Lecture 6 Flashcards

1
Q

Test performed on blood and other body fluids

Blood collection:

A

Venous or capillary
Serum most often used (SST)
Could also include plasma (heparinized) or whole blood

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2
Q

Test performed on blood and other body fluids Arterial

A

For blood gas measurements – Heparinized sample

Place on ice and analyze immediately

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3
Q

Serum is commonly used for

A

most clinical chemistry tests
Depending on the analyzer and methods, serum, plasma and/or whole blood may be used
Be familiar with all blood collection tubes and anticoagulants
Chemistry – SST, red top, green, grey, royal blue

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4
Q

What should you not do:

A

Avoid collecting blood from - an arm with IV, or collecting above an IV line
Specimen must be free from hemolysis - Falsely elevated results – K+, LD, AST, Mg+, Iron, Vitamin B12, Folate
Timing of specimen – fasting, random, 2hr PC, antibiotic testing
Avoid delay in delivery to the lab or testing – test within one hour of collection
Refrigerate the serum at 40C if testing is delayed

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5
Q

Analyte

A

Chemical substance/test for analysis

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6
Q

Profiles

A

– Group of tests performed to determine the condition of patients, function of organs or systems
Profiles/Panel include – Kidney/renal, liver/hepatic, cardiac, lipid, thyroid

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7
Q

Units of measurement – SI units

A

Analytes – millimoles per liter – mmol/L
Enzymes – units per liter – U/L
Therapeutic Drugs – often in mg/dL

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8
Q

Electrolytes – ions in body fluids

A

Measurement of electrolytes include:
Na+, K+, Cl-, HCO3-
Cations and Anions
Electrolyte balance within the body is important in maintaining fluid and acid-base balance

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9
Q

What are ELECTROLYTES?

A

Substance when dissolved in solution separates into ions; is able to carry an electrical current

CATION - positively charged electrolyte
ANION - negatively charged electrolyte 
# Cations must = # Anions for homeostatsis to exist in each fluid compartment
Commonly measured in mmol/liter
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10
Q

INTRACELLULAR FLUID (ICF) - 63%

A
Inside cell
Most of body fluid here - 63% weight
Decreased in elderly
POTASSIUM
MAGNESIUM
PHOSPHOROUS
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11
Q

EXTRACELLULAR FLUID (ECF) - 37%

A

Outside cell
Intravascular fluid - within blood vessels (5%)
Interstitial fluid - between cells, blood vessels (15%)
Transcellular fluid - cerebrospinal, pericardial , synovial
SODIUM CALCIUM
CHLORIDE
BICARBONATE

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12
Q

Significance of Electrolytes

A
Blood volume
Blood pressure
Blood pH
Nerve impulses
Muscular activity
Buffer body fluids and control movement of fluids between intra and extracellular departments
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13
Q

ADH (Antidiuretic Hormone)

A

Made in hypothalamus; water conservation hormone
Acts on renal collecting tubule to regulate reabsorption or elimination of water
If blood volume decreases, then ADH is released water is reabsorbed by kidney. Urine output will be lower but concentration will be increased.

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14
Q

ALDOSTERONE RENIN

A

Produced by adrenal cortex
Acts on renal distal convoluted tubule
Regulates water reabsorption by increasing sodium uptake into the blood
Renin - Released by kidneys in response to decreased blood volume which impacts blood pressure

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15
Q

Sodium Functions

A

Transmission of nerve impulses
Responsible for osmolarity of vascular fluids
Regulation of body fluid levels
Assists with regulation of acid-base balance by combining with Cl or HCO3 to regulate the balance

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16
Q

Hypernatremia

A

Occurs with excess loss of H2O or excessive retention of Na

Can lead to death if not treated
Causes
Vomiting/diarrhea (Dehydration)
Inadequate ADH (Antidiuretic hormone)
Diabetes Insipidus
Burns
17
Q

Hyponatremia

A
Excessive sodium loss or H2O gain
Causes
Prolonged diuretic therapy (drugs)
Diabetic acidosis (also known as ketoacidosis or metabolic acidosis)
Renal disease
18
Q

