Tranexamic Acid and Thromboelastography During Cesarean Delivery

The aim of this study is to characterize the coagulation changes, using thromboelastography
(TEG), after prophylactic tranexamic administration during cesarean delivery. Specifically,
TEG values will be compared in patients who receive prophylactic tranexamic acid or placebo
before surgery, during elective cesarean delivery, and 2 hours postpartum.

Postpartum hemorrhage (PPH) is increasing in incidence in the United States, renewing
interest in multimodal approaches to blood conservation during cesarean delivery.
Pharmacologic therapy with the antifibrinolytic agent, tranexamic acid (TA), has been shown
to reduce estimated blood loss (EBL) during cesarean delivery, but its effect on global
coagulation as assessed by TEG, and how this correlates with lowering blood loss, has not
been elucidated.

This study will be conducted as a randomized, double-blind, controlled trial with two study
arms: control (60 patients); and treatment (60 patients).

Subjects will be pre-medicated with routine pre-cesarean delivery medications including oral
sodium citrate 30 mL and intravenous (IV) metoclopramide 10 mg. A peripheral IV and
noninvasive hemoglobin monitor will be placed, and baseline labs sent: type and screen, serum
hemoglobin, platelet count, fibrinogen, activated partial thromboplastin time (aPTT),
prothrombin time (PT), and baseline TEG values (r time, k time, alpha angle, and maximum
amplitude). Patients will have blood pressure, heart rate, and pulse oximetry measured
throughout surgery as per standard of care. Patients will all receive IV lactated Ringers'
(LR) solution prior to surgery and throughout surgery, with volume recorded and a goal of
less than 2 L unless more IV fluid is clinically indicated. All patients will have a spinal
anesthetic as per standard of care, with hyperbaric bupivacaine 12 mg, fentanyl 10 μg, and
hydromorphone 100 μg. If the anesthetic plan is altered (combined spinal-epidural, general
anesthesia conversion, general anesthesia planned), indications and medication doses used
will be noted for analysis.

Immediately following induction of anesthesia and prior to skin incision, infusion of study
solution will be initiated.

Study solutions will consist of:

1. Control group: 100 mL 0.9% normal saline (NS).

2. Treatment group: 100 mL 0.9% NS containing 1g tranexamic acid (TA). Study solution will
be infused via an infusion pump over 10 minutes. Blood loss will be measured by visual
estimate and weight of surgical sponges. Noninvasive hemoglobin will be measured
throughout the study. All routine care lab values will be noted. At minimum, one lab
panel will be sent one hour after study solution initiation (hemoglobin, fibrinogen,
platelet count, aPTT, PT, and TEG).