Roediger, Regine, Beck-Schimmer, Beatrice, Theusinger, Oliver M., Rusch, Denise, Seifert, Burkhardt, Spahn, Donat R., Schmid, Edith R., and Baulig, Werner
Objective: The aim of this study was to validate the revised SenTec V-Sign 2 sensor (SenTec AG, Therwil, Switzerland) for combined noninvasive continuous assessment of pulse rate, pulse oximetry (SpO2), and transcutaneous carbon dioxide tension (PtcCO2) in adults after cardiac surgery. Design: A prospective clinical study. Setting: A single-center university hospital. Participants: Twenty adult patients aged 36 to 84 years after cardiac surgery. Interventions: SpO2 and PtcCO2 values of three V-Sign 2 sensors (SenTec AG) attached at the earlobe, forehead, and cheek and SpO2 values of the Nellcor Durasensor (Model DS-100A; Nellcor Puritan Bennett Inc, Pleasanton, CA) were compared with simultaneous measurements of blood gases and end-expiratory carbon dioxide. Measurements and Main Results: Measurements were performed during periods of hyper-, normo-, and hypocapnia and then at 30-minute intervals up to 5 hours. Bland-Altman analysis and simple regression analysis were used. Results: The detection failures for PtcCO2 were 0.3% to 1.3%, for SpO2 10% to 25%, and for pulse rate 5% to 10%. The V-Sign 2 earlobe sensor provided the best results. The mean bias and limits of agreement for PtcCO2ear and PaCO2 were 1.1 and −3.4/+5.5 mmHg. The drift of PtcCO2 was negligible at all locations. The mean bias and limits of agreement of V-Sign SpO2ear and SaO2, as well as V-Sign pulse rate and the electrocardiogram, were −1.7% and −6.8/+3.9% and 1.2 beats/min and −3.3/+5.8 beats/min. End-expiratory carbon dioxide showed a weak correlation with PaCO2 (r 2 = 0.47). Conclusions: Transcutaneous capnometry using the revised V-Sign 2 sensor at the earlobe is a reliable monitoring tool during the recovery period of patients after cardiac surgery. This approach has the potential to reduce the number of arterial blood gas samples. [Copyright &y& Elsevier]