LETTERS Pneumomediastinum and Pneumopericardium after Endobronchial Ultrasound–Guided Transbronchial Needle Aspiration To the Editor: Pneumomediastinum is defined as an abnormal accumulation of air within the mediastinum. It occurs most often when increased alveolar pressure leads to alveolar rupture, and less frequently when there is perforation of the tracheobronchial tree (1). Pressure gradients then allow air to spread via the fascia to the surrounding soft tissues, mediastinum, and/or retroperitoneum. Here we report, to our knowledge, the first case of pneumomediastinum and pneumopericardium following endobronchial ultrasound–guided fine needle aspiration (EBUSTBNA) of mediastinal lymph nodes, widely regarded as a safe procedure (2, 3). A 66-year-old man with an 80-pack-year history of tobacco use was admitted with hemoptysis. Computed tomographic (CT) scanning of the lungs revealed a right upper lobe mass and extensive paraseptal emphysema with biapical bullae (Figure 1). On hospital Day 2, he underwent bronchoscopy with EBUS-TBNA of nodal stations 4R and 7 (Figure 2) using a 21-gauge needle. The procedure was performed under deep sedation after uneventful placement of a laryngeal mask airway. The procedure was performed while the patient breathed spontaneously without application of pressure support. There were no immediate complications. One hour after completion of the procedure, the patient complained of chest pain. His physical examination was notable for tachycardia, and crepitus that extended from his sternum to his neck. Bedside ultrasonography revealed the presence of B-lines and chest radiograph showed no obvious pneumothorax. A post-procedure
Figure 1. Pre-procedural computed tomography (CT) showing right biapical bullae, extensive emphysema, and right upper lobe mass.
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Figure 2. Endobronchial ultrasound image of nodal station 7 during transbronchial needle aspiration. The arrow is pointing to the needle.
CT scan of the chest revealed extensive pneumomediastinum, subcutaneous emphysema, and pneumopericardium without pneumothorax (Figure 3). The patient was transferred from the general medicine floor to the intermediate care unit (IMC) for continuous pulse oximetry and telemetry. He was hemodynamically stable and showed no clinical signs of tamponade physiology. After 48 hours of close monitoring, his crepitus markedly improved. Cytopathology of lymph node station 4R revealed stage IIIA adenocarcinoma of the lung. There are three reported clinical causes of pneumomediastinum: soft tissue infection, mucosal disruption, and spontaneous pneumomediastinum (4). While any one or combination of these mechanisms can lead to abnormal accumulation of air in the mediastinum, most cases of intraprocedural iatrogenic pneumomediastinum are caused by the Macklin effect (5) or ventilation-induced barotrauma that causes mucosal disruption and spreading of air to nearby tissues via the fascial planes that connect them (6). However, bronchoscopy in this case was performed using no pressure support, and post-radiographic findings did not indicate alveolar rupture, thus making barotrauma an unlikely cause. Another potential cause of pneumomediastinum following bronchoscopy is blunt airway trauma by the bronchoscope. However, in our case, a post-procedure chest CT scan showed no evidence of airway defects. In additionally, forceful coughing can lead to tracheal microperforation, which can then go on to cause pneumomediastinum (7). Our patient, though, was not coughing; thus, in this case, the mucosal injury was most likely AnnalsATS Volume 11 Number 4 | May 2014
LETTERS
Figure 3. Post-procedural CT scan revealing extensive pneumomediastinum (A), subcutaneous emphysema, and pneumopericardium (B) without any indication of airway defect following endobronchial ultrasound–guided transbronchial needle aspiration.
secondary to needle trauma in the setting of severe emphysema during the TBNA portion of the procedure. Air leakage through endovascular sheaths may have then produced the pneumopericardium. Management of pneumomediastinum and pneumopericardium depends on the clinical severity and underlying etiology. If the air surrounding the heart impairs venous return causing tamponade physiology, then pericardial drainage is indicated for urgent decompression (8). In rare cases, surgery may be required to correct pneumomediastinum when caused by severe tracheobronchial disruption. The lack of pneumothorax in our patient, which is often a secondary complication of pneumomediastinum, combined with the lack of any identifiable lesion and hemodynamic stability, allowed for conservative management. In conclusion, we report a case of iatrogenic pneumomediastinum and pneumopericardium during EBUSTBNA. Although rare, this is a complication that can occur and must be recognized promptly to avoid delay in treatment if clinically indicated. Author disclosures are available with the text of this letter at www.atsjournals.org. Ricardo Ortiz*, B.S. Margaret Hayes*, M.D. Sixto Arias, M.D. Hans J. Lee, M.D. David Feller-Kopman, M.D. Lonny Yarmus, D.O.
