title: Dedicated monitoring of anesthetic and respiratory gases by Raman scattering.
abstract: The monitoring of respiratory and anesthetic gases in the operating room is important for patient safety. This study measured the accuracy and response time of a multiple-gas monitoring instrument that uses Raman light scattering. Measurements of oxygen, carbon dioxide, nitrogen, nitrous oxide, halothane, enflurane, and isoflurane concentrations were compared with a gas mixer standard and with measurements made with an infrared anesthetic agent analyzer. Correlation coefficients were all greater than 0.999, and probable errors were less than 0.43 vol% for the gases and less than 0.03 vol% for the volatile anesthetics. Response time was 67 ms with a sample flow rate of 150 ml/min. There was some signal overlap between nitrogen and nitrous oxide and between the volatile anesthetic agents. Such overlap can be compensated for by linear matrix analysis. The Raman instrument promises a monitoring capability equivalent to the mass spectrometer and should prove attractive for the monitoring of respiratory and anesthetic gases in the operating room.
mesh_terms: D000388:Air / Q000032:analysis*; D000777:Anesthetics / Q000032:analysis*; D002245:Carbon Dioxide / Q000032:analysis; D006801:Humans; D007834:Lasers; D009584:Nitrogen / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D013059:Spectrum Analysis, Raman / Q000295:instrumentation* / Q000379:methods
chemical_list: D000777:Anesthetics; D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen