Prediction of blood pressure changes during surgical incision using minimum evoked current of vascular stiffness value under sevoflurane anesthesia

Opioid sensitivity is difficult to predict, and varies among individuals. We previously reported that sympathetic responses to nociceptive stimuli under propofol anesthesia can be predicted by measuring the minimum evoked current of the vascular stiffness value (MECK). We now propose that MECK can also be used in the same capacity for volatile anesthetic. Thirty patients undergoing laparotomy with sevoflurane anesthesia received intravenous remifentanil at a constant concentration of 2 ng/mL followed by tetanic stimulation. The first-order linear regression equation of MECK and the rate of change of systolic blood pressure during the skin incision (ROCBP) under sevoflurane anesthesia were almost the same as those for propofol. We fitted the data in the present study to the prediction equation for ROCBP obtained under propofol anesthesia and performed a Bland-Altman plot analysis. Fixed bias was minimal, at -1.86%, and the precision range at 9.96% was almost the same as 10.17% that from the previous study. No significant proportional errors were observed. These results suggest that MECK can be used as a predictive index for ROCBP under sevoflurane anesthesia. Additionally, the prediction equation for ROCBP under propofol anesthesia can be used for sevoflurane anesthesia without a decrease in predictive performance. Clinical trial registration Registry: University hospital medical information network; Registration number: UMIN000047425; principal investigator name: Noboru Saeki; date of registration: April 8th, 2022.