MLS 407 Pre-Analytical Process

The pre-analytical phase of the laboratory testing process is

Before patient specimen testing

What does the Pre-analytical Phase include?

• Patient test ordered

• Specimen collection

• Specimen handling and transport

• Specimen processing

• Specimen acceptability and rejection criteria

When looking for information regarding specimen collection criteria, handling and transport, processing, and rejection criteria you should utilize

• Test procedures

• Online laboratory testing directory

• Package inserts

When determining the suitability of a specimen for testing you must examine

• Test ordered

• Labeling and source

• Quality and quantity

A specimen label must contain:

• Patient name (Last, First)

• Second identifier (DOB, MRN, etc)

• Collection date and time

• Initials of collector

MAY include

• Test ordered

• Source

• Pertinent additional information

What does this label contain?

• Name

• Gender

• DOB

• PST (plasma separator tube)

• Date

• Time

• Test ordered

• Collector initials

Requisition

A piece of paper, like a test order/request form

Can be used as a cross-reference for a specimen label

Includes: name, MRN, patient location, date, ordered test, test status, DOB, accession number, physician, time testing required, source, special precautions

A urine specimen for culture is placed in preservative immediately following collection (transferred from sterile urine cup). This is considered appropriate specimen ____

handling and transport

T/F: You can tell if a centrifuged specimen contains serum or plasma by visual inspection

True and false

• You cannot differentiate between the two without a label/designated tube, or when it has been poured off

A specimen in a heparin/green/PST tube has been centrifuged. This specimen now contains

plasma

Which is the hemolyzed specimen?

C

Hemolysis: pink to red appearance of plasma or serum, due to red cell trauma which causes errors in many tests

• A: Normal (plasma/serum is a translucent yellow color)

• B: Lipemic (milky turbid appearance of plasma/serum, result of non-fasting state)

T/F: This specimen is acceptable for culture

False

• Low quantity

• No labels

• Spills = contamination

T/F: This specimen is acceptable for urinalysis testing

False

• Label needs to be put on specimen directly (on the side), cannot be on the bag

Place the following in order of priority of testing: ASAP/urgent, routine, timed, STAT

1. STAT specimen (immediate, critical)

2. ASAP/Urgent

3. Timed specimen (must collect sample at a specific time)

4. Routine specimen (collected in timely manner, no urgency)

An EDTA tube (purple top) is submitted for CBC analysis. When mixing, the MLS noticed small clumps rolling back and forth in the tube. The next course of action for this patient specimen includes:

Reject the specimen and request a redraw due to the clot

T/F: This centrifuge is balanced correctly

True; tubes (of similar volume/weight) must be placed on opposite side of each other

T/F: A red top tube is submitted for analysis. The specimen can be placed in the centrifuge immediately after collection for processing

False

A red and gold top have to be clotted for 30 minutes before centrifugation. They do not contain anticoagulants but clot activators. These produce serum after centrifugation.

A lipid panel which requires 12-16 hours fasting should be drawn:

12-16 hours after last food intake

Reasons for recollection of a specimen include

• Specimen submitted quantity not sufficient (QNS)

• Improperly labeled specimen

• Wrong specimen type/container for test ordered

• Outside of stability time for testing

• Compromised specimen (clotted, hemolyzed)

• Do not have to recollect if there is no order with specimen submitted, just request for an order

Which fluid is associated with the lungs?

Pleural

If a specimen handling requirement is to keep proper storage conditions at 4-6C, the specimen should be placed in which environment?

Refrigerator

Instructions on appropriate patient preparation for specimen collection for a specific laboratory test can be found on/in the:

• Test procedure

• Test directory

This is an example of:

Blood bank armband placed on patient

• Armband usually has stickers (the YGJs) for extra labeling

• Labeled at patient’s bedside

• 2 unique patient identifiers, collection date, ID of PB (phlebotomist)

What are the three phases of the laboratory testing process?

1. Pre-analytical phase (occurs prior to analysis)

2. Analytical phase (during analysis)

3. Post-analytical phase (after analysis)

What is the most fundamental responsibility of the laboratory?

To ensure the quality of test results

• Accurate patient values and results are used to rule out disease, diagnose, and monitor treatmetn

What is the pre-analytical phase?

• Begins when test is ordered and ends when testing begins

• Most errors occur in this phase

What types of specimens are analyzed by the laboratory ?

