Order of A Blood Draw

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Posted on 31st March 2011 by admin in Uncategorized

The order that blood is collected in collection tubes during a multiple tube draw or filled from a syringe must be done correctly otherwise there is an increased chance of contamination due to additive carryover, tissue thromboplastin, or microorganisms.  The order of draw is a specific sequence of tube collection that should be used to minimize problems.  The order of the draw may vary among institutions.  A phlebotomist should always use the institutional protocol.

It can be difficult to remember which additives affect which tests.  This is why the order of the draw is helpful.  By following the specific order you can eliminate confusion and use a sequence of collection that will prevent the least amount of interference should any carryover happen.  The best way to minimize the chances of carryover is to fill specimen tubes from the bottom up during collection.  Also try and prevent the tube from coming into contact with the needle during the draw or when transferring blood into tubes from a syringe.

There are several types of contamination that can occur during a multiple tube draw or filled from a syringe.

Carryover/Cross Contamination- This type of contamination occurs from the transferring of additive from one tube to another tube.  It can occur when blood in an additive tube touches the needle during evacuated tube system (ETS) blood collection.  It can also occur when blood is transferred from a syringe into ETS tubes.  If blood remains on or within the needle, it can be transferred from a syringe into ETS tubes.

Tissue Thromboplastin Contamination- This form of contamination can occur when tissue thromboplastin interferes with coagulation tests.  This can happen when a needle picks up tissue thrombinoplastin during venipuncture and fills the first tube during ETS collection.

Microbial Contamination- Blood culture tubes are sterile and should be collected first to ensure that they maintain their sterility to prevent microbial contamination of the needle from the unsterile tubes that are used to collect other blood specimens.  Special site-cleaning measures should be taken prior to collection to prevent specimen contamination by microoganisms that are found on the skin.

Special Anticoagulants and Antiglycolytic Agents

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Posted on 30th March 2011 by admin in Uncategorized

There are special-use anticoagulants that are combined with other additives for special blood testing situations that must be learned when studying how to become an allied health professional and especially how to become a phlebotomist technician.

Acid citrate dextrose (ACD)- This is a solution that is used for DNA testing and human leukocyte antigen phenotyping for paternity evaluation and determining transplant compatibility.  Acid citrate is able to bind calcium and prevent coagulation.

Citrate-Phosphate-Dextrose (CPD)- This anticoagulant is used when collecting blood for transfusions.  Citrate is able to prevent clotting by binding with calcium, phosphate stabilizes pH, and dextrose helps to keep cells alive and energized.

Sodium polyanethol sulfonate (SPS)-  SPS is able to prevent coagulation by binding with calcium.  This anticoagulant is commonly used for blood culture collection because it is also able to reduce the action of complement proteins that destroy bacteria, slows down phagocytosis, and reduces the activity of certain antibiotics.

An antiglycolytic agent is a substance that is used to prevent glycolysis, the breakdown of blood sugar, by blood cells.  If this process is not prevented by using an antiglycolytic agent, the blood sugar in a blood specimen will decrease at a rate of 10 mg/dL per hour.

Glycolysis has been found to occur much faster in newborns due to their high metabolisms.  Also patients with leukemia have higher rates of glycolysis because they have a higher rate of metabolic activity from the activity of white blood cells.

Sodium fluoride is the most common antiglycolytic agent used.  It is able to preserve glucose for up to 3 days and is also useful at inhibiting the growth of bacteria.

Anticoagulants

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Posted on 29th March 2011 by admin in Uncategorized

When blood samples are collected blood coagulation is activated due to the intrinsic pathway that is triggered by contact with negatively charged surfaces such as glass.  This is why blood begins to coagulate in a test tube.  To prevent blood from clotting anticoagulant substances can be added.  There are two methods a coagulant can use to prevent blood clotting.  It can either chelate or precipitate calcium from the blood making it unavailable to the coagulation process or it can inhibit the formation of thrombin that is needed to convert fibrinogen to fibrin during the coagulation process.  An anticoagulant should be added to whole blood specimens immediately after collection to prevent microclot formation.

There are several different types of anticoagulants that can be used for different types of testing.  There are four common anticoagulants that are used for certain types of testing.

EDTA- This anticoagulant is a sodium or potassium-based salt that is used to prevent coagulation by binding calcium.  Many blood banks use it when collecting blood from donors.  It is also used because it is able to preserve cell morphology and inhibit platelet aggregation for hematology tests.

Citrates- Citrates are able to prevent coagulation by binding calcium.  Sodium citrate is used for coagulation tests because it is very effective at preserving the coagulation factors of the blood, which are performed on plasma.  In order to add this anticoagulant to plasma the specimens must be centrifuged so that the plasma is separated from the cells.  Calcium is added back to the specimen to initiate clotting during testing.  As the calcium is added the clotting process is timed.

Heparin- This anticoagulant is used to prevent clotting by inhibiting the formation of the enzyme thrombin.  This enzyme is necessary for clot formation.  As with other anticoagulants, heparin should be mixed into a collected specimen immediately to prevent clot formation and fibrin generation.  There are three heparin formulations that are used to prevent clotting.  They are ammonium, lithium, and sodium heparin.  The most commonly used formulation is lithium heparin because it causes the least interference in chemistry testing and widely used for plasma and whole-blood chemistry tests.

