QUALITY ASSURANCE Sample Integrity Lecture 2. A test result is no better than the quality of the...

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QUALITY ASSURANCE Sample Integrity Lecture 2

Transcript of QUALITY ASSURANCE Sample Integrity Lecture 2. A test result is no better than the quality of the...

QUALITY ASSURANCESample Integrity

Lecture 2

• A test result is no better than the quality of the specimen received in the laboratory

• A poor quality specimen will probably produce an inaccurate and potentially dangerous result

• Blood and other body fluids removed from the body start to change immediately

• Precautions must be taken to minimize these changes and to ensure that the test result will accurately reflect the physiologic and pathologic state of the patient

• Lab. is responsible for the test result and therefore is obliged to take precautions so that a good-quality sample is received

• When all of the following criteria are fulfilled, the sample received in the lab. will be of good diagnostic value• Specimen collection procedure is clearly defined• When concisely designed requisition and report forms

are used• Proper method of collection, transportation, processing

and storage are provided

Specimen Collection Manual

• The Specimen Collection Manual is important in that it provides written instructions for the proper and adequate collection of specimens capable of giving timely and medically important data

• Many times the collection of specimens may be beyond the laboratory's control as nurses, medical students, and physicians will be responsible for the acquisition of the specimen

• A complete and up-to-date collection procedure manual, covering every test that the laboratory offers, should be distributed to all collection and nurses stations

Specimen Collection Manual

• Laboratory personnel are responsible for • for training other personnel involved in specimen

collection and transport and for communicating effectively in order to maintain optimal quality of specimens for laboratory testing

• minimizing preanalytical errors based on acceptance or rejection of the received specimens

• Since preanalytical errors seem to make up the majority of most laboratory test problems, proper training is an important area to address

The Specimen Collection Manual (in brief)

1. Test name with alternate names and commonly used abbreviations

2. Patient preparation

3. Nature of specimen

4. Specimen timing for collection

5. Preservative or anticoagulant

6. Special handling between collection time and delivery to the laboratory

7. Labeling requirements

8. Required requisition

9. Criteria for unacceptable specimens

10. Performing laboratory's phone number and hours of operation

Specimen Collection Manual Contents• The manual should contain the following information for

each test

1- Test Name: • The name of each test with alternate names and commonly used

abbreviations are listed in alphabetical or some other logical order• Some tests are referred to by more than one name or by their

initials• An example would be SGPT, GPT, serum glutamic pyruvic

transaminase, ALT, or alanine aminotransferase—all referring to the same enzyme

2- Patient preparation: • How the patient should be prepared prior to collection of the

sample should be detailed here • For example, should the patient be fasting or two hours prandial; be

sitting or recumbent

Specimen Collection Manual Contents

3- Nature of specimen: • The type of material to be collected should be clearly

indicated• Blood, urine, some other body fluid, or tissue sample should be

clearly stated as the preferred specimen

4- Special timing for collection: • Should the sample be a random one or timed to

coincide with the administration of a drug or with some pathologic event?

• This is especially important when looking for specific responses to treatment• such as a glucose tolerance test, antibiotic, anti-convulsant, or

antiarrhythmic drugs

Specimen Collection Manual Contents5- Preservative or anticoagulant:

• To maintain the specimen in an acceptable state, it may be necessary to use an anticoagulant, preservative, or even to store the specimen on melting ice or ice water

6- Transportation requirements: • Special handling between the collection time and delivery to the

laboratory may be required.

• Chemicals can be altered, microorganisms die, and the specimen altered if improperly handled during transportation.

• Transportation considerations include: • Time

• Temperature

• Exposure to light

• Excessive vibration and rough handling

Specimen Collection Manual Contents

7 Labeling procedures:• Specific requirements for labeling the sample should he clearly

defined• A minimum of patient name, identification number, collector's

initials, and the date and time of collection should be labeled on the sample

• Some specimens will require more information:• Microbiological specimens need to have site of the sample included• A blood sample collected for crossmatching needs to be exactly and

correctly labeled for acceptance

Specimen Collection Manual Contents

8- Required requisition: Specific requisitions with test names and reference ranges will help in processing the result

9- Criteria for unacceptable specimens: • A description of unacceptable specimens may prevent the improper

collection

10- Performing laboratory: • Each test should be listed with the phone number and hours of

operation of the performing laboratory• If the physicians and nursing staff who will collect the samples

know where the samples should go and the hours of operation of the performing laboratory, then improperly timed specimens may be avoided

Sample Rejection

• A specimen should be rejected for any of the following reasons:

a- Inadequate or improper labeling: • Sample tubes or collection containers with no label or the wrong

name should not be accepted

b- Inadequate sample volume for amount of additive used:

• If less than the required volume of blood is collected, there will be an excessive amount of additive that may affect the accuracy of the test result. • For example, too much liquid anticoagulant relative to the blood volume

will result in a dilution error for prothrombin time in any sample collected in a citrated tube

