Placement of the Univent tube without fiberoptic bronchoscope assistance

In this study, we evaluated the feasibility and accuracy of Univent tube (Fuji Systems, Tokyo, Japan) placement with the aid of auscultation (AUS) or as guided by a lighted stylet (LS) compared with placement guided by the fiberoptic bronchoscope (FOB) or the blind intubation technique as recommended by the manufacturer's guidelines.

Eighty ASA physical status I-II adult patients requiring single-lung ventilation for elective thoracic surgery were randomly allocated into 4 groups according to the method used for Univent tube positioning: manufacturer-recommended (MR) group (n = 20); FOB group (n = 20); AUS group (n = 20); and LS group (n = 20). Tracheal placement of the Univent tube was accomplished with direct rigid laryngoscopy after anesthetic induction and was positioned by the same anesthesiologist using 1 of the above-described methods. Its position was then checked by another anesthesiologist with an FOB. The number of attempts required for successful tube positioning, the volume of air needed for blocker cuff inflation, and intubation times were recorded, as were the times for single-lung ventilation and the potential for bronchial injury.

The intubation time was 182 +/- 42 s in the AUS group and 176 +/- 50 s in the LS group, shorter than that in the FOB (278 +/- 111 s) and MR (266 +/- 127 s) (P < 0.05) groups. The success rate of bronchial blocker insertion into the left bronchus on the first attempt was 100% in the AUS group, 79% in the LS group, and 25% in the MR group. The number of blocker insertion attempts and the volume of air in the blocker cuff in the MR group were significantly higher than those in the AUS and LS (P < 0.05) groups. In the supine position, the number of acceptable bronchial blocker placements was 14 of 20 attempts (70%) in the MR group, significantly fewer than that in the FOB group (18 of 20, 90%) (P < 0.05). In the AUS and LS groups, the number of acceptable bronchial blocker placements was 19 of 20 (95%) and 16 of 20 (80%), respectively. After patients were turned to the lateral decubitus position, the number of acceptable bronchial blocker placements was 10 of 18 (56%) in the MR group, significantly fewer than that in the FOB group (17 of 19, 89.5%) (P < 0.05). In the AUS and LS groups, the number of acceptable bronchial blocker placements was 15 of 20 (75%) and 15 of 19 (79%), respectively.

The placement of the Univent tube with the aid of AUS or an LS is feasible, and both techniques require less time than placement aided by an FOB or as recommended by the manufacturer.