Anesthesia was the complete or partial loss of sensation induced by anesthetic drugs. Anesthetic drugs, or anesthetics, were strong sedatives used to numb a patient's response to pain, often by inducing a deep sleep, immediately prior to medical treatment, such as surgery. Anesthetics could be applied in varying degrees and forms depending on the patient's health and requirement of the medical procedure.
Anesthetics were frequently administered intravenously into the patient's bloodstream with a hypospray or syringe. (VOY: "Critical Care") Anesthetics also existed in gaseous form and could be administered on a large scale through a ship's ventilation system. An example of the latter occurred when The Doctor and the USS Prometheus' EMH Mark II released neurozine gas to incapacitate Romulan Tal Shiar agents who had stolen the vessel. (VOY: "Message in a Bottle")
- Anesthesia gas
- Hyvroxilated quint-ethyl metacetamin
- Nasal numbing agent
- Neurazine gas