Geisinger Medical Laboratories Test Catalog

Order Display Name: Geisinger Epic Procedure Code Or ID CPT Code:  


Geisinger Epic Procedure Code: LAB3774         Geisinger Epic ID: 140937

Specimen type:
Whole Blood
Preferred collection container:
Alternate Collection Container:
Other size blue-top (3.2% sodium citrate) tubes (e.g., 1.8 mL, 4.5 mL)
Specimen required:
One (1) full 2.7 mL light blue top (3.2% sodium citrate) tube of whole blood.
Special notes:
Test may only be collected and performed at testing laboratories (see below).
  • If the patient’s hematocrit (HCT) is >55%, the volume of anticoagulant in the tube should be adjusted. Contact a performing location for special tube preparation to reduce the citrate in the collection tube. For those patients with HCT >65.4% see LAB3632 Stago Sodium Citrate Adjustment Chart for formula to determine amount of citrate removal required.
  • When possible, use fresh venipuncture to collect blood to avoid activation of coagulation by tissue thromboplastin. Blood may be drawn from an indwelling catheter or vascular access device. Draw sample from a lumen that has not been heparinized or flush the line with 5 mL of saline, and discard or use for other purposes the first 5-10 mL of blood.
  • Butterfly device collections, draw a discard tube first to remove air from collection tubing.
  • Tubes should be >90% filled.
  • Immediately mix gently after collection by inverting the tube end over end 5 to 6 times. Avoid vigorous mixing or additional inversion. Observe for the presence of clots. Recollect if fibrin clots observed.
  • Hand-deliver to the laboratory immediately after collecting at ambient temperature.

Specimen processing instructions:
Deliver to laboratory immediately after collection. Do not send sample through the pneumatic tube system. 
Transport temperature:
Room temperature
Specimen stability:
2 hours
Rejection criteria:
Clotted specimen, arterial or capillary specimen, improperly filled tube, centrifuged specimen, stability limits exceeded (2hr). Sample sent through pneumatic tube system. HCT > 55% without citrate adjusted tube.

Reference interval:
R 2.5-8.3 min
K 0.5-3.7 min 
Angle 46.8-78.4 degrees 
MA 50.6-72.5 mm  
LY 30 0–7.5%
CI -3 to 3
Interpretation guide:
Table 1: TEG Measured Parameters and Meanings
Measurement Definition
(Reaction time)
Start of reaction to initial clot formation. Prolonged by anticoagulants (heparin, low molecular weight heparin, direct thrombin inhibitors, warfarin, etc.) and factor deficiencies. Shortened by hypercoagulable conditions. Most similar tests are PT and APTT.
(Kinetic time)
Period at the end of R-time to the 20mm. Represents when fibrin strands crosslinked into fibrin meshwork.
Angle (alpha) The rate of clot formation and growth. Angle reflects fibrinogen activity.
(Maximum Amplitude)
Maximum clot strength, which is the result of two components: fibrin (minor component) and platelets (major component). Most similar test is platelet count.
(Lysis at 30 min)
Represents clot breakdown. Similar tests include fibrin degradation products, D-dimer, or soluble fibrin monomer. It is increased in DIC or other hyperfibrinolytic states.
Coagulation Index (CI) Global measurement of the coagulation status. The normal range is between -3 and 3. Any value -3 is indicative of hypocoagulability and values over 3 are indicative of hypercoagulability.
Additional information:
TEG tracing available for real-time review using TEG Manager (requires GOAL course completion for website access).
CPT code(s):
85347 x2, 85384 x2, 85576 x2
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.  The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.
Test includes:
Kaolin, Kaolin + Heparinase.
Viscoelastic measurement of clot formation
Viscoelastography, Thromboelastogram
Clinical significance:
Global assessment of hemostasis using whole blood that is typically utilized to guide transfusion in patients with trauma, recent surgery, organ transplantation, or post-partum hemorrhage. If analysis of platelet function for aspirin or clopidogrel is needed, recommend ordering VerifyNow analysis since this study is not sensitive for these medications.
Doctoral Director(s:)
Michelle Grant DO    
Review Date: 02/09/2023

Performing Locations

Geisinger Medical Center

Performing laboratory: Coagulation
Technical Lead: Margaret Knowles-Tuchman
Frequency: Daily, all shifts
Performed STAT? Yes

Geisinger Wyoming Valley Medical Center

Performing laboratory: ATL+
Technical Lead: Mary Glazenski    
Frequency: Daily, all shifts    
Performed STAT? Yes

Geisinger Community Medical Center

Performing laboratory: Hematology
Technical Lead: Robert Furcon  
Frequency: Daily    
Performed STAT? Yes
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