A year in review in Minerva Anestesiologica 2012

COPYRIGHT 2013 EDIZIONI MINERVA MEDICA Y E A R I N R E V I E W A year in review in Minerva Anestesiologica 2012 D. CHIUMELLO 1, M. ALLEGRI 2, F. CAVALIERE 3, G. DE COSMO 3 G. IOHOM 4, O. LANGERON 5, D. PIETRINI 3, M. ROSSI 6 1Dipartimento di Anestesia, Rianimazione (Intensiva e Subintensiva) e Terapia del Dolore, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Milano, Italia; 2Department of Surgical Clinical Diagnostic and Pediatric Science, Pain fterapy Service, University of Pavia-Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; 3Istituto di Anestesia e Rianimazione, Università Cattolica Sacro Cuore, Policlinico “A. Gemelli”, Roma, Italia; 4Department of Anesthesia and Intensive Care Medicine, Cork University Hospital and University College Cork, Wilton, Cork, Ireland; 5Department of Anesthesiology and Intensive Care, Hôpital de la Pitié-Salpêtrière, Paris, France; 6Dipartimento di Anestesia, Terapia Intensiva e Terapia del Dolore, Centro di ricerche e formazione ad Alta Tecnologica nelle Scienze Biomediche “San Giovanni Paolo II”, Università Cattolica Sacro Cuore, Campobasso, Italia General anesthesia he analysis of electroencephalogram (EEG) signal is of the outmost importance in the perioperative period. It is indeed useful to evalu- ate the depth of anesthesia, particularly when muscle relaxant are used; to point out early al- terations of cerebral metabolism due to hypoxia or ischemia, such as during carotid surgery; to diagnose seizure disorders; and to titrate drugs in pharmacologically-induced coma.1 Gross EEG abnormalities (absence of electrical activ- ity, burst suppression) are immediately apparent even to non-specialists, but subtle pronounced changes are more difficult to detect. For this rea- son, some computerized systems are now avail- able that process EEG signals and provide anes- thetists with numeric scores informative of the depth of anesthesia.2 As each system is based on its own mathematical algorithm, the usefulness of these indices should be tested by comparison with clinical data and with scores provided by other systems. Pilge et al. challenged two wide- spread devices (BIS A-2000 and Cerebral State monitors) with the same EEG signals previously recorded in a group of patients under general an- esthesia.3 ftey showed that, although the scores provided by the two devices correlated well (r=0.68), depth of anesthesia was similar in only 51% of cases and the scores differed by more than 10 points in over 40% of cases. fte authors hypothesized that such inconsistencies might originate from different latencies in recording EEG changes. Interestingly, the inconsistencies were greater during sevoflurane anesthesia com- pared to propofol anesthesia. ftis finding sug- gests that the two anesthetics may affect EEG differently or that the cerebral state index algo- rithm is less effective when applied to sevoflu- rane anesthesia because it was developed from a database recorded during propofol anesthesia.3 During extracranial carotid surgery, shunt- ing is sometimes necessary to prevent cerebral ischemia, although it increases the complexity of the procedure. fte decision of placing a shunt is taken immediately after clamping the carotid ar- tery on the basis of clinical, hemodynamic, and instrumental data. If the procedure is performed in awake patients under regional anesthesia, cerebral hypoperfusion is promptly detected by neurological evaluation. If the patient is under general anesthesia, trans-cranial cerebral oxym- etry (TCCO) can help to detect cerebral hypop- erfusion.4 To verify the effectiveness of TCCO, Stilo et al. compared the information collected by neurological examination (considered the gold standard) with that obtained by TCCO in a series of 100 patients who underwent carotid surgery under local anesthesia.5 fte decision of COPYRIGHT 2013 EDIZIONI MINERVA MEDICA A yEAR IN REVIEW IN MI