Review and new use for the univent tube.

The univent tube has been used maily for one lung anesthesis.There are other clincal settings where the tube was found to be useful. The univent tube can be used in cases of difficult intubation while supplimenting oxygen and monitoring ETCO2. Macintosh first used the gum-elastic bougie as an aid to intubation in 1943 when he found that the tracheal tube could obstruct his view of the cords. The lubricated gum elastic catheter was therefore first threaded through the tube and then gently placed into the trachea. The tube was pushed down into the trachea over the catheter and the catheter removed. The technique was also used when exposure of the larynx was inadequate [ 1]. The technique is now commonly advocated when the cords cannot be seen at laryngoscopy. The catheter briefly retains the approximate shape into which it is bent. It is important to keep the catheter in the midline and to bend the distal end forward after it has been passed through the tracheal tube. The catheter can then be advanced blindly towards the cords and the tube then 'railroaded' over the catheter. It is necessary to check very carefully that the tube has passed into the trachea. In addition to listening to the chest and observing chest movement it is mandatory to listen over the stomach and if possible to measure expired carbon dioxide levels to exclude accidental esophageal intubation.