Objective — to execute verification research of the importance of monitoring of a surgical plethysmographic index (SPI) when carrying out the general combined anesthesia with use of the automated control of concentration of anesthetic.Materials and Methods. In a prospective study there were 112 patients included operated for the pathology of the spine and the spinal cord of varying severity, extent and localization. The estimation of the ratio of numerical values of SPI, the level of stress hormone (ACTH, cortisol), the standard hemodynamic measures of the low-flow anesthesia with Et-control using the extended (due to entropy and SPI) monitoring.Results. Monitoring the adequacy of antinociceptive protection based on the performance of surgical plethysmographic index (SPI) allows detection of nociceptive responses to an earlier stage.Conclusion. The study revealed that the use of SPI monitoring the operations of high-risk permits anesthesia, with optimum concentration of opioids required, and minimal hemodynamic response of the patient.