Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PNEUMOMEDIASTINUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1995

[Three patients with spontaneous pneumomediastinum, including one in whom pneumomediastinum recurred].

We encountered three patients with spontaneous pneumomediastinum. All three (two men and one woman) were previously healthy. They complained of chest pain or dyspnea. On admission, physical examination revealed subcutaneous emphysema. Chest roentgenograms and computed tomograms revealed pneumomediastinum and subcutaneous emphysema. All other findings were normal. All patients were treated with bed rest and all recovered in 7 to 9 days. Pneumomediastinum recurred in one patient after 20 months.

Adolescent↗
PubMed2006

[Clinical analysis of pneumomediastinum complicated in polymyositis and dermatomyositis].

OBJECTIVE: To analyze the clinical features of pneumomediastinum complicated in polymyositis and dermatomyositis (PM/DM) and to study the pathogenesis thereof. METHODS: The clinical data of 4 patients with pneumomediastinum complicated in dermatomyositis out of 447 PM/DM patients hospitalized in Peking Union Medical College (PUMC) Hospital Jan 1989 to June 2005, were analyzed. The records of patients with PM/DM available in English throughout the world were reviewed to collect those with pneumomediastinum as a complication. And the data of these patients were analyzed, focusing mainly on the age, gender, peak of serum creatine kinase (CK), presence of pneumomediastinum, cutaneous vasculopathy, chest radiographic changes, tracheal cannula, management, and outcome. RESULTS: Among the 447 patients with PM/DM hospitalized in PUMC Hospital, 134 males and 313 females, aged 42 +/- 17, pneumomediastinum was observed as a complication in four patients, 3 males and 1 female, aged 12 - 43, with a prevalence rate of 0.9%. Together with 17 cases reported in the English literatures there were 21 patients with pneumomediastinum complicated in polymyositis and dermatomyositis (PM/DM in all. Only one of the literatures reported a prevalence rate as high as 8.3% (4/48), and other literatures were merely case reports. Compared with the PM/DM patients without pneumomediastinum the mean age of the PM/DM patients with pneumomediastinum was significantly younger (34:42, P < 0.01), the male: female ratio significantly higher (13:8 to 132:311, P < 0.01), the morbidity rates of interstitial lung disease and of cutaneous vasculopathy significantly higher (18/21 to 134/443, and 12/21 to 44/443, both P < 0.01). Although statistic analysis could not be undertaken because of the peak of CK not being provided in details in the literatures, the CK levels of the patients with pneumomediastinum were mostly normal or mildly higher with a peak lower than 500 U/L Three of the 4 patients with pneumomediastinum hospitalized in PUMC Hospital and 5 of the 443 patients (1.1%) without this complication received tracheal cannula. There was a significant association of pneumomediastinum with tracheal cannula (P = 0.000). CONCLUSION: Vasculopathy is strongly suspected as being responsible for the pneumomediastinum in DM, and male gender, younger age, interstitial lung disease, and tracheal cannula may be the risk factors of this pneumomediastinum complicated in PM/DM.

Adolescent↗
PubMed2000

Pneumomediastinum in dermatomyositis: association with cutaneous vasculopathy.

OBJECTIVES: To study the pathogenesis of pneumomediastinum in polymyositis/dermatomyositis (PM/DM). PATIENTS AND METHODS: The clinical records of 48 patients with PM/DM were reviewed, focusing mainly on the presence of pneumomediastinum and cutaneous vasculopathy, and the chest radiographic changes. A patient with pneumomediastinum with a characteristic change in his bronchus is described in detail. Case reports of pneumomediastinum in PM/DM in English publications are reviewed. RESULTS: Among the 48 patients with PM/DM, pneumomediastinum was observed as a complication in four patients with DM and none of the patients with PM. Three of the four patients with pneumomediastinum, but only six of the 44 patients without this complication, had associated cutaneous vasculopathy. There was a significant association of pneumomediastinum with cutaneous vasculopathy (p = 0.02) and younger age (p = 0.04), but not with the prevalence of lung disease. A 30 year old man (patient 1) with DM, who had interstitial pneumonitis and skin ulceration due to vasculopathy, developed pneumomediastinum. Fibreoptic bronchoscopy showed white plaques on the bronchial mucosa, which were confirmed by microscopic examination as representing subepithelial necrosis. A literature review showed 13 cases of DM but no patient with PM with pneumomediastinum. CONCLUSIONS: In patient 1, bronchial necrosis due to vasculopathy was strongly suspected as being responsible for the pneumomediastinum. The results suggest that pneumomediastinum was associated not with interstitial pneumonitis but with the complication of vasculopathy appearing as skin lesions in DM.

