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Retropharyngeal emphysema and acute upper respiratory distress: A complication of mediastinal emphysema
Brief Reports
Retropharyngeal Emphysema andAcuteUpper RespiratoryDistress: A Complication of Mediastinal Emphysema ERIC Z. SILFEN, MD
Acute upper respiratory distress is often treated in emergency departments. The recognized causes are infectious (e.g., acute epiglottitis, acute spasmodic croup, laryngeal diphtheria, tetanus, laryngeal tuberculosis, and nasopharyngeal mycoses), neurologic (e.g., tabes dorsalis, medullary infarct, Guillian-Barre syndrome), toxic (e.g., botulism, organophosphate poisoning), metabolic (e.g., hypocalcemia, hypomagnesemia), neoplastic (e.g., laryngeal carcinoma), immunologic (e.g., hereditary angioedema, allergic angioedema), rheumatic (e.g., relapsing polychondritis with laryngeal cartilage collapse), congenital (e.g., laryngeal web), and traumatic (e.g., laryngeal fracture, foreign body aspiration, near drowning with laryngospasm, post-tracheostomy tracheal stenosis). Mediastinal emphysema has frequently been associated with symptoms of upper respiratory distress including dysphagia, hoarse voice, dyspnea, sore throat, and neck pain. Subcutaneous emphysema due to dissection of mediastinal air along the tracheobronchial tree into the neck via the thoracic outlet is the presumed cause of these symptoms. In this report, two cases of mediastinal emphysema complicated by acute respiratory distress due to retropharyngeal emphysema are discussed. CASE REPORTS Patient 1. A 15year-old boy was brought to the emergency department with acute difficulty in breathing. He had been treated for the previous several days with erythromycin for a respiratory illness. The present episode was associated with difficulty in swallowing, hoarseness, and neck pain. Upon admission the patient appeared anxious. He was most comfortable breathing in the upright position. Chest pain with breathing was present. Initial vital signs were temperFrom the Department of Emergency versity Hospital, Washington, DC. Manuscript 1983.
received
November
Medicine,
4,1983;
Address reprint requests to Dr. Silfen: gency Medicine, Georgetown University voir Road, Washington, DC 20007.
Key Words: Barotrauma, geal emphysema. 402
mediastinal
Georgetown
accepted
November
Uni-
25,
Department of EmerHospital, 3800 Reser-
emphysema,
retropharyn-
ature 37°C pulse rate 100 beats/min, blood pressure 110/70 mm Hg, and respiratory rate 28/min. On physical examination the patient was not cyanotic. Neck tenderness, with subcutaneous emphysema of the upper part of the chest and neck, was present. An oropharyngeal examination was not attempted. Breath sounds were equal bilaterally with diffuse, crepitant rales. Wheezing was absent. Heart sounds were increased in intensity. A Hamman’s crunch was not heard. The patient was made comfortable sitting in the upright position and his respirations became less labored. Humidified oxygen by hand-held mask, and racemic epinephrine nebulization, were administered. A portable chest radiograph and a lateral radiograph of the soft tissue of the neck were obtained (Fig. 1). The patient was admitted to the intensive care unit for observation. A repeat chest radiograph showed normally expanded lungs without evidence of pneumothorax (Fig. 1). Laboratory evaluation showed a hematocrit of 42%; the leukocyte count was 6,7OO/cu mm with a differential count of 50% segmented cells, 5% band cells, 30% lymphoctyes, 12% mononuclear cells, and 3% eosinophils. Arterial blood gas determinations on room air showed a PO, of 93 mm Hg, a Pco, of 32 mm Hg, and a pH of 7.48. The patient was observed and humidified oxygen was given, but no further therapy, such as antibiotics, corticosteroids, or carbogen inhalations, was given. The patient’s mediastinal and retropharyngeal emphysema cleared, and the symptoms subsided after five days. The patient was discharged home without residual symptoms. Patient 2. A lZyear-old girl was brought to the emergency department with wheezing and difficulty in breathing. She had a history of asthma and recently had been treated for an acute upper respiratory infection associated with bronchospasm. The present episode began as wheezing with shortness of breath followed by neck pain, swelling of her neck, hoarseness, and increased respiratory distress. Upon admission to the emergency department, the patient was anxious and sitting upright, with occasional stridorous sounds. Initial vital signs were temperature, 37”C, pulse, 110 beats/min, blood pressure, 100/60 mm Hg, and respiratory rate, 36 min. On physical examination the patient did not appear cyanotic. Facial pufftness, neck tenderness, emphysema of the upper part of the chest, and subcutaneous emphysema were present. Breath sounds were present bilaterally with diffuse wheezing and crepitant rales. Heart sounds were increased in intensity. The patient was kept in the upright sitting position. Racemic epinephrine nebulization followed by humidified ox-
SILFEN
W RETROPHARYNGEAL
EMPHYSEMA
FIGURE 1. Radiographs of Patient 1. Upper left, Anteroposterior view of chest shows subcutaneous, interstitial, and mediastinal emphysema at the time of admission. Lower lefr, Marked clearing after 48 hours. Upper right, Anteroposterior view of neck shows cervical subcutaneous air; notice the evidence of retropharyngeal, esophageal, and prevertebral air, as well as the posterior epidural air stripe on the lateral view (lower righf).
