Airway Management During Tracheostomy

Fig. 13.1

Characteristics of double-lumen endotracheal tube (DLET). The figure shows the upper channel dedicated for bronchoscopy, the lower channel for patient’s ventilation

The upper lumen should be positioned at the level of the vocal cords, while the lower lumen to the level of carina. The lower lumen has: (1) an elliptical shape to better lean on the posterior tracheal wall without taking up too much space of the trachea and (2) a distal cuff to be cuffed at the carina. PDT with DLET in place may be performed with the same step of a conventional PDT. The intubation with the DLET may be safely achieved with a proper tube exchanger under a direct laryngoscopy. The correct positioning of DLET with the upper lumen at the level of vocal cords and the lower lumen at the carina has to be checked with the bronchoscope. Once the correct position of the DLET is confirmed and the distal cuff is inflated, the PDT should be conventionally performed. The DLET is now available for single-step tracheostomy and for guide wire dilating forceps technique, both with a proper cannula (Fig. 13.2).

Fig. 13.2

Different available kits with double-lumen endotracheal tube (DLET). (a) Kit for Ciaglia single-step tracheostomy. (b) Kit for Griggs guide wire dilating forceps tracheostomy. (c) Tracheostomy tube for DLET

The puncture of anterior tracheal wall, Seldinger insertion, dilatation and cannulation are performed with the DLET placed in trachea (Figs. 13.3, 13.4, and 13.5).

Fig. 13.3

Double-lumen endotracheal tube procedural steps. (a) Puncture of anterior tracheal wall with DLET placed on the posterior tracheal wall. (b) Pre-dilation of anterior tracheal wall with DLET placed on the posterior tracheal wall

Fig. 13.4

Double-lumen endotracheal tube procedural steps. (a) Initial dilation with DLET placed on the posterior tracheal wall. (b) End of dilation of anterior tracheal wall with DLET placed on the posterior tracheal wall

Fig. 13.5

Double-lumen endotracheal tube procedural steps. (a) Cannula placement with DLET placed on the posterior tracheal wall. (b) Control of correct cannula placement with DLET still placed on the posterior tracheal wall

DLET has been tested in in vitro and in vivo studies [4, 11]. In a lung model, DLET showed the lower resistance, according Rohrer equation, during an increasing continuous flow [4]. The Rohrer equation, Delta P _ETT = K ₁ F + K ₂VF₂, describes the resistive properties of an ETT. DLET showed the lower resistance when compared with conventional ETT also in inspiratory and expiratory phases of volume-controlled ventilation [4]. These results are consistent with the fact that DLET is the first device that allows a ventilation independent from bronchoscopy.

In further unpublished in vitro evaluation, DLET compared with ETT showed the lower resistance also in a setting of volume-controlled ventilation with airway resistance was calculated as pressure drop/flow across each ETT (Fig. 13.6). Volume-controlled ventilation was set with V _t of 500 mL, PEEP 5 cm H₂O and inspiratory to expiratory ratio 1:1 and 1:2.