Adolescent↗
PubMed2001

Medical causes of pneumomediastinum in children.

The purpose of this study was to determine the possible causes, clinical findings, and associated complications of pneumomediastinum in children. Medical records from January 1985 to December 1994 were retrospectively reviewed at Children's Hospital Medical Center of Akron using International Classification of Diseases, ninth revision, codes to identify cases of pneumomediastinum. The medical causes, nontraumatic and noniatrogenic, of pneumomediastinum were studied; intubated or trauma patients and patients having undergone procedures were excluded. Neonates were also excluded. Twenty-nine cases of pneumomediastinum were identified. Two patients (7%) had recurrent pneumomediastinum. Only the first episode of pneumomediastinum was included in the data analysis. Twenty males (69%) and nine females (31%) were affected. The most common medical causes of pneumomediastinum were asthma exacerbations (17/59%) and infections (8/28%). Over the 10-year period, the prevalence of pneumomediastinum in children with asthma exacerbations was 0.2% (21/10,472); 1% (1/126) in children with airway foreign bodies and 0.2% (1/351) in children with esophageal foreign bodies. The most common signs and symptoms were subcutaneous emphysema (22/76%), sore throat or neck pain (11/38%), and Hamman's crunch (3/10%). The most common complication was pneumothorax with small pneumothoraces in 2 patients (7%) and a tension pneumothorax in 1 asthmatic with recurrent pneumomediastinum. Patients without sore throat or neck pain and patients admitted to the intensive care unit had greater hospital lengths of stay. Pneumomediastinum appears to be uncommon in children. The most common medical causes were asthma and infections. The most common signs and symptoms were subcutaneous emphysema, sore throat or neck pain, and Hamman's crunch. The most common complication was pneumothorax. The clinical significance of pneumomediastinum is its cause and association with significant complications.

Adolescent↗
PubMed2005

Thin-section CT assessment of spontaneous pneumomediastinum in interstitial lung disease: correlation with serial changes in lung parenchymal abnormalities.

PURPOSE: The purpose of this study was to analyze thin-section computed tomography (CT) appearances of interstitial lung diseases before and at the time of detection of pneumomediastinum, and to evaluate the relationship between pneumomediastinum and parenchymal changes on thin-section CT. MATERIALS & METHODS: We reviewed CT images before and at the time of detection of pneumomediastinum in 13 patients with idiopathic pulmonary fibrosis (8 patients) and collagen vascular diseases (5 patient). The extent of the total area of reticular opacity, increased opacity (ground-glass opacity and consolidation), and honeycombing were scored, and these scores were compared before and at the time of detection of pneumomediastinum. We also divided patients into two groups according to therapy received. Patients in group 1 experienced pneumomediastinum after or during treatment with corticosteroids or immunosuppressive agents for acute or subacute exacerbation of interstitial lung disease. Patients in group 2 experienced pneumomediastinum without therapy. RESULTS: The mean score of all patients for honeycombing significantly increased at the time of detection of pneumomediastinum (P=0.003). In group 1, the extent of increasing opacity had been decreased significantly at the time of detection of pneumomediastinum (P=0.028). In group 2, the mean CT score of reticular opacity, increasing opacity, and honeycombing significantly increased at the time of detection of pneumomediastinum (P=0.028, 0.018, and 0.018, respectively). CONCLUSIONS: Spontaneous pneumomediastinum associated with interstitial lung disease appears to have a tendency to occur under conditions of altered of parenchymal interstitial lesions.

Adrenal Cortex Hormones↗
PubMed1992

Spontaneous pneumomediastinum: clinical and natural history.

