title: Transcutaneous PTCCO2measurement in combination with arterial blood gas analysis provides superior accuracy and reliability in ICU patients.
abstract: Hyper or hypoventilation may have serious clinical consequences in critically ill patients and should be generally avoided, especially in neurosurgical patients. Therefore, monitoring of carbon dioxide partial pressure by intermittent arterial blood gas analysis (PaCO2) has become standard in intensive care units (ICUs). However, several additional methods are available to determine PCO2including end-tidal (PETCO2) and transcutaneous (PTCCO2) measurements. The aim of this study was to compare the accuracy and reliability of different methods to determine PCO2in mechanically ventilated patients on ICU. After approval of the local ethics committee PCO2was determined in n = 32 ICU consecutive patients requiring mechanical ventilation: (1) arterial PaCO2blood gas analysis with Radiometer ABL 625 (ABL; gold standard), (2) arterial PaCO2analysis with Immediate Response Mobile Analyzer (IRMA), (3) end-tidal PETCO2by a Propaq 106 EL monitor and (4) transcutaneous PTCCO2determination by a Tina TCM4. Bland-Altman method was used for statistical analysis; p < 0.05 was considered statistically significant. Statistical analysis revealed good correlation between PaCO2by IRMA and ABL (R2= 0.766; p < 0.01) as well as between PTCCO2and ABL (R2= 0.619; p < 0.01), whereas correlation between PETCO2and ABL was weaker (R2= 0.405; p < 0.01). Bland-Altman analysis revealed a bias and precision of 2.0 ± 3.7 mmHg for the IRMA, 2.2 ± 5.7 mmHg for transcutaneous, and -5.5 ± 5.6 mmHg for end-tidal measurement. Arterial CO2partial pressure by IRMA (PaCO2) and PTCCO2provided greater accuracy compared to the reference measurement (ABL) than the end-tidal CO2measurements in critically ill in mechanically ventilated patients patients.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Cologne, Kerpener Str. 62, 50931, Cologne, Germany. oliver.spelten@uk-koeln.de.
authors.forename: Oliver
authors.initials: O
authors.lastname: Spelten
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, St. Elisabeth-Hospital, Cologne, Germany.
authors.forename: Fritz
authors.initials: F
authors.lastname: Fiedler
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Cologne, Kerpener Str. 62, 50931, Cologne, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Schier
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Cologne, Kerpener Str. 62, 50931, Cologne, Germany.
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Wetsch
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Cologne, Kerpener Str. 62, 50931, Cologne, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Hinkelbein
mesh_terms: D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis / Q000379:methods*; D001785:Blood Gas Monitoring, Transcutaneous / Q000379:methods*; D002245:Carbon Dioxide / Q000097:blood; D003362:Cost-Benefit Analysis; D003422:Critical Care; D016638:Critical Illness; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D010313:Partial Pressure; D000067716:Point-of-Care Testing; D015203:Reproducibility of Results; D012121:Respiration, Artificial / Q000379:methods*; D018401:Sample Size; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide
keywords: Arterial blood gas analysis; Capnography; Capnometry; Point-of-care testing