Spontaneous pneumomediastinum: experience in 18 adult patients

Pneumomediastinum

Pneumomediastinum, air within the mediastinum, is the manifestation of a variety of causes including those that are benign and some resulting in severe morbidity and even mortality. This article reviews the epidemiology, etiology, and pathophysiology of pneumomediastinum as an independent pathologic and physiologic entity, as well as reviews the workup and management of those patients who are diagnosed with pneumomediastinum.

Spontaneous Pneumomediastinum: A Diagnostic Challenge in a Patient Presenting With Excessive Vomiting and Neck Swelling

Hamman's syndrome, or spontaneous pneumomediastinum, refers to free air in the mediastinum without an apparent cause and typically affects young people. This case report describes a 33-year-old man who presented with neck swelling following excessive vomiting due to alcohol consumption. Clinical examination revealed subcutaneous emphysema of the neck, and imaging confirmed pneumomediastinum. Initial suspicion of Boerhaave syndrome led to aggressive supportive management, but further imaging ruled out oesophageal perforation, confirming Hamman's syndrome. The patient was treated conservatively and discharged after a successful trial of a light diet. This case highlights the diagnostic challenges of Hamman's syndrome, given that its symptoms overlap with more serious conditions like Boerhaave syndrome. Prompt recognition and appropriate conservative management are essential for favourable outcomes, emphasizing the benign and self-limiting nature of Hamman's syndrome.

Spontaneous pneumomediastinum: A comprehensive review of diagnosis and management

Pneumomediastinum is a rare condition defined by the presence of air in the mediastinum. In the absence of traumatic injury, iatrogenic injury, or clear etiology, it is called spontaneous pneumomediastinum (SPM). Spontaneous pneumomediastinum most commonly occurs in younger individuals and has a self-limiting course with a good outcome. The purpose of the present manuscript is to systematically review the existing literature on SPM evaluation and management for updated clinical understanding of this condition. A literature search was conducted of publications about SPM on MEDLINE/PubMed and Google Scholar by identifying all the articles with key search terms "pneumomediastinum" and "spontaneous pneumomediastinum". Inclusion criteria were case series published in English between 1980 and 2023. In total, 24 case series were selected and reviewed to determine presenting symptoms, clinical signs and predisposing factors associated with spontaneous pneumomediastinum. Most patients were male; the average age at diagnosis was 26.3 years. The most common presenting symptoms were chest pain and dyspnea. The most common exam finding was subcutaneous emphysema, in 35.4% of patients. Only 5.9% had the classic Hamman's sign. Risk factors include history of asthma, history of smoking, and recent physical activity. This manuscript presents an extensive review of relevant literature highlighting the diagnosis and essential management of spontaneous pneumomediastinum.

Pneumomediastinum in COVID-19: Risk factors and outcomes from a multicentre case-control study

BACKGROUND

An increased incidence of pneumomediastinum has been observed among patients hospitalized with coronavirus disease 2019 (COVID-19) pneumonia. The study aimed to identify risk factors for COVID-19-associated pneumomediastinum and investigate the impact of pneumomediastinum on clinical outcomes.

METHODS

In this multicentre retrospective case-control study, we included consecutive patients with COVID-19 pneumonia and pneumomediastinum hospitalized from March 2020 to July 2020 at ten centres; then, we identified a similarly sized control group of consecutive patients hospitalized with COVID-19 pneumonia and respiratory failure who did not develop pneumomediastinum during the same period. Clinical, laboratory, and radiological characteristics, as well as respiratory support and outcomes, were collected and compared between the two groups. Risk factors of pneumomediastinum were assessed by multivariable logistic analysis.

RESULTS

Overall 139 patients with pneumomediastinum and 153 without pneumomediastinum were analysed. Lung involvement ≥75 %, consolidations, body mass index (BMI) < 22 kg/m2, C-reactive protein (CRP) > 150 mg/L, D-dimer >3000 ng/mL FEUs, and smoking exposure >20 pack-year were all independently correlated with the occurrence of pneumomediastinum. Patients with pneumomediastinum had a longer hospital stay (mean ± SD 31.2 ± 20.2 days vs 19.6 ± 14.2, p < 0.001), higher intubation rate (73/139, 52.5 % vs 27/153, 17.6 %, p < 0.001), and in-hospital mortality (68/139, 48.9 % vs 36/153, 23.5 %, p < 0.001) compared to controls.

