Anaesthesia, amnesia and harm

Anaesthesia causes unconsciousness by suppressing neural mechanisms mediating arousal and awareness. It also causes amnesia by disrupting mechanisms of memory consolidation. Some patients under general anaesthesia unexpectedly become aware during surgery and form a traumatic memory of their experience. After describing the neural underpinning of phenomenal consciousness and memory, I examine the respects in which patients who experience anaesthesia awareness can be harmed by it. In cases where awareness is detected intraoperatively, I consider whether an anaesthetist would be justified in administering a drug to prevent a memory of the experience, as well as reasons for and against preoperatively informing patients of the possibility of awareness. In cases where awareness is reported postoperatively, I consider reasons for taking a drug to erase a memory of awareness against reasons for retaining the memory. A decision to take or decline such a drug would be informed by the potential harm of these memories and the potential benefits and risks of drugs intended to erase them.