Oral-Trac® Oral/Nasal EtCO2 Divided Sampling Cannula with Oxygen Delivery - With Unique Oral Sampling TRUNK - Accurate End Tidal Sampling with Simultaneous Oxygen Delivery. The Salter Oral-Trac® oral/nasal cannula features dual EtCO2 sampling through both nasal prong and a unique oral sampling trunk. This allows accurate patient monitoring even during spontaneous breathing or with mouth breathers. Simultaneously oxygen can be delivered through a separate tube and nasal prong. A permanent barrier in the facepiece separates the oxygen delivery and EtCO2 sampling pathways to permit an undiluted gas sample. Salter-Eyes®, safety apertures (a Salter exclusive) are incorporated in the nasal prongs to reduce possible occlusions.