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TEG in Obstetrics R α MA LY-30

Erica Coffin, MD

Overview

Spoiler: Reading TEG

How TEG is Performed

Patient Blood Management

Clotting cascade, a short version

Postpartum hemorrhage

Applications in obstetric anesthesia

How to Interpret a Thromboelastogram (TEG)

TEG Parameters

• R > 10

• α < 53

• MA < 50

• LY-30 > 3%

What to do

• FFP (Factors)

• Cryoprecipitate (Fibrinogen)

• Platelets

• Antifibrinolytics (TXA)

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TEG

TEG Technique

Patient Blood Management

•Risk reduction

•Cost savings

• Increase product availability

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PBM: Transfusion Risks

• TRALI

• TACO

• Graft-vs-Host Disease

• Viral transmission

• Bacterial transmission

• Alloimmunization

• Acute hemolytic reaction

• Immunomodulation

• Microchimerism

• Increased LOS

• Increased cost

• Febrile reaction

• Allergic reaction

• Storage defects (K+, Coagulopathy)

• Hypothermia

• Death

The number one risk for postpartum transfusion is antepartum anemia

Bodnar, L.M., Scanlon, K.S., Freedman, D.S., Siega-Riz, A.M., and Cogswell, M.E. High prevalence of postpartum anemia among low-income women in the United States. Am J Obstet Gynecol. 2001; 185: 438–443

Coagulation

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Platelet Plug

Clotting Cascade: A Few Updates

Tissue factor (III) initiates the

extrinsic pathway

Intrinsic pathway is an amplification

system

Factor XII demoted

Thrombin Burst

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Fibrin Mesh

Plasminogen

TEG

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TEG vs. Traditional Tests

TEG

• 5-15 minutes for most data

• Whole blood coagulation

• Able to differentiate mechanism

• Better predictor of component transfusion

• Reduces use of products

Traditional Tests

• 45-60 min

• Component data

• Lack sensitivity

Obstetric Use of TEG

Postpartum hemorrhage

Maternal Coagulopathy

Postpartum Hemorrhage:

Definition ?

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Postpartum Hemorrhage: Components

Maternal changes

Massive hemorrhage

Loss of clotting factors

Hemodilution

Early DIC

Exaggerated thrombin formation

DIC caused by uterine atony is phenotypically different from surgical or traumatic hemorrhage.

Severe PPH: Molecular mechanisms

Charbit B, Mandelbrot L, Samain E, et al. The decrease of fibrinogen is an early predictor of the severity of postpartum hemorrhage. J Thromb Haemost. 2007;5(2):266-73.

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Severe PPH: Molecular Mechanisms

Charbit B, Mandelbrot L, Samain E, et al. The decrease of fibrinogen is an early predictor of the severity of postpartum hemorrhage. J Thromb Haemost. 2007;5(2):266-73.

Severe PPH: DIC

The DIC seen in severe postpartum hemorrhage appears to be a result of

increased intravascular fibrin formation and

exaggerated thrombin activation

Postpartum Hemorrhage: Interventions

Pharmalogic

• Pitocin

• Methylergonovine

• Carboprost

• Prostaglandin E2

Surgical

• Massage

• Rapid closure

• UAE/L

• Tamponade

• Compression

• Hysterectomy

Blood/Fluid management

• Cell salvage

• IVF

• Point of care testing

• Transfusion

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Postpartum Hemorrhage

• TEG • Reduces blood product use

• Evidence lacking for mortality/morbidity benefit

• Correlates with fibrinogen decrease

Maternal Coagulopathy

Spinal Hematoma and Neuraxial Anesthesia

Chestnut DH, M.D. CA, M.D. LC et al. Chestnut's Obstetric Anesthesia, Principles and Practice. Saunders; 2014. pp 749-

750

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Maternal Coagulopathies

• Gestational thrombocytopenia

• Pre-Eclampsia

• HELLP

• Acute fatty liver of pregnancy

• Pre-existing conditions • vWB

• ITP

• Medication-induced

Maternal Thrombocytopenia What level is safe?

Maternal Coagulopathy

Use of TEG increasing despite limited evidence.

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What about 1:1:x?

Decreases

Platelet count

Hematocrit

Fibrinogen

INR

Result of storage defects and preservation products

Evidence is weak, controversial, consists of

retrospective studies confounded by survivorship

bias

“The most influential way of reducing transfusion is following established transfusion guidelines, using algorithms that optimize the transfusion of plasma and platelets and, most importantly, recognizing that patients, and not purely full blood count numbers, should be treated. An anemic patient without symptoms or co-morbidities, which represents the vast majority of our patients, should not be transfused.”

Clark V, Waters JH. Blood transfusions: more is not necessarily better. Int J Obstet Anesth. 2009;18(4):299-301.

TEG Examples

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TEG Examples

TEG Examples

TEG Examples

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Munroe, randall. “Survivorship Bias.” Xkcd: Survivorship Bias, Xkcd, m.xkcd.com/1827/.

References

1. Rodgers RP, Levin J. A critical reappraisal of the bleeding time. Semin Thromb Hemost. 1990;16(1):1-20.

2. Harker LA, Slichter SJ. The bleeding time as a screening test for evaluation of platelet function. N Engl J Med. 1972;287(4):155-9.

3. Chestnut DH, M.D. CA, M.D. LC et al. Chestnut's Obstetric Anesthesia, Principles and Practice. Saunders; 2014. Spinal Hematoma. pp 749-750

4. Lee LO, Bateman BT, Kheterpal S, et al. Risk of Epidural Hematoma after Neuraxial Techniques in Thrombocytopenic Parturients: A Report from the Multicenter Perioperative Outcomes Group. Anesthesiology. 2017;126(6):1053-1063.

5. Ahmad A, Kohli M, Malik A, et al. Role of Thromboelastography Versus Coagulation Screen as a Safety Predictor in Pre-eclampsia/Eclampsia Patients Undergoing Lower-Segment Caesarean Section in Regional Anaesthesia. J Obstet Gynaecol India. 2016;66(Suppl 1):340-6.

6. Chen GY, Ou yang XL, Wu JH, et al. [Comparison of thromboelastography and routine coagulation tests for evaluation of blood coagulation function in patients]. Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2015;23(2):546-51.

7. Hall S, Murphy MF. Limitations of component therapy for massive haemorrhage: is whole blood the whole solution?. Anaesthesia. 2015;70(5):511-4.

8. Bloch EM, Jackman RP, Lee TH, Busch MP. Transfusion-associated microchimerism: the hybrid within. Transfus Med Rev. 2013;27(1):10-20.

9. Waters JH, Frank SM. Patient Blood Management, Multidisciplinary Approaches to Optimizing Care. A A B B Press; 2016.

10. Waters JH. Role of the massive transfusion protocol in the management of haemorrhagic shock. Br J Anaesth. 2014;113 Suppl 2:ii3-8.

11. Mcquilten ZK, Crighton G, Brunskill S, et al. Optimal Dose, Timing and Ratio of Blood Products in Massive Transfusion: Results from a Systematic Review. Transfus Med Rev. 2018;32(1):6-15.

12. Bodnar, L.M., Scanlon, K.S., Freedman, D.S., Siega-Riz, A.M., and Cogswell, M.E.High prevalence of postpartum anemia among low-income women in the United States. Am J Obstet Gynecol. 2001; 185: 438–443