Lung (2007) DOI 10.1007/s00408-006-0002-7
Spontaneous Pneumomediastinum: Experience in 18 Adult Patients Baldassare Mondello Æ Rosaria Pavia Æ Paolo Ruggeri Æ Mario Barone Æ Pietro Barresi Æ Maurizio Monaco
Accepted: 16 November 2006 Ó Springer Science+Business Media, Inc. 2007
Abstract Spontaneous pneumomediastinum (SPM) is defined as the presence of air in the mediastinum, developing in the absence of traumatic, iatrogenic, or preceding pulmonary pathologies (emphysema, chronic bronchitis, and lung cancer). The aim of this study was to review our experiences with SPM, underlining its symptomatology, diagnosis, treatment, and followup, and defining a reasonable course of assessment and management. A retrospective case series was conducted to identify adult patients with SPM who were diagnosed and treated in our institution between 1998 and 2005. Eighteen patients (10 males) were identified (average age = 25 ± 4.8 years). Acute onset of chest pain was the predominant symptom at presentation. All patients developed clinically evident subcutaneous emphysema and underwent chest computerized tomography. Fiber bronchoscopy and echocardiogram were used selectively (8 patients). The average hospital stay was 6 (±1.4) days. Sixteen patients were conservatively treated, and only two B. Mondello R. Pavia M. Barone P. Barresi M. Monaco Unit of Thoracic Surgery, Department of Cardiovascular and Thoracic Sciences, Azienda Ospedaliera Universitaria ‘‘G. Martino,’’ Messina, Italy P. Ruggeri Unit of Respiratory Diseases, Department of Cardiovascular and Thoracic Sciences, Azienda Ospedaliera Universitaria ‘‘G. Martino’’, Messina, Italy P. Ruggeri (&) Unit of Respiratory Diseases, Department of Cardiovascular and Thoracic Sciences, Azienda Ospedaliera Universitaria ‘‘G. Martino’’, Via Consolare Valeria, 98125 Messina, Italy e-mail:
[email protected]
patients were treated with thoracic drainage due to a related pneumothorax. The disease followed a benign evolution in all patients and, as of today, no relapse has been reported. SPM is an uncommon pathology with a usually benign course. The authors discuss SPM. A diagnostic algorithmic approach is necessary to rule out severe secondary entities and consequences that need urgent treatment. Keywords Pneumomediastinum Spontaneous pneumomediastinum Mediastinal emphysema
Introduction Spontaneous pneumomediastinum (SPM) is an uncommon and usually benign entity, characterized by the presence of free air in the mediastinum, developing in the absence of traumatic or iatrogenic causes or a preceding pulmonary pathology like emphysema, chronic bronchitis, or lung cancer [1]. It usually affects young subjects, with an incidence of 1:33,000 (total population) or 1:25,000 (age range = 5–34 years) [1, 2]. Spontaneous pneumomediastinum produces a dramatic increase of endopulmonary pressure [2] that results in rupture of alveolar septa, which causes interstitial air to extend along peribronchial and perivascular space into the mediastinum [3, 4]. Frequently, air extends to the cervical zone by the mediastinum cervical fascia, developing into subcutaneous emphysema. The most common symptoms at presentation are thoracic pain and dyspnea [5]. Differential diagnosis includes tracheobronchial rupture, esophageal perforation, mediastinitis, and pneumothorax [6], which may require urgent treatment [8]. Chest
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radiography [2, 6] and computerized tomography (CT) [6, 7, 9, 10] are fundamental diagnostic tools. Thoracic endoscopy (tracheobronchial and/or esophageal) is infrequently required and may cause additional morbidity [3, 11]. The aim of this study was to describe our experience with SPM and to emphasize symptomatology, assessment, and management.
