Univent[registered sign] endotracheal tube (Fuji Systems, Tokyo, Japan) damage is rare, but we have encountered two such cases: a fragmented tube and a fractured tube.
The patient was a 62-yr-old, 158-cm, 58-kg man scheduled for surgery with a diagnosis of esophageal cancer. After placement of a 8.5-mm single-lumen cuffed Univent[registered sign] tube made of silicon, the built-in cuff was advanced into the right mainstem bronchus with the aid of fiberoptic bronchoscopy. The bronchial blocker cuff was inflated to permit one-lung ventilation that was confirmed by auscultation of the lungs. The patient was in a left semilateral decubitus position, and the operating Table wasrotated to the left according to the surgical procedure. During two-lung ventilation, analysis of arterial blood gases was normal, and pulse oximetry showed 99%-100% oxygen saturation. However, during one-lung ventilation, oxygen saturation decreased to 93%, and PaO2 gradually decreased from 130 to 52 mm Hg despite the inhalation of 100% oxygen. One-lung ventilation time was 90 min in total, and during this period, both lungs were ventilated manually a few times until oxygen saturation recovered to 100%. Surgery was completed in 6 h 20 min; the anesthesia time was 7 h 40 min. The patient entered the intensive care unit with the Univent[registered sign] endotracheal tube still in place. When the trachea was suctioned, using a fiberoptic bronchoscope, we found a foreign body at the proximal region of the left anterior segmental bronchus, and the object was removed. As it seemed to be a silicon fragment, the Univent[registered sign] endotracheal tube was replaced with a single-lumen tube, and we inspected the Univent[registered sign] tube carefully. The inner part where a slip joint (a tracheal tube connector) attached to the tube was broken, and the object that was removed from the patient's bronchus fit perfectly into the defective area (Figure 1). Neither atelectasis nor the foreign object was seen on chest radiograph taken immediately after the patient entered the intensive care unit.
The patient was a 57-yr-old, 160-cm, 56-kg man undergoing surgery for esophageal cancer. A 9.0-mm Univent[registered sign] tracheal tube was used. During surgery, the slip joint disconnected from the Univent[registered sign] tube several times and had to be reconnected. After extubation, we checked the Univent[registered sign] tube for fracture and noticed that the inside of the tube was damaged (Figure 2).
Before intubation, the tube and the slip joint must be joined together because the Univent[registered sign] tube itself and its connector, the slip joint, are packed separately. It seems to be easier to detach the slip joint from the Univent[registered sign] tube after inserting it into the tube if a fiberoptic bronchoscope with a large diameter is used to verify adequate placement of the tube. The inner diameter of the tube is smaller than the outer diameter of the slip joint by 1 mm (Figure 1). Consequently, if a tube and a slip joint are attached improperly, they can easily disconnect. However, so much force is needed to connect them properly that it may cause a fracture in the inner layer of the tube. The silastic Univent[registered sign] tubes are more elastic and fragile than conventional tubes made of polyvinyl chloride.
In the first case, we assume that a silicon fragment chipped away from the tube on connection and traveled into the patient's bronchus  when we were performing fiberoptic bronchoscopy or when the airway was suctioned. Fortunately, the silicon tip fragment did not cause a serious complication, such as airway obstruction [2,3] or atelectasis. In the second case, the tube was fractured at the same place as in the first case, and this was not noticed until tracheal extubation. Our experiences illustrate that the tracheal tube connector can damage the Univent[registered sign] tube. The two parts should be connected cautiously.
1. Saah D, Braverman I, Sichel JY, et al. An unusual bronchial foreign body: a fragment of a tracheostomy tube. Harefuah 1996;130:519-20.
2. Rabb MF, Larson ST, Greger JR. An unusual cause of partial ETT obstruction. Anesthesiology 1998;88:548-9.
3. Bhargava M, Pothula SNM, Joshi S. The obstruction of an endotracheal tube by the plastic coating sheared from a stylet: a revisit. Anesthesiology 1998;88:549.