The effects of 2-chloroprocaine on coagulation and fibrinolysis in the parturient: an in vitro study.

Abstract

Amide local anesthetics are known to inhibit coagulation. 2-chloroprocaine is the only ester agent used in obstetric anesthesia. It is used during obstetric emergencies, and also to supplement inadequate epidural block produced by amide local anesthetics. There is no study to date that has evaluated the effect of ester local anesthetics on blood coagulation and fibrinolysis in the parturient. In this study, we obtained blood samples from healthy, term-parturients and mixed them with varying amounts of 2-chloroprocaine for final concentrations ranging from 0.26 to 7.8 mM. Thromboelastograph(®) was used to study the coagulation profile of these samples. Chloroprocaine impaired coagulation in a dose dependent manner, with increased R and K, and decreased MA and α. The difference, when compared to saline controls, reached statistical significance at a dose of 7.8 mM. An additional significant finding was that 2-chloroprocaine also enhanced fibrinolysis. Amide local anesthetics are known to impair coagulation, but 2-chloroprocaine produced significant fibrinolysis in addition to decreasing coagulation. This is the first study to date to demonstrate fibrinolytic properties of an ester local anesthetic. Further study evaluations are required to determine the cause of the variation in fibrinolysis. There is also a need to address the mechanism of increased fibrinolysis observed with 2-chroloprocaine.