In-Flight Air Embolism in a Child To the Editor: We report a case of a severe air embolism affecting a child with a previously unrecognized pulmonary cyst. Favorable evolution, with complete recovery, was observed after flight diversion, intensive care management, and hyperbaric oxygen therapy. Supported by the French Health Administration – Hospices Civils de Lyon. Author Contributions: The manuscript was written and approved by all authors.
Letters
Division of Pulmonary/Critical Care Johns Hopkins University Baltimore, Maryland *These authors are co-first authors contributing equally to all aspects of this letter.
References 1 Bejvan SM, Godwin JD. Pneumomediastinum: old signs and new signs. AJR Am J Roentgenol 1996;166:1041–1048. 2 Bartheld MB Breda Av, Annema JT. Complication rate of endosonography (endobronchial and endoscopic ultrasound): a systematic review. Respiration 2014;87:1–9. 3 Eapen GA, Shah AM, Lei XD, Jimenez CA, Morice RC, Yarmus L, Filner J, Ray C, Michaud G, Greenhill SR, et al.; American College of Chest Physicians Quality Improvement Registry, Education. Complications, consequences, and practice patterns of endobronchial ultrasoundguided transbronchial needle aspiration: results of the AQuIRE registry. Chest 2013;143:1044–1053. 4 Maunder RJ, Pierson DJ, Hudson LD. Subcutaneous and mediastinal emphysema: pathophysiology, diagnosis, and management. Arch Intern Med 1984;144:1447–1453. 5 Macklin CC. Transport of air along sheaths of pulmonic blood vessels from alveoli to mediastinum. Arch Intern Med 1939;64:913–926. 6 Kumar A, Pontoppidan H, Falke KJ, Wilson RS, Laver MB. Pulmonary barotrauma during mechanical ventilation. Crit Care Med 1973;1:181–186. 7 Leung PO, Lai CC. Tension pneumopericardium. J Emerg Med (In press) 8 Wang H, Nugent WC. Cough-induced bilateral spontaneous pneumothorax. Ann Thorac Surg 2010;90:1363–1365. Copyright © 2014 by the American Thoracic Society
A 4-year-old girl suffering from flu-like symptoms took a short-distance flight, experiencing a sudden loss of consciousness 32 minutes after takeoff. Oxygen support was administered; a medical examination identified hemodynamic instability and a Glasgow Coma Score (GCS) of 8, which led to an immediate flight diversion. Upon landing, 2 mg of diazepam were administered intravenously, resulting in an improvement of neurological status as the GCS increased to 14. The child was then transferred to a pediatric intensive care unit (PICU). Upon admission, the child’s neurological status was fluctuant. The right leg was hypertonic, and the left foot revealed a Babinski sign. Clinical cardiovascular and pulmonary examinations and 681
Figure 1. Pre-procedural computed tomography (CT) showing right biapical bullae, extensive emphysema, and right upper lobe mass.
680
Figure 2. Endobronchial ultrasound image of nodal station 7 during transbronchial needle aspiration. The arrow is pointing to the needle.
CT scan of the chest revealed extensive pneumomediastinum, subcutaneous emphysema, and pneumopericardium without pneumothorax (Figure 3). The patient was transferred from the general medicine floor to the intermediate care unit (IMC) for continuous pulse oximetry and telemetry. He was hemodynamically stable and showed no clinical signs of tamponade physiology. After 48 hours of close monitoring, his crepitus markedly improved. Cytopathology of lymph node station 4R revealed stage IIIA adenocarcinoma of the lung. There are three reported clinical causes of pneumomediastinum: soft tissue infection, mucosal disruption, and spontaneous pneumomediastinum (4). While any one or combination of these mechanisms can lead to abnormal accumulation of air in the mediastinum, most cases of intraprocedural iatrogenic pneumomediastinum are caused by the Macklin effect (5) or ventilation-induced barotrauma that causes mucosal disruption and spreading of air to nearby tissues via the fascial planes that connect them (6). However, bronchoscopy in this case was performed using no pressure support, and post-radiographic findings did not indicate alveolar rupture, thus making barotrauma an unlikely cause. Another potential cause of pneumomediastinum following bronchoscopy is blunt airway trauma by the bronchoscope. However, in our case, a post-procedure chest CT scan showed no evidence of airway defects. In additionally, forceful coughing can lead to tracheal microperforation, which can then go on to cause pneumomediastinum (7). Our patient, though, was not coughing; thus, in this case, the mucosal injury was most likely AnnalsATS Volume 11 Number 4 | May 2014
LETTERS
Figure 3. Post-procedural CT scan revealing extensive pneumomediastinum (A), subcutaneous emphysema, and pneumopericardium (B) without any indication of airway defect following endobronchial ultrasound–guided transbronchial needle aspiration.
