MLS 414 — LEC | CLINICAL CHEM 1 PRELIMS

VIDEO LECTURE | JANUARY 19, 2022 A.Y. 2021- 2022

WEEK 1: PATIENT PREPARATION

OVERVIEW
to lactic acid contributing now to the increased
• There are certain practices/activities that may interfere
levels of lactate
with the result
o Ex: Eating prior to blood collection and analysis =
FATTY ACIDS:
glucose level temporarily increases

PRE-ANALYTICAL VARIABLES/FACTORS
CONTRIBUTING TO THE VARIATION OF RESULTS:
• Exercise
• Fasting
• Diet
• Posture and Position
• Tourniquet Application
• Tobacco Smoking
• Alcohol ingestion
• Stress (anxiety)
• Drugs • TAG = Triacylglycerol = Triglycerides = Storage
form of Fat
NOTE: o structure: 3 fatty acids + 1 glycerol backbone

• During exercise, glucose (the primary source of

“Pre” Before Even before the time of
energy) will easily be consumed
analysis, a variation in the
• Hence, the body will use another energy source
patient’s analytes has
“Analytical” Analyze/Test which are triglycerides
already occurred
Sample o In order to produce energy, Fatty acids of
triglycerides will be liberated via oxidation
which contributes to the increased levels of fatty
1. EXERCISE acid during exercise
• Volume shifts between the vascular and interstitial
compartments, volume loss by sweating and changes AMMONIA:
in hormone concentrations ● Ammonia is the product of protein catabolism
• Transient increase in lactate, fatty acid, and o Proteins are used by our muscles and tissue
ammonia during exercise
o “Transient” = temporary
o Just remember LAF
• Long-term increase in Creatine Kinase (CK),
LACTATE: Aspartate Aminotransferase (AST), Lactate
Dehydrogenase (LD), and aldolase
o These enzymes are found in the muscles that is
and they concentrations increase when the
muscles are active
• Elevated levels of proteins in urine (proteinuria)
• Vigorous hand exercise (fist clenching) increases
potassium, lactate, and phosphate
o In blood drawing, make sure that the patient is
only doing a “relaxed” clenching of fist as this may
cause false results

2. FASTING
• 8-10 hrs: glucose/sugar test
• 10-14 hrs: lipids and lipoproteins/lipid profile test
• Overfast: 48 hrs fasting - increases serum bilirubin
o Serum bilirubin will increase because the liver
• During exercise, there is insufficient oxygen in cannot excrete/metabolize the bilirubin
some tissues since the body will prioritize the more • 72 hrs fasting - increase triglycerides
important parts for functionality • Basal state collection: GLUCOSE, CHOLESTEROL,
o Glycogen/Glucose will now undergo anaerobic TRIGLYCERIDE, AND ELECTROLYTES
glycolysis/fermentation converting pyruvic acid o NOTE: Basal state collection is early morning
blood collection, 12 hrs after the last ingestion
of food

THE AVENGERS SQUAD 1

MLS 414 — LEC | CLINICAL CHEM 1 PRELIMS
VIDEO LECTURE | JANUARY 19, 2022 A.Y. 2021- 2022

WEEK 1: PATIENT PREPARATION

• These require fasting specimen: Fasting Blood o 5-Hydroxyindole Acetic Acid = product of
Sugar (FBS), Oral Glucose Tolerance Test (OGTT), serotonin which is 5-HT (5-Hydroxytryptamine)
TAG, Lipid panel, Gastrin, Aldosterone/Renin, and o 5-HT → 5-HIAA
Insulin • Caffeine increases concentrations of glucose; it
o OGTT usually performed among pregnant promotes release of catecholamines from the adrenal
patients medulla and brain tissue
o All of these increases when food is present o Catecholamines can increase glucose
o 8-14 hrs fasting • In obese persons: increased Lactate Dehydrogenase
(LD), Cortisol, and Glucose
3. DIET o “CLOG” - Cortisol, Lactate Dehydrogenase LD,
• High protein diet increases urea Obese, Glucose
o Urea’s other name BUN: Blood, Urea, and
Nitrogen 4. POSTURE AND POSITION
• Preferred position during phlebotomy: upright
position or supine
UREA:
• Changing from supine to sitting or standing position =
increase albumin, enzymes, and calcium levels
o These analytes are present in the blood

ALBUMIN, ENZYMES, CALCIUM LEVELS:

● Proteins will become amino acids; amino acids will

be metabolized by the body into urea
o Urea is a product of protein metabolism

• Glucose, Lipids, and catecholamines may show

variation-postabsorptive hormonal effects
• High protein, low carbohydrate diets = increased
ketones in urine and fat
o Since the primary energy source (carbohydrate) is
deficient, the body will use protein and fat for Broken lines: blood vessel
energy production which lead to ketone formation
• When you are lying down and then you suddenly
stand up, your blood vessels will constrict (magliit
KETONE: siya)
o As a result, Intravascular fluid will exit to the
interstitial fluid
• As water would exit, the solutes within the
intravascular will become concentrated because
there is less liquid volume
o Hence, this activity can also increase other
analytes in the blood

• Changing from standing to supine position = decrease

cholesterol, triglycerides, and lipoprotein levels
o Blood vessels would dilate, which allows water
from the interstitial fluid to re-enter the
intravascular area now diluting the solutes in the
• Fatty acids or Proteins can become ketone bodies blood
▪ As a result cholesterol, TAG, and lipoprotein
levels decrease
• Serotonin-rich food (ex: banana, pineapple, tomato,
and avocado) increase the urinary excretion of 5-HIAA

