Effects of using two airway exchange catheters on laryngeal passage during change from a double-lumen tracheal tube to a single-lumen tracheal tube

Background. A thin airway exchange catheter (AEC) is often used for changing from a double-lumen tracheal tube (DLT) to a single-lumen tracheal tube. However, passage of the tube into the trachea is often difficult. The purpose of this study was to evaluate the effectiveness of using two AECs for tracheal tube exchange. Methods. In Study 1, 30 patients were randomly allocated to two groups and one AEC was inserted into the trachea in one group, and two AECs in the other group. A tracheal tube was advanced into the pharynx over the AEC(s). A blinded observer assessed the difficulty of passing the tube into the trachea. In Study 2, another group of 30 patients (whose airways had been managed with DLTs) were randomly allocated to two groups, and either one or two AECs were inserted into the XT depending upon the group allocation. The difficulty of passing the tube into the trachea was assessed and the time required for exchange was measured. Results. The use of two AECs reduced the incidence of impingement of the tube into the trachea during the AEC-guided tracheal intubation (Study 1) from 93 to 33% (P < 0.05) and during exchange from a DLT to a single-lumen tracheal tube (Study 2) from 100 to 27% (P < 0.05). The exchange time was similar: 106 (7) and 116 (4) s [mean (SD)] for one and two AECs, respectively. Conclusion. The use of two AECs reduces the incidence of impingement of the tube into the trachea during tracheal tube exchange.