Evaluation of transcutaneous and endtidal carbon

Authors: Kenichi Satoh Mami Chikuda Ayako Ohashi Miho Kumagai Akiyoshi Kuji Shigeharu Joh

Publish Date: 2015/07/16

Volume: 30, Issue: 4, Pages: 423-428

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Abstract

Measurement of endtidal carbon dioxide PETCO2 is useful because of its noninvasiveness continuity and response time when sudden changes in ventilation occur during inhalation sedation We compared the accuracy of PETCO2 using a nasal mask and nasal cannula with the accuracy of transcutaneous carbon dioxide TCCO2 and determined which method is more useful during inhalation sedation in volunteers We used a modified nasal mask MNM and modified nasal cannula MNC for measurement of PETCO2 The capnometer measured PETCO2 in the gas expired from the nasal cavity by means of two devices The volunteers received supplemental O2 by means of each device at a flow rate of 6 L/min After the volunteers lay quietly for 5 min with a supply of 100  O2 they received supplemental N2O by means of each device at concentrations of 10 20 and 25  for 5 min and 30  for 25 min The correlation coefficient was poorer in the MNM than in the MNC and the mean difference between TCCO2 and PETCO2 in the MNM was greater than that in the MNC The difference between the TCCO2 and PETCO2 ranged from 3 to 6 mmHg in the MNM and from 2 to 5 mmHg in the MNC The difference between two variables against the TCCO2 and the CO2 waveforms obtained by means of the two devices were within the clinically acceptable range Our two devices can provide continuous monitoring of PETCO2 with a supply of N2O/O2 in patients undergoing inhalation sedation

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