[Awareness detection in anaesthesia during otorhino-maxillofacial surgery using bispectral index-monitoring technology].

Introduction: Awareness is characterized by intraoperative presence of consciousness and recollecting of the events occurring during general anaesthesia. The study was aimed at detecting awareness during general anaesthesia in otorhino-maxillofacial procedure.

Methods: The study is a part of a prospective, phase IV academic study carried out at the Department for Otorhinolaringology, Clinical Centre of Serbia, and Maxillofacial Surgery. The study was approved by the Ethics Committee of the Clinical Centre of Serbia and performed in accordance with European Union Clinical Trials Directive. The evaluation included 40 patients (T-propofol and E-sevofluran group) subjected to different surgical procedures (American Society ofAnesthesiologists I-III). Depth of anaesthesia was monitored during surgical procedures according to the hemodynamic parameters (blood pressure, pulse, oxygen saturation, electrocardiography, capnometry). Bispectral index monitoring was applied; however, the insight into the obtained bispectral index values was possible only after the completion of the surgery when the comparison with hemodynamic values was performed. Modified Brice interview was postoperatively applied to the patients in whom awareness was suspected.

Results: Based on the hemodynamic parameter values obtained in 40 anesthetized patients, no cases of awareness were expected. After the completion of the surgical procedures, the recorded graphic and numeric bispectral index values obtained in the course of anaesthesia were analyzed. Higher bispectral index values (BIS > 60) were recorded in 1 T-group patient.

Conclusion: It is possible to miss an awareness episode without using bispectral index technology monitoring during general anaesthesia in otorhinolaryngology and maxillofacial surgery. Bispectral index monitoring should be the clinical standard in general anaesthesia.