ABSTRACT
The modern practice of anaesthesia most commonly involves the administration of an intravenous anaesthetic agent to induce rapid loss of consciousness, amnesia and inhibition of autonomic and sensory reflexes. Anaesthesia is maintained conventionally by the continuous administration of an inhalational anaesthetic agent and cessation of administration results in rapid recovery. An opioid is often administered for analgesia, and in many cases a muscle relaxant is given in order to produce paralysis. A combination of drugs is normally used and the concept of a ‘triad of anaesthesia’ (Figure 24.1) describes general anaesthesia as a combination of relaxation, hypnosis and analgesia.
