TRIPASS XR تري باس

 

Normal Values

SI units

Potassium

Adults 3.5–5.3 mEq/L 3.5–5.3 mmol/L

Premature infants 5.0–10.2 mEq/L 5.0–10.2 mmol/L

Cord blood 5.0–10.2 mEq/L 5.0–10.2 mmol/L

2 days 3.0–6.0 mEq/L 3.0–6.0 mmol/L

Full-term newborn

Cord blood 5.6–12.0 mEq/L 5.6–12.0 mmol/L

Newborn 3.7–5.0 mEq/L 3.7–5.0 mmol/L

Infants 4.1–5.3 mEq/L 4.1–5.3 mmol/L

Children 3.4–4.7 mEq/L 3.4–4.7 mmol/L

Panic levels

Adults < 2.5 mEq/L < 2.5 mmol/L

or > 6.6 mEq/L or > 6.6 mmol/L

Newborn < 2.5 mEq/L < 2.5 mmol/L

or > 8.1 mEq/L or > 8.1 mmol/L

Sodium

Adults 136–145 mEq/L 136–145 mmol/L

Umbilical cord 116–166 mEq/L 116–166 mmol/L

Infants 139–146 mEq/L 139–146 mmol/L

Children 138–145 mEq/L 138–145 mmol/L

Alterations of Sodium and Extracellular Fluid (ECF)

Hyponatremia (Serum Sodium Concentration Lower

than Normal)

Total-body sodium and ECF volume low:

¾ GIT fluid loss

¾ Burns

¾ “Third compartment” accumulation

¾ Salt losing renal disorders

¾ Diuretic overuse.

Total body sodium and ECF volume normal

¾ Acute water intoxication, usually iatrogenic

¾ Syndrome of inappropriate ADH secretion.

¾ Glucocorticoid deficiency.

¾ Severe whole body potassium depletion.

Total body sodium and ECF volume increased

¾ Acute renal failure with superimposed water load

¾ Congestive heart failure

¾ Cirrhosis

¾ Nephrotic syndrome.

Hypernatremia (serum sodium concentration higher

than normal)

Total body sodium normal, ECF volume low

¾ Gastroenteritis

¾ Osmotic diuresis

¾ Pronounced sweating.

Total body sodium increased proportionately more than

increased ECF volume

¾ Salt ingestion, deliberate or accidental.

¾ Inappropriate intravenous therapy.

Hyperosmolality, without sodium alterations

¾ High blood ethanol

¾ Hyperglycemia

¾ Radiographic contrast media.

Abnormalities of Serum and Whole Body Potassium

Hyperkalemia (serum potassium concentration more

than normal)

Inappropriate cellular metabolism

¾ Insulin deficiency

¾ Acidemia

¾ Hypoaldosteronism

¾ Cell necrosis (burns, crush, hemolysis, anti-leukemia

therapy).

Decreased renal excretion

¾ Acute renal failure

¾ Chronic interstitial nephritis

¾ Tubular unresponsiveness to aldosterone

¾ Hypoaldosteronism.

FIG. 21.4: Standard air compressor for flame photometers

Blood Gases and Electrolytes 561

FIG. 21.5: Bayer 614 electrolyte analyzer

•  20 character alphanumeric vacuum fluorescent display

• Caliberation and slope solutions are contained within instrument

• Extremely easy to use

• Stable: the measured calibration value will change by less than

+/– 2 mmol/L na+ and +/– 0.1 mmol/L K+ in a 1 hour period at

constant ambient temperature

Specifications 614 634 644 654 664

Test performed Na+

/K+ Ca++/pH Na+

/K+

/Cl– Na+

/K+

/Li+ Na+

/K+

/Cl–

/tCO2

Measurement

method

ISE ISE ISE ISE ISE, thermal cond

Contd...

Increased potassium intake

¾ Inappropriate use of salt substitutes or K+ replacement.

¾ Potassium salts of antibiotics.

Hypokalemia (serum potassium concentration lower

than normal)

Inappropriate cellular metabolism

¾ Alkalemia

¾ Familial periodic paralysis

¾ Very rapid generation of cells (leukemia, treated

megaloblastic anemia).

Increased excretion

¾ Vomiting and/or diarrhea

¾ Diuretic overuse

¾ Hyperaldosteronism

¾ Renal tubular acidosis.

Decreased potassium intake

¾ Anorexia nervosa

¾ Diet deficient in vegetables, meat

¾ Clay eating (binds potassium and prevents absorption).

RAPID DIAGNOSTICS IN ELECTROLYTE ANALYSIS

Within a remarkably short period of only a few years,

a variety of analyzers have appeared in the market

which use ion-selective electrodes (ISE) for quantitative

measurements of biologically relevant cations and anions.

The electrode (ISE) permits measurement of the activity of

a specific ion under the presence of a given amount of other

ions. The selective transport of a certain ion species from

the solution into the membrane phase of the electrode

allows a potential difference that can be calculated and the

ion concentration can be deduced thereof.

Ion selective electrodes are available for H+ (for pH

measurement), Li+ (Lithium), Na+, K+, Ca++ and Cl¯.

Bayer 614 Na+ K+ Electrolyte Analyzer (Fig. 21.5)

The Corning 614 is designed for whole blood, plasma—

using lithium heparin as anti-coagulant. Fresh samples

can be analyzed at temperatures up to 40°C.

Serum may be used (free from hemolysis) within a

range of 5 to 40°C.

Urine may be used, diluted 1 part sample to 9 parts

urine diluents as long as samples are not collected into

strong acid preservatives.

Sample presentation may be syringe, blood collection

tube, centrifuge tube, vial, vacutainer, etc. A sample

measurement result will be displayed within 35 seconds of

pressing analyze blood? or analyze urine? button. Sample

to sample measurement result will be displayed within

35 seconds of pressing analyze blood? Or analyze urine?

