Changes in renal function in valvular and coronary patients.

ETCO2 increased to 45 mmHg. We could not pass a suction catheter beyond a distance of 24 cm from the entrance of the tracheal tube. Using a fibrescope, we could see the appearance of a meniscus and a crescent shape on the inner wall. Because of the prone position, we could not change the tube but managed to maintain ventilation, saturation and ETCO2 within the normal range by a change of ventilatory mode for the remaining 5 h of the procedure. After returning to the supine position at the end of the operation, we extubated the patient and her self-respiration was good. Unfortunately, we found mild left lower lobe atelectasis postoperatively, which responded to physiotherapy. Her lung condition had returned to normal without complication by the second postoperative day. Examination of the reinforced tube showed two internal blisters, one at the entrance and one at 24 cm from the entrance. Examination using a rigid fiberscope and computed tomography (Fig. 1) showed a dissection of the inner layer of the tube. The dissection had caused longitudinal blisters of 2.8 and 4.2 cm length and reduction of the internal diameter to 3.5 and 2.9 mm at the proximal and distal parts, respectively. We assumed that the damage of the tube was caused by faulty manufacture. However, we subsequently discovered that the cause was multiple reuse of the single-use tube. Similar complications have been reported during anaesthesia with use of N2O [2,3] or even without N2O [4], exposure of heat, ethylene oxide [4–6] and gluteraldehyde solution [6] and stretching of a reinforced endotracheal tube [6]. The tube in this case had been cleaned after each use with hypochlorous acid (Medilox solution; Hicro-S, Soosan GIC Co Ltd, Seoul, Korea) after ultrasonic cleansing for 30 min. We should bear in mind that repeated reuse of reinforced endotracheal tubes that are designed for single use is unwise.