Mass spectrometer with a membrane interface for intraoperative monitoring the elimination of inhalation anesthetic and CO$_2$ through the skin

A new method is implemented in order to measure the concentration of CO$_2$ and inhalation anesthetic sevoflurane eliminated through the skin during surgery. The concentration of inhalation anesthetic has been measured during general combined anesthesia (sevoflurane, fentanyl) and total intravenous anesthesia (propofol, fentanyl). The dependence of the concentration of CO$_2$ and the inhalation anesthetic from the relaxation of smooth muscles in the walls of blood vessels under the effect of sevoflurane and propofol and on the stress response to surgical injury has been revealed for the first time.