Awareness during surgery and a 'third state' of consciousness: dysanaesthesia

Date: Sep-20-2013Awareness during surgery - wherein a patient consciously experiences and remembers things that happen during their surgery - is a rare yet alarming prospect for patients. In a presentation at the Annual Congress of the Association of Anaesthetists of Great Britain and Ireland (AAGBI), in Dublin, Ireland, Professor Jaideep Pandit, Consultant Anaesthetist & Fellow of St John's College, Oxford, UK, will discuss the difficulties inherent in monitoring the conscious state. He will present an argument that there can exist a third state of consciousness that is neither fully conscious nor unconscious, termed 'dysanaesthesia', and that this presents a challenge for monitoring.

"Even in 2013, we are still struggling to define what consciousness actually is," says Prof Pandit. "We can obviously see when someone is awake and responding, and when someone is asleep or unconscious, but our understanding of what changes us from one state to the other is still evolving."

Data from studies worldwide show that if patients are directly asked following surgery if they recalled anything, about 1 in 500 will say they did. But the initial baseline report of the large, national project NAP5 found that only 1 in 15,000 of patients spontaneously report awareness during their surgery, and only a third of those (so 1 in 45000 patients undergoing surgery) reported any pain or distress as part of the experience. "The difference between the incidence of 1:500 and 1:15,000 suggest that even in the rare instances where patients are experiencing awareness, in most cases the sensation is a 'neutral' and not necessarily unpleasant one," says Prof Pandit. "What we are possibly seeing is a third state of consciousness - dysanaesthesia - in which the patient is certainly aware of events, but not concerned by this knowledge (especially as they are not in pain)."

Prof Pandit will also discuss evidence for dysanaesthesia coming from experiments in which patients are anaesthetised, but have their whole body paralysed with neuromuscular blocking drugs apart from their forearm, allowing them to move their fingers in response to commands or to signify they are awake or in pain during surgery. "To date no patients in these experiments have moved their fingers voluntarily to indicate wakefulness, yet 1 in 3 (a third) of them can move their fingers if asked to by medical teams. This again suggests that in a majority of those patients who experience awareness, it may not be unpleasant or distressing to them, since they are not moving their fingers to make medical teams aware of this."

AAGBI President Elect Dr Andrew Hartle said "Patient safety and research are two of the AAGBI's major priorities. The work of Prof Pandit, and his colleagues at the NAP5 project is possibly the world's biggest study of the problem of awareness, something we know is a major concern for patients needing anaesthesia. The AAGBI is committed to research of this sort, helping to make modern anaesthesia even safer for patients"

Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.