General anesthesia

• Published in: Current biology 1999-02, Vol.9 (3), p.R81-R82
• Main Author: Nash, Howard A.
• Format: Article
• Language: English
• Subjects: Anesthesia, General; Anesthetics, General - pharmacology; Anesthetics, Inhalation - pharmacology; Brain - drug effects; Consciousness - drug effects; Humans; Membrane Lipids - chemistry; Membrane Proteins - drug effects; Memory - drug effects; Nerve Tissue Proteins - drug effects; Neurotransmitter Agents - metabolism; Receptors, Cell Surface - drug effects; Receptors, Cell Surface - metabolism; Spinal Cord - drug effects
• ISSN: 0960-9822; 1879-0445
• DOI: 10.1016/S0960-9822(99)80055-4

Modern anesthesiologists generally use ethers and alkanes that are heavily substituted with halogen atoms, because of their lower flammability. These agents, such as halothane and isoflurane, are delivered by bubbling oxygen through a container containing the liquid form of the compound. Anesthetic liquids are volatile and the oxygen stream that emerges from the container is saturated with anesthetic vapor; the stream is diluted with oxygen and the patient inhales the mixture. It is a tribute to their efficacy that, despite the major advances of modern pharmacology, inhalation agents remain an important tool of clinical anesthesiology. Volatile general anesthetics (VGAs) induce a reversible state that is well suited for surgery. The anesthetized patient fails to move in response to the trauma of surgery and even fails to have a serious visceral response. During the surgery the patient is not aware of pain (or any other sensation) and when the anesthetic has worn off, the patient has no memory of events during its administration. Despite these dramatic losses of neural function, many parts of the nervous system remain active under anesthesia. The relatively specific loss of consciousness and memory make VGAs inviting tools for studying these higher functions. In addition, anesthesiologists would like to use rational drug design to limit the dangerous side-effects of these drugs while retaining their efficacy. There is thus great interest in both the clinical and basic science communities in understanding where and how VGAs produce their effects.