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• Pre-analytical errors can occur during blood specimen collection and transport
• There are various means of pre-analytical error prevention
• Proactive steps can reduce potential pre-analytical errors associated with blood collection and transport

Laboratory Testing Phases

• Pre-analytical, analytical, and post-analytical are the three phases of laboratory testing
• Pre-analytical phase involves specimen collection, transport, and processing
• Analytical phase involves testing
• Post-analytical phase involves testing results transmission, interpretation, follow-up, and retesting

Phlebotomy Errors

• Phlebotomy requires expert knowledge, dexterity, and critical judgment, making it a highly complex skill
• Phlebotomy errors may cause harm to patients or result in needlestick injury to the phlebotomist

Pre-Analytical Errors

• Pre- and post-analytical errors are estimated to constitute 90% of errors
• Errors at any stage of the collection, testing, and reporting process can potentially lead to a serious patient misdiagnosis
• Errors during the collection process are not inevitable and can be prevented with diligent quality control, continuing education, and effective collection systems

Types of Collection Errors

• Patient Identification
• Phlebotomy Technique
• Test Collection Procedures
• Specimen Transport
• Specimen Processing

Patient Identification Errors

• Errors in correctly identifying the patient are indefensible
• Reasons for patient identification errors include not following proper patient identification procedures
• Patient identification from identification bracelet (inpatients)
• Patient identification by asking patients to state or spell their full name (inpatients/outpatients)
• Patient identification by staff or family member if patient is unable to identify themselves
• Specimen tubes unlabeled
• Requisition or collection tube labels not affixed to tubes
• Requisition or collection tube labels in bag containing collection tubes
• Requisition or collection tube labels rubber-banded to tubes
• Collection tube labels not affixed to all tubes
• Specimen collection tubes labeled insufficiently with at minimum patient's full name, date/time of collection, and phlebotomist's initials
• Collection tubes labeled with the wrong patient
• Wrong computerized labels affixed to collection tubes at bedside
• Collection tubes not labeled at the time of collection
• Collection tubes incorrectly labeled by someone other than the phlebotomist who collects the specimen

Patient Complications

• Some patient variables that affect blood specimens:
• Diet, including fasting
• Exercise
• Obesity
• Allergies to alcohol or iodine used to clean venipuncture site, and the use of an alternative cleanser such as chlorhexidine, if necessary

Phlebotomy Technique Errors

• Ensures test result validity
• Minimizes trauma to patient
• Minimizes potential for phlebotomist injury
• Reduces recollections

Vein Selection

• Essential for successful venipuncture
• Three veins in antecubital fossa in order of selection:
  • (1) median cubital
  • (2) cephalic
  • (3) basilic

Site Selection

• Avoid sites with IV:
  • Use alternative arm or draw below IV to avoid contamination/dilution from IV
  • Document arm if IV
• Mastectomy—avoid site due to lymphostasis
• Infection risk/alteration in body fluids and blood analytes
• Edematous areas avoid due to accumulation of body fluids:
  • Possible contamination/dilution of specimen

Venous Access Difficulties

• Obstructed, hardened, scarred veins
• Veins difficult to locate
• Use of Alternative sites:
  • Top of hand/Side of wrist
  • Areas to avoid
• Vein Collapse:
  • Use of appropriate needle size
  • Smaller evacuated collection tube
• Tourniquet Application:
  • Tied too close to the venipuncture site can cause hematoma
  • Veins may not become prominent if tourniquet is tied too high (more than 3 to 4 inches above venipuncture site)
  • Left on longer than one minute can result in hemoconcentration, affecting some test results
  • Should be released as soon as needle is in the lumen of the vein and blood flow established
• Cleansing of venipuncture site:
  • Thorough cleaning with alcohol
  • Allow alcohol to dry completely to avoid stinging sensation upon needle entry and hemolysis of sample
  • Samples such as blood cultures should be collected using iodine to cleanse site to ensure sterility of sample
  • Recollection rate for blood cultures ranges due to contamination is as high as 50% in hospitals with increased costs, and patient overtreatment

Collection

• Correct collection system
• Evacuated tube system (Vacutainer) for large veins in antecubital fossa
• Syringe for small, fragile veins or veins outside antecubital fossa

Venous Access

• Needle entry should be at 15 to 30 degrees depending on depth of vein
• Needle entry should be in same direction as vein, centered over vein
• Anchor vein to prevent movement during needle entry and reduce pain to patient

Test Collection Errors

• Order of Draw:
• Can affect the quality of the sample and can lead to erroneous test due to contamination with the additive from the previous blood collection tube
• Hemolysis:
  • Blood collected insufficient to amount of additive in tube,
  • Traumatic venipuncture
  • Blood collected from area with hematoma
  • Vigorous shaking of tubes after collection
• Milking the site when collecting capillary samples and blood collected using a small diameter needle

Timing of Collection

• Timed Draws:
• Therapeutic Drug Monitoring
• Peak and trough collection times
• Basal State Collections:
  • Fasting requirements—no food or liquid except water
• Specimens affected by time of day, for example, cortisol
• Improper collection tube drawn for test ordered
• Collection tube not completely filled:
  • Example-light blue top tube for Coagulation Studies.
• Incomplete filling results in specimen dilution and erroneous Prothrombin and aPTT test results

Capillary Collections

• Finger stick or heel stick
• Appropriate site:
• Heel stick-sides of the bottom surface of the heel
• Finger stick-third or fourth fingers, perpendicular to fingerprint lines on fleshy pads on finger surface
• Warming-Warm before collection to increase capillary blood flow near skin surface
• Cleaning-cleanse site with alcohol and allow to air dry
• Massaging site to increase blood flow
• Milking site can cause hemolysis or tissue fluid contamination
• Heel sticks-gently squeeze infant's heel before performing puncture.
• Perform puncture while firmly squeezing finger or heel
• Wipe away first two drops of blood
• Ensure that full blood drop wells up each time
• Avoid touching capillary collection tube or micro collection tube to skin or scraping skin surface
• Contaminates puncture site
• Blood may become hemolyzed
• Mixing micro collection tubes with additive frequently to avoid micro clots
• Collecting tubes with additives first
• Protecting tubes for bilirubin from light

Blood Specimen Errors

• Transport of blood specimens in the proper manner after collection ensures the quality of the sample
• Timing:
  • Some specimens must be transported immediately after collection, for example Arterial Blood Gases.
  • Specimens for serum or plasma chemistry testing should be centrifuged and separated within two hours

Transport Errors

• Temperature:
• Specimens must be transported at the appropriate temperature for the required test:
  • On ice-ABGs, Ammonia
  • Warmed --98.6 degrees (37 C), cryoglobulins
  • Avoid temperature extremes if transported from via vehicle from other collection site
• Transport Container:
  • Some samples need to be protected from light, for example, bilirubin
  • Transport in leak-proof plastic bags in lockable rigid containers

Error Prevention

• Standard academic course in phlebotomy with on-the-job training under the supervision of a senior phlebotomist
• Regular educational competency assessments (written and observational)
• Professional Licensure
• Adequate staffing to maintain collection standards
• Use of barcode scanners for patient identification