title: Diagnosis and treatment of patients with spontaneous pneumomediastinum.
abstract: BACKGROUND
  Although many patients complaining of chest pain visit the emergency department, very few are diagnosed with spontaneous pneumomediastinum (SPM). We present the management of 20 patients with SPM.
  
  
  METHODS
  We retrospectively analyzed the clinical features, past history, chest X-rays (CXRs), 64-slice helical computed tomography (CT) images, and clinical course of 20 patients with SPM (19 men and 1 woman) who visited the emergency department of the Tokyo Metropolitan Bokutoh Hospital between 2005 and 2010.
  
  
  RESULTS
  SPM predominantly resulted from physical exertion during such activities as sports and weight lifting (8 patients). The most common complaint was chest pain (15 patients), followed by dysphagia (10 patients), and dyspnea (8 patients). Subcutaneous emphysema was detected in 9 patients. The mean body mass index of the patients was 20.8±1.4kg/m(2). Although CXR findings of pneumomediastinum were absent in 5 patients, CT showed findings of the Macklin effect in all patients-interstitial gas was observed in the perihilar area in all patients and in the peripheral lung area in 9 patients (45%). Ten patients were hospitalized. The others received ambulatory care in the form of analgesics without antibiotics. All patients fully recovered without complications.
  
  
  CONCLUSIONS
  Our results showed that 64-slice helical CT is more reliable than CXRs for diagnosing SPM. Moreover, some patients with SPM can be treated without hospitalization, thus decreasing medical expenses for these patients.
authors.affiliation: Department of Emergency Medicine, Tokyo Metropolitan Bokutoh Hospital, 23-15 Kotohbashi4-chome, Sumida-ku, Tokyo 130-8575, Japan. Electronic address: bokutouer-okada@bokutoh-hp.metro.tokyo.jp.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Okada
authors.affiliation: Department of Cardiovascular Surgery, Saitama Medical Center, Jichi Medical University, 1-847 Amanuma, Omiya-ku, Saitama 330-8503, Japan. Electronic address: hadachi@omiya.jichi.ac.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Adachi
authors.affiliation: Department of Respiratory Medicine, Tokyo Metropolitan Bokutoh Hospital, 23-15 Kotohbashi4-chome, Sumida-ku, Tokyo 130-8575, Japan. Electronic address: shibuyay@jichi.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shibuya
authors.affiliation: Department of Cardiothoracic Surgery, Tokyo Metropolitan Bokutoh Hospital, 23-15 Kotohbashi4-chome, Sumida-ku, Tokyo 130-8575, Japan. Electronic address: susumuishikawa@hotmail.co.jp.
authors.forename: Susumu
authors.initials: S
authors.lastname: Ishikawa
authors.affiliation: Tertiary Emergency Medical Center, Tokyo Metropolitan Bokutoh Hospital, 23-15 Kotohbashi4-chome, Sumida-ku, Tokyo 130-8575, Japan. Electronic address: yhamabe-tky@umin.ac.jp.
authors.forename: Yuuichi
authors.initials: Y
authors.lastname: Hamabe
mesh_terms: D000293:Adolescent; D000328:Adult; D000553:Ambulatory Care; D000700:Analgesics / Q000627:therapeutic use; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008478:Mediastinal Emphysema / Q000175:diagnosis* / Q000628:therapy*; D011379:Prognosis; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed; D055815:Young Adult
chemical_list: D000700:Analgesics
keywords: 64-Slice helical computed tomography; BMI; C-reactive protein; CRP; CT; CXR; Computed tomography; Macklin effect; PM; Pneumomediastinum; SPM; body mass index; chest X-ray; computed tomography; pneumomediastinum; spontaneous pneumomediastinum