ygen, intravenous aminophylline, corticosteroids, and ampicillin were administered. A portable chest radiograph and a lateral radiograph of the soft tissue of the neck were obtained (Fig. 2). The patient was hospitalized in the pediatric intensive care unit. Laboratory evaluation showed a hematocrit of 37%; the leukocyte count was 12,OOO/cu mm with a differential count of 76% segmented cells, 10% band cells, 12% lym-
phocytes, 1% mononuclear cells, and 1% eosinophils. Arterial blood gas determinations on room air showed a Po, of 78 mm Hg, a Pcq of 32 mm Hg, and a pH of 7.49. The initial therapy was continued, and the patient’s retropharyngeal and mediastinal emphysema cleared after several days without complications. Intravenous medication was changed to oral amoxicillin, prednisone, and theophylline, and the patient was discharged home. 403
AMERICAN
JOURNAL
OF EMERGENCY
MEDICINE
W Volume 2, Number 5 n September
1984
FIGURE 2. Radiographs of Patient 2. Lefr, Anteroposterior view of chest shows hyperinflation as well as cervical and thoracic subcutaneous emphysema. Right, Lateral view of neck shows hyperinflation of the hypopharynx as well as the retropharyngeal. esophageal, and subcutaneous emphysema.
DISCUSSION Mediastinal emphysema occurs with uncertain frequency. Although nontraumatic mediastinal emphysema is usually considered to be spontaneous, causes can be discerned in most cases.’ Conditions associated with mediastinal emphysema include diabetic ketoacidosis with Kussmaul respirations; eosinophilic granuloma; alpha-1-anti-trypsin deficiency; vigorous cough; emesis; Valsalva maneuver; neoplasia; pulmonary infection; SCUBA and skin diving; trauma to the chest, face, neck, esophagus, and tracheobronchial tree; acute and chronic obstructive pulmonary disease; mechanical ventilation; respiratory disease of the newborn; and anorexia nervosa.2 If the cause of the mediastinal emphysema remains obscure, before the term spontaneous pneumomediastinum can be applied, a barium or technitium swallow, endoscopy, and/or bronchoscopy may be appropriate to exclude connections between the mediastinum and either the tracheobronchial tree or the alimentary tract.3 Five mechanisms have been postulated as causes of mediastinal emphysema. The most common is alveolar rupture due to overdistention or to bleb formation with air trapping beyond a functional or mechanical obstruction, (e.g., mucous plug, foreign body, tumor, “ball valve” phenomenon due to bronchospasm) with dissection of air through the perivascular sheath to the hilum and mediastinum.1*4T5 The other causes include pneumoperitoneum with dissection of air into the mediastinum via diaphragmatic connections, tracheobronchial or esophageal perforation with dissection of air into the mediastinum, transdiaphragmatic dissec404
tion of air into the mediastinum, and dissection of cervical subcutaneous emphysema into the mediastinum.6 Subcutaneous emphysema results from air being forced into the subcutaneous tissues. The air travels along the paths of least resistance, and the real planes of dissection are believed to be the various fascial planes of the neck. When air dissects along the deep fascial planes of the neck, dyspnea, neck pain, laryngeal obstruction, dysphagia, pseudodysphagia, and changes in phonation may occur.2’7 Three pathophysiological mechanisms can account for subcutaneous emphysema: (1) disruption of the pleura and intercostal muscles (e.g., pneumothorax associated with rib fracture), (2) outward dissection of mediastinal emphysema (e.g., rupture of the esophagus or tracheobronchial tree, or pneumothorax with a break in the mediastinal pleura), or (3) direct connection of the subcutaneous tissues with an external w0und.j In the two cases described here, the mediastinal emphysema was related to acute upper respiratory infection associated with vigorous coughing and Valsalva maneuvers, resulting in rupture of alveoli and air trapping.8 In asthmatic patients, the complication was observed in only 16 of 325 (5%) asthmatic children studied by Eggleston et a1,9 and the incidence in patients with other viral or respiratory infections is unknown. The complication is more common in children and young adults. The symptoms of acute upper airway obstruction (hoarse voice, neck pain, dyspnea, and dysphagia) were believed to be due to subcutaneous and retropharyngeal emphysema from dissec-