Materials and Methods Between January 1998 and June 2005, all adult patients with SPM, diagnosed and treated by the Unit of Thoracic Surgery in Messina Azienda Ospedaliera Universitaria ‘‘G. Martino,’’ Italy, were investigated. Only pneumomediastinum cases that occurred spontaneously were included. Subjects who developed pneumomediastinum in association with positive pressure ventilation or had a recent history of trauma were excluded. Pneumomediastinum following Valsalva’s maneuver or smoking of illicit drugs were considered ‘‘spontaneous’’ [13]. Hospital records were reviewed with respect to past medical history, symptoms, clinical finding at presentation, precipitating factors, diagnostic
Fig. 1 Proposed algorithm for diagnostic approach to SPM
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workup, treatment, length of hospital stay, and outcome. Our diagnostic algorithmic approach, reported in Figure 1, was characterized by medical history and physical examination, chest X-ray, and chest CT. Contrast-enhanced swallow and esophagoscopy were reserved for only highly suspicious cases of esophageal perforation. Other tests were performed as indicated only when there were doubts about the diagnosis and to exclude the possibility of secondary pneumomediastinum. Discharge criteria were established according to clinical improvement, even if cervical and mediastinal emphysema persisted. A one-month followup program after discharge was established.
Results Eighteen (10 males; 55%) patients meeting the criteria for SPM were identified. The average age was 25 ± 4.8 (range = 18–33) years. Eight patients had been transferred from the emergency room immediately to our Thoracic Surgery Unit for hospitalization; two were moved from the Allergology Unit, and eight were observed in the Intermediate Care Unit. Cough attacks
Lung (2007) Table 1 Onset symptoms and signs in 18 adult patients with spontaneous pneumomediastinum.
Symptoms Thoracic pain Dyspnea Cough Nasal voice Cervical pain Dysphagia Anxiety Fever Signs Subcutaneous supraclavicular and cervical emphysema Hamman’s sign
Patients (n)
%
18 16 14 12 8 4 4 4
100 88 77 66 44 22 22 22
18
100
8
44
accounted for 12 cases (66%) and acute exacerbations of chronic bronchitis accounted for four cases (22%). The precipitating factor in eight patients was an asthma attack (44%). Six patients reported physical activity during work (4 patients) or gymnastics (1 patient); also, no one reported previous incidents of either pneumomediastinum or pneumothorax. Onset symptoms included thoracic pain (100%), cervical pain (44%), dyspnea (88%), cough (77%), nasal voice (66%), and dysphagia (22%). Subcutaneous supraclavicular and cervical emphysema were physical findings present in all patients (100%) (Table 1). When pneumomediastinum was suspected, an urgent chest radiograph was performed; subjects were hospitalized for observation and to rule out perforation of intrathoracic aircontaining organs or other complications. The Hamman’s sign was found in 8 patients (44%); 16 were dyspnoic (88%); 4 were anxious (22%); and 4 were feverish (22%) with an average body temperature of 38–38.5°C. Serum C-reactive protein and erythrocyte sedimentation velocity were out of range in 4 (22%) patients, the arterial gas analysis was normal in 12 (66%), but highlighted a mild hypoxemia in 6 subjects (33%). Electrocardiogram (EKG) displayed a reduction in amplitude of the QRS complex in four patients (22%) with distant heart sound. All patients had a CT of the cervical-thoracic area to confirm pneumomediastinum and to rule out concurrent pneumothorax, pneumopericardium, pleural effusion, or preexisting bullous emphysema. Four patients with fever and dysphagia had a CT with concomitant oral administration of diatrizoate meglumine to rule out esophageal perforation. Four patients with distant heart sound had an echocardiogram to rule out pericardial effusion or pericarditis. Treatment included bed rest, intermittent oxygen therapy, analgesics, antitussive medications,
Fig. 2 Left anterior pneumothorax in a 24-year-old obese asthmatic patient following SPM
corticosteroids for asthmatic subjects, sedatives (4 cases), and drainage of subcutaneous air (10 patients). All patients were connected to a three-lead electrocardiographic, plethysmographic blood pressure, and finger pulse oximeter monitor. Several arterial gas analyses, according to the clinical state of the patient, have been performed. Two patients developed worsening chest pain, dyspnea, and subcutaneous emphysema on the second and third day of their hospital stay; a chest CT demonstrated a left pneumothorax in one patient that was treated with a chest tube (Fig. 2). In all the patients reviewed , the disease course was characterized by full recovery from pneumomediastinum, both clinically and radiologically; the average hospital stay was 6 (±1.4) days (range = 4–9 days). During followup no patient developed recurrent pneumomediastinum.
