Induction of anaesthesia

Induction of anaesthesia aims to produce a rapid, smooth transition from consciousness to unconsciousness by achieving adequate concentration of anaesthetic agents in the central nervous system. Careful planning is required, which includes pre-operative assessment, consent and explanation to the patient, and checking of all equipment and drugs. There are two main methods of inducing anaesthesia: inhalational and intravenous. The choice will depend upon patient and surgical factors as well as the anaesthetist's preference and experience. Rapid sequence induction is a modified induction technique (usually intravenous, but can be inhalational) used when there is increased risk of aspiration of gastric contents. At induction of anaesthesia, there is great physiological change; the complications that can occur can be classified into drug-related and airway-related. Once anaesthesia has been induced, the patient's airway must be maintained; a variety of airway maintenance techniques are available, including endotracheal intubation and laryngeal mask airway.