Actions of vasopressors

• A. Increase duration of LA and promote hemostasis
• B. Decrease duration of LA
• C. Increase tissue toxicity
• D. Cause vasodilation

Answer: (A)

Vasopressors cause constriction of blood vessels at the injection site, which slows the local anesthetic’s entry into the bloodstream. This keeps the anesthetic concentrated near the nerve longer, extending its duration, and the reduced blood flow helps with hemostasis during the procedure. They do not shorten duration, nor do they increase tissue toxicity; they actually limit systemic exposure. They also do not cause vasodilation—in this context they promote vasoconstriction.