Pre-analytical Phase of Testing
- Begins when test is ordered
- Ends when testing begins
Reference Ranges/Intervals
- Tests confirm health or screen, diagnose, & monitor disease
- Test results are compared with specimens of healthy people
- Consist of range of values with high & low limits
- Most often based on healthy, fasting people
Basal State
Resting state of body early in morning after fasting twelve (12) hours
Basal State Specimen
- Ideal for establishing reference ranges on inpatients
- Effects of diet, exercise, etc... on test result are minimized
Basal State is Influenced by
- Age
- Gender
- Conditions of body
Physiological Variables: Age
Red Blood Count and White Blood Count values are normally higher in newborns than in adults.
Example: creatinine clearance, a measure of kidney function, is directly related to the age of the patient, which must be factored in when test results are being
Physiological Variables: Altitude
Test results for some blood analyses show significant variation at higher elevations compared with results at sea level. Red Blood cell Counts are a prime example
Physiological Variables: Dehydration
A person with persistent vomiting or diarrhea, causes hemoconcentration, a condition in which blood components that cannot easily leave the blood stream because concentrated in the smaller plasma volume.
Blood components affected include RBCs, enzymes, ir
Physiological Variables: Diet
Blood analyze composition can be altered by the ingestion of food and drink. Blood specimens collected after a meal or snack are unsuitable for many laboratory tests. Diet effects on analyses are generally temporary and vary depending upon the amount and
Physiological Variables: Diurnal/Circadian Variations
- "___": Happening daily
- "___": Having a 24 hour cycle
Physiological Variables: Drug Therapy
- Chemotherapy drugs can cause a decrease in blood cells, especially White Blood Cells and platelets
- Many are toxic to the liver, as evidenced by increase levels of liver enzymes such as aspartate aminotransaminase (AST) also called serum glutamic-oxalo
CRUD
Compounds Reacting Unfortunately as the Desired
Physiological Variables: Exercise
Affects the number of blood components, raising levels of some and lowering levels of others. Depending on the patient's physical condition and the duration and intensity of the activity
Examples of the effects on a number of blood components:
(1) Arteria
Physiological Variables: Fever
Affects the levels of hormones, also increases cortisol and may disrupt its normal diurnal variation
Physiological Variables: Gender
RBC, Hgb, and Hct normal values are higher for males than for females
Physiological Variables: Intramuscular Injection
Can increase levels of creatine kinase (CK) and skeletal muscle fraction of (LDH) It's recommended that CK and LDH levels be drawn before intramuscular injection or atlas one (1) hour after injection
Jaundice
Also called icterus, a condition characterized by increased Bilirubin (a product of the breakdown of RBC's) in the blood, leading to deposits of yellow bile pigment in the skin, mucous membranes, and sclerae, giving the patient a yellow appearance
Position
From Supine (laying down on the back) to an upright sitting or standing position causes blood fluids to filter into the tissues, decreasing plasma volume in an adult up to 10%. Only protein free fluids can pass through the capillaries that are protein in
Burns, Scars, & Tattoos
- Veins are difficult to palpate
- May have impaired circulation
- New burns are painful
- Tattoos may be more susceptible to infection, dyes may interfere
Sclerosed
Hardened
Thrombosed
Clotted
Edema
- Swelling caused by abnormal accumulation of fluid in tissues
- Results when fluid from IV infiltrates surrounding tissues
- Contaminates blood with tissue fluid
- Veins are harder to locate, and tissue is fragile
Hematoma
A swelling or mass of blood (often clotted) that can be caused by blood leaking from a blood vessels during or filling venipuncture
Mastectomy
- Surgical breast removal
- Lymph flow is obstructed with removal of lymph nodes
- Swelling & Infection may be present
- Applying tourniquet here can cause injury
- Can change blood composition
BLOOD SHOULD NEVER BE DRAWN ON THE SIDE AS A "___
Obesity
- Veins may be deep and hard to find
- Use longer tourniquet and try median cubital or cephalic vein
Arterial Line (A-line or Art-line)
- A catheter placed in an artery (usually radial)
- Provides accurate & continuous measurement of blood pressure
- No tourniquet or venipuncture on an arm with an "___
Arteriovenous Shunt or Fistula
- The permanent, surgical fusion of an artery or a vein
- Created to provide access for dialysis
- Located on back of arm above wrist
Blood Sampling Device
- Connected to arterial or central venous catheter to collect blood
- Reduces chance of infection
- Prevents needle sticks
- Minimizes waste from line draws
Heparin or Saline Lock
- A catheter or cannula connected to a stopcock/cap with diaphragm