Discussion The first description of spontaneous pneumomediastinum is attributed to Hamman [14], and it is from the 1939 report that the term Hamman’ syndrome arose. SPM is a rare entity with a usually benign course, marked by the presence of free air inside the mediastinum and developing in the absence of traumatic or iatrogenic causes or chronic pulmonary pathologies [1]. It generally affects young adults [2, 5, 15, 16], especially tall thin males [2, 10, 12]. Moreover, ten of our patients
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(55%) were overweight or even obese. This is the first description of the possible association between obesity and SPM but further studies are needed. Pneumomediastinum can be the sequel to an increase of endopulmonary pressure [2, 5–7] which is a consequent to several factors: cough attacks [2, 5–7] due to asthmatic crises or exacerbations of chronic bronchitis; vomit [5, 6] as in cases of diabetic ketoacidosis [17, 18] or selfinduced [19]; labor [1, 5]; Valsalva maneuvers[1, 4] such as defecation [5]; smoking of illicit drugs (cocaine, marijuana, ecstasy) [20]; extreme effort when the glottis is kept closed [21]; acute bronchial obstruction [5] as in asthmatic attacks [7]; acute laryngitis [5]; and positive mechanical ventilation [5]. The rise in pressure inside distal alveoli, usually up to values greater than 40 mmHg, produces a pressure gradient between them and the adjacent vessels; alveoli rupture follows [4], and, depending on the pressure gradient, air moves from lung interstices through the hilum and triangular ligament to reach the mediastinum, occasionally the pericardium, and the retropharyngeal and the retroperitoneal spaces [5]. Air can easily pass through in the cervical region because of the close proximity between mediastinum and deep cervical band [22]. Airflow moved through visceral pleura explains the onset of pneumothorax [5]; however, it is quite uncommon. Symptoms include thoracic pain [2, 4, 7, 12], retrosternal or posterior dyspnea [21], cough [2, 7], dysphagia [2, 6], dysphonia [10], and anxiety [2, 7]. The sign of Hamman, characterized by a dry crackling noise detected during the auscultation of precordial space, especially during cardiac systole but also during diastole, is present in about half the cases [23]. Nonetheless, it is not a strictly peculiar feature of pneumomediastinum [7], having been described also in cases of left pneumothorax [24] or lingular bullous emphysema. However, it is important to emphasize that the concurrent detection of subcutaneous emphysema with the Hamman’s sign is virtually pathognomonic for pneumomediastinum [1]. Suspected diagnosis of SPM is confirmed by chest radiography [2, 4, 6, 7]. The most common radiologic signs [25] include several thin shining bundles that surround the mediastinal organs [2]; mediastinal pleura lifting from the cardiac edge, more frequent on the left than on the right side [7]; the ‘‘continuous diaphragm sign’’ produced by air trapped posterior to the pericardium, which gives the appearance of a continuous collection of air at anteroposterior radiography (Fig. 3) [26]. Air from the mediastinum can extend laterally between the parietal pleura and the diaphragm to produce the ‘‘extrapleural air sign’’ [27]. If there is sufficient air, the thymus can become elevated to produce ‘‘the thymic
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Fig. 3 Spontaneous pnemomediastinum in a 22-year-old obese patient. Lateral radiograph demonstrates the ‘‘continuous diaphragm sign’’
Fig. 4 Spontaneous pneumomediastinum in a 16-year-old male with negative chest X-ray. Chest CT demonstates SPM
sail sign’’ [28, 29]. Suspecting pneumomediastinum, lateral chest radiography is more sensitive for showing the continuous diaphragm sign, especially when extension of pneumomediastinum is limited [2]. Chest CT may be needed when there is clinical suspicion and a negative chest X-ray [30] (Fig. 4). CT is
