These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Accuracy of a central mass spectrometer system at high respiratory frequencies.
    Author: Scamman FL.
    Journal: J Clin Monit; 1988 Jul; 4(3):227-9. PubMed ID: 3145330.
    Abstract:
    We have shown that in a laboratory setting the long lengths of sampling catheters necessary to access a central mass spectrometer restrict the high-frequency response of the system. Reported here are the results from a clinically operating Perkin-Elmer Advantage system. The sampling catheter was 50 meters long and the sampling flow was 240 ml/min. Rapid changes in carbon dioxide concentration were created by an electronically operated solenoid valve switching between 6.94% CO2 in 50% O2 balance N2 and 100% O2. The frequency of this simulated breathing was varied between 10 and 100 breaths/min with the ratio of inspiration to expiration fixed at 1:2. Data were taken from the terminal in the operating room. Errors greater than 5% of the true value occurred at 35 breaths/min for the indicated inspired concentration and 73 breaths/min for the indicated expired concentration. For critical situations in which respiratory frequencies exceed 40 breaths/min, a centrally located mass spectrometer may not be adequate for measuring CO2 because of errors introduced by the long sampling catheters.
    [Abstract] [Full Text] [Related] [New Search]