STUDY OBJECTIVE: To evaluate the clinical characteristics and natural history of patients presenting with spontaneous pneumomediastinum. DESIGN: A retrospective case series was conducted to identify patients diagnosed with spontaneous pneumomediastinum. ICD-9 discharge codes were used for 1984 to 1990 at two institutions, and emergency department records of a third hospital were reviewed for 1981 to 1986. Clinical features, interventions, complications, setting, etiology, symptoms, and length of hospital stay were recorded. SETTING: Three university tertiary care hospitals. PARTICIPANTS: All ED patients more than 12 years old with a diagnosis of spontaneous pneumomediastinum. INTERVENTIONS: None. RESULTS: Seventeen cases were identified. Age range was 15 to 41 years (mean, 25 years). Presenting symptoms were chest pain in eight (47%), dyspnea in three (18%), both symptoms in three (18%), and neither in three (18%). Three patients complained only of throat discomfort. Nine (52%) had a Hamman's crunch, 11 (65%) had subcutaneous emphysema, and two (11%) had a small pneumothorax. Five (29%) were smokers, and five (29%) had normal esophograms. Thirteen of 17 (76%) cases were associated with illicit inhalation drug use. Twelve cases (70%) had history of a "Valsalva-type" maneuver. All but three were admitted to a hospital, with a mean stay of 2.5 days (range, one to six). No patient suffered complications or required interventions for spontaneous pneumomediastinum. Specifically, no patient developed a subsequent pneumothorax or airway compromise. The three patients not admitted were followed up by telephone contact. All did well with rapid resolution of their symptoms. CONCLUSION: Most spontaneous pneumomediastinum cases occur in the setting of inhalational drug use. One hundred percent of patients will have a symptom directly related to the spontaneous pneumomediastinum, with 82% presenting with either dyspnea or chest pain. Most (88%) will present with either subcutaneous emphysema or a Hamman's crunch on examination. Simple spontaneous pneumomediastinum has a very benign course and does not require hospitalization. Serial radiographs, likewise, did not change the medical management of spontaneous pneumomediastinum.

Administration, Inhalation↗
PubMed2000

Incidence and significance of pneumomediastinum after laparoscopic esophageal surgery.

BACKGROUND: Pneumomediastinum can be a sign of esophageal perforation. During laparoscopic esophageal surgery, the mediastinum is exposed to carbon dioxide gas under pressure that can cause pneumomediastinum. METHODS: Forty-five patients undergoing laparoscopic esophageal procedures had erect, inspiratory, single-view chest radiographs (CXR) performed in the recovery room (RR). Patients with extraabdominal gas underwent daily erect, inspiratory, single-view CXR until resorption of the gas or discharge from the hospital. Insufflation time and pressure were recorded, and morbidity was evaluated. Results are expressed as mean +/- SEM. RESULTS: Twenty-five men (56%)and 20 women (44%) aged 33.0 +/- 2.9 years underwent 10 Heller myotomies (22.2%), 27 Nissen fundoplications (60.0%), six Toupet fundoplications (13.3%), and two paraesophageal hernia repairs (4.4%). Twenty-four patients (53.3%) had normal CXR in RR, and 21 (46.7%) had extraabdominal gas. Eighteen (85.7%) of the 21 had pneumomediastinum, three (14.3%) had pneumothorax, and 12 (57.1%) had subcutaneous emphysema in RR. Sixteen of these 21 remained hospitalized and had repeat CXR on postoperative day 1. Of these 16, five (31.3%) had normal CXR, 11 (68.8%) had pneumomediastinum, and seven (43.8%) had subcutaneous emphysema. There were no esophageal perforations and no chest tube insertions, and there was no morbidity related to pneumomediastinum. CONCLUSION: Pneumomediastinum is observed frequently following laparoscopic esophageal operations and often persists past 24 h. After these operations, pneumomediastinum is not necessarily indicative of esophageal perforation. In this group, it caused no clinically significant events that altered the course of the patients.

Adolescent↗
PubMed1991

Disposition of spontaneous pneumomediastinum.

In the evaluation of spontaneous pneumomediastinum, it is important to exclude pathological causes of pneumomediastinum, including Boerhaave's syndrome, which carries a high mortality rate. The literature varies greatly as to the care of patients with presumed spontaneous pneumomediastinum. The authors present an illustrative case of spontaneous pneumomediastinum treated with intravenous antibiotics and intensive care unit (ICU) admission despite a normal esophagram. Spontaneous pneumomediastinum is a benign entity that may not require observation in an ICU, and patients may do as well with close outpatient follow-up. For those patients in which the etiology of the pneumomediastinum is unclear, a contrast esophagram is recommended to assess for esophageal disruption. The signs, symptoms, pathophysiology, and disposition of spontaneous pneumomediastinum are discussed.

