Post on 01-Apr-2020
09/05/2018
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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