Sample Rejection

c- Improper collection tube or container: • Certain tests require specific anticoagulants or preservatives to

maintain the integrity of the specimen• The wrong additive can have a detrimental effect on the specimen,

resulting in an inaccurate result

d- Improper transportation: • Specimens received in the laboratory that have been improperly

transported should be rejected. • Examples include:

• samples that should be chilled during transport but that are received at room temperature

• or specimens for anaerobic culture that are received after being exposed to air

Sample Rejection

e- Hemolysis: • Cell counts and certain chemistry analyses (e.g., potassium or LD)

will be adversely affected by the lysis of red cells. • Hemolysis may result from a difficult venipuncture or from too

vigorous handling. • A new sample should be requested

Additional Information • In addition to the collection manual, the laboratory should

provide for the nursing and medical staffs information on laboratory operations

• This information will facilitate smooth test ordering, result reporting, and communication between the laboratory and users of its services

• This information can be included as an introduction to the collection manual

Additional Information 1. Discuss the method by which to order tests from the

laboratory, including directions for ordering, both by manual and by electronic methods

2. Include a list of tests offered by the laboratory

3. Provide information on how to request test results

4. Include telephone numbers to call and hours of operation for each department of the laboratory

5. Present a list of the tests that are routine or stat (urgent)

6. Include a list of reference intervals

7. Describe the proper disposal procedures of needles and syringes

8. list the proper collection procedure for infectious patients

9. Include color key for vacuum tubes, describe the additive used for each test

Interaction With Patients and Other Hospital Personnel• Many times the only contact the public has with laboratory

personnel is the phlebotomist at the time of sample collection

• It is important that the collector present a professional appearance and have a courteous manner when approaching a patient

• The collector must clearly communicate to the patient who he is, why he is there, and what is required of the patient

• A relaxed and cooperative patient will more likely provide an adequate specimen and correct information

Interaction With Patients and Other Hospital Personnel

• The phlebotomist must "realize that he is an integral-part of the health-care team

• An attitude of cooperation with the doctors, nurses, and other health-care professionals is necessary to provide high-quality health care

• Unclear instructions, duplicate orders, or conflicting orders should be clarified or questioned before processing

• Unusual circumstances and significant events or happenings should be reported to the nursing staff so as not to jeopardize the patient's health

The Collection Process

• The first step in the collection process, be it venipuncture, urine collection, or throat swab, is the proper identification of the patient

• Outpatients should be asked for their name, not "Are you Mrs. Ali?“

• An inpatient's identification bracelet should be matched with the Specimen Request Form for name and hospital ID number

• Misidentification of the name of the patient from which the specimen is received may result in the improper treatment to the wrong patient

The Collection Process

• Proper selection of the collection site is important in obtaining a valid sample

• Certain blood chemistries have different concentrations in the arterial as compared to the venous blood

• Sites of infection need, to be properly sampled when collecting culture material

• The proper collection equipment and procedures are vital for obtaining a valid sample

• A listing of materials and their proper use should be outlined in the collection manual in detail and included in the procedure manual

• The training checklist should include the use of the equipment

The Collection Process- Sample Labeling

• The specimen should be labeled with the patient's name, history number, date and time of collection, and the initials of the person collecting the sample

• This information should be identical to that on the test requisition

• If there is a discrepancy between the name or history number on the sample label and that on the requisition, the sample should not be processed until the difference is resolved

• Some samples, especially those to be used for crossmatches, should not be considered properly labeled unless the collector's initials and the date and time of collection are on the sample

The Collection Process- Sample Labeling

• But there are exceptions to some rules:• In cases of extreme medical emergency, labeling protocol may be

temporarily waived• If one can be certain that the problem is a clerical rather than a

substantive one, it would be improper to withhold results in a medical emergency just because the sample was not properly labeled

• Hard-to-collect samples, such as cerebrospinal fluid, are sometimes received unlabeled• Delay in performing cell counts or culturing may result in the destruction

of significant cells or microorganisms. • In cases such as this, a decision must be made whether to process the

specimen while attempting to identify it properly or to request another specimen

• Withholding the results on the specimen until positive identification ofthe source is one method of preventing incorrect reporting

The Collection Process- Sample Accessioning System• Once the sample and the requisition have reached the laboratory

it should be processed immediately• At some point the sample and the requisition will be separated• A sample accessioning system provides a means of keeping the

specimen and the requisition together• As it enters the laboratory each sample is assigned a unique

number• That number is also placed on the accompanying requisition• As the sample and requisition become separated during the

sample preparation process, it is by this number that the two can be united again

• In laboratories utilizing computer systems to report results, the accessioning number is used to log the test request into the laboratory and to report the results in the laboratory computer system

The Report Form

• In many institutions the test requisition also serves as the test report form, especially in hospitals that are not served by a hospital computer system

• The report form includes much of the same information that the test request form contains.

• The report form should have the following information:

• Date and time the specimen was collected

• Patient name and history number

• Date and time the specimen was received in the laboratory

• Patient location

• Date and time of the analysis • Patient diagnosis

• Results of the analysis • Name of the ordered test

• Ordering physician