CONCLUSIONS

Extensive lung parenchyma involvement, consolidations, low BMI, high inflammatory markers, and tobacco exposure are associated with a greater risk of pneumomediastinum in COVID-19 pneumonia. This complication significantly worsens the outcomes.

Spontaneous pulmonary interstitial emphysema, pneumomediastinum and cervical subcutaneous emphysema secondary to the Macklin effect in dogs with no clinical signs: 12 cases

Pneumomediastinum denotes the presence of gas within the mediastinum and generally occurs by leakage of air from an aerated viscus that traverses or abuts the mediastinal plane. The Macklin effect has been described in several veterinary studies and describes gas tracking along the perivascular interstitium following alveolar rupture causing interstitial emphysema, pneumomediastinum and subsequently cervical subcutaneous emphysema. This retrospective case series describes incidental spontaneous pulmonary interstitial emphysema, pneumomediastinum and cervical subcutaneous emphysema secondary to the Macklin effect in dogs with no related clinical signs. Twelve dogs were identified from the author's institution, of which 75 % were Sighthounds (Greyhounds, Whippets or Lurchers). Pulmonary interstitial emphysema had a predominantly paravascular distribution, although in some cases a parabronchial distribution was also identified. We conclude that incidental pulmonary interstitial emphysema, pneumomediastinum and secondary cervical subcutaneous emphysema can be incidental, presumed secondary to the Macklin effect and that Sighthound breeds may be overrepresented.

Pneumomediastinum in the COVID-19 era: to drain or not to drain?

Pneumomediastinum (PNM) is a rare clinical finding, usually with a benign course, which is managed conservatively in the majority of cases. However, during the COVID-19 pandemic, an increased incidence of PNM has been observed. Several reports of PNM cases in COVID-19 have been reported in the literature and were managed either conservatively or surgically. In this study, we present our institutional experience of COVID-19 associated PNM, propose a management algorithm, and review the current literature. In total, 43 Case Series were identified, including a total of 747 patients, of whom 374/747 (50.1%) were intubated at the time of diagnosis, 168/747 (22.5%) underwent surgical drain insertion at admission, 562/747 (75.2%) received conservative treatment (observation or mechanical ventilation. Inpatient mortality was 51.8% (387/747), while 45.1% of the population recovered and/or was discharged (337/747). In conclusion, with increased incidence of PNM in COVID-19 patients reported in the literature, it is still difficult to assign a true causal relationship between PNM and mortality. We can, however, see that PMN plays an important role in disease prognosis.  Due to increased complexity, high mortality, and associated complications, conservative management may not be sufficient, and a surgical approach is needed.

Pneumomediastinum in COVID-19: a phenotype of severe COVID-19 pneumonitis? The results of the United Kingdom (POETIC) survey

BACKGROUND

There is an emerging understanding that coronavirus disease 2019 (COVID-19) is associated with increased incidence of pneumomediastinum. We aimed to determine its incidence among patients hospitalised with COVID-19 in the United Kingdom and describe factors associated with outcome.

METHODS

A structured survey of pneumomediastinum and its incidence was conducted from September 2020 to February 2021. United Kingdom-wide participation was solicited via respiratory research networks. Identified patients had SARS-CoV-2 infection and radiologically proven pneumomediastinum. The primary outcomes were to determine incidence of pneumomediastinum in COVID-19 and to investigate risk factors associated with patient mortality.

RESULTS

377 cases of pneumomediastinum in COVID-19 were identified from 58 484 inpatients with COVID-19 at 53 hospitals during the study period, giving an incidence of 0.64%. Overall 120-day mortality in COVID-19 pneumomediastinum was 195/377 (51.7%). Pneumomediastinum in COVID-19 was associated with high rates of mechanical ventilation. 172/377 patients (45.6%) were mechanically ventilated at the point of diagnosis. Mechanical ventilation was the most important predictor of mortality in COVID-19 pneumomediastinum at the time of diagnosis and thereafter (p<0.001) along with increasing age (p<0.01) and diabetes mellitus (p=0.08). Switching patients from continuous positive airways pressure support to oxygen or high flow nasal oxygen after the diagnosis of pneumomediastinum was not associated with difference in mortality.

CONCLUSIONS

Pneumomediastinum appears to be a marker of severe COVID-19 pneumonitis. The majority of patients in whom pneumomediastinum was identified had not been mechanically ventilated at the point of diagnosis.

