Most common is the Robertshaw tube, available as both a L and R-sided tube. Sizes include a 28F (pediatric) as well as 35F, 37F, 39F, and 41F. All are PVC with D-shaped lumens, disposable. Blue represents the endobronchial lumen/cuff. Note that R-sided tubes have a donut-shaped endobronchial cuff, which allows separate access to the RUL.
Traditional positioning of the DLT is accomplished as follows:
Positioning of the DLT: Traditional Approach
- Always check both cuffs, lubricate the inside and outside of the tube, and place a stylet prior to insertion
- Attempt your DL with a Mac-3 (leaves the largest amount of physical space with which to work in the oropharynx), and remove the stylet as soon as the tube is past the glottis
- Rotate the tube appropriately, then inflate the tracheal cuff and verify bilateral inflation / equal breath sounds
- Next, clamp the tracheal lumen (clear) and slowly inflate the endobronchial cuff until no air leak occurs (so as not to overinflate)
- Unclamp the tracheal lumen (clear) and verify that both lungs are inflated with both cuffs up (i.e. to ensure that the endobronchial cuff is not obstructing the opposite bronchus)
- Lastly, clamp each lumen individually and verify unilateral chest movement
The aforementioned technique, when studied in 23 patients, showed a 48% failure rate [Smith et al. Br J Anaesth 58: 1317, 1986], although most of these malpositioning incidences were clinically insignificant. While FOB is necessary for positioning, it is not necessarily needed for initial placement – one study comparing blind to FOB-based placement in 59 showed a higher success rate and 93 seconds of saved time when initial placement relied on the blind technique [Boucek LD et al. J Clin Anesth 10: 557, 1998]
The major malpositioning errors are 1) entrance into opposite bronchus [opposite lung will collapse] 2) too deep into the bronchus [diminished breath sounds contralaterally] 3) underinsertion [no breath sounds when tracheal lumen used, as endobronchial cuff is still in the trachea 4) right-sided DLT may occlude the RUL [mean distance to RUL 2.2 cm] 5) LUL may be obstructed by the L endobronchial tube. Key FOB landmarks in DLT placement include [tracheal lumen initially] 1) lack of herniated bronchial cuff 2) visualization of three orifices in the RUL (only lobe to have three orifices), [bronchial lumen] 3) LUL and RUL orifices.
Double lumen ETT: Positioning
- G B Smith, N P Hirsch, J Ehrenwerth Placement of double-lumen endobronchial tubes. Correlation between clinical impressions and bronchoscopic findings. Br J Anaesth: 1986, 58(11);1317-20 [PubMed:3778796]
- C D Boucek, R Landreneau, J A Freeman, D Strollo, N G Bircher A comparison of techniques for placement of double-lumen endobronchial tubes. J Clin Anesth: 1998, 10(7);557-60 [PubMed:9805696]