| Summary: |
Anaesthesia consists of unconsciousness (depth of anaesthesia), analgesia (pain relief) and paralysis (not required for all types of surgery). Nowadays, there is no clinical sign that can completely describe the unconsciousness (depth of anaesthesia). Usually, the anaesthetist uses a variety of clinical sings and his/her own experience so as to decide the level of unconsciousness. The danger of consciousness, with or without pain, during anaesthesia is one of the aspects that concerns patients and clinics alike. Signals from within the central nervous system have been the topic of research and have proved to be related to the level of unconsciousness. The bispectral index (BIS) of the electroencephalogram and the auditory evoked potentials (AEP) can normally be used to monitor the patient during general anaesthesia. However, these signals are not completely reliable to detect awareness and thus cannot prevent it. It is therefore of great importance the development of new sensors that can detect patient responses to pain in the form of movement (spontaneous or not), muscle tension, temperature changes and other possible physiological responses. A sensor that, could help to detect pain reactions, loss of consciousness and predict arousal during general anaesthesia for surgical interventions, would highly improve the quality of anaesthesia and patient safely and comfort.
This information can be used to prevent drugs overdosage/underdosage and help the clinicians to adequately react to unexpected anaesthesia situations. |