secondary to needle trauma in the setting of severe emphysema during the TBNA portion of the procedure. Air leakage through endovascular sheaths may have then produced the pneumopericardium. Management of pneumomediastinum and pneumopericardium depends on the clinical severity and underlying etiology. If the air surrounding the heart impairs venous return causing tamponade physiology, then pericardial drainage is indicated for urgent decompression (8). In rare cases, surgery may be required to correct pneumomediastinum when caused by severe tracheobronchial disruption. The lack of pneumothorax in our patient, which is often a secondary complication of pneumomediastinum, combined with the lack of any identifiable lesion and hemodynamic stability, allowed for conservative management. In conclusion, we report a case of iatrogenic pneumomediastinum and pneumopericardium during EBUSTBNA. Although rare, this is a complication that can occur and must be recognized promptly to avoid delay in treatment if clinically indicated. Author disclosures are available with the text of this letter at www.atsjournals.org. Ricardo Ortiz*, B.S. Margaret Hayes*, M.D. Sixto Arias, M.D. Hans J. Lee, M.D. David Feller-Kopman, M.D. Lonny Yarmus, D.O.
In-Flight Air Embolism in a Child To the Editor: We report a case of a severe air embolism affecting a child with a previously unrecognized pulmonary cyst. Favorable evolution, with complete recovery, was observed after flight diversion, intensive care management, and hyperbaric oxygen therapy. Supported by the French Health Administration – Hospices Civils de Lyon. Author Contributions: The manuscript was written and approved by all authors.
Letters
Division of Pulmonary/Critical Care Johns Hopkins University Baltimore, Maryland *These authors are co-first authors contributing equally to all aspects of this letter.
References 1 Bejvan SM, Godwin JD. Pneumomediastinum: old signs and new signs. AJR Am J Roentgenol 1996;166:1041–1048. 2 Bartheld MB Breda Av, Annema JT. Complication rate of endosonography (endobronchial and endoscopic ultrasound): a systematic review. Respiration 2014;87:1–9. 3 Eapen GA, Shah AM, Lei XD, Jimenez CA, Morice RC, Yarmus L, Filner J, Ray C, Michaud G, Greenhill SR, et al.; American College of Chest Physicians Quality Improvement Registry, Education. Complications, consequences, and practice patterns of endobronchial ultrasoundguided transbronchial needle aspiration: results of the AQuIRE registry. Chest 2013;143:1044–1053. 4 Maunder RJ, Pierson DJ, Hudson LD. Subcutaneous and mediastinal emphysema: pathophysiology, diagnosis, and management. Arch Intern Med 1984;144:1447–1453. 5 Macklin CC. Transport of air along sheaths of pulmonic blood vessels from alveoli to mediastinum. Arch Intern Med 1939;64:913–926. 6 Kumar A, Pontoppidan H, Falke KJ, Wilson RS, Laver MB. Pulmonary barotrauma during mechanical ventilation. Crit Care Med 1973;1:181–186. 7 Leung PO, Lai CC. Tension pneumopericardium. J Emerg Med (In press) 8 Wang H, Nugent WC. Cough-induced bilateral spontaneous pneumothorax. Ann Thorac Surg 2010;90:1363–1365. Copyright © 2014 by the American Thoracic Society
A 4-year-old girl suffering from flu-like symptoms took a short-distance flight, experiencing a sudden loss of consciousness 32 minutes after takeoff. Oxygen support was administered; a medical examination identified hemodynamic instability and a Glasgow Coma Score (GCS) of 8, which led to an immediate flight diversion. Upon landing, 2 mg of diazepam were administered intravenously, resulting in an improvement of neurological status as the GCS increased to 14. The child was then transferred to a pediatric intensive care unit (PICU). Upon admission, the child’s neurological status was fluctuant. The right leg was hypertonic, and the left foot revealed a Babinski sign. Clinical cardiovascular and pulmonary examinations and 681
