Awareness and traumatic recall of cricoid pressure

A 54-year-old-man underwent general anaesthesia for a sinus tract endoscopy during the course of his treatment for acute pancreatitis following cholecystectomy. On pre-operative assessment, he was judged to be at risk of aspiration, and the discussion of the anaesthetic with him included an explanation of cricoid pressure. For the procedure, a standard rapid sequence induction (RSI) was conducted. The operation proceeded largely uneventfully, although some regurgitation during the procedure confirmed that an RSI had indeed been indicated. At the postoperative visit by the anaesthetist, the patient stated that he had an unpleasant recollection of the induction of anaesthesia and in particular the application of cricoid pressure. He had no recall of being intubated or of any subsequent intra-operative events. The anaesthetist reassured the gentleman, reiterated the nature and purpose of cricoid pressure, and offered to arrange formal counselling, though this was declined. The anaesthetic team was requested to visit the gentleman again 10 days later as he had complained of persistent and intrusive recall of these events. At this visit, he described remembering a nurse tapping on his neck prior to induction followed by her ‘clamping’ his throat in her hands. He remembered feeling he was unable to breath and attempting to bring up his hands to release the pressure on his neck. He felt extreme distress and anxiety before losing consciousness shortly after. Since then, the recall of these events was triggered whenever he was falling asleep, causing him to awaken with feelings of panic, and although these symptoms seemed to be slowly improving, they had resulted in him actually fearing the onset of normal sleep. He also now expressed a profound and regrettable apprehension regarding any necessary anaesthesia in the future. Several further follow up visits prior to his discharge from hospital confirmed that his symptoms steadily improved. He continued to decline referral for formal assessment and support; a letter was therefore sent to his General Practitioner in anticipation of a possible need for further care regarding this matter in the future. The rationale for the application of cricoid pressure necessitates that it is applied at the loss of consciousness during rapid sequence induction, and indeed some authors recommend that it be partially applied before loss of consciousness [1]. During rapid induction, however, it may not be possible to determine the precise moment when sufficient ‘loss of consciousness’ has occurred to render the patient insensate to cricoid pressure. Cricoid pressure therefore, may be fully applied at a level of anaesthesia where awareness, and possibly recall, of the manoeuvre occurs. It would be natural for a patient who is unprepared to be extremely distressed should they be aware of this. Intra-operative awareness under anaesthesia is known to be associated with significant emotional morbidity, including post-traumatic stress disorder [2,3]. Awareness of cricoid pressure, though not reported and not obviously preventable, could also contribute to the same. Most anaesthetists in our department routinely explain cricoid pressure to patients at some point prior to a planned rapid sequence induction, as happened in this case. Perhaps more emphasis should be placed on the pre-operative explanation of cricoid pressure, and in particular firm reassurance given to the patient that if they are not asleep at the time of its application they should not fear being choked or strangled. As incorrect application of cricoid pressure may indeed obstruct the airway, perhaps distressingly, we must also ensure that our assistants are correctly performing the technique [1].