What term describes the administration of an anesthetic agent directly into the bloodstream?

The administration of an anesthetic agent directly into the bloodstream is correctly described by the term "injection." This method involves delivering the anesthetic solution directly via a syringe into a vein, allowing for rapid absorption and effect throughout the body. This technique is commonly used in various medical settings, such as during surgical procedures, to induce sedation or general anesthesia quickly.

In contrast, inhalation refers to the administration of anesthetic gases or vapors via the respiratory system, where the agent is absorbed through the lungs. Intravenous infusion usually involves a continuous delivery of medication through an intravenous line but may not specifically indicate the method of administering solely anesthetic agents. Topical application involves the local administration of an agent directly onto the skin or mucous membranes, which is not applicable when discussing intravenous delivery. Thus, "injection" is the most accurate term for this specific method of administering anesthetic directly into the bloodstream.