CLINICAL CHEMISTRY LEC UNIT 1

Laboratory Medicine

refers to the discipline involved in the selection, provision, and interpretation of diagnostic testing that uses primarily samples from patients

diabetes mellitus, clinical

Associated disease in carbohydrates

Kidney

Associated organ in NPN

metabollic syndrome

Associated disease in proteins

Selection of correct specimen to use
Selection of method to use
Selection of supplies to use

What are the three selections?

False (cannot)

True or False: Provide all services needed by the patient and there are instances wherein a laboratory can cater some services

True

True or False: a primary laboratory offers only
limited services unlike a tertiary laboratory
wherein services offered are mostly
complete. However, there are cases when a
tertiary laboratory cannot perform or do a
certain test; thus, it performs send-out
services.

False: Tertiary laboratory

Send out services occur when a
primary laboratory that does not offer a
test/service collects the specimen needed for
testing and sends the collected specimen to
another laboratory that offers thet certain
service or is capable of doing the test.

False: not allowed

True or False: Medtechs are allowed to interpret the results

Confirming a clinical suspicion
Excluding diagnosis
Assisting in the selection, optimization, and monitoring of
treatment
Providing a prognosis
Screening for disease in the absence of clinical signs and
symptoms
Establish and monitor the severity of a physiological
disturbance

Importance of Laboratory Medicine

Organic chemistry
General Chemistry
Biochemistry

Clinical chemistry (physiology and anatomy)

Clinical chemistry

It is a linkage among Organic Chemistry, General
Chemistry, Biochemistry, and Physiology and Anatomy

Clinical chemistry

Laboratory section that performs qualitative and
quantitative analyses of blood, urine, spinal fluid, feces, calculi and other materials.

Clinical Biochemistry and Chemical
Pathology

Clinical chemistry is also known as:

Biochemical Marker:

any biochemical compound that is
sufficiently altered in a disease to serve as an aid in
diagnosing or predicting susceptibility to the disease

Analyte

substance we are looking for either qualitatively or
quantitatively

Blood borne

carried or transmitted by blood

Pathogen

causative agent of a disease

Pathologic

Instead of pathogenic, we use\________in clinical chemistry

Accuracy

ability to determine the true and known value of
a substance

Precision

ability to reproduce the same results in repeated
analysis of the sample

Accuracy

Which of the following does not belong to the group?
-Precision
-Accuracy
-Reproducibility
-Repeatability

Reliability

ability of an analytical procedure to maintain its
original accuracy, precision, specificity, and sensitivity over an extended period of timer

Analytical Specificity

measures one compound only

Analytical sensitivity

measures even small, minute amount of a compound

GOD-Pod Glucose: specific for glucose
only

Example of analytical specificity

- Human Chorionic Gonadotropin (HCG):
hormone (biomarker) released during the 2nd
or 3rd week of pregnancy.
- Covid antigen test kit: not sensitive

Example of analytical sensitivity

Specimen

any material coming from the patient's human body
submitted to the laboratory for processing and testing

Blood

Most common specimen used in the clinical laboratory

phlebotomy

The process of collecting blood is termed as

venipuncture, arterial puncture, or skin/capillary
puncture

Collecting of blood may be done in three ways

Whole blood
Serum
Plasma
Arterial blood
Venous blood
Capillary blood

Blood collections specimens:

1. median cubital vein
2. cephalic vein
3. basilic vein

Blood Collection sites (antecubital fossa; in order from best to last resort):

antecubital fossa

Where is the best venipuncture site?

1. Brachial vein
2. Femoral vein
3. Radial vein
4. Ankle vein
5. Veins of the dorsal hand

Other veins that can be used for venipuncture

1. Brachial artery
2. Femoral artery
3. Radial artery

Arterial puncture sites:

ABG (Arterial blood gas)

pH

What tests are done using arterial blood?

Neonates

extremely obese patients

severe burn victims

thrombotic tendencies

When is a skin puncture performed?

1. Arm on mastectomy
2. edematous areas
3. Hematomas
4. arm in which blood is being transfused
5. scarred area
6. arms with fistula or vascular grafts
7. Sites above an IV cannula

Inappropriate venipuncture sites:

False: thinner walls but lower pressure

True or False: Veins have thicker walls but higher pressure compared to arteries

True

True or False: Only doctors can execute arterial blood puncture

-Antecubital fossa
-Basilic vein
-Cephalic vein

Venipuncture sites:

Antecubital fossa (median)

first choice in venipuncture and anchored by 2 veins

Cephalic

has a tendency to roll

Basilic vein

it hurts more to collect blood from here (skin is thinner in this area) and there's an artery and a nerve under this vein so the risk of puncturing
either one is greater

EDTA

It contains an anticoagulant

True

True or False: EDTA should be centrifuged immediately

Serum

This is the liquid portion of clotted blood

red top tube

it is the absence of anticoagulant

Plasma

This is the liquid portion of unclotted blood

False: 10 to 15 min

True or False: Red top tube Should allow the blood to clot for 15-20 minutes before putting the tube in the centrifuge

Qualitative Determination and Quantitative Determination

Two types of laboratory determination

Quantitative determination

exact amount of the compound present (high or low)

Qualitative determination

presence or absence of a certain compound

Label

a unit that defines the physical quantity or dimension

Diagnosis

the identification of the nature of an illness
or other problem by examination of the symptoms. Keyword: detection

Prognosis

an opinion, based on medical experience,
of the likely course of a medical condition. How long
does it take for the patient to recover or to expire. It
predicts what will happen to the patient based on their condition.

