Please use this identifier to cite or link to this item:
|Title:||Frontal alpha-delta EEG does not preclude volitional response during anaesthesia: prospective cohort study of the isolated forearm technique.||Authors:||Gaskell, AL
Hight, D F
Sanders, R D
|Issue Date:||1-Oct-2017||Source:||British journal of anaesthesia 2017-10-01; 119(4): 664-673||Journal Title:||British journal of anaesthesia||Abstract:||The isolated forearm test (IFT) is the gold standard test of connected consciousness (awareness of the environment) during anaesthesia. The frontal alpha-delta EEG pattern (seen in slow wave sleep) is widely held to indicate anaesthetic-induced unconsciousness. A priori we proposed that one responder with the frontal alpha-delta EEG pattern would falsify this concept. Frontal EEG was recorded in a subset of patients from three centres participating in an international multicentre study of IFT responsiveness following tracheal intubation. Raw EEG waveforms were analysed for power-frequency spectra, depth-of-anaesthesia indices, permutation entropy, slow wave activity saturation and alpha-delta amplitude-phase coupling. Volitional responses to verbal command occurred in six out of 90 patients. Three responses occurred immediately following intubation in patients (from Sites 1 and 2) exhibiting an alpha-delta dominant (delta power >20 dB, alpha power >10 dB) EEG pattern. The power-frequency spectra obtained during these responses were similar to those of non-responders (P>0.05) at those sites. A further three responses occurred in (Site 3) patients not exhibiting the classic alpha-delta EEG pattern; these responses occurred later relative to intubation, and in patients had been co-administered ketamine and less volatile anaesthetic compared with Site 1 and 2 patients. None of the derived depth-of-anaesthesia indices could robustly discrimate IFT responders and non-responders. Connected consciousness can occur in the presence of the frontal alpha-delta EEG pattern during anaesthesia. Frontal EEG parameters do not readily discriminate volitional responsiveness (a marker of connected consciousness) and unresponsiveness during anaesthesia. NCT02248623.||URI:||http://hdl.handle.net/11055/257||DOI:||10.1093/bja/aex170||PubMed URL:||https://www.ncbi.nlm.nih.gov/pubmed/29121278||Type:||Journal Article|
|Appears in Collections:||Scholarly and Clinical|
Show full item record
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.