Combined pulse oximetry and carbon dioxide tension ear sensor in adult patients early after cardiac surgery

Introduction: Knowledge of the patient’s arterial oxygen saturation (Sao2) and arterial carbon dioxide partial tension (Paco2) is a sine qua non for determining adequacy of ventilation. Today, pulse oximetry (POX) provides a surrogate measure (Spo2) of Sao2. Reliable determination of Paco2, however, still requires frequent arterial blood sampling. Here we report on a new, non-invasive digital ear sensor (VSignTM, SenTec AG) combining POX with the measure of carbon dioxide partial pressure (Pco2).