SILFEN n RETROPHARYNGEAL
tion of air along the deep fascial planes of the neck, both anterior and posterior to the trachea. Therapy is usually supportive. Tracheostomy or endotracheal intubation is rarely necessary for respiratory support. If trauma is believed to be the cause of the emphysema, further diagnostic evaluation is indicated. One hundred per cent oxygen by mask will increase the gradient for tissue absorption of nitrogen (79% of the “tissue air” is nitrogen) and thus enhance resolution of the subcutaneous emphysema. Corticosteroids are not indicated in the therapy of mediastinal emphysema. Antibiotics are not routinely indicated and are necessary only for suppurative complications or as prophylaxis for injury associated with wound contamination. 2*4
EMPHYSEMA
REFERENCES 1. McMahon DJ. Spontaneous pneumomediastinum. Am J Surg 1976;131:550. 2. Lubow HW. Pneumomediastinum. Stat 1981;2:117-121. pneumomediastinum. J 3. Adwers JR, et al. Spontaneous Trauma 1974;14:414. 4. Munsell WP. Pneumomediastinum. JAMA 1967;202:129. 5. Zuidema GD (ed). The Management of Trauma. Philadelphia: W. B. Saunders Co, 1979:379-380. emphysema. JAMA 1945;128:1. 6. Hamman L. Mediastinal 7. Shuster MJ. Pneumomediastinum as a cause of dysphagia and pseudodysphagia. Ann Emerg Med 1961;10:648-651. with massive collapse from ex8. Macklin CC. Pneumothorax perimental local overinflation of the lung substance. Can Med Assoc J 1937;36:414. PA, et al. Radiographic abnormalities in acute 9. Eggleston asthma in children. Pediatrics 1974;54:442.
Retropharyngeal Emphysema andAcuteUpper RespiratoryDistress: A Complication of Mediastinal Emphysema ERIC Z. SILFEN, MD
Acute upper respiratory distress is often treated in emergency departments. The recognized causes are infectious (e.g., acute epiglottitis, acute spasmodic croup, laryngeal diphtheria, tetanus, laryngeal tuberculosis, and nasopharyngeal mycoses), neurologic (e.g., tabes dorsalis, medullary infarct, Guillian-Barre syndrome), toxic (e.g., botulism, organophosphate poisoning), metabolic (e.g., hypocalcemia, hypomagnesemia), neoplastic (e.g., laryngeal carcinoma), immunologic (e.g., hereditary angioedema, allergic angioedema), rheumatic (e.g., relapsing polychondritis with laryngeal cartilage collapse), congenital (e.g., laryngeal web), and traumatic (e.g., laryngeal fracture, foreign body aspiration, near drowning with laryngospasm, post-tracheostomy tracheal stenosis). Mediastinal emphysema has frequently been associated with symptoms of upper respiratory distress including dysphagia, hoarse voice, dyspnea, sore throat, and neck pain. Subcutaneous emphysema due to dissection of mediastinal air along the tracheobronchial tree into the neck via the thoracic outlet is the presumed cause of these symptoms. In this report, two cases of mediastinal emphysema complicated by acute respiratory distress due to retropharyngeal emphysema are discussed. CASE REPORTS Patient 1. A 15year-old boy was brought to the emergency department with acute difficulty in breathing. He had been treated for the previous several days with erythromycin for a respiratory illness. The present episode was associated with difficulty in swallowing, hoarseness, and neck pain. Upon admission the patient appeared anxious. He was most comfortable breathing in the upright position. Chest pain with breathing was present. Initial vital signs were temperFrom the Department of Emergency versity Hospital, Washington, DC. Manuscript 1983.
received
November
Medicine,
4,1983;
Address reprint requests to Dr. Silfen: gency Medicine, Georgetown University voir Road, Washington, DC 20007.