Adult↗
PubMed2003

Pneumomediastinum simulating a panic attack in a patient with anorexia nervosa.

OBJECTIVE: Pneumomediastinum is a rare complication of anorexia nervosa. Although the mechanism is unknown, severe malnutrition may affect lung mechanics by altering the connective tissue, predisposing to pneumomediastinum. METHOD: We describe a young male with anorexia nervosa and panic disorder who presented with symptoms similar to those of a panic attack and was diagnosed with spontaneous pneumomediastinum. RESULTS: This case illustrates the importance of considering pneumomediastinum in the differential diagnosis of panic attack in patients with eating disorders. DISCUSSION: Although spontaneous pneumomediastinum has a generally benign course, it must be differentiated from the potentially life-threatening secondary pneumomediastinum due to an esophageal tear.

Adult↗
PubMed2004

Sports-related spontaneous pneumomediastinum.

BACKGROUND: Spontaneous pneumomediastinum is a rare medical entity occurring almost exclusively in otherwise healthy young individuals without known predisposing factors. We reported our experience with patients presenting with spontaneous pneumomediastinum related to sports. METHODS: Between January 1991 and December 2002, 10 patients were admitted with spontaneous pneumomediastinum related to sporting activities. We retrospectively reviewed their medical records with regard to predisposing factors, clinical presentation, diagnostic evaluation, and outcome. RESULTS: The mean age of our patients was 18.9 years (range 15 to 25 years). Retrosternal chest pain was the most common symptom (90%), and subcutaneous emphysema the most common physical finding (90%). Hamman's sign was present in 9 patients. In all 10 patients, physical exertion during sports was the only implicating factor (scuba diving in 4 patients, basketball in 2, soccer in 3, and volleyball in 1). All patients were treated conservatively. Complete resorption of the pneumomediastinum occurred in 3 to 8 days. Hospital stay ranged from 2 to 6 days (mean 3.8 days). Follow-up was complete in 8 patients (80%), and ranged from 6 to 84 months (mean 35 months). Only 1 recurrence of pneumomediastinum was found that was treated similarly. CONCLUSIONS: Spontaneous pneumomediastinum after sporting activities is a benign disease that generally resolves without clinical sequelae. Restriction of physical and athletic activity after the first episode is unnecessary, the only exception being that of scuba diving.

Adolescent↗
PubMedDate not supplied

Pneumomediastinum revisited.

Pneumomediastinum may result from a variety of causes that may be either intrathoracic (eg, narrowed or plugged airway, straining against a closed glottis, blunt chest trauma, alveolar rupture) or extrathoracic (eg, sinus fracture, iatrogenic manipulation in dental extraction, perforation of a hollow viscus [corrected]. The radiographic signs of pneumomediastinum depend on the depiction of normal anatomic structures that are outlined by the air as it leaves the mediastinum. These signs include the thymic sail sign, "ring around the artery" sign, tubular artery sign, double bronchial wall sign, continuous diaphragm sign, and extrapleural sign. In distal esophageal rupture, air may migrate from the mediastinum into the pulmonary ligament. Pneumomediastinum may be difficult to differentiate from medial pneumothorax and pneumopericardium. Occasionally, normal anatomic structures (eg, major fissure, anterior junction line) may simulate air within the mediastinum. Iatrogenic entities that may simulate pneumomediastinum include helium in the balloon of an intraaortic assist device. In addition, pneumomediastinum may be simulated by the Mach band effect, which manifests as a region of lucency adjacent to structures with convex borders. The absence of an opaque line, which is typically seen in pneumomediastinum, can aid in differentiation. Computed tomographic (CT) digital radiography and conventional CT can also be helpful in establishing or confirming the diagnosis.

Adolescent↗
PubMed2003

Clinical features of medical pneumomediastinum.