[Spontaneous pneumomediastinum]

INTRODUCTION

Pneumomediastinum, which can be spontaneous or secondary, is defined by the presence of free air in the mediastinum as shown on a chest X-ray and/or chest CT, with or without subcutaneous emphysema. Secondary pneumomediastinum develops in various contexts (thoracic traumatism, perforation of central airway or digestive tract, pneumothorax, barotraumatism complicating mechanical ventilation…). Spontaneous pneumomediastinum , which will be the focus of this review, develops without any of the above-mentioned conditions.

STATE OF ART

Spontaneous pneumomediastinum is a rare entity which usually occurs in young people either without medical history or with an history of asthma. A trigger event is detected in 40% to 60% of cases. Positive diagnosis is made on chest radiographt but thoracic CT is more sensitive. Distinction between spontaneous pneumomediastinum and secondary pneumomediastinum is in general easy but may sometimes be more difficult, particularly in case of oesophageal perforation. The evolution of spontaneous pneumomediastinum is most often benign but, rare complications may occur. Management is most often conservative.

PERSPECTIVES

There is no consensual management of spontaneous pneumediastinum because of the lack of randomized prospective studies. This may be explained by the rarity of the disease. The actual trend is to offer to the patients a conservative treatment, which could be ambulatory in some cases.

CONCLUSIONS

Spontaneous pneumomediastinum is a rare entity developing mainly in young subjects. The evolution is in general benign, justifying a conservative approach.

Pneumomediastinum, pneumopericardium and subcutaneous emphysema following acute lymphoblastic leukemia and chemotherapy: A case report

Background:

Pneumomediastinum and subcutaneous emphysema are mostly detected in non-malignant conditions such as certain infections, thoracic surgeries, and trauma. Although this condition is asymptomatic in most cases, sometimes it could be symptomatic and may even be lethal in some patients.

Case Presentation:

This letter reports a 9-year-old girl with acute lymphoblastic leukemia (ALL) on chemotherapy who developed pneumothorax with the clinical feature of respiratory distress for that a chest tube was inserted immediately. Following the insertion, pneumomediastinum and pneumopericardium developed in the patient. As the next step, a pericardium window was inserted by an expert heart surgeon. During these procedures, all the evaluations for any bacterial or fungal infection were negative. Unfortunately, the patient expired before any further complementary evaluations and it was not clear that the mentioned situation was a result of chemotherapy or ALL.

Conclusion:

Although pneumomediastinum and subcutaneous emphysema are rare in patients with ALL, authors strongly suggest clinicians consider them in any similar patients presenting respiratory signs/symptoms for faster onset of action.

A narrative review of primary spontaneous pneumomediastinum: a poorly understood and resource-intensive problem

Primary spontaneous pneumomediastinum (PSPM) is a benign self-limited condition that can be difficult to discriminate from esophageal perforation. This may trigger costly work-up, transfers and hospital admissions. To better understand this diagnostic dilemma and current management, we undertook the most comprehensive and up to date review of PSPM. The PubMed database was searched using the MeSH term "Mediastinal Emphysema"[Mesh], to identify randomized controlled trials, meta-analyses and case series (including 10 or more patients) relevant to the clinical presentation and management of patients with PSPM. There were no relevant randomized controlled trials or meta-analyses. Nineteen case series met our criteria, including a total of 535 patients. The average mean age was 23 years with a 3:1 male predominance. Chest pain was the most common symptom, found in 70.9% of the patients. Dyspnea and neck pain were the second and third most common symptoms, found in 43.4% and 32% of the patients, respectively. Subcutaneous emphysema was the most common sign (54.2%). Common histories included smoking (29.6%), cough (27.7%), asthma (25.9%), physical exertion (21.1%) and recent retching or emesis (13%). Nearly all patients (96.9%) underwent chest X-ray (CXR). Other diagnostic studies included computed tomography (65%) and esophagram (35.6%). Invasive studies were common, with 13% of patients undergoing esophagogastroduodenoscopy and 14.6% undergoing bronchoscopy. The rate of hospital admission was 86.5%, with an average length of stay of 4.4 days. No deaths were reported. Notably, we identified a dearth of information regarding the vitals, laboratory values and imaging findings specific to patients presenting with PSPM. We conclude that PSPM is a benign clinical entity that continues to present a resource-intensive diagnostic challenge and that data on the vitals, labs, and imaging findings specific to PSPM patients is scant. An improved understanding of these factors may lead to more efficient diagnosis and management of these patients.

