Which statements about vasoconstrictors as additives to local anesthetics are true?

Which statements about vasoconstrictors as additives to local anesthetics are true?

• A. They provide hemostasis, reduce systemic toxicity, and prolong the duration of effect
• B. They only provide hemostasis but do not affect duration
• C. They increase systemic toxicity
• D. They shorten duration

Answer: (A)

Vasoconstrictors added to local anesthetics work by producing local vessel constriction. This lowers blood flow at the injection site, which reduces how much anesthetic enters the bloodstream, thereby decreasing potential systemic toxicity. At the same time, keeping more of the drug in the local tissue traps it there longer, so the anesthetic effect lasts longer. The reduced bleeding from the constricted vessels provides hemostasis during the procedure. So this combination offers all three benefits: hemostasis, lower systemic toxicity, and prolonged duration. The other statements don’t fit because they claim only hemostasis with no duration gain, or they suggest increased toxicity, or they say the duration is shortened.

Vasoconstrictors added to local anesthetics work by producing local vessel constriction. This lowers blood flow at the injection site, which reduces how much anesthetic enters the bloodstream, thereby decreasing potential systemic toxicity. At the same time, keeping more of the drug in the local tissue traps it there longer, so the anesthetic effect lasts longer. The reduced bleeding from the constricted vessels provides hemostasis during the procedure. So this combination offers all three benefits: hemostasis, lower systemic toxicity, and prolonged duration. The other statements don’t fit because they claim only hemostasis with no duration gain, or they suggest increased toxicity, or they say the duration is shortened.