PURPOSE: The clinical features of pneumomediastinum are clarified. METHODS: Eight patients with pneumomediastinum, caused by other than trauma or operative, diagnostic, or therapeutic trouble (medical pneumomediastinum), were studied retrospectively. RESULTS: There were seven men and one woman with an average age of 17.5 years. The incidence was about 1:320 in thoracic surgical inpatients. The causes were bronchial asthma in three patients, physical exertion in one, and forced swallowing in one. There were three spontaneous cases. The chief complaints were dyspnea in five patients including three patients with bronchial asthma, chest pain in two, and pharyngeal pain in one. Subcutaneous emphysema was observed in all patients. Hamman's sign was audible in only one patient. Roentgenologically, subcutaneous emphysema was observed in all patients. Pneumomediastinum parallel to the heart was observed in five patients. The continuous diaphragm sign was detected in three patients. Five patients were prohibited from eating and drinking excluding those with pneumomediastinum due to bronchial asthma, considering the esophageal origin. Prophylactic antibiotics were prescribed for all patients. Pneumomediastinum improved within 7 days in all patients. The mean length of hospitalization was 7.8 days, ranging from 4 to 13 days. CONCLUSION: In consideration of air of the esophageal origin, non per oral was prescribed. With the prevention of mediastinitis using antibiotics, all patients recovered. Emergency endoscopic examination was unnecessary.

Adolescent↗
PubMed1998

Pneumomediastinum in a high school football player: a case report.

OBJECTIVE: To provide athletic trainers with information about the mechanism, evaluation, and treatment of pneumomediastinum. BACKGROUND: This is a case study of a high school football player who suffered pneumomediastinum as a result of a flat-handed thump to his sternal area during a blocking drill. Pneumomediastinum is a relatively rare occurrence in sports. Common mechanisms include direct blunt trauma, vomiting, sneezing, Valsalva maneuver, and forceful coughing. Typical signs and symptoms include chest pain, dyspnea, tenderness, crepitus in the neck that can be aggravated with swallowing, and a positive Hamman's sign with auscultations. DIFFERENTIAL DIAGNOSIS: Pneumothorax, pneumopericardium, sternal contusion, rib fracture, upper respiratory infection, and myocardial infarction. TREATMENT: Conservative management includes restriction from athletic activities, prophylactic antibiotics, and sleeping in a semireclined position. Surgical repair of the defect may be indicated if repeat radiographs fail to show improvement after 1 week. UNIQUENESS: It is rare that a relatively light blow through shoulder pads would result in a pneumomediastinum. Review of the literature does not include this athlete's symptoms of congestion, nasal voice, or sore throat as typical signs of pneumomediastinum. CONCLUSIONS: The literature indicates that an uncomplicated pneumomediastinum will typically resolve in 2 weeks' time. In this case, symptomatic evaluation warranted only 1 week of rest before the athlete was allowed to return to full activity.

Journal Article↗
PubMedDate not supplied

Pneumomediastinum presenting as acute airway obstruction.

Pneumomediastinum is an entity with diverse underlying etiologies and variable clinical presentations. We present a case of pneumomediastinum that on initial presentation appeared to be an upper airway emergency most consistent with adult epiglottitis. The pathophysiology of pneumomediastinum involves extravasation of air through perivascular interstitial tissues. Once air has gained access into the soft tissues, it may dissect upward into the neck and distend upper airway structures. This may cause patients with pneumomediastinum to have symptoms such as a sore throat or dysphagia. The patient we describe had such dramatic upper airway symptomatology that adult epiglottitis was the initial suspected diagnosis, and acute airway intervention was required. The various etiologies, presentations, and pathophysiology of pneumomediastinum are discussed.

Acute Disease↗
PubMed2003

Spontaneous pneumomediastinum: a rare benign entity.

OBJECTIVE: Spontaneous pneumomediastinum usually occurs in young people without an apparent precipitating factor or disease. Thoracic surgeons are involved in the diagnosis and management of this entity because of the potentially life-threatening conditions that either must be treated as an emergency or excluded, such as esophageal perforation or necrotizing mediastinitis. We present our modest experience in treating spontaneous pneumomediastinum. MATERIALS: Between 1988 and 1998 we treated 22 cases of spontaneous pneumomediastinum in 18 male patients and 4 female patients, ranging in age between 12 and 32 years. All traumatic cases were excluded. Retrosternal chest pain was the main symptom the patients presented. In only 11 cases was subcutaneous emphysema present. Chest radiography was diagnostic in all our cases. Computed tomographic scan, when performed, confirmed the diagnosis. An esophagogram was essential to exclude an esophageal rupture. Last, a cardiologic examination especially focusing on pericarditis excluded cardiac disease. RESULTS: Conservative treatment consisted of bed rest, oxygen therapy, and analgesics, which led to rapid resolution of the spontaneous pneumomediastinum. The mean hospital stay ranged between 3 and 10 days. In a follow-up of 3 to 12 years only 1 recurrence was observed. CONCLUSION: Spontaneous pneumomediastinum is usually an undiagnosed benign entity that responds very well to conservative treatment. It should be considered in the differential diagnosis of chest pain, especially in healthy adolescents and young adults.