Key Words: Barotrauma, geal emphysema. 402
mediastinal
Georgetown
accepted
November
Uni-
25,
Department of EmerHospital, 3800 Reser-
emphysema,
retropharyn-
ature 37°C pulse rate 100 beats/min, blood pressure 110/70 mm Hg, and respiratory rate 28/min. On physical examination the patient was not cyanotic. Neck tenderness, with subcutaneous emphysema of the upper part of the chest and neck, was present. An oropharyngeal examination was not attempted. Breath sounds were equal bilaterally with diffuse, crepitant rales. Wheezing was absent. Heart sounds were increased in intensity. A Hamman’s crunch was not heard. The patient was made comfortable sitting in the upright position and his respirations became less labored. Humidified oxygen by hand-held mask, and racemic epinephrine nebulization, were administered. A portable chest radiograph and a lateral radiograph of the soft tissue of the neck were obtained (Fig. 1). The patient was admitted to the intensive care unit for observation. A repeat chest radiograph showed normally expanded lungs without evidence of pneumothorax (Fig. 1). Laboratory evaluation showed a hematocrit of 42%; the leukocyte count was 6,7OO/cu mm with a differential count of 50% segmented cells, 5% band cells, 30% lymphoctyes, 12% mononuclear cells, and 3% eosinophils. Arterial blood gas determinations on room air showed a PO, of 93 mm Hg, a Pco, of 32 mm Hg, and a pH of 7.48. The patient was observed and humidified oxygen was given, but no further therapy, such as antibiotics, corticosteroids, or carbogen inhalations, was given. The patient’s mediastinal and retropharyngeal emphysema cleared, and the symptoms subsided after five days. The patient was discharged home without residual symptoms. Patient 2. A lZyear-old girl was brought to the emergency department with wheezing and difficulty in breathing. She had a history of asthma and recently had been treated for an acute upper respiratory infection associated with bronchospasm. The present episode began as wheezing with shortness of breath followed by neck pain, swelling of her neck, hoarseness, and increased respiratory distress. Upon admission to the emergency department, the patient was anxious and sitting upright, with occasional stridorous sounds. Initial vital signs were temperature, 37”C, pulse, 110 beats/min, blood pressure, 100/60 mm Hg, and respiratory rate, 36 min. On physical examination the patient did not appear cyanotic. Facial pufftness, neck tenderness, emphysema of the upper part of the chest, and subcutaneous emphysema were present. Breath sounds were present bilaterally with diffuse wheezing and crepitant rales. Heart sounds were increased in intensity. The patient was kept in the upright sitting position. Racemic epinephrine nebulization followed by humidified ox-
SILFEN
W RETROPHARYNGEAL
EMPHYSEMA
FIGURE 1. Radiographs of Patient 1. Upper left, Anteroposterior view of chest shows subcutaneous, interstitial, and mediastinal emphysema at the time of admission. Lower lefr, Marked clearing after 48 hours. Upper right, Anteroposterior view of neck shows cervical subcutaneous air; notice the evidence of retropharyngeal, esophageal, and prevertebral air, as well as the posterior epidural air stripe on the lateral view (lower righf).
ygen, intravenous aminophylline, corticosteroids, and ampicillin were administered. A portable chest radiograph and a lateral radiograph of the soft tissue of the neck were obtained (Fig. 2). The patient was hospitalized in the pediatric intensive care unit. Laboratory evaluation showed a hematocrit of 37%; the leukocyte count was 12,OOO/cu mm with a differential count of 76% segmented cells, 10% band cells, 12% lym-
phocytes, 1% mononuclear cells, and 1% eosinophils. Arterial blood gas determinations on room air showed a Po, of 78 mm Hg, a Pcq of 32 mm Hg, and a pH of 7.49. The initial therapy was continued, and the patient’s retropharyngeal and mediastinal emphysema cleared after several days without complications. Intravenous medication was changed to oral amoxicillin, prednisone, and theophylline, and the patient was discharged home. 403
AMERICAN
JOURNAL
OF EMERGENCY
MEDICINE
W Volume 2, Number 5 n September
1984
FIGURE 2. Radiographs of Patient 2. Lefr, Anteroposterior view of chest shows hyperinflation as well as cervical and thoracic subcutaneous emphysema. Right, Lateral view of neck shows hyperinflation of the hypopharynx as well as the retropharyngeal. esophageal, and subcutaneous emphysema.
