8th CONFERENCE OF THE EUROPEAN STUDY GROUP ON CARDIOVASCULAR OSCILLATIONS

Movement responses to noxious stimuli during general anesthesia are regarded as a sign of nociception. We compared the qNOX Index and Analgesia Nociception Index (ANI) as predictors of movement during propofol and remifentanil anaesthesia. Both indices are compared using the calculated propofol/remifentanil effect site concentrations (Ce) and the response to noxious stimuli recorded in 20 patients. The ANI was transformed to 100-ANI in order to follow the same scale as qNOX, and make the statistical interpretation consistent. The prediction probabilities (remapped Pk-value) and their standard errors (SE) were obtained for the evolution of the indices versus Ce remifentanil: qNOX =0.78, SE=0.003; 100-ANI= 0.526, SE=0.004 (qNOX significantly larger). For the responses of noxious stimuli the Pk-value and their SE were: qNOX=0.71, SE=0.049; 100-ANI=0.68, SE=0.050. We conclude that the qNOX better predicts the Ce remifentanil while both qNOX and ANI detect equally well movement as a response to noxious stimulation.