Small tidal volume ventilation using a zero deadspace tracheal tube

Abstract

The zero deadspace tracheal tube (ZEDS-TT) is a double-lumen endobronchial tube with a truncated bronchial limb. Functionally it is unrelated to the familiar endobronchial tube used in lung isolation surgery. It is placed in the same position as a regular tracheal tube and, by means of special connectors, one limb is used for inspiration and the other for expiration, thereby greatly reducing anatomical and apparatus deadspace. In this study, we have compared respiratory and ventilatory effects of reduction of tidal volume (VT) via a single-lumen tracheal tube and the ZEDS-TT during controlled ventilation with a Siemens Elema 900C Servo ventilator. Eleven consenting adult patients (ASA I and II) undergoing elective peripheral surgery were studied. Starting at a VT value of 10 ml kg-1, data were recorded for each tube type. VT was reduced by 2.5 ml kg-1 every 10 min and stabilized data recorded. Minute volume was kept constant by increasing ventilatory frequency at each reduction in VT. We found that the ZEDS-TT produced a significant reduction in PaCO2 and airway pressure for any VT used, while maintaining oxygenation.