Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Department of Psychology and Speech-Language Pathology, and Turku Brain and Mind Center, University of Turku, Turku, Finland; Department of Perioperative Services, Intensive Care and Pain Medicine, Turku University Hospital, Turku, Finland.
Br J Anaesth. 2018 Jul;121(1):260-269. doi: 10.1016/j.bja.2018.03.014. Epub 2018 May 10.
Experiences during anaesthetic-induced unresponsiveness have previously been investigated by interviews after recovery. To explore whether experiences occur during drug administration, we interviewed participants during target-controlled infusion (TCI) of dexmedetomidine or propofol and after recovery.
Healthy participants received dexmedetomidine (n=23) or propofol (n=24) in stepwise increments until loss of responsiveness (LOR1). During TCI we attempted to arouse them for interview (return of responsiveness, ROR1). After the interview, if unresponsiveness ensued with the same dose (LOR2), the procedure was repeated (ROR2). Finally, the concentration was increased 1.5-fold to achieve presumable loss of consciousness (LOC), infusion terminated, and the participants interviewed upon recovery (ROR3). An emotional sound stimulus was presented during LORs and LOC, and memory for stimuli was assessed with recognition task after recovery. Interview transcripts were content analysed.
Of participants receiving dexmedetomidine, 18/23 were arousable from LOR1 and LOR2. Of participants receiving propofol, 10/24 were arousable from LOR1 and two of four were arousable from LOR2. Of 93 interviews performed, 84% included experiences from periods of unresponsiveness (dexmedetomidine 90%, propofol 74%). Internally generated experiences (dreaming) were present in 86% of reports from unresponsive periods, while externally generated experiences (awareness) were rare and linked to brief arousals. No within drug differences in the prevalence or content of experiences during infusion vs after recovery were observed, but participants receiving dexmedetomidine reported dreaming and awareness more often. Participants receiving dexmedetomidine recognised the emotional sounds better than participants receiving propofol (42% vs 15%), but none reported references to sounds spontaneously.
Anaesthetic-induced unresponsiveness does not induce unconsciousness or necessarily even disconnectedness.
NCT01889004.
先前的研究通过受访者苏醒后的访谈来调查麻醉诱导无反应期间的体验。为了探索药物输注期间是否会出现体验，我们在接受右美托咪定或丙泊酚靶控输注（TCI）以及苏醒后对参与者进行了访谈。
健康参与者逐步递增接受右美托咪定（n=23）或丙泊酚（n=24）输注，直至出现无反应（LOR1）。在 TCI 期间，我们尝试唤醒他们进行访谈（反应恢复，ROR1）。访谈后，如果相同剂量仍导致无反应（LOR2），则重复该程序（ROR2）。最后，将浓度增加 1.5 倍以达到假定的意识丧失（LOC），停止输注，并在苏醒后对参与者进行访谈（ROR3）。在 LOR 和 LOC 期间呈现情绪声音刺激，并用恢复后的识别任务评估对刺激的记忆。对访谈记录进行内容分析。
接受右美托咪定的 23 名参与者中，有 18 名可从 LOR1 和 LOR2 中唤醒。接受丙泊酚的 24 名参与者中，有 10 名可从 LOR1 中唤醒，4 名中有 2 名可从 LOR2 中唤醒。在进行的 93 次访谈中，84%的访谈包括无反应期的体验（右美托咪定 90%，丙泊酚 74%）。报告的无反应期内有 86%存在内源性体验（做梦），而外源性体验（意识）则很少见且与短暂唤醒有关。在输注期间和苏醒后，药物之间的体验发生率或内容没有差异，但接受右美托咪定的参与者比接受丙泊酚的参与者更常报告做梦和意识（42%比 15%），但没有人自发地提到声音。
麻醉诱导的无反应不会引起无意识或必然的意识中断。
NCT01889004。
