Hematology

Retic Count

Clinical Significance

Reticulocyte Count, Automated - Use in evaluating erythropoietic activity.

Test Details

Methodology: Electronic Cell Sizing and Counting/Cytometry/Microscopy

Reference Range(s): See Laboratory Report

Preferred Specimen(s): Whole blood full EDTA (lavender-top) tube - mix well by gentle inversion

Alternative Specimen(s): Whole blood from a full EDTA (tan-top) tube

Minimum Volume: Microtainer 0.5 mL • 1 mL whole blood EDTA tube

Collection Instructions: Maintain specimen at room temperature. If multiple draw, collect EDTA (lavender-top) tube last.

Note: If drawn with lead testing, EDTA (tan-top) is required.

Transport Container: EDTA (lavender-top) tube

Transport Temperature: Room temperature

Specimen Stability:

• Room temperature: 48 hours
• Refrigerated: Not established
• Frozen: Not established

Reject Criteria: Clotted

Setup Schedule:  Set up: Mon-Sat (Day shift); Report available: 2 days

Prothrombin Time with INR

Clinical Significance

Prothrombin Time with INR - Screening test for abnormalities of coagulation factors that are involved in the extrinsic pathway. Also used to monitor effects of Warfarin therapy and to study patients with hereditary and acquired clotting disorders.

Test Details

Methodology

Photo-Optical Clot Detection

Reference Range(s)

INR

≤3 months
Not established
>3 months

Reference range

0.9-1.1
Moderate-intensity Warfarin therapy
2.0-3.0
Higher-intensity Warfarin therapy
3.0-4.0

PT

≤3 months
Not established
>3 months
9.0-11.5 sec

Flagging not provided. Pediatric reference intervals have not been established. Based on published literature, the adult reference interval (9.0-11.5 seconds) is generally applicable down to approximately 3 months of age with younger patients having a slightly higher upper limit by several seconds. Warfarin Therapeutic INR Range: 2.0 - 3.0

Alternative Name(s): PT

Preferred Specimen(s): One full unopened 3.2% sodium citrate (light blue-top) tube

Alternative Specimen(s):
1 mL frozen plasma:z If the specimen will be delayed longer than 48 hours, centrifuge specimen for 15 minutes at 2500-3500 rpm. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet (buffy) layer and place into a transport tube and freeze at -20° C. Ship on dry ice.

Minimum Volume: Ratio of blood to citrate is critical. Submit difficult draws in pediatric (light blue-top) tube 0.5 mL frozen plasma

Collection Instructions:

A completely filled tube is necessary because the correct ratio of blood to citrate is critical (9:1). Mix by gentle inversion 3-4 times. Do not uncap.

Transport Container: 3.2% sodium citrate (light blue-top) tube

Transport Temperature: Room temperature

Specimen Stability

• Unopened light blue-top tube
• Room temperature: 48 hours
• Refrigerated: Unacceptable
• Frozen: Unacceptable
• Separated platelet-poor plasma
• Room temperature: Unacceptable
• Refrigerated: Unacceptable
• Frozen: 14 days

Reject Criteria:

Gross hemolysis • Grossly lipemic • Improper blood to citrate ratio • High hematocrit • Improper blood collection

tup Schedule
Set up: Mon-Sat (All shifts), Sun: STAT ONLY; Report available: 1 day

aPTT

Clinical Significance

Partial Thromboplastin Time, Activated - The aPTT is a screening test that will detect deficiencies or inhibitors to the intrinsic (Factors VIII, IX, XI and XII) and common (Factors II, V, X and fibrinogen) pathway coagulation factors.

Test Details

Methodology: Photo-Optical Clot Detection

Reference Range(s)
≤6 months
Not established
>6 months
23-32 sec

Flagging not provided. Pediatric reference intervals have not been established. Based on published literature, the adult reference interval (23-32 seconds) is generally applicable down to approximately 6 months of age with younger patients having a slightly higher upper limit by several seconds.

Alternative Name(s): APTT, PTT

Preferred Specimen(s): One full unopened 3.2% sodium citrate (light blue-top) tube

Alternative Specimen(s): 1 mL frozen plasma

Minimum Volume: >0.3 mL

Collection Instructions:

Unopened light blue-top tube: Correct ratio of blood to citrate is critical. Do not overfill or underfill collection tube. Mix by inversion 4 times. For non-heparinized patients, maintain specimen at room temperature. Do not uncap. Stable 24 hours at room temperature.

