Introduction to Inhaled Anesthetics

Introduction to Inhaled Anesthetics

Inhalation anesthesia refers to the delivery of gases or vapors in to the lungs via respiratory tract to produce anesthesia. Inhalation anesthetics are particularly useful in the induction of pediatric patients in whom it may be difficult to start an intravenous line. In contrast, adults usually prefer rapid induction with intravenous agents. Regardless of the patient's age, anesthesia is often maintained with inhalation agents. Although the mechanism of action of inhalation anesthetics remains unknown, it is assumed that their ultimate effect depends on attainment of a therapeutic tissue concentration in the central nervous system.

Ideally, inhalation agents should provide a quick induction and emergence from anesthesia, good analgesia, muscle relaxation, quick changes and easy maintenance of anesthesia, and no side effects. Unfortunately, the real world of medicine doesn't provide us with such an ideal agent. Relatively long and unpleasant induction times can be overcome by using an intravenous anesthetic. Neuromuscular blockers will provide muscle paralysis and adding opioids can enhance analgesia. This technique, the so-called balanced anesthesia, allows the anesthetist to take advantage of different beneficial effects of several drug classes.