Measurement of the lung and skin excretion of CO2 during anesthesia

Abstract

A mass spectrometer with capillary and membrane interfaces was used during anesthesia to deliver the gas mixture from the breathing circuit of the inhalation anesthesia machine (IAM) into the ionic source of an analyzer and to measure the concentration of CO₂ released from the skin in real time. The extent of the stress response during surgery correlated with the time course of changes in the concentrations of CO₂ released from the lungs and skin. The CO₂ concentration and the BIS index of changes in EEG frequency spectrum were measured simultaneously during intravenous total propofol–fentanyl anesthesia. The BIS index and the concentrations of CO₂ released from the lungs and skin were found to correlate with the most traumatic steps of the surgical procedure.