Spontaneous Pneumomediastinum in an Adolescent Soccer Player

Spontaneous pneumomediastinum (SPM) is an uncommon and usually benign self-limiting clinical disorder found in young people, often without apparent precipitating factors or diseases. A pressure gradient exists between the peripheral pulmonary alveoli and the hilum, and increased intra-alveolar pressure causes rupture of the terminal alveoli. We present the case of a 15-year-old male soccer player who presented with a complaint of anterior chest pain and dysphagia after stopping the strong ball with his chest. His symptom gradually progressed over hours. We can make the diagnosis of SPM using by chest X-ray and computed tomography (CT) scanning. His symptoms were gradually resolved over the course of approximately one week with no exercise and careful observation. We believe that our case provides very useful information to alert clinicians and coaches regarding this rare disease that may occur in anyone including adolescent soccer players.

Spontaneous pneumomediastinum in H1N1 infection: uncommon complication of a common infection

H1N1 viral infection leads to complications, such as pneumonia, respiratory failure, myocarditis and encephalitis. Spontaneous pneumomediastinum (SPM) is an extremely rare consequence of H1N1 infection and such cases have been sparsely reported. SPM is identified only by a careful clinical examination and obtaining a timely roentgenogram. We report a case of a young male admitted with H1N1 infection complicated by pneumomediastinum. He was treated successfully with oseltamivir, high-flow oxygen and prompt care in the intensive care unit.

Spontaneous Pneumopericardium in a U.S. Marine: Do not Lose Heart

We report an unusual case of extensive subcutaneous emphysema, pneumomediastinum, and pneumopericardium identified in an otherwise healthy U.S. Marine who was enrolled in the Marine Corps School of Infantry. His training regimen included prolonged periods of yelling and elevation changes during sustained hiking through hilly terrain. The patient presented to the Fast Track with normal vital signs but complained of dyspnea, cough, and subjective fevers. Although he lacked a history of trauma, he was found to have pneumopericardium, pneumomediastinum, and subcutaneous emphysema without pneumothorax. He was admitted to the general surgery service for observation and was ultimately released back to his unit after 24 hours. To our knowledge, pneumopericardium has never been attributed to persistent yelling in the setting of a lower respiratory tract infection and should be considered in the differential of atraumatic chest symptomatology in otherwise healthy military service members.

Spontaneous pneumomediastinum: Experience in 13 patients

Spontaneous pneumomediastinum (SPM) is a rare clinical entity that concerns mainly young adults. We report 13 cases (11 males/2 females) of SPM. The average age was 31 ± 0.85 years. The most common precipitating factor was asthma attack. The onset symptoms were mainly chest pain (11 cases). Synchronous pneumothorax was found in 5 cases and it was bilateral in 2 patients. The evolution was marked by the spontaneous resorption. SMP is an underrecognized cause of chest pain in young adults. Chest radiography is usually sufficient for the diagnosis, and further diagnostic procedures are generally not necessary. The prognosis is often favorable.

Facial swelling and dysphonia during labour: a case of Hamman's syndrome

We present the case of a previously fit and well 30-year-old primiparous woman who developed Hamman's syndrome during the second stage of labour. This is an unusual and peculiar condition, characterised by spontaneous pneumomediastinum and subcutaneous emphysema. The rarity of the condition means it can easily be misdiagnosed. Its exact aetiology is unknown, but it is believed that extreme Valsalva manoeuvre during prolonged or difficult labours may contribute to its development. Chest X-ray is the first investigation of choice in this presentation, followed by CT scanning. Fortunately, it is usually a benign condition that can be managed conservatively and resolved quickly, with no long-term effects and low risk of recurrence in future pregnancies. We are pleased to say that this case does not differ in this respect. It is, however, important to rule other more serious pathologies that present in a similar way, for example, Boerhaave syndrome, pneumothorax or pulmonary embolism.

A Case of Spontaneous Pneumomediastinum with Subcutaneous Emphysema in Children

Spontaneous pneumomediastinum is defined as free air or gas contained within the mediastinum, which almost invariably originates from the alveolar space or the conducting airways. It is rare in pediatric patients; however, occasional cases are reported to result from forced Valsalva’s maneuver due to cough, emesis, a first attack of wheeze, or asthma exacerbations. We report the case of a 7-year-old previously healthy girl, with a history of persistent dry cough one day before, who was brought to our unit with face, neck and chest swelling. The chest X-ray and computed tomography (CT) scan showed subcutaneous emphysema with pneumomediastinum and pneumopericardium without evidence of the origin of this air leak. Laboratory tests and the bronchoscopy were normal. The patient was admitted in the pediatric critical care and received noninvasive monitoring, analgesia, oxygen, and omeprazole as a prophylaxis for a gastric ulcer. The patient improved, subcutaneous emphysema resolved, and she was discharged on the third day.

