Response Entropy™ is not more sensitive than State Entropy™ in distinguishing the use of esmolol instead of remifentanil in patients undergoing gynaecological laparoscopy

Self Cite

Section: Discussionmentioning

confidence: 99%

Surgical stress index reflects surgical stress in gynaecological laparoscopic day-case surgery †

Ahonen

Jokela

Uutela

et al. 2007

Self Cite

“…Therefore, RE−SE difference may indicate nociception or inadequate anaesthesia, an assumption supported by one recently published article, 8 but disputed by another. 9 …”

mentioning

confidence: 99%

Facial muscle activity, Response Entropy, and State Entropy indices during noxious stimuli in propofol–nitrous oxide or propofol–nitrous oxide–remifentanil anaesthesia without neuromuscular block

Aho

Yli‐Hankala

Lyytikäinen

et al. 2009

BackgroundEntropy™ is an anaesthetic EEG monitoring method, calculating two numerical parameters: State Entropy (SE, range 0–91) and Response Entropy (RE, range 0–100). Low Entropy numbers indicate unconsciousness. SE uses the frequency range 0.8–32 Hz, representing predominantly the EEG activity. RE is calculated at 0.8–47 Hz, consisting of both EEG and facial EMG. RE–SE difference (RE−SE) can indicate EMG, reflecting nociception. We studied RE−SE and EMG in patients anaesthetized without neuromuscular blockers.MethodsThirty-one women were studied in propofol–nitrous oxide (P) or propofol–nitrous oxide–remifentanil (PR) anaesthesia. Target SE value was 40–60. RE−SE was measured before and after endotracheal intubation, and before and after the commencement of surgery. The spectral content of the signal was analysed off-line. Appearance of EMG on EEG was verified visually.ResultsRE, SE, and RE−SE increased during intubation in both groups. Elevated RE was followed by increased SE values in most cases. In these patients, spectral analysis of the signal revealed increased activity starting from low (<20 Hz) frequency area up to the highest measured frequencies. This was associated with appearance of EMG in raw signal. No spectral alterations or EMG were seen in patients with stable Entropy values.ConclusionsIncreased RE is followed by increased SE at nociceptive stimuli in patients not receiving neuromuscular blockers. Owing to their overlapping power spectra, the contribution of EMG and EEG cannot be accurately separated with frequency analysis in the range of 10–40 Hz.

“…Patient movement, a clinical sign of inadequate analgesia during or after tracheal intubation, was observed in patients receiving esmolol, whereas in a previous study no movement was observed in the patients receiving remifentanil. 13 These findings suggest that the antinociceptive effect of b1-adrenoceptor antagonists is weaker than that of remifentanil or, because b1-adrenoceptors are present in various parts of the reticular activating system, the effect-site of b1-adrenoceptor-mediated antinociception may differ from that of remifentanil.…”

Section: Discussionmentioning

confidence: 89%

“…Little is known, however, about the effect of b1-adrenoceptor antagonists on the entropy index responses to tracheal intubation. 13 In the present study, we investigated the effect of landiolol on BIS and entropy index responses to tracheal intubation in a double-blind manner. We hypothesized that entropy indices, and BIS, increase in response to tracheal intubation and that the antinociceptive effect of landiolol, observed as a reduction in the RE2SE response, suppresses the arousal response to tracheal intubation.…”

mentioning

confidence: 99%

Effect of landiolol on bispectral index and spectral entropy responses to tracheal intubation during propofol anaesthesia

Kawaguchi

Takamatsu

Masui

et al. 2008