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useful for detecting tracheobronchial ruptures, esophageal perforation, and/or pneumothorax, all of which require urgent attention [8]. Chest CT allows one to rule out possible pathologies affecting the intrathoracic organs, that are responsible for air flow into mediastinum [9, 10], and concurrent or chronic pleural and pulmonary pathologies [6, 7]. The Boerhaave syndrome, characterized by spontaneous esophageal perforation, is a life-threatening condition that demands early diagnosis and urgent management [31]. Boerhaave syndrome must be considered for any case of a history of vomiting followed by chest pain with dyspnea. Radiologic studies are mandatory to confirm clinical diagnosis. Chest CT shows a high sensitivity for detecting a possible air or liquid expansion outside the esophagus and a thickening of bowel walls, or even mediastinitis [10, 32]. Only in highly suspicious cases is contrast-enhanced swallow necessary [33]. In our experience we have performed chest CT in all patients in which BS is suspected, using oral contrast agent administration in four feverish patients with dysphagia. The role of esophagoscopy is controversial [2, 10]. Suspecting a tracheobronchial rupture, the use of tracheobronchial endoscopy and esophagoscopy is still controversial [3, 11]. In our experience, two patients with extended pneumomediastinum and suspected of a tracheobronchial rupture underwent fiber bronchoscopy under heavy sedation with no complications. However, this technique must be reserved for limited cases. Once SPM is diagnosed, the treatment is generally conservative and characterized by bedrest; analgesics and anticough drugs; and if the subcutaneous emphysema is remarkable, subcutaneous needle drainage (SND) is necessary. We recommended use of prophylactic antibiotics to reduce the possibility of mediastinitis during SND [34, 35]. Once SPM diagnosis and clinical and radiologic stability are obtained, patients can be discharged after being educated about the possible presenting symptoms that require immediate hospitalization, reducing the length of stay [1, 2, 6]. However, severe complications of SPM must be considered [4]: hypertensive or bilateral pneumothorax, hypertensive pneumomediastinum with cardiac compression, and respiratory tract compromise [22]. We reported the onset of pneumothorax in one of our patients as a result of worsening of the clinical condition, between the second and third day of hospital stay. It was drained with subsequent full pulmonary re-expansion.
Conclusions SPM is a entity with a generally benign evolution that is sometimes not accurately diagnosed [2, 7]. SPM must be suspected in young patients who report thoracic pain, especially with accompanying subcutaneous emphysema. The diagnosis is confirmed radiographically. It is essential to differentiate SPM from pneumomediastinum due to tracheobronchial rupture, esophageal perforation, mediastinitis, and pneumothorax, all of which require urgent treatment. Chest CT assists in ruling out esophageal perforation, mediastinitis, and concurrent, i.e., pleural and pulmonary, pathologies. The treatment of SPM is conservative. Usually hospitalization is necessary. Patients are discharged when clinically and radiologically stable.
References 1. Panacek EA, Singer AJ, Sherman BW, Prescott A, Rutherford WF (1992) Spontaneous pneumomediastinum: clinical and natural history. Ann Emerg Med 21:1222–1227 2. Jougon JB, Ballester M, Delcambre F, et al. (2003) Assessment of spontaneous pneumomediastinum: experience with 12 patients. Ann Thorac Surg 75:1711–1714 3. Ralph-Edwards AC, Pearson FG (1994) Atypical presentation of spontaneous pneumomediastinum. Ann Thorac Surg 58:1758–1760 4. Macklin MT, Macklin CC (1944) Malignant interstitial emphysema of the lungs and mediastinum as an important occult complication in many respiratory diseases and other conditions: an interpretation of the clinical literature in the light of laboratory experiment. Medicine 23:281–358 5. Raley JC, Andrews JI (2001) Spontaneous pneumomediastinum presenting as jaw pain during labor. Obstet Gynecol 98:904–906 6. Gerazounis M, Athanassiadi K, Kalantzi N, Moustardas M (2003) Spontaneous pneumomediastinum: a rare benign entity. J Thorac Cardiovasc Surg 126(3):774–776 7. Bodart E, de Bilderling