Button. Sample to sample measurement time is 60 seconds.

35 uL blood required

150 uL urine required.

Ranges

Whole blood, serum, plasma, and QC material)

80–200 mmol/L Na+

0.5–9.99 mmol/L K+.

Urine

10–350 mmol/L Na+

5–250 mmol/L K+.

562 Concise Book of Medical Laboratory Technology: Methods and Interpretations Sample types Whole blood, serum,

plasma, diluted urine

Whole blood, serum,

plasma, diluted urine

Whole blood, serum,

plasma, diluted urine

Whole blood, serum,

plasma, diluted urine

Whole blood, serum,

plasma

Sample volume 35 uL, 150 uL

Diluted urine

35 uL 65 uL, 250 uL

Diluted urine

65 uL, 250 uL

Diluted urine

170 uL, 85 uL in

Micro mode,

100 uL diluted urine

Analysis time 35 seconds Within 60 Sec 35 seconds 40 seconds 35 seconds,

100 samples/h

Measuring ranges:

Na+ 80–200 mmol/L N/A 80–200 mmol/L 80–200 mmol/L 50–200 mmol/L

Na+

 (Urine) 10–350 mmol/L N/A 10–350 mmol/L 10–350 mmol/L 10–350 mmol/L

K+ 0.5–9.99 mmol/L N/A 0.5–9.99 mmol/L 0.5–9.99 mmol/L 0.5–20 mmol/L

K+

 (Urine) 5–250 mmol/L N/A 5–250 mmol/L 5–250 mmol/L 5–300 mmol/L

Cl– N/A N/A 50–200 mmol/L N/A 20–200 mmol/L

Cl–

 (Urine) N/A N/A 10–350 mmol/L N/A 15–400 mmol/L

tCO2 N/A N/A N/A N/A 3–60 mmol/L

Ca++ N/A 0.2–5.0 mmol/L N/A N/A N/A

pH N/A 6.50–8.00 mmol/pH N/A N/A N/A

Li+ N/A N/A N/A 0.2–0.50 mmol/L N/A

Dimensions

(W×D×H)

11.0” × 0.16” × 12.6” 11.0” × 10.6” × 12.6” 11.0” × 10.6” × 12.6” 11.0” × 10.6” × 12.6” 25.5” × 19.0” × 16.0”

Weight 14 lbs 14 lbs 14 lbs 14 lbs 64 lbs

Additional

features

604 autosampler

interface

pH at 7.4 or

manually adjustable

between 7.2 and

7.6 pH

604 autosampler

interface

604 interface

autosampler. Dual

mode of operation:

Na+

/K+

/Li+

Interface with 550

Express clinical

chemistry analyzer

Contd...

22

Serology/Immunology

C H A P T E R

BASIC IMMUNOLOGY

The immune system offers protection against invading

microorganisms, viruses and other foreign materials.

Somehow, it must distinguish between Valuable what

“belongs” and what doesn’t “belong”. Failure to detect

and expel foreign materials can lead to problems due to

immunodeficiency (i.e. AIDS) and misidentification of

“self” (autoimmunity).

Antigen-Immunogen

Antigen is a molecule that binds with an antibody or T

cell receptor (antigenicity is the ability to bind to the

antibody).

Immunogen is a molecule that can elicit an immune

response (immunogenicity is the ability to elicit an

immune response).

Antigenicity

Several factors influence how “antigenic” a molecule is.

Most important is how foreign it is, with molecules that

are most unlike self-being the most antigenic. There are

also numbers of physical and chemical determinants,

which also matter molecular size — the larger the better,

generally. 1000 Daltons are about the lower limit.

¾ Complexity: The more complex the better. For example,

simple repeating polysaccharides like starch aren’t

very good, while proteins with a constantly changing

sequence of 20 or so different amino acids are good

¾ Structural stability: A fixed shape is helpful. For

example, gelatin (which wobbles) is a poor antigen

unless it is stabilized

¾ Degradability

¾ Foreignness.

Epitopes (Fig. 22.1)

For a molecule such as a protein, a given antibody will

“be directly against” only one of all the possible parts of

the entire molecule. This part is known as an EPITOPE.

A molecule may have several epitopes. Also, a complex

antigen (such as a cell) will have many molecules, each of

which will contain several epitopes.

An epitope is also known as an antigenic determinant.

Some epitopes are better able to elicit antibodies than

others. They are known as Immunodominant Epitopes.

How Big is an Epitope?

About 6 units of a polysaccharide chain, or about 6–8 amino

acids. For a protein epitope, it is the shape of the epitope,

rather than the specific amino acid sequence that is

FIG. 22.1: Sites for obtaining blood by venipuncture from forearm

564 Concise Book of Medical Laboratory Technology: Methods and Interpretations

important. For example, a few amino acids, which come

from different parts of the chain, can come together in one

physical spot to create an epitope.

When an antibody directed against one epitope can

bind to another epitope, this is known as “cross-reactivity”.

If this happens, it will be because the two epitopes ‘look

alike” in some way.

Some intestinal bacteria possess antigens that look

like blood group A and B antigens which can be absorbed

through the intestinal wall into the bloodstream; therefore,

people of blood group A will have antibodies against the B

antigens even if they never have been exposed to B-type

blood cells.

Antibodies directed against human serum will crossreact with serum from chimpanzees, gorillas, orangutans

and spider monkeys to an increasingly lesser extent.

What are the Different Kinds of Epitopes?

Conformational

Discontinuous.

Some Examples of Antigens

Proteins: Most antigens are proteins, such as the ones on

the outer coverings of microorganisms.