Chloride Functions

A

Found in ECF
Maintains serum osmolarity
Works with Na in retention of water
Assists with regulation of acid-base balance
Combines with other ions for homeostasis; Cl combines with hydrogen to form hydrochloric acid in the stomach
Increased Cl-: dehydration and respiratory difficulties (hyperventilation)
Decreased Cl-: renal diseases

19
Q

Potassium Function

A

Potassium is the most abundant cation in the body cells
97% is found in the intracellular fluid
If Serum is left sitting on a blood clot the potassium will leak out of the cells, causing the potassium level in the serum to increase
A serum K+ level below 2.5 or above 7.0 can cause cardiac arrest
80-90% is excreted through the kidneys
Functions
Promotes transmission of nerve impulses
Regulates heart beat and muscle function
Promotes enzyme action
Assist in the maintenance of acid-base
Daily intake of K is necessary because it is poorly conserved by the body

20
Q

Hyperkalemia:

A

Results from impaired renal function
Diabetic/Metabolic acidosis
Acts as myocardial depressant; decreases or causes irregular heart rate
Paralysis of the lungs – absence of oxygen (Anoxia)

21
Q

Hypokalemia:

A

Prolonged diuretic therapy (loss of water)
Inadequate intake of potassium
Severe diarrhea, vomiting – loss of water
Increased aldosterone

22
Q

Bicarbonate (HCO3- ):

A
regulates the amount of carbon dioxide
Help to maintain blood pH
Usually measured as total CO2
Changed by respiration
Diabetic/Ketoacidosis
Renal failure

22 - 28 mmol/L

23
Q

Calcium

A

Necessary for proper bone and teeth development/hardness
Reserves of calcium are in the bones
Highest concentration of minerals in the body
One half of blood calcium is bound to protein and the rest is in ionized form Ca2+ necessary for muscle contraction/relaxation and blood coagulation
Vitamin D is necessary for the absorption of calcium in the intestine

Reference Range 1.15 – 1.33 mmol/L

24
Q

Hypercalcemia

A

High calcium blood levels- hyperparathyroidism, kidney stones

25
Q

Hypocalcemia

A

Life threatening – Vitamin D deficiency, impaired absorption, removal of thyroid gland (hypoparathyroidism)

26
Q

Phosphorus / Phosphate

A

Necessary for proper bone and teeth development and cell membrane
Part of high energy compounds (ATP) within the cells
Building blocks for cell membrane and DNA
Reserves of phosphorus are in the bones

Reference Range 0.96 – 1.44 mmol/L

27
Q

Magnesium

A

Help in the functioning of the heart, nerves and muscles
Plays role in carbohydrate and protein metabolism and storage
Supports a healthy immune system
Reference Range 0.7 – 1.0 mmol/L

28
Q

Phosphorus (Phosphate – HPO4- )

A

Besides the bones, it is essential for energy production within the cells, major building block for cell membrane and DNA

29
Q

Kidney/Renal Function - Profile

A

Kidneys – eliminate waste products for homeostasis; production of hormones
Profile (test) for kidney disease include:
Creatinine, BUN, eGFR, Uric Acid and 24 hour urine

30
Q

Creatinine profile

A

Waste product of creatine phosphatase (muscles)
Increased in impaired kidney functions
Very useful in assessing kidney disease
Reference Range 62 – 125 µmol/L

31
Q

Uric Acid profile

A

Used to diagnose and treat gout
Gout – Precipitation of uric acid in tissues and joints causing pain
Reference Range 0.21 – 0.44 mmol/L

32
Q

BUN/Urea – Blood Urea Nitrogen profile

A

Measurement of urea in the blood
Urea – is the by-product when proteins are broken down into amino acids
Influenced by diet, hormones and kidney functions
Reference Range 2.9 – 6.4 mmol/L

33
Q

eGFR - Estimated Glomerular Filtration Rate

A

To assess kidney function
Performed by ordering a creatinine test and calculating the eGFR using the age, gender, and race of the patient
Normal values are 90 – 120 mL/min
Below 60 mL/min suggest that some kidney damage has occurred

24 hour urine – Quantitative test for urine analytes
Previously discussed