Retrospective analysis of cases of intraoperative awareness in a large multi-hospital health system reported in the early postoperative period

Table 1 Summary of key characteristics of identified AWR cases done under general anesthesia

Case #	Surgery Type	Age (decade)	Gender	ASA PS	Premedication	Patient risk factors for AWR	Maintenance anesthetics used	Notes	Classification of Recall
1	Spine	30s	M	2	midazolam & fentanyl	none	Sevoflurane, remifentanil	Early lowering of anesthetic agent and discontinuation of remifentanil infusion. BIS not used.	Possible; Class 2
2	Head & Neck	70s	M	3	midazolam	morbid obesity	Sevoflurane	BIS not used	Possible; Class 1
3	Orthopedic	60s	F	3	midazolam	obesity	Sevoflurane	Sevoflurane < 0.5 aaMAC for much of case, with BIS < 60	Probable; Class 5D
4	General	30s	F	3	none	morbid obesity	TIVA with propofol, dexmedetomidine, & ketamine	BIS > 65 during entire case	Possible; Class 2
5	General (abdominal)	50s	F	3	midazolam	none	TIVA with propofol, dexmedetomidine, & ketamine	BIS < 47 for entire case	Possible; Class 2
6	General	60s	F	2	midazolam	none	TIVA with dexmedetomidine and remifentanil, then propofol	BIS > 60 for much of case	inconclusive
7	Plastic	20s	F	2	midazolam	obesity	TIVA with propofol, & dexmedetomidine & ketamine	IV infiltration occurred. BIS not used	inconclusive

Classification of recall event is based on concordance of authors. Each case is classified as Probable, Possible, or inconclusive, for the likelihood of a true AWR event. Further, the perceptions described are described using the Michigan Awareness Classification Instrument [18], as described in the text

ISSN: 1471-2253