney function.

36. Review of Kidney Function
Recall the urinary system consists of two
kidneys, two ureters and the bladder.

37. Review of Kidney Function
Also recall the role of blood - to bring
nutrients and oxygen to cells of the body
and to carry waste materials away from
those cells.
The kidney has the largest role in
controlling the chemical composition of
the blood in order to maintain proper cell
function in the body.

38. Review of Kidney Function
More specifically, the kidney has the functions of:
removal of waste products from the blood
retention of nutrients such as proteins and
glucose
maintenance of acid-base balance
regulation of water and electrolyte (salt) content of
the body
hormone synthesis

39. Review of Kidney Function
Urine is formed in the kidney
structure called the nephron.
Each kidney contains about one
million nephrons.
The nephron is made up of a
glomerulus and a set of tubules.
Cross section of a nephron

40. Review of Kidney Function
 The processes of glomerular filtration and renal tubular
reabsorption and secretion are can become affected
when the kidney is compromised by disease.
 Loss of renal function can be caused by variety of
conditions such as:
 congestive heart failure
 injury to the glomerulus or tubules caused by drugs,
heavy metals and viral infections
diabetes, hypertension and kidney stones.

41. Urinalysis
Renal function tests, such as the urinalysis, are
used to screen for the cause and the extent of renal
dysfunction.
Urinalysis consists of the following measurements:
Macroscopic exam
Chemical exam
Microscopic exam of the sediment

42. Macroscopic Exam
Examination of the
physical properties
including….
Color
Clarity (or
transparency)

43. Macroscopic Exam
 Color - normal
yellow (straw to amber)
 Color - abnormal (due to disease, drugs or diet)
pale to colorless
amber (dark yellow)
orange
pink or red
green
brown or black

44. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
GROSS EXAMINATION OF URINE:
Normal urine is clear and pale yellow (straw) in colour.
1. Colourless: Dilution, diabetes mellitus/insipidus,
nervousness, diuretic or alcohol intake
2. Milky: Purulent geneto-urinary tract disease; chyluria
3. Orange: Urobilinogenuria, fever, excessive sweating,
concentrated urine
4. Red: Beet root ingestion, heamaturia, haemoglobinuria,
phenophth, pyridium, sulfonal
5. Greenish: Jaundice, phenol, poisoning
URINALYSI
S

45. Macroscopic Exam
Clarity (or transparency) - normal
clear
Clarity - abnormal (due to insoluble
elements such as cells, crystals, etc.)
hazy
cloudy
turbid

46. Macroscopic Exam
Left to right: Straw, clear; yellow, clear; yellow, hazy;
yellow, clear; red-orange, clear; brown, hazy.

47. Chemical Exam
 The presence of normal
and abnormal chemical
elements in the urine are
detected using dry
reagent strips.
 These plastic strips
contain absorbent pads
with various chemical
reagents for determining
a specific substance.

48. Chemical Exam
When the test strip
is dipped in urine
the reagents are
activated and a
chemical reaction
occurs.
The chemical
reaction results in a
specific color
change.

49. Chemical Exam
After a specific
amount of time has
elapsed, this color
change is
compared against
a reference color
chart provided by
the manufacturer
of the strips.

50. Chemical Reaction Chart

51. Typical Substances Tested &
Significance
 pH - partial assessment of acid base status;
alkaline pH indicates old sample or urinary tract
infection
 Specific Gravity - state of kidney and hydration
status of patient
 Protein - primarily detects protein called albumin;
important indicator in the detection of renal
disease
 Glucose - primarily detects glucose (sugar);
important indicator of diabetes mellitus

52. Typical Substances Tested &
Significance
Nitrite - certain bacteria convert normal
urine nitrate to nitrite; indicator of urinary
tract infection
Leukocyte Esterase - detects esterase
enzyme present in certain white blood cells
(e.g, neutrophils, monocytes); indicator of
urinary tract infection

53. Elevated pH (alkaline)
(Normal for comparison)

54. Positive Glucose
(Normal for comparison)

55. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
Urine preservatives:
1. Touline: for preservation of chemical constituents. Add
2ml of Touline/100ml of urine
2. Thymol: a small floating lump of thymol can preserve
the urine for several days in a bottle. However it may
cause false positive reaction for protein
3. Formalin: 1 drop/30ml urine. It is good for preserving
formed elements. It can precipitate protein and reduce
Benedict’s solution
4. Boric acid: 0.3g/120ml urine. However yeast can still
grow and uric acid crystals get precipitated
URINALYSI
S

56. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
ODOUR OF URINE:
 This is important in fresh specimen only
 Urine is aromatic because of volatile fatty
acids
 Bacterial action causes ammonical odour
 While ketosis leads to a fruity odour in urine
URINALYSI
S

57. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
CHEMICAL EXAMINATION OF URINE:
1. Test for Protein
If urine is not clear, filter or centrifuge the specimen. Both
bile and protein cause urine to froth. Tests include:
a. Heat and acetic acid test
b. Sulfosalicylic acid test
2. Bence Jones Protein tests
a. Heat and SSA test
b. Toluenesulfonic acid
c. Electrophoresis
URINALYSI
S

58. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
CHEMICAL EXAMINATION OF URINE:
3. Tests for Glucose
a. Benedict’s qualitative (semi-quantitative) Glucose
test
4. Tests for Ketone bodies
a. Rothera’s test
b. Legal’s test
c. Paper strip/tablet methods
d. Diaacetic acid test (Gerhardt’s test)
URINALYSI
S

59. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
CHEMICAL EXAMINATION OF
URINE:
5. Tests for Bile pigment
a. Foam test
b. Iodine ring test
c. Harrison test
d. Diazo test (Ictotest)
e. Paper strip method
URINALYSI
S

60. PRIMARY CARE BIOCHEMICAL TESTS (Contd)
CHEMICAL EXAMINATION OF URINE:
6. Test for Urobilinogen
a. Ehrlich’s test
b. Test for Urobilin
c Schlesinger’s test
7. Tests for Blood in urine
a. Guaic test
b. Benzidine test
c. Paper strip (Haemastrix)
URINALYSI
S

61. CONCLUSION
In conclusion, I want to tell you that you are
very important; and you play a key role in
health care delivery at the primary level,
before referrals are made to secondary or
tertiary health care facilities. So you must
take your rightful place and do your work as
a well trained personnel that you are. God
bless you as you do that

62. Thank you for
your attention!