Korean J Anesthesiol the chest tube was left in place for ten days. Follow-up radiographs of the chest and abdomen revealed near-complete resolution of the pneumothorax, pneumomediastinum, and pneumoperitoneum. Given these findings and the cessation of symptoms, the patient was discharged two weeks after her tracheostomy. The follow-up chest radiograph three months after discharge showed no further evidence of pneumothorax or pneumoperitoneum. Discussion Percutaneous tracheostomy involves several potential complications. The incidence of subcutaneous emphysema has been reported to be 1.4% and that of a pneumothorax to be 0.8% for percutaneous tracheostomy [2]. On the other hand, the occurrence of subcutaneous emphysema, pneu- mothorax, pneumomediastinum, pneumoperitoneum and pneumoretroperitoneum in the same individual is extremely rare. Although there are several such case reports [3,4], the incidence of this situation has not been reported. The other cases were associated with bowel perforation during endoscopic retrograde cholangiography and with an accidental insufflation of compressed air [3]. Both cases were managed conservatively, and the patients recovered without surgical intervention. There are many proposed mechanisms for emphysema and pneumothorax after percutaneous tracheostomy. They included damage to the anterior [5] or posterior tracheal walls [6], complications related to using a fenestrated cannula [7], cannula dislocation, paratracheal placement, and barotraumas [5,7]. These mechanisms lead to air leakage from the trachea into the subcutaneous tissue, which then follows the path of least resistance. The present case was not a procedure-related complication of percutaneous tracheostomy itself. The complication was attributed to a misconnection of T-cannula to the oxygen line with a non-perforated connector after the otolaryngologist examined the inner tracheal lumen of the tracheostomy site, surgical wound and bronchial tree thoroughly, but found no abnormalities. The accidental connection with a closed connector at the recovery room initially lead to an insufflation of 5 L/min oxygen into the patient’s lung for approximately one minute, which might have caused the volutrauma to the lung. This may have led to bilateral pneumothoraces, followed by air penetration into several body compartments, including the subcutaneous tissue, mediastinum, peritoneum, and retroperitoneum. Despite the extensive dissemination of air into multiple body compartments, the patient recovered without complications after a closed thoracostomy and conservative care in the ICU. This case illustrates the dramatic results of direct insufflation of the lungs for a relatively short time. www.ekja.org Kim and Kim The airway obstruction may have been caused by a blood clot contributed to the pneumothorax [2]. Postoperative bleeding was observed at the tracheostomy site, into which blood may have been aspirated, causing an airway obstruction. An obstructing blood clot can act as a one-way valve, resulting in high airway pressures and subsequent pneumothorax. On the other hand, the bronchoscopic examination performed by the otolaryngologist in the recovery room revealed no definite abnormalities, reducing the plausibility of this explanation. Nevertheless, he may have failed to examine the entire bronchial tree, leaving the possibility of a partial airway obstruction that contributed to the development of a pneumothorax. This case illustrates the possible pathways of communication between the pleural space, mediastinum, peritoneal cavity and retroperitoneal space. A rupture of the alveolar wall or small bronchi allows air into the mediastinum along the bron- choalveolar bundle [8] and directly into the thoracic cavity. Although the thoracic and peritoneal cavities are separated by the diaphragm, they may communicate through congenital defects, such as a pleuroperitoneal canal [9] or defects adjacent to the aorta or esophagus. Air trapped in the pleural space or the mediastinum can travel to the retroperitoneum along the tissue planes [10]. Air in the peritoneal cavity can travel to the retroperitoneal space along the mesenteric roots and vessels [3]. This type of injury also carries the risk of orbital emphysema, which can injure the optic nerve [11]. By understanding the dynamic anatomical communications between the body cavities, one can avoid an unnecessary laparotomy in the instance of pneumothorax, pneumomediastinum, pneum- operitoneum, and pneumoretroperitoneum resulting from non-surgical injuries, such as the present case. An MRI scan of the brain was performed to rule out any brain injury or cerebral air embolism associated with the pneumothorax. A cerebral arterial air embolism can develop after a pneumothorax [12]. Fortunately, our patient escaped any hypoxic brain injury or neurological sequela despite the hypoxic episode (SpO2 < 70%) that lasted for approximately three minutes. Although the treatment of pneumomediastinum is contro- versial, supportive care is the mainstay, which includes bed rest, reassurance, pain control and no oral intake to prevent esophageal rupture [13]. The treatments for pneumoperitoneum and pneumoretroperitoneum are also mainly supportive except in cases with obvious peritonitis or sepsis [14,15]. In conclusion, we experienced a rare case of air passage into multiple body compartments. This case highlights the poten- tially serious complications of percutaneous tracheostomy as well as the need for intensive supportive care during recovery. 491