Comparison of the qCON and qNOX indices for the assessment of unconsciousness level and noxious stimulation response during surgery
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The objective of this work is to compare the performances of two electroencephalogram based indices for detecting loss of consciousness and loss of response to nociceptive stimulation. Specifically, their behaviour after drug induction and during recovery of consciousness was pointed out. Data was recorded from 140 patients scheduled for general anaesthesia with a combination of propofol and remifentanil. The qCON 2000 monitor (Quantium Medical, Barcelona, Spain) was used to calculate the qCON and qNOX. Loss of response to verbal command and loss of eye-lash reflex were assessed during the transition from awake to anesthetized, defining the state of loss of consciousness. Movement as a response to laryngeal mask (LMA) insertion was interpreted as the response to the nociceptive stimuli. The patients were classified as movers or non-movers. The values of qCON and qNOX were statistically compared. Their fall times and rise times defined at the start and at the end of the surgery were calculated and compared. The results showed that the qCON was able to predict loss of consciousness such as loss of verbal command and eyelash reflex better than qNOX, while the qNOX has a better predictive value for response to noxious stimulation such as LMA insertion. From the analysis of the fall and rise times, it was found that the qNOX fall time (median: 217 s) was significantly longer (p value <0.05) than the qCON fall time (median: 150 s). At the end of the surgery, the qNOX started to increase in median at 45 s before the first annotation related to response to stimuli or recovery of consciousness, while the qCON at 88 s after the first annotation related to response to stimuli or recovery of consciousness (p value <0.05). The indices qCON and qNOX showed different performances in the detection of loss of consciousness and loss of response to stimuli during induction and recovery of consciousness. Furthermore, the qCON showed faster decrease during induction. This behaviour is associated with the hypothesis that the loss of response to stimuli (analgesic effect) might be reached after the loss of consciousness (hypnotic effect). On the contrary, the qNOX showed a faster increase at the end of the surgery, associated with the hypothesis that a higher probability of response to stimuli might be reached before the recovery of consciousness.
KeywordsAnesthesia monitor Nociception Electroencephalography Clinical indices
The qNOX was based on an idea from the Department of Anesthesia Hospital CLINIC de Barcelona (Spain) funded by grant PS09/01209 of the Fondo de Investigaciones Sanitarias (FIS), Health Department, Government of Spain and has been developed in collaboration with Quantium Medical.
Compliance with ethical standards
Conflicts of interest
Umberto Melia, Erik Weber Jensen, Joan Fontanet, Eva Gabarron and Patricia Pineda are employees of Quantium Medical. Quantium Medical is the commercial developer of both qCON and qNOX indices.
The study was performed after IRB approval (Committee on Ethics in Research, Hospital CLINIC de Barcelona no 2013/8356). All the patients has written informed consent.
- 2.Vakkuri A, Yli-Hankala A, Sandin R, Mustola S, Høymork S, Nyblom S, Talja P, Sampson T, van Gils M, Viertiö-Oja H. Spectral entropy monitoring is associated with reduced propofol use and faster emergence in propofol–nitrous oxide–alfentanil anesthesia. Anesthesiology. 2005;103:274–9.CrossRefPubMedGoogle Scholar
- 6.Mashour GA, Shanks A, Tremper KK, Kheterpal S, Turner CR, Ramachandran SK, Picton P, Schueller C, Morris M, Vandervest JC, Lin N, Avidan MS. Prevention of intraoperative awareness with explicit recall in an unselected surgical population: a randomized comparative effectiveness trial. Anesthesiology. 2012;117(4):717–25.CrossRefPubMedPubMedCentralGoogle Scholar
- 7.Migeon A, Desgranges FP, Chassard D, Blaise BJ, De Queiroz M, Stewart A, Cejka JC, Combet S, Rhondali O. Pupillary reflex dilatation and analgesia nociception index monitoring to assess the effectiveness of regional anesthesia in children anesthetised with sevoflurane. Paediatr Anaesth. 2013;23(12):1160–5.PubMedGoogle Scholar
- 10.Rehberg B, Ryll C, Hadzidiakos D, Dincklage FW, Baars JH. Variability comparison of the composite auditory evoked potential index and the bispectral index during propofol-fentanyl anesthesia. Technol Comput Simul. 2008;107(1):117–24.Google Scholar
- 20.Bouillon TW, Bruhn J, Radulescu L, Andresen C, Shafer TJ, Cohane C, Shafer SL. Pharmacodynamic interaction between propofol and remifentanil regarding hypnosis, tolerance of laryngoscopy, bispectral index, and electroencephalographic approximate entropy. Anesthesiology. 2004;100:1353–72.CrossRefPubMedGoogle Scholar
- 21.Vereecke HEM, Hannivoort L N, Proost J H, Eleveld D J, Struys MMRF, Luginbühl M (2014) Predictive performance of the noxious stimulation response index as a measure of anesthetic potency during sevoflurane, propofol and remifentanil anesthesia. International Society for Anaesthetic Pharmacology (ISAP) Annual Meeting 2014. http://f1000research.com/posters/1097048.
- 22.von Dincklage F, Correll C, Schneider MH, Rehberg B, Baars JH. Utility of nociceptive flexion reflex threshold, bispectral index, composite variability index and noxious stimulation response index as measures for nociception during general anaesthesia. Anaesthesia. 2012;67(8):899–905.CrossRefGoogle Scholar
- 26.Minto CF, Schnider TW, Egan TD, Youngs E, Lemmens HJ, Gambus PL, Billard V, Hoke JF, Moore KH, Hermann DJ, Muir KT, Mandema JW, Shafer SL. Influence of age and gender on the pharmacokinetics and pharmacodynamics of remifentanil: I model development. Anesthesiology. 1997;86:10–23.CrossRefPubMedGoogle Scholar
- 28.Altman DG. Practical statistics for medical research. London: Chapman & Hall; 1991.Google Scholar
- 32.Stuart PC, Stott SM, Millar A, Kenny GN, Russell D. Propofol with and without nitrous oxide. Br J Anaesth. 2000;85:666.Google Scholar
- 34.Borrat X, Trocóniz IF, Valencia JF, Rivadulla S, Sendino O, Llach J, Castells A. Modeling the Influence of the A118G polymorphism in the OPRM1 gene and of noxious stimulation on the synergistic relation between propofol and remifentanil sedation and analgesia in endoscopic procedures. J Am Soc Anesthesiol. 2013;118(6):1395–407.CrossRefGoogle Scholar
- 43.Gambús PL, Jensen EW, Jospin M, Borrat X, Martínez Pallí G, Fernández-Candil J, Valencia JF, Barba X, Caminal P, Trocóniz IF. Modeling the effect of propofol and remifentanil combinations for sedation-analgesia in endoscopic procedures using an adaptive neuro fuzzy inference system (ANFIS). Anesth Analg. 2011;112(2):331–9.CrossRefPubMedGoogle Scholar