The use of thromboelastography as a guide to epidural placement in a pre-eclamptic patient with a platelet count of 27K
Abstract Number: 191
Abstract Type: Case Report/Case Series
Introduction: There are no clear guidelines in the literature on the safe level of platelet count at which epidural anesthesia can be performed. We present a case of severe pre-eclampsia with a platelet count of 27,000 where epidural anesthesia administration was guided by thromboelastography (TEG).
Case: A 21 yr old, gravida 1 was admitted at 34 weeks gestation with pre-eclampsia and HELLP syndrome (epigastric pain, BP of 167/103mmHg, thrombocytopenia, elevated AST and ALT). Laboratory findings include AST 419, ALT 294, ALP 315, uric acid 9.3, platelet count 27,000, PT 13.9, PTT 31.2, and INR 1.1. The decision was made to proceed with induction of labor. She was started on intravenous magnesium prophylaxis. A TEG was within normal limits (Fig). The epidural catheter was placed without complications and PCEA started. The patient had an uncomplicated spontaneous vaginal delivery of a viable female infant 6 hours later. A repeat platelet count was 71,000 and the epidural catheter was removed without incident. The patient was discharged four days later with normal labs.
Discussion: Pre-eclampsia is often associated with abnormalities of hemostasis. Thrombocytopenia may occur in up to 50% of patients with severe preeclampsia; platelet dysfunction may also be present despite adequate numbers. Coagulation factors are usually reduced in the presence of thrombocytopenia. Hence, a platelet count is a good screening test. Further coagulation tests should be reserved for those with reduced platelets. The TEG measures the interaction between protein coagulation cascade, fibrinogen and platelet surface, from initiation of clotting to the final stages of clot lysis or retraction. The measured variables in a TEG (r, K, α, MA) reflect the interdependence of platelets and clotting factors. TEG measures the clotting process in whole blood, unlike laboratory tests which measure isolated aspects of coagulation in plasma. The TEG variables (k and MA) correlate well with platelet numbers and MA correlates well with platelet aggregation.
Conclusion: The TEG can be a useful tool in the guidance of epidural placement in a patient with thrombocytopenia and preeclampsia.