Reduction in the incidence of awareness using BIS monitoring

• Reduction in the incidence of awareness using BISmonitoringA. EKMAN1,M-L.LINDHOLM1,C.LENNMARKEN2and R. SANDIN11Department of Anaesthesia and Intensive Care, Regional hospital, Kalmar, and The Karolinska Institute, Stockholm, and2Department ofAnaesthesia and Intensive Care, University Hospital, Linko¨ping, SwedenBackground: Explicit recall (ER) is evident i n a pproximat ely0.2% of patients given general anaesthesia including musclerelaxants. This prospective study was performed to evaluate ifcerebral monitoring using BIS to guide the conduction ofanaesthesia could reduce this incidence significantly.Patients and methods: A prospective cohort of 4945 consecutivesurgical patients requiring muscle relaxants and/or intubationwere monitored with BIS and subsequently interviewed for ERon three occasions. BIS values between 40 and 60 were recom-mended. The results from the BIS-monitored group of patientswas compared with a historical group of 7826 similar cases in aprevious study when no cerebral monitoring was used.Results: Two patients in th e BIS-monitored grou p, 0 .0 4% ,hadER as c ompared with 0.18% in the control group (P < 0.038).Both BIS-monitored patients with ER were aware during intub-ation when they had high BIS values (>60) for 4 min andmore than 10 min, respectively. However, periods with high BIS ¼ 4 min were al so eviden t in other patient s with no ER .Episodes with high BIS, 4 min or more, were found in 19% ofthe monitored patients during induction, and in 8% of casesduring maintenance.Conclusions: The use of BIS monitoring during general anaes-thesia requiring endotracheal intubation and/or muscle relax-ants was associated with a significantly reduced incidence ofawareness as compared with a historical control population.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Anestesi och intensivvård (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Anesthesiology and Intensive Care (hsv//eng)

Keyword

Anaesthesia Awareness

Brain function monitoring

BIS

Medicin

Medicine

MEDICINE

Publication and Content Type

ref (subject category)

art (subject category)