A comparison was made between the Robertshaw and the Carlens or White tubes for ease of insertion and success of positioning in patients about to undergo thoracotomy. The Carlens and the left Robertshaw tubes performed equally but the 35 Carlens was successfully used in three patients in whom the small Robertshaw had proven to be unsuitable. The White tube, however, was inferior to the right Robertshaw because it was found impossible to seal the bronchial cuff satisfactorily in many of the cases in which it was used.