Potassium oxlates- Oxlates are able to precipitate calcium from the blood.  The most commonly used oxalate is potassium oxalate, which is often used to provide plasma for glucose testing.

Heart Rate and Cardiac Output

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Posted on 24th March 2011 by admin in Uncategorized

The heart beats non stop day and night.  The number of heat beats that occur per minute is called the heart rate.  This rate is used to determine how much blood is pumped through the heart in a given amount of time.  The volume of blood pumped by the heart is called the cardiac output.  On average, a normal adult heart pumps about 5 liters of blood per minute through the body. A person’s heart rate can vary depending on activity.

However a marked and persistent rate change usually signals cardiovascular disease.

Some people have heart irregularities that affect the heart rate and rhythm.  A heart irregularity is called an arrhythmia.  There are several types of heart arrhythmias.  A person with a slow heart rate that is less than 60 beats per minute has a heart arrhythmia condition called bradycardia.  There are several potential causes of bradycardia that include low body temperature, certain drugs, or parasympathetic nervous activation.  Many endurance athletes have bradycardia because the physical and cardiovascular conditioning that they undergo causes the heart to hypertrophy and stroke volume to increase.  This change allows the resting heart rate to be lower while still providing the same cardiac output.

A fast heat rate over 100 beats per minute is called trachycardia.  This condition can result from elevated body temperature, stress, certain drugs, or heart disease.  It can commonly occur when someone has a high fever.  Persistent trachycardia is a pathological condition because it can promote fibrillation of the heart.  Heart fibrillation is a condition of rapid and irregular heart contractions that result when control of heart rhythm is taken away from the sinoatrial (SA) node due to rapid activity in other regions of the heart.  The rapid, uncoordinated contrations caused by heart fibrillations can result in lack of pumping action.

Common Types of Arthritis

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Posted on 21st March 2011 by admin in Uncategorized

Inflammation occurs in the body as a response to tissue injury.  Many types of inflammatory conditions affect millions of people every year.  Common types of arthritis are caused from inflamed tissues.

Osteoarthritis is a degenerative joint disease that affects a large majority of people over the age of 70.  Many symptoms for this disease manifest during the fifth and sixth decade of life.  The exact cause of osteoarthritis is still unknown but some researchers believe that it is caused from compounded problems with digestion, which inevitably manifest later in life.

Rheumatoid arthritis usually occurs in women between 30 and 70 years of age.  The early symptoms include fatigue, weakness, joint pain and stiffness.  Affected joints are usually inflamed and the range of motion in those joints is often limited.  This type of arthritis usually progresses causing joint deformity.  Research has found heat therapy, weight control, and exercise to be helpful at reducing inflammation as well as the use of aspirin-type products and Disease Modifying Anti-Rheumatic Drugs.

Gout is an inflammatory condition that affects the joints, tendons, and other tissues of the body.  It is most commonly manifest in the joint of the big toe.  Diet is usually the cause of this inflammation.  A build up of uric acid in the body can cause urate crystals to form.  These crystals can form into urate calculi stones that may appear in the tissues of earlobes, elbows, hands and at the base of the large toe.  A person suffering with gout should increase fluid intake and avoid foods high in purines, such as wine, meats, salmon, seafood and gravy.

Nursing: How to Administer Eardrops or Nosedrops to Patients

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Posted on 1st March 2011 by admin in Uncategorized

How to become a nurseInstillations are liquid medications that can be administered to the eyes, ears and nose.  There are several important steps that should be followed to prevent the spread of disease and to prevent unnecessary discomfort to the patient when administering eardrops and nasal drops or sprays.

When administering eardrops to patients, the following guidelines can be helpful for anybody studying how to become a nurse.

-Always check the prescriber’s order.  It is important to read the prescriber’s orders so that you are aware of any special instructions or considerations as well as the correct dosage amounts.

-Always wash your hands and apply clean gloves before administering eardrops.  This can help to prevent the spread of disease.

-Positions the patient’s head so that the side that needs the medication is tilted slightly upward.

-Straighten the external ear canal.  A patient that is 3 years old or older should have his or her ear straighted by pulling the auricle up and back.  If the patient is younger than three years the ear canal should be pulled down and back to straighten.

-Only the prescribed number of drops should be administered into the ear.

-Avoid touching the ear with the dropper because the dropper can easily become contaminated.

-After the drops are administered, the patient should remain with his or head tilted for 2-3 minutes so that the medication does not drain out of the ear.

Nose drops should be administered in the following manner.

-The prescriber’s orders should be looked over.

-The patient should be given a tissue and asked to blow his or her nose.

-If nose drops are to be used, the patient should position his head back if the infection is located in the frontal sinus.  Position the patients head to the affected side if the infection is in the ethmoid sinus.  Administer the prescribed number of drops into the nose and ask the patient to keep his or her head in the same position for five minutes after the drops have been administered.

-If nose sprays are administered, ask the patient to close the unaffected nostril.  Have the patient tilt his or her head to the side of the closed nostril and spray the medication into the affected nostril.  The medication instructions will specify whether the patient should hold his or her breath or open the closed nostril and breathe following administration of the nasal spray.