Platelet-poor plasma: Centrifuge light blue-top tube 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcl). Freeze immediately and ship on dry ice.

Whole blood: The tubes should be at 100% +/- 10% fill volume in order to obtain the correct ratio.

Transport Container: 3.2% sodium citrate (light blue-top) tube

Transport Temperature: Room temperature

Specimen Stability

• • Unopened light blue-top tube
  • Room temperature: 24 hours
  • Refrigerated: Unacceptable
  • Frozen: Unacceptable

Separated platelet-poor plasma

• Room temperature: Unacceptable
• Refrigerated: Unacceptable
• Frozen: 14 days

Reject Criteria: Gross hemolysis • Grossly lipemic • Improper blood to citrate ratio • Clotted • High hematocrits • Thawed plasma received room temperature or refrigerated

Setup Schedule: >Set up: Mon-Sat (All shifts); Sun (STAT only); Report available: 1 day

Fibrinogen

Clinical Significance

Fibrinogen Activity, Clauss - Fibrinogen is essential for the formation of a blood clot. Deficiency can produce mild to severe bleeding disorders.

Test Details

Methodology: Photometry/Optical, Clauss

Reference Range(s): 175-425 mg/dL

Alternative Name(s): Factor I

Preferred Specimen(s): One full 3.2% sodium citrate (light blue-top) tube

Alternative Specimen(s): 1 mL platelet-poor anticoagulated plasma collected in a 3.2% sodium citrate (light blue-top) tube, separated and frozen immediately

Minimum Volume: 0.5 mL if as a single test

Collection Instructions: Correct ratio of blood to citrate is critical.Do not overfill or underfill collection tube.  Mix by inversion 4 times. Do not pool plasma from multiple tubes.

For non-heparinized patients, maintain specimen at room temperature. Do not uncap. Non-heparinized patients are stable up to 72 hours at room temperature. Heparinized patients stable for 24 hours at room temperature. If testing cannot be completed within stability limits, centrifuge specimen within 1 hour of collection at 1500 g. Transfer plasma to a transport tube and freeze at -20° C immediately.

Transport Container:
Whole blood:  3.2% sodium citrate (light blue-top) tube
Plasma: Transport tube (frozen)

Transport Temperature:
Room temperature: 3.2% sodium citrate (light blue-top) tube
Frozen: Plasma in transport tube

Specimen Stability

• Whole blood (3.2% sodium citrate)
• Room temperature: 72 hours (non-heparinized)
• Platelet-poor plasma
• Frozen -20° C: 30 days
• Frozen -70° C: 6 months

Reject Criteria:
Gross hemolysis • Clotted

Setup Schedule:
Set up: Mon-Sat (All shifts); Report available: 1 day

D-Dimer

Clinical Significance

D-Dimer, Quantitative - D-Dimer is one of the measurable by-products of activation of the fibrinolytic system. Quantitation of D-Dimer assesses fibrinolytic activation and intravascular thrombosis. D-Dimer is of particular value in excluding the diagnosis of venous thromboembolism among patients at high risk.

Test Details

Methodology: Immunoturbidimetric

Reference Range(s): <0.50 mcg/mL FEU

Preferred Specimen(s):

One full unopened 3.2% sodium citrate (light blue-top) tube

Alternative Specimen(s): 1 mL frozen plasma: Centrifuge specimen for 15 minutes at 2500-3500 rpm. Using a plastic pipette, remove plasma, taking care to avoid the WBC/Platelet (buffy) layer and place into a plastic transport tube and freeze at -20° C. Ship on dry ice.

Minimum Volume: 0.5 mL plasma - ratio of blood to citrate is critical. Submit difficult draws in pediatric (light blue-top) tube

Collection Instructions: A completely filled tube is necessary because the correct ratio of blood to citrate is critical (9:1). Mix by gentle inversion 3-4 times. Do not uncap.

Transport Container: 3.2% sodium citrate (light blue-top) tube

Transport Temperature: Room temperature

Specimen Stability

• Unopened light blue-top tube
• Room temperature: 72 hours
• Refrigerated: 24 hours
• Frozen: Unacceptable
• Separated platelet-poor plasma
• Room temperature: Unacceptable
• Refrigerated: Unacceptable
• Frozen: 30 days

Reject Criteria:
Gross hemolysis • Grossly lipemic • Clotted specimen • Improper blood to citrate ratio • Plasma received room temperature • Plasma received refrigerated

Setup Schedule: Set up: Mon-Sat (Day shift); Report available: 2 days