The Thai Anesthesia Incident Monitoring study (Thai AIMS): an analysis of 21 awareness events

To demonstrate the characteristics, outcomes, and the circumstances associated with intraoperative recall of awareness.

Relevant data of intra-operative recall of awareness were extracted from the Thai Anesthesia Incident Monitoring study (Thai AIMS) database of 1996 incident reports and 2537 incidents which were conducted among 51 hospitals throughout Thailand from January to June, 2007. Details regarding patients, surgical, anesthetic and systematic factors were recorded in a structured data record form. The completed record forms were reviewed independently by three anesthesiologists. The descriptive statistic was analyzed by using SPSS software version 11.5 and demonstrated in number and percent.

Twenty-one incidents (21/1996 = 1.05%) of intra-operative recall of awareness were reported. Awareness was predominantly found in females (76.2%) and with ASA physical status I (47.6%). Most of the patients recalled events during the maintenance period and reported sound (71.4%), pain (52.4%), feeling operated (38.1%), paralysis (33.3%), recognizing intubated (4.8%) and panic (4.8%). Anxiety (33.3%), temporary emotional stress (19%), and post traumatic stress (4.8%) were found during immediate outcome assessment but scarcely sustained on the hospital discharged date. The factors associated with the incidents were anesthetic related in the majority especially ineffective monitoring (100%), pre-medication abandonment (100%) and light anesthesia (71.5%).

Intra-operative recall of awareness in the Thai AIMS was 1.05% of all incident reports. Most of the events were considered as anesthesia related. The suggested corrective strategies were quality assurance activity, effective monitoring and equipment maintenance.