G, Nisolle JF, Trigaux JP, Tuerlinckx D (1999) Spontaneous pneumomediastinum in an adolescent: an underestimated cause of chest pain. Arch Pediatr 6(12):1293–1296 8. Koelliker PD, Brannam LA (1999) Epidural pneumatosis associated with spontaneous pneumomediastinum: case report and review of the literature. J Emerg Med 17:247–250 9. Gorbach JS, Counselman FL, Mendelson MH (1997) Spontaneous pneumomediastinum secondary to hyperemesis gravidarum. J Emerg Med 15:639–643 10. Hoover LR, Febinger DL, Tripp HF (2000) Rhinolalia: an underappreciated sign of pneumomediastinum. Ann Thorac Surg 69:615–616 11. Dechambre S, d’Odemont JP, Cornelis JP, Fastrez J (1995) Spontaneous pneumomediastinum after sneezing. Ann Thorac Surg 60(5):1457 12. Abolink I, Lossos IS, Brewer R (1991) Spontaneous pneumomediastinum. Chest 100:93–95
123
Lung (2007) 13. Birrer RB, Calderon J (1984) Pneumothorax, pneumomediastinum, and pneumopericardium following Valsalva’s maneuver during marijuana smoking. N Y State J Med 12:619–620 14. Hamman L (1939) Spontaneous mediastinal emphysema. Bull Johns Hopkins Hosp 64:1–21 15. Aribas OK, Gormus N, Aydogdu Kiresi D (2001) Epidural emphysema associated with primary spontaneous pneumothorax. Eur J Cardiothorac Surg 20(3):645–646 16. Sutherland FW, Ho SY, Campanella C (2002) Pneumomediastinum during spontaneous vaginal delivery. Ann Thorac Surg 73(1):314–315 17. O’Sullivan AJ, Casey JH (1997) Spontaneous pneumomediastinum and diabetic ketoacidosis. Med J Aust 166:245–246 18. Weathers LS, Brooks WG, DeClue TJ (1995) Spontaneous pneumomediastinum in a patient with diabetic ketoacidosis: a potentially hidden complication. South Med J 88(4):483– 484 19. Rey C, Alvin P, Pariente D, Courtecuisse V (1994) Pneumomediastinum in a young girl with anorexia nervosa. Arch Pediatr 1(7):652–654 20. Le Floch AS, Lapostolle F, Danhiez F, Adnet F (2002) Pneumomediastinum as a complication of recreational ecstasy use. Ann Fr Anesth Reanim 21(1):35–37 21. Morgan EJ, Henderson DA (1981) Pneumomediastinum as a complication of athletic competition. Thorax 36:155–156 22. Maravelli AJ, Skiendzielewski JJ, Snover W (2000) Pneumomediastinum acquired by glass blowing. J Emerg Med 19(2):145–147 23. Gray JM, Hanson GC (1966) Mediastinal emphysema: aetiology, diagnosis and treatment. Thorax 21:325–332 24. Bauman MH, Sahn SA (1992) Hamman’sign revisited. Chest 102:1281–1282 25. Bejvan SM, Godwin JD (1996) Pneumomediastinum. Old signs and new signs. AJR Am J Roentgenol 166:1041–1048
123
26. Levin B (1973) The continuous diaphragm sign: a newly recognized sign of pneumomediastinum. Clin Radiol 24:337– 338 27. Lillard RL, Allen RP (1965) The extrapleural air sign in pneumomediastinum. Radiology 85: 1093–1097 28. Schwartz M, Rossoff L (1994) Pneumomediastinum and bilateral pneumothoraces in a patient with hyperemesis gravidarum. Chest 106:1094–1096 29. Zylak CM, Standen JR, Barnes GR, Zylak CJ (2000) Pneumomediastinum revisited. RadioGraphics 20:1043–1057 30. Koullias GJ, Korkolis DP, Wang XJ, Hammond GL (2004) Current assessment and management of spontaneous pneumomediastinum: experience in 24 adult patients. Eur J Cardiothorac Surg 25(5):852–855 31. Freixinet J, Garcia F, Rodriguez PM, et al. (2005) Spontaneous pneumomediastinum long-term follow-up. Respir Med 99(9):1160–1163 32. Dayen C, Mishellany H, Hellmuth D, et al. (2001) Spontaneous rupture of the esophagus or Boerhaave syndrome. Report of 3 cases and review of the literature. Rev Mal Respir 18(5):537–540 33. Triaridis S, Konstantinidis I, Noussios G, Karagiannidis K, Permekerlis A (2002) A diagnostic challenge: investigating suspected tracheobronchial and pharyngoesophageal tears. Are there gold standards? Acta Otorhinolaryngol Belg 56(3):331–334 34. Newcomb AE, Clarke CP (2005) Spontaneous pneumomediastinum: a benign curiosity or a significant problem? Chest 128(5):3298–3302 35. Koscielny S, Gottschall R (2005) Diagnostic and therapeutic procedure for spontaneous emphysema of the neck and mediastinum. HNO 53(7):645–650 36. Miura H, Taira O, Hiraguri S, Ohtani K, Kato H (2003) Clinical features of medical pneumomediastinum. Ann Thorac Cardiovasc Surg 9(3):188–191
