Korean J Anesthesiol dramatic results of such insufflation and the possible pathways of communication between the pleural space, mediastinum, peritoneal cavity, retroperitoneal space and subcutaneous tissue. Informed consent to publish this case report was obtained from the patient. We report this case with a review of the relevant literature. Case Report A 72-year-old woman (72 kg, 158 cm) was admitted to hospital with dyspnea and hoarseness. She had been experiencing these symptoms for a year since she had undergone a thymectomy to remove a thymoma. In the hospital, she was diagnosed with bilateral vocal cord paralysis and was scheduled to undergo a percutaneous dilatational tracheostomy with a right laser cordectomy using a suspension laryngoscope under general anesthesia. Her vital signs were stable, she had no current medical problems, and her laboratory test values were within the normal limits. The preoperative chest radiograph was unremarkable except for evidence of previous surgery. She was a non-smoker with was no history of asthma, chronic obstructive lung disease or pneumothoraces. Before the induction of anesthesia, the patient’s blood pressure, heart rate and SpO2 was 130/80 mmHg, 80 beats/min and 98%, respectively. The patient was induced with pentothal sodium 5 mg/kg and succinylcholine 1 mg/kg in preparation for a potentially difficult intubation. A 6.5-mm reinforced endotracheal tube was inserted successfully with a stylet on the first attempt. Anesthesia was maintained with air 1 L/min, O2 1 L/min, sevoflurane 1.5-3 vol%, and rocuronium. During the procedure, the end tidal CO2 was maintained at approximately 30-35 mmHg, peak airway pressure was < 20 cm H2O, and SpO2 approximately 97-99%. Her vital signs, airway pressures, and end-tidal CO2 remained stable during surgery. The total time under anesthesia was two hours; the operative time was 90 minutes. There was minimal blood loss during the surgery, and the patient received a total of 800 ml Lactated Ringer’s solution. The procedure was performed as planned. The patient was extubated after confirming full recovery of motor function as tested by the hand grip strength and head control. At the time of extubation, a T-cannula was inserted through the stoma site, and the patient was encouraged to breathe through the cannula. After confirming that the patient was stable, she was transferred to the recovery room. Her vital signs first recorded in the recovery room were a blood pressure, heart rate and SpO2 of 130/80 mmHg, 85 beats/ min and 99%, respectively. Approximately two minutes after arrival, her blood pressure decreased to 70/50 mmHg, heart rate increased to 140 beats/min and SpO2 dropped to approximately 65%. The patient experienced severe dyspnea and appeared www.ekja.org Kim and Kim cyanotic. Blood oozing from the tracheostomy site had saturated the gauze dressing. A physical examination revealed decreased bilateral breath sounds and diffuse crepitus around the neck and shoulder, suggesting subcutaneous emphysema. 10 mg ephedrine was injected to increase her blood pressure, and an arterial line was inserted through the right radial artery for continuous blood pressure monitoring. Initially, a perforated endotracheal connector (Fig. 1B) was attempted because a T-piece was not available at that time. But the connector was not perforated (Fig. 1A). As the connector was changed with perforated piece immediately after the patient's vital signs and SpO2 became poor, the oxygen supply through this closed connector would be maintained for approximately one minute at 5 L/min. The results of the first arterial blood gas analysis approximately three minutes after changing the connector were as follows: pH 7.342, PaCO2 49.0 mmHg, PaO2 87.7 mmHg, HCO3- 26.0 mmol/L, SaO2 94.3%, and bicarbonate -0.2 mmol/L. To identify the potential focus of bleeding that might have been the cause of the airway obstruction, the T-cannula was removed temporarily and suction was applied after confirming the stabilization of her vital signs and SpO2 but only a small amount of blood-tinged secretions was removed. The otolaryngologist examined the stoma site with a portable bronchoscope and found no complications related directly to the tracheostomy. At this point, the cause of deterioration of patient’s condition was attributed to the closed endotracheal connector. A portable chest radiograph was requested to check for a potential pneumothroax. The portable chest radiograph revealed mild to moderate bilateral pneumothoraces as well as extensive subcutaneous emphysema over both shoulders, supraclavicular area, and left chest wall (Fig. 2A). Fig. 1. This figure shows the oxygen line connectors used in this case. On the left side (A) is the mistakenly used non-perforated connector used in the recovery room; the perforated connector is on the right (B). A perforated connector or T-piece should have been used. 489