DISCUSSION Mediastinal emphysema occurs with uncertain frequency. Although nontraumatic mediastinal emphysema is usually considered to be spontaneous, causes can be discerned in most cases.’ Conditions associated with mediastinal emphysema include diabetic ketoacidosis with Kussmaul respirations; eosinophilic granuloma; alpha-1-anti-trypsin deficiency; vigorous cough; emesis; Valsalva maneuver; neoplasia; pulmonary infection; SCUBA and skin diving; trauma to the chest, face, neck, esophagus, and tracheobronchial tree; acute and chronic obstructive pulmonary disease; mechanical ventilation; respiratory disease of the newborn; and anorexia nervosa.2 If the cause of the mediastinal emphysema remains obscure, before the term spontaneous pneumomediastinum can be applied, a barium or technitium swallow, endoscopy, and/or bronchoscopy may be appropriate to exclude connections between the mediastinum and either the tracheobronchial tree or the alimentary tract.3 Five mechanisms have been postulated as causes of mediastinal emphysema. The most common is alveolar rupture due to overdistention or to bleb formation with air trapping beyond a functional or mechanical obstruction, (e.g., mucous plug, foreign body, tumor, “ball valve” phenomenon due to bronchospasm) with dissection of air through the perivascular sheath to the hilum and mediastinum.1*4T5 The other causes include pneumoperitoneum with dissection of air into the mediastinum via diaphragmatic connections, tracheobronchial or esophageal perforation with dissection of air into the mediastinum, transdiaphragmatic dissec404
tion of air into the mediastinum, and dissection of cervical subcutaneous emphysema into the mediastinum.6 Subcutaneous emphysema results from air being forced into the subcutaneous tissues. The air travels along the paths of least resistance, and the real planes of dissection are believed to be the various fascial planes of the neck. When air dissects along the deep fascial planes of the neck, dyspnea, neck pain, laryngeal obstruction, dysphagia, pseudodysphagia, and changes in phonation may occur.2’7 Three pathophysiological mechanisms can account for subcutaneous emphysema: (1) disruption of the pleura and intercostal muscles (e.g., pneumothorax associated with rib fracture), (2) outward dissection of mediastinal emphysema (e.g., rupture of the esophagus or tracheobronchial tree, or pneumothorax with a break in the mediastinal pleura), or (3) direct connection of the subcutaneous tissues with an external w0und.j In the two cases described here, the mediastinal emphysema was related to acute upper respiratory infection associated with vigorous coughing and Valsalva maneuvers, resulting in rupture of alveoli and air trapping.8 In asthmatic patients, the complication was observed in only 16 of 325 (5%) asthmatic children studied by Eggleston et a1,9 and the incidence in patients with other viral or respiratory infections is unknown. The complication is more common in children and young adults. The symptoms of acute upper airway obstruction (hoarse voice, neck pain, dyspnea, and dysphagia) were believed to be due to subcutaneous and retropharyngeal emphysema from dissec-
SILFEN n RETROPHARYNGEAL
tion of air along the deep fascial planes of the neck, both anterior and posterior to the trachea. Therapy is usually supportive. Tracheostomy or endotracheal intubation is rarely necessary for respiratory support. If trauma is believed to be the cause of the emphysema, further diagnostic evaluation is indicated. One hundred per cent oxygen by mask will increase the gradient for tissue absorption of nitrogen (79% of the “tissue air” is nitrogen) and thus enhance resolution of the subcutaneous emphysema. Corticosteroids are not indicated in the therapy of mediastinal emphysema. Antibiotics are not routinely indicated and are necessary only for suppurative complications or as prophylaxis for injury associated with wound contamination. 2*4
EMPHYSEMA
REFERENCES 1. McMahon DJ. Spontaneous pneumomediastinum. Am J Surg 1976;131:550. 2. Lubow HW. Pneumomediastinum. Stat 1981;2:117-121. pneumomediastinum. J 3. Adwers JR, et al. Spontaneous Trauma 1974;14:414. 4. Munsell WP. Pneumomediastinum. JAMA 1967;202:129. 5. Zuidema GD (ed). The Management of Trauma. Philadelphia: W. B. Saunders Co, 1979:379-380. emphysema. JAMA 1945;128:1. 6. Hamman L. Mediastinal 7. Shuster MJ. Pneumomediastinum as a cause of dysphagia and pseudodysphagia. Ann Emerg Med 1961;10:648-651. with massive collapse from ex8. Macklin CC. Pneumothorax perimental local overinflation of the lung substance. Can Med Assoc J 1937;36:414. PA, et al. Radiographic abnormalities in acute 9. Eggleston asthma in children. Pediatrics 1974;54:442.