title: [Evaluation of a compact device for capnometry of main-stream type compared with one of side-stream type in a postoperative care unit].
abstract: BACKGROUND
  Pulse oximetry is insufficient for postoperative respiratory monitoring. It is better to use capnometry for postoperative patients because it is easy to use and useful to monitor patients' breathing. However, capnometry must be improved in its wearability and detection capability. Therefore it is not used often for postoperative patients as a respiratory monitor.
  
  
  METHODS
  We have examined a side-stream type capnometer and an improved main-stream type capnometer in a post-anesthesia care unit (PACU) to determine which is better as a monitor for detection of breathing. A total of 55 patients participated in this study. Patients wore a device including a main-stream capnometer and a side-stream capnometer. Capnograms were recorded while patients were staying in the PACU.
  
  
  RESULTS
  The main-stream system could detect breathing in all the patients, but the side-stream system failed to detect breathing in five patients. The side-stream device showed a warning of "apnea" for five patients, even though these patients were breathing normally.
  
  
  CONCLUSIONS
  We conclude that the main-stream system is a better monitor of postoperative respiratory condition.
authors.affiliation: Department of Anesthesiology, Faculty of Advanced Techno-surgery, Institute of Advanced Biomedical Engineering & Science, Tokyo Women's Medical University, Tokyo.
authors.forename: Jobutada
authors.initials: J
authors.lastname: Morioka
authors.forename: Shinji
authors.initials: S
authors.lastname: Yamamori
authors.forename: Makoto
authors.initials: M
authors.lastname: Ozaki
mesh_terms: D019296:Capnography / Q000295:instrumentation*; D002245:Carbon Dioxide / Q000032:analysis*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation; D011182:Postoperative Care / Q000295:instrumentation
chemical_list: D002245:Carbon Dioxide