Care and Monitoring of the Anaesthetized Patient Including the Prevention of Injuries

Abstract

Effective anaesthetic care aims to reduce the morbidity, mortality and complication rates from surgery. General anaesthesia renders the patient in a suitable state for surgery but, by interfering with control of vegetative functions, has many side effects. Sedation is often accomplished using lower doses of the same drugs used for general anaesthesia and forms part of a smooth continuum of increasing depth of general anaesthesia. The sedated patient should therefore be monitored just as diligently. Control of the airway is lost in general anaesthesia or ‘deep’ sedation by abolition of the protective reflexes which normally prevent aspiration. Control of breathing is impaired, leading to hypoventilation. Circulatory control is similarly blunted, with a tendency to vasodilatation whether general or regional anaesthesia is employed. Under general or regional anaesthesia, reflexes protecting the patient from noxious events are abolished (e.g. blinking, limb withdrawal, movement to relieve uncomfortable pressure points). Control of body temperature is impaired by both regional and general anaesthesia.