Publications

American Society for Veterinary Clinical Pathology
2424 American Lane
Madison, WI 53704

Telephone: +1-608-443-2479
Fax: +1-608-443-2474
email: info@asvcp.org

Principles of Quality Assurance and Standards for Veterinary Hematology and Coagulation

I. Preanalytical Factors Important in Hematology and Coagulation

II. Analytical Factors Important in Hematology and Coagulation

III. Postanalytical Factors Important in Hematology and Coagulation


I. Preanalytical Factors Important in Hematology and Coagulation [Return to Top]

A. Specimen Collection, Handling, and Transport to the Laboratory

Samples should be appropriately collected, handled and transported to the laboratory in a timely manner, dependent on the type of specimen and its stability. For any assay performed in the laboratory, information concerning sample requirements, proper collection, handling, and delivery or shipping procedures should be available to clients in a laboratory services manual, special information sheets, journal or newsletter articles, other written materials, or by personal or telephone conversation.

B. Specimen Identification

Specimens should be identified with pertinent information as determined by the laboratory (such as owner, species, animal signalment, name of clinic or doctor, address, telephone and fax numbers, e-mail address, location from which the specimen was collected, etc.) on the submission container and submission form.

C. Test Identification

The requested test(s) should be clearly stated on the submission form.

D. Specimen Accessioning

The specimen should be correctly entered into the laboratory system. Test request entry, delivery of the specimen to the correct location, and specimen aliquoting (if necessary) or sharing between laboratories or departments (ie, hematology and immunology) should be coordinated.

E. Client Communication and Education

Communication between laboratory personnel and clients should be timely and courteous regarding pre-analytical factors influencing laboratory test results (eg, incomplete submission forms, inappropriate sample or sample handling or poor sample quality). Clients should be informed of the expected time for receipt of preliminary and final reports.

F. Personnel Safety

Personal protective equipment should be appropriate for handling specimens and equipment used for hematology. Safety procedures and disposal of all samples and supplies should be appropriate for the type of specimen. Personnel should receive safety and biohazard training and information about exposure to potentially hazardous chemicals or infectious agents. All training should be documented.

G. Laboratory Environment

The laboratory space should be clean, well lit, and organized to ensure proper achievement of the above goals.

H. Personnel Requirements

Laboratory personnel should have training in specimen handling and sample preparation. Documentation of training, continuing education and periodic proficiency assessment should be at the discretion of the laboratory director.

Return to Top


II. Analytical Factors Important in Hematology and Coagulation [Return to Top]

A. Quality Control for Hematology

1. Automated assays

(a) Erythrocyte (RBC) count

(b) Hemoglobin concentration

(c) Hematocrit

(d) RBC morphology

(e) Total leukocyte (WBC) count

(f) WBC differential cell counts

(g) WBC morphology

(h) Platelet count

(i) Platelet morphology

2. Recommendations

(a) All quality control (QC) activities should be defined.

(b) All QC activities should be documented.

(c) Laboratories performing automated hematology tests should establish criteria or verify manufacturer’s criteria for an acceptable range of performance for QC materials.

(d) Individual laboratories should define "hours of operation" and/or "shift" length.

(e) At least 2 levels of controls should be run each shift on hematology instruments.

(f) Automated differentials should be verified by a manual (visual microscopic) evaluation of the blood smear.

(g) After any major repair, maintenance or calibration, at least 2 levels of control materials should be analyzed.

(h) Manufacturer’s instructions for maintenance and calibration should be followed unless laboratories have modified them for their own use and documented appropriate instructions.

3. Manual cell counts

(a) Cell counts performed manually using a hemacytometer must be performed in duplicate. If there is >10% difference between the counts obtained, the chambers should be reloaded and counted again in duplicate.

(b) If a control is used for manual WBC, RBC, or platelet counts, 1 level of assayed material or procedural control should be analyzed each shift.

(c) A procedural control is defined as one of the following:

  • Duplicate dilutions of either assayed control or a previously assayed patient specimen. Results may be compared to previously defined acceptable limits for differences between duplicates. (This is the only acceptable procedural control for manual RBC counts.)
  • WBC and platelet counts may be compared with a value estimated from a peripheral blood smear.

(d) At least 2 new methylene blue-stained smears should be evaluated in counting reticulocytes. Counts from the duplicate smears should not differ by >10%.

B. Quality Control for Coagulation

1. Assays

(a) Platelet count

(b) Activated partial thromboplastin time (APTT)

(c) Prothrombin time (PT)

(d) Thrombin time (TT) or thrombin clot time (TCT)

(e) Fibrinogen concentration

(f) Fibrin(ogen) degradation products (FDPs)

2. Recommendations

(a) All QC activities should be defined.

(b) All QC activities should be documented.

(c) The laboratory performing automated coagulation assays must either establish criteria or verify manufacturer’s criteria for acceptable range of performance for QC materials.

(d) Individual laboratories must define hours of operation and/or shift.

(e) At least 1 level of control material should be run on instruments each shift if a coagulation profile is requested. This may be prior to or concurrent with testing patient samples.

(f) At least 1 level of control material should be run after a reagent lot is changed.

(g) After any major repair, maintenance or calibration, at least 1 level of control material should be analyzed.

(h) Manufacturer’s instructions for maintenance and calibration should be followed unless laboratories have documented different, appropriate instructions.

3. Manual and mechanical methods

(a) The laboratory should establish control limits or verify manufacturer’s control limits for an acceptable range of control material performance.

(b) Patient and control specimens should be tested in duplicate.

(c) Each individual performing manual coagulation assays should test 1 level of control material each shift (if a coagulation profile is requested), prior to or concurrent with testing patient samples.


Postanalytical Factors Important in Hematology and Coagulation [Return to Top]

A. Computer Entry of Data

Reports should be accurate whether created manually or electronically, and in a standard format as established by the laboratory. Established laboratory standards for uniform reporting should be met.

B. Report Generation

Reports should be in a format that is readable and easily understood, with appropriate references or explanations as needed. They should be generated in a timely manner relative to preanalytical and analytical components.

C. Report Delivery

Report delivery should be timely, to the correct client, and in a manner agreed upon by the client and the laboratory.

D. Specimen Storage

Specimens should be stored under appropriate conditions for a predetermined time period, as determined by specimen stability, laboratory policy and/or certification/accreditation requirements.

E. Specimen Disposal

Laboratories should appropriately dispose of biohazardous and non-biohazardous materials and specimens, including timely emptying of all containers and trash bins.

F. Personnel Safety

Conditions should be appropriate for computer entry, transcription, handling of specimens, specimen disposal and all other postanalytical tasks.

G. Laboratory Environment

Laboratory environment should meet standard requirements necessary for safe, rapid, efficient and effective performance.

Return to Top