[Evaluation of a compact device for capnometry of main-stream type compared with one of side-stream type in a postoperative care unit].
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.
Morioka
Jobutada
J
Department of Anesthesiology, Faculty of Advanced Techno-surgery, Institute of Advanced Biomedical Engineering & Science, Tokyo Women's Medical University, Tokyo.
Yamamori
Shinji
S
Ozaki
Makoto
M
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
D002245:Carbon Dioxide