Adolescent↗
PubMed1996

Mediastinal tube placement in children with pneumomediastinum: hemodynamic changes and description of technique.

OBJECTIVE: To describe the technique, hemodynamic response, and complication rate after the insertion of a percutaneous mediastinal tube for drainage of pneumomediastinum. DESIGN: A combined retrospective and prospective study in mechanically ventilated children with pneumomediastinum. SETTING: Multidisciplinary pediatric intensive care unit at a children's hospital. PATIENTS: The medical records and chest radiographs of 25 (15 retrospective and 10 prospective) patients who had placement of a mediastinal tube for drainage of pneumomediastinum from 1990 to 1995 were reviewed. Hemodynamic data were collected prospectively in the ten consecutive children from January 1994 to April 1995. INTERVENTION: Mediastinal tube placement: The subxyphoid area was cleansed with povidone-iodine and draped. An 18-gauge, thin-walled introducer needle was inserted 1 to 2 cm below the xyphoid process at an angle of 20 degrees from the anterior abdominal wall, directed at the substernal space. Either a 9-Fr or 11-Fr pericardiocentesis catheter was inserted over a wire and advanced to the third intercostal space. The catheter was secured and connected to 10 cm H2O suction, using a standard thoracostomy tube drainage device. MEASUREMENTS AND MAIN RESULTS: The size of the mediastinal air column on a lateral chest radiograph was measured before and after placement of the mediastinal tube. The mean change in the size of the mediastinal air column was -1.6 cm (median -1.5, p < .001). In the ten prospective patients, hemodynamic data were recorded immediately before and after placement of a mediastinal tube from previously placed arterial and central venous pressure catheters. The mean hemodynamic changes after the mediastinal tube placement were: heart rate -4 beats/min (median = -1, p = .14); systolic blood pressure 16 mm Hg (median = 10, p = .007); diastolic blood pressure 11 mm Hg (median = 11, p = .005); mean arterial pressure 12 mm Hg (median = 8, p = .005); and central venous pressure -2 mm Hg (median = -1, p = .04). In four patients with pulmonary artery thermodilution catheters, the mean increase in cardiac index immediately following placement of the mediastinal tube was 34%. No complications, including bleeding, cardiac puncture, or infection occurred. CONCLUSIONS: These findings suggest that hemodynamic compromise commonly accompanies pneumomediastinum in children. Decompression of the mediastinal space and drainage of the pneumomediastinum, using this simple bedside technique for continuous drainage, can be performed rapidly and safely in children, resulting in immediate hemodynamic improvement, and allowing for continuous drainage.

Adolescent↗
PubMedDate not supplied

Frequent cause of the Macklin effect in spontaneous pneumomediastinum: demonstration by multidetector-row computed tomography.

OBJECTIVE: The purpose of this study was to evaluate the Macklin effect in patients with spontaneous pneumomediastinum by multidetector-row computed tomography (MDCT). METHODS: Chest computed tomography (CT) reports between July 2000 and January 2003 at our institution were retrospectively reviewed. Nine patients with spontaneous pneumomediastinum were identified, and their CT scans were evaluated to detect the Macklin effect. The patient diagnoses included interstitial lung diseases (n=4), bronchiolitis obliterans organizing pneumonia or pneumonia (n=3), asthma (n=1), and spontaneous pneumomediastinum without definite pulmonary disease (n=1). RESULTS: The Macklin effect was observed in 8 (89%) of 9 patients. In 4 patients, the Macklin effect was observed in perihilar and peripheral areas, and in 4 patients, it was observed only in the perihilar area. CONCLUSIONS: The Macklin effect can frequently be demonstrated in patients with spontaneous pneumomediastinum of nontraumatic respiratory causes by MDCT. A CT-proven Macklin effect may be useful in differentiating respiratory from other causes of pneumomediastinum.

Adolescent↗