• Blood (most common) - venous, capillary, arterial

• Urine (second most common) - voided, clean-catch, catheterized

• Other bodily fluids - cerebrospinal, synovial (joints), pleural (lungs), pericardial (heart), amniotic, semen

• Tissue, sputum, feces, bone marrow, saliva, nails, hair

• Culture: all of the above specimen types using sterile collection devices (except feces)

What types of collection tubes/containers/methods are used?

• Blood collection tubes for whole blood, plasma, or serum

• Leak-proof and screw-cap containers for non-blood specimens (may be sterile)

• Others: swabs, syringes

• Transport media or preservatives are used if necessar

T/F: For each test ordered, the required tube or container type, specimen volume, and handling requirements can be reviewed after the specimen is collected

False, it should be reviewed BEFORE collection

Does the laboratory collect all patient specimens? Who is responsible for specimen collection?

• Can be collected by

  • lab personnel

  • other healthcare professionals

  • patients

• The lab is responsible no matter who collects the specimen

A critical part of specimen collection is correct patient ____ and proper ____

identification; labeling

What is the order of specimen prioritization?

1. STAT

2. ASAP

3. Timed

4. Fasting

5. Routine

T/F: Information on requisition and label MUST match

True

Why is proper handling and transport of specimens to the laboratory important?

It maintains specimen integrity

Handling and transport requirements may include

• Time limits for testing

• Specific temperatures

• Avoiding light exposure

• Transport systems or preservatives

T/F: Processing of the specimen prior to testing usually does not require centrifugation and preparation of aliquot tubes

False, may include these

What happens after centrifugation?

Specimens are examined for errors/conditions that may cause invalid results

Prior to testing, each specimen is evaluated for acceptability based on

• Test ordered and procedure

• Labeling and source

• Quantity and quality

If testing will be delayed, the specimen may be

stored per conditions stated in procedure

What are examples of unacceptable specimens?

• Improperly labeled specimen

• Wrong specimen/container

• QNS

• Outside of stability time for testing

• Compromised specimen (clotted, hemolyzed)

What does “Labile” mean?

Analytes or organisms that are time or environment sensitive

What are the temperature ranges for

• Room

• Refrigerator

• Freezer

• Incubator

• Room = 20 to 25C

• Refrigerator = 2 to 8C

• Freezer = -10C or below

• Incubator = 35 to 37C and humidified

Aliquot

a portion of a specimen transferred into one or more aliquot/transfer tubes, labeling is critical!

Lipemic

milky, turbid appearance of plasma/serum, result of non-fasting state

Icteric

dark yellow/amber appearance of plasma, serum, or urine. Due to bilirubin

What are the types of specimens analyzed in the laboratory?

• Blood

  • venous

  • capillary

  • central line or “PICC” line port (from peripherally inserted central catheter)

  • arterial

• Urine

  • midstream/clean-catch

  • catheter

  • suprapubic (aspiration from bladder via needle)

  • voided (skin not cleansed before collection)

• Percardial fluid (heart)

• cerebral spinal fluid (CSF)

• Synovial fluid (cavity of synovial joints: elbow, knee, shoulder)

• Pleural fluid (lungs)

• Peritoneal fluid (abdominal organs)

• Bone marrow

• Bronchoalveolar lavage (BAL) (lungs)

• Sputum

• Nasopharyngeal (pharynx, upper throat)

• Stool/feces

• Genital

• Abcess

• Tissue

• Wound

• Saliva

Factors that occur during the _____  phase are the most common source of erroneous laboratory results.

Pre-analytical

Who can collect specimens?

• Patient

• Nurse/health professionals

• Lab personnel

The most common type of specimen submitted to the clinical laboratory for analysis is:

Blood

Which of these tests are most affected if the patient is not fasting?

A. Blood count

B. Glucose

C. Pregnancy Test

D. Urinalysis

B

Which of the following urine specimens would be suitable for microbial analysis or culture and sensitivity testing?

A. Midstream clean-catch

B. Regular voided

C. First morning urine specimen

D. 24-hour urine specimen

A

Blood specimen tubes are typically placed in ________ for transportation to the laboratory.

Biohazard plastic bag

If a specimen is of insufficient quantity for testing, the medical laboratory scientist should:

Reject specimen

Increased levels of bilirubin in the blood will cause plasma or serum specimens to be:

Icteric