Evaluation of a System for Transcutaneous Long-Term Capnometry

Background: The measurement of CO 2 partial pressure (P CO 2 ) is of great importance. Former systems of transcutaneous capnometry combining the measurement of oxygen partial pressure (P O 2 ) and P CO 2 had their limitations due to skin irritations caused by the heating-up of the sensor and a short application time of 4 h. Objectives: To evaluate for the first time combined monitoring of transcutaneous P CO 2 (tcP CO 2 ) and oxygen saturation applying a lower temperature (sensor temperature 42 ° C) and a new sensor technology in healthy individuals during sleep. Methods: Twenty-nine healthy individuals [12 males, age 35.2 8 17.0 years, body height: 170.2 8 12.0 cm (mean 8 SD), weight: 76.3 8 15.8 kg, body mass index 26.5 8 5.4] were monitored for more than 6 h at night with the TOSCA 500 instrument (Radiometer, Basel, Switzerland). tcP CO 2 was continuously monitored and its correlation with selective measured capillary P CO 2 values (Pcap CO 2 ) was monitored at 0.00 and 4.00 h. Results: At 0.00 h, Pcap CO 2 was 37.1 8 5.1 mm Hg and tcP CO 2 was 43.4 8 6.6 mm Hg (p ! 0.001). At 4.00 h, Pcap CO 2 was 37.0 8 5.6 mm Hg and tcP CO 2 was 43.5 8 5.4 mm Hg (p ! 0.001). Received: July 29, 2009 Accepted after revision: December 30, 2009 Published online: March 11, 2010 Prof. Winfried J. Randerath, MD, FCCP, Institute of Pneumology at the University Witten/Herdecke, Clinic for Pneumology and Allergology Center of Sleep Medicine and Respiratory Care, Bethanien Hospital Aufderhöherstrasse 169–175, DE–42699 Solingen (Germany) Tel. +49 212 63 6000, Fax +49 212 63 6005, E-Mail randerath @ klinik-bethanien.de © 2010 S. Karger AG, Basel 0025–7931/10/0802–0139$26.00/0 Accessible online at: www.karger.com/res D ow nl oa de d by : 54 .7 0. 40 .1 1 12 /2 3/ 20 17 7 :1 2: 01 P M