- Provides access for administering medicine or drawing blood
- Placed in vein in lower arm above the wrist for up to 48 hours
- Flushed with heparin or saline to prevent clogging
IV Line
- A catheter inserted in a vein to administer fluids
- Avoid collecting blood from arm with an IV
- Blood may be contaminated with IV fluid
- If necessary, collect below IV
Previously Active IV Sites
- Avoid collecting from known IV sites for 24-48 hours
Central Vascular Access Devices (CVADs)
- Known as indwelling lines
- Consist of tubing inserted into a main vein or artery used for:
(1) administering fluids and medications
(2) monitoring pressures
(3) drawing blood
Central Venous Catheter or Line
- Inserted into large vein (subclavian)
- Advanced into superior vena cava
Implanted Port
- A small chamber attached to indwelling line
- Surgically implanted under skin (upper chest or arm)
Peripherally Inserted Central Catheter
- Inserted in veins of extremities and threaded into central veins
Adhesive Allergy
- Place gauze square over site; have patient remove in 15 minutes
- Have patient apply pressure for 5 minutes instead of bandage
Antiseptic Allergy
- Use alternative antiseptic
Latex Allergy
- Look for sign indicating latex allergy on patient's door
- Use non latex equipment (gloves, tourniquet, bandages)
Excessive Bleeding
- Patients on aspirin or anticoagulant may bleed longer
- Maintain pressure until bleed stops
- If bleeding continues for more than 5 minutes, notify appropriate personnel
Syncope (Fainting)
- A loss of consciousness and postural tone
- Caused by insufficient blood flow to the brain
- Have patient with history of fainting lay down
Nausea and Vomiting
- Discontinue blood draw until feeling subsides
- Give patient emesis basin or wastebasket
- Apply cold, damp washcloth to forehead
Pain
- Warn patient before needle insertion
- Avoid excessive, deep, blind, or lateral redirection of needle
- Extreme "___" or numbness indicates nerve involvement; remove needle immediately, apply ice, and document incident if persists
Petechiae
- Tiny, non raised red spots that appear when arm tourniquet is applied
Seizures/Convulsions
- Discontinue draw immediately
- Hold pressure over site without restricting patient's movement
- Do not put anything in the patients mouth
- Protect patient from self-injury
- Notify first-aid personnel
Hematoma Formation
- Discontinue draw immediately and hold pressure over the site for 2 minutes
- Offer cold compress or ice pack if it is large and swollen
Iatrogenic Anemia
- Anemia brought about by blood loss from blood draws
- Life is threatened if over 10% of blood volume is removed at once
- Collect only minimum required specimen volumes
Inadvertent Arterial Puncture
- Signs:
(a) rapidly forming hematoma
(b) blood filling tube quickly
Situations That Can Trigger Hematoma Formation
(1) Excessive or blind probing to locate the vein
(2) Inadvertent arterial puncture
(3) Vein is fragile or too small for needle size
(4) Needle penetrates right through the vein
(5) Needle is only partly inserted in the vein
(6) Needle is removed while to
Infection
- Avoid doing the following:
(a) don't open bandages or tape ahead of time
(b) don't preload needles onto tube holders
(c) don't touch needle site once sterilized
(d) minimize time between cap removal and venipuncture
(e) remind patient to keep bandage on
Reflux of Anticoagulant
- Blood flows back into vein from collection tube
- Tube additives may cause adverse reaction
- Keep arm in downward position and tube below venipuncture site
Vein Damage
- Avoid numerous venipuncture in the same area
- Avoid blind probing and improper technique
Hemoconcentration
- A decrease in fluid content of blood
- An increase in non filterable large molecules
- Caused by stagnation of normal venous flow due to tourniquet
Hemolysis
- Damage to or destruction of RBCs
- Hemoglobin escapes into fluid part of specimen
Short Draw
- Partially filled tubes, blood to additive ratio may be incorrect
Ways to Help Hemoconcentration During Venipuncture
(a) ask the patient to release fist upon blood flow
(b) choose an appropriate patient vein
(c) do not allow patient to pump the fist
(d) do not excessively massage the area to locate a vein
(e) do not probe or redirect the needle multiple times
(f) releas
Specimen Contamination
- Allowing alcohol residue, fingerprints, glove powder, baby powder, urine on newborn screen samples
- Getting glove powder on blood films or capillary specimens
- Dripping perspiration into capillary specimens
- Following improper antiseptic procedure
-
Tube Position Failure
- Improper seating
- needle fails to penetrate stopper
Collapsed Vein
- Veins draw together temporarily, shutting off blood blow
Caused by:
(1) vacuum of tube or plunger pressure too strong
(2) tourniquet is too tight or close to site
(3) tourniquet is removed during draw
Tube Vacuum
- Loss of vacuum due to level partially out of skin
- Loss of vacuum due to damage of tube
A "___" can keep a patient in the hospital for
Up to 4.5 days