Difficulties with positioning Robertshaw double lumen tubes.

Difficulties in positioning Robertshaw tubes have been reviewed in a retrospective and a prospective series. Pre-operative cheat X-rays did not help in predicting difficulties. The performance of the Robertshaw tube was carefully recorded for each malposition in the prospective series, and the relationship of the malplaced tube to the tracheobronchial tree was reconstructed. This exercise allowed a more precise definition of the dangers of malpositions and formulation of procedure to minimize their incidence.