Mass spectrometry monitoring of sevoflurane in the breathing circuit of an inhalation anesthesia machine

The results of controlling the amount of inhalation anesthetics sevoflurane in the patient breathing circuit of an inhalation anesthesia machine (IAM) by mass spectrometry are presented. A vacuum system with a differential chamber providing pressure difference in the range 1 × 10⁵–1.5 ×10⁻⁴ Pa was used to inject the studied gas sample from the delivery circuit into the mass spectrometer. The concentrations of the anesthetic obtained using mass and IR spectrometry are compared. The potency of mass spectrometry for monitoring the anesthetic gas in the real time mode is demonstrated. The time dependences of the concentration of the anesthetic gas corresponding to different periods of anesthesia are given.