Abnormalities, Disease Diagnosis, and Treatment to correct the abnormalities

Clinical Chemistry measures biochemical compounds
to detect abnormalities on the levels of such
compounds.

Also known as Clinical pathology/Clinical laboratory

Laboratory medicine

Laboratory medicine is also known as... (2)

Clinical Pathology
Clinical Laboratory

What are the two sections of the laboratory?

- Anatomical Pathology
- Clinical Laboratory

This laboratory of Pathology is isolated from thehospital.

Anatomical Pathology

It deals with tissue processing and autopsy

Anatomical Pathology

Plays a key role in the diagnosis of different diseases,particularly, the metabolic disturbances (e.g. diabetesmellitus) and some hormonal imbalances.

Clinical Laboratory

The Clinical Laboratory plays a key role in the diagnosis of different diseases,particularly, the \____________________ (e.g. diabetesmellitus) and some \_______________________________.

metabolic disturbances; hormonal imbalances

Laboratories are important in confirming a \________________________ (patient's possible disease) from clinical signs and symptoms.

clinical suspicion

True or False: One importance of laboratory medicine is excluding diagnosis. Since some diseases have similar manifestations,running laboratory tests may help narrow down andexclude diagnosis.

True

Clinical laboratory assists in the \_______________, \________________, and \____________________ of treatment.

selection, optimization, monitoring

This is helpful in providing a prognosis, screening for disease in the absence of clinical signs andsymptoms, and establishing and monitoring the severity of a physiologicaldisturbance.

Clinical Laboratory

What are the sections of the laboratory medicine abroad?

○ Clinical Chemistry
○ Molecular diagnostics
○ Toxicology and drug monitoring
○ Endocrine and organ function testing
○ Microbiology
■ Parasitology is under Microbiology
○ Hematology
■ Coagulation testing is under Hematology
○ Hemostasis and thrombosis
○ Blood banking/ transfusion medicine
○ Immunology
○ Identity testing
○ Cytology and anatomic pathology

True or False: In the Philippines, sections are already found in one laboratory and are not divided like abroad.

True

What are the sections of laboratory medicine in the Philippines?

○ Clinical chemistry
○ Molecular diagnostics
○ Drug testing
■ Can be under Clinical Chemistry
○ Microbiology
○ Hematology
○ Blood banking/ transfusion medicine
■ Can be under Clinical Chemistry
○ Serology and immunology
○ Clinical microscopy
○ Cytology and anatomic pathology

Linkage or incorporation among the knowledge of generalchemistry, organic chemistry (carbons, carbohydrates),biochemistry (chemical compounds and processes inorganisms), and physiology and anatomy.

Clinical Chemistry

Laboratory section that performs qualitative andquantitative analysis of blood urine, spinal fluid, feces,calculi and other materials.

Clinical Chemistry

A division concerned with the analysis of body fluids toyield timely, relevant, accurate and precise information onthe clinical status of the human body

Clinical Chemistry

True or False: Relevance is an important element in Clinical Chemistry testings. These body fluids should be yielded timely(routine, STAT, emergency rooms such as point ofcare). Results should also be released while the informationis still relevant to the patient

True

Branch of medical science that involves the analysis ofbiological materials, usually body fluids, to providediagnostic information on the state of the human body

Clinical Chemistry

What is the most important analyte of humans?

Blood

Detects the presence or absence of an analyte; Tests for general or physical characteristic

Qualitative

Quantifies the amount of an analyte in a specimen; Also known as clinical biochemistry and chemicalpathology

Quantitative

Quantitative is also known as... (2)

- Clinical Biochemistry
- Chemical Pathology

Clinical Chemistry Consists of studying the substancessuch as... (4)

○ Carbohydrates
○ Proteins
○ Lipids
○ Nucleic Acid

Any biochemical compound that issufficiently altered in a disease to serve as an aid indiagnosing or predicting susceptibility of the disease

Biochemical marker

Another substance we are looking for eitherqualitatively or quantitative

Analyte

Carried or transmitted by blood

Blood borne

HIV, Hepatitis B and C, Malaria, Autoimmunediseases are examples of...

Blood-borne diseases

Causative agent of a disease

Pathogen

Virus, Bacteria, and Fungi are...

pathogens

ability to determine the true and known valueof a substance

Accuracy

Close to the true value

Accuracy

True or False: Accuracy is independent of precision but not theother way around.

True

Ability to reproduce the same results inrepeated analysis of the sample

Precision

Closeness of the Value, not necessarily accurate

Precision

True or False: If the test is accurate, it is always precise. But if it is precise, itis not always accurate.

True

Ability of an analytical procedure to maintainits original accuracy, precision, specificity, and sensitivityover an extended period of time

Reliability

For the detection of the specific analyte, willonly measure a certain substance

Specificity

It will only measure the specific substance (e.g. beta*). Interfering substances will not affect the test

Specificity

Detect even a small amount of the substance accurately

Sensitivity

True or False: In the laboratory, we prefer a test procedure with both high precision, specificity and sensitivity.

True

Any material coming from the patient's human body submitted to the laboratory for processing and testing

Specimen