THE AVENGERS SQUAD 2

MLS 414 — LEC | CLINICAL CHEM 1 PRELIMS
VIDEO LECTURE | JANUARY 19, 2022 A.Y. 2021- 2022

WEEK 1: PATIENT PREPARATION

• Prolonged standing for more than 30 minutes = 7. ALCOHOL INGESTION

increased potassium • Increase level of Urate, Lactate, Triglycerides, and
o Same case with the clenching of the fist Gamma Glutamyl Transferase (GGT).
o Remember that potassium is found within the cells o GGT (Enzyme) is found in the Liver
of the muscle and when our muscles are used • Hypoglycemia (Chronic Alcoholism)
surely these potassium would leave the cell o Hypoglycemia - Low Blood Sugar
• Prolonged bed rest = decreased plasma albumin ▪ Hypo= low
o The fluid in the blood vessels are retained ▪ Gly= glucose
▪ Emia= blood
5. TOURNIQUET APPLICATION
• 1 minute application is recommended 8. STRESS (ANXIETY)
• Prolonged application = Hemoconcentration and • Affects adrenal hormone secretion
Anaerobiosis • Increased: ACTH (Adrenocorticotropic Hormone),
o Tourniquet is used to obstruct the veins (from the Cortisol, Catecholamines, TSH (Thyroid
body to the heart) Stimulating Hormone)
o Hemoconcentration = increased of blood
constituents (due to the prolonged obstruction of
the blood within the vein)

o Anaerobiosis = lack of flow of oxygen (due to the

obstruction of the vein)
▪ Anaerobic - increase of lactate
• Increased levels: potassium, proteins (albumin),
enzymes, lactate, cholesterol, and ammonia
• Prolonged use of tourniquet with fist exercise -
increase potassium (1 mmol/L) o When there is Stress: Brain will send signal to the
• For measurement of lactate - tourniquet use should pituitary gland to produce ACTH → ACTH will go
be minimal, and the patient should not clench his or to the Adrenal Gland to produce Glucocorticoids
her fist (Cortisol) and Catecholamines.
• Total Cholesterol has been reported to increase with
6. TOBACCO SMOKING mild stress, and HDL Cholesterol to decrease by as
• Increase in plasma catecholamines and cortisol much as 15%.
o Catecholamines and Cortisol are stress o Makapataba ang stress
hormones. o HDL (Good Cholesterol)
o Our body will get stressed when smoking
• Increase in glucose, growth hormone, cholesterol, 9. DRUGS
triglycerides, ammonia, urea, lactate, insulin and • Hepatotoxic drugs can elevate liver function
urinary 5-HIAA. enzymes.
o Nicotine (found in cigarette) - has hormonal • Diuretics can cause decreased plasma sodium and
effects potassium
o Increase some analytes within the blood
• Decrease plasma levels of Vitamin B12
o Vitamin B12 or Cyanocobalamin
o Used in cell maturation
o So most smokers are anemic (unable to mature
cells)

THE AVENGERS SQUAD 3

MLS 414 — LEC | CLINICAL CHEM 1 PRELIMS
VIDEO LECTURE | JANUARY 19, 2022 A.Y. 2021- 2022

WEEK 1: PATIENT PREPARATION

• Affected by gender (increased levels):

Male: Albumin, ALP, creatinine, uric acid, cholesterol,
BUN, CK, AST,
Female: HDL, iron and cholesterol
● Affected by recent food ingestion:
Increased levels- glucose, insulin, TAG, gastrin
ionized calcium
Decreased levels- electrolytes (CL-, K+, P+), ALP,
amylase

TEST AFFECTED BY DIURNAL VARIATION,

POSTURE, AND STRESS
Cortisol Peaks 4-6 AM; lowest 8
o Glomerulus will filter out sodium, potassium and PM – 12 AM; 50% lower at
other constituents from the blood to the kidney 8 PM than 8 AM; increase
with stress
● Opiates cause increases in liver and pancreatic Adrenocorticotropic Lower at night; increase
enzymes hormone with stress
o Opiates: e.g: Heroine, Morphine,etc
Plasma renin activity Lower at night; higher
o Also used as anti-pain medicine
standing than supine
Aldosterone Lower at night
HEMOLYSIS
Insulin Lower at night
• BREAKDOWN OF RBC
Growth hormone Higher in afternoon and
• Increase in: K, Ammonia, PO4, Fe, ALT, AST, LD,
evening
ALP, ACP, Catecholamines, CK - in marked
Acid phosphate Higher in afternoon and
hemolysis
evening
o These are found inside the RBC
o Need to be centrifuged in order to see results Thyroxine Increase with exercise
Prolactin Higher with stress; higher
levels at 4 and 8 AM and
at 8 and 10 PM
Iron Peaks early to late
morning; decrease up to
30% during the day
Calcium 4% decrease supine

PHYSIOLOGIC VARIATION
• Changes that occur within the body such as cyclic
changes (diurnal or circadian) or those resulting from
exercise, diet, stress, gender, age, drugs, posture or
underlying medications.
• Affected by diurnal variation:
Increased in AM: ACTH, aldosterone, cortisol and
iron.
Decreased in PM: Acid Phosphatase, Growth
Hormone, Parathyroid Hormone, Thyroid Stimulating
Hormone
• Affected by age (decreased levels):
Creatinine clearance, Hormones
o Found in the kidney

THE AVENGERS SQUAD 4