Spontaneous pneumomediastinum: Case presentation to a college student health clinic

The author describes a case of spontaneous pneumomediastinum (SPM) in a 19-year-old man presenting to a college student health clinic. The author also provides a review on SPM, including clinical manifestations, diagnostic evaluation, and management.

An Uncommon Cause of Spontaneous Pneumomediastinum and Subcutaneous Emphysema

A 79-year-old gentleman presented with spontaneous pneumomediastinum and subcutaneous emphysema with pneumonia but no pre-existing lung disease. He presented with a 4-day history of increased shortness of breath, pleuritic chest pain, fevers, and non-productive cough. After 4 days of intravenous antibiotics, the patient developed considerable subcutaneous emphysema and pneumomediastinum. Pneumomediastinum presents most commonly with chest pain, shortness of breath, and subcutaneous emphysema. It has previously been associated with cases of pneumonia but often with rare strains such as P. jirovecii pneumonia in immunocompromised patients. This case highlights spontaneous pneumomediastinum as a rare complication of pneumonia. Treatment of pneumomediastinum is typically conservative, and although options may be limited, aggressive management of any causative factor may be essential in selected cases.

LEARNING POINTS

Pneumomediastinum and subcutaneous emphysema are rare complications of pneumonia.Computerised tomography is a valuable diagnostic tool for identifying pneumomediastinum in patients with subcutaneous emphysema.While pneumomediastinum is typically a benign condition, aggressive management may occasionally be required. Evidence regarding use of non-invasive/invasive ventilation remains limited but it may theoretically aggravate any air leakage.

[Blunt chest trauma with pneumomediastinum and pneumoperitoneum secondary to Macklin effect. Case report]

BACKGROUND

Pneumomediastinum is the presence of free air around mediastinal structures, which may be spontaneous or secondary, and can occur in 10% of patients with blunt chest trauma, with the Macklin effect being its main pathophysiology.

CLINICAL CASE

A 21 year old male, hit by motor vehicle, with alvéolopalatal fracture and blunt chest trauma, who, 72 hrs after admission, shows subcutaneous emphysema in the anterior chest. A simple tomography of the chest and abdomen was performed, finding a pneumomediastinum, bilateral pulmonary contusions and pneumoperitoneum. Oesophageal, tracheobronchial or intra-abdominal viscera injuries were ruled out, establishing the cause of pneumomediastinum and pneumoperitoneum due to the Macklin effect. This required conservative management in intensive care unit, with a favourable clinical course and discharged after a 10 day hospital stay.

DISCUSSION

Macklin effect is caused by dissection of air medially along the bronchoalveolar sheath (interstitial emphysema), secondary to alveolar breakdown and extending into mediastinal and other anatomical structures (pneumoperitoneum). It has been documented in blunt trauma, as well as in acute asthma, positive pressure ventilation, or after Valsalva manoeuvres. The imaging method of choice is computed tomography, and its characteristic findings, interstitial emphysema adhering to a bronchus and pulmonary blood vessel.

CONCLUSIONS

In the presence of pneumomediastinum and pneumoperitoneum is necessary to rule out oesophageal and tracheobronchial injury before establishing the Macklin effect as its cause. The diagnosis is made with computed tomography and managed conservatively.

Spontaneous pneumomediastinum: Experience in 13 adult patients

BACKGROUND

Spontaneous pneumomediastinum is an uncommon disorder. There is a lack of information on spontaneous pneumomediastinum in India. We aimed to understand the clinical profile, hospital course, and long-term outcome of such patients.

METHODS

We retrospectively reviewed all patients (aged ≥15 years) diagnosed with spontaneous pneumomediastinum in the respiratory ward of a tertiary care hospital over a 7-year period from 2005.

RESULTS

Of the 3326 patients hospitalized during the study period, 13 (10 male) were diagnosed with spontaneous pneumomediastinum, constituting 0.39% of all hospitalizations. The median age was 37 years (interquartile range 20-55 years). The most common presenting symptom was dyspnea in 85% followed by neck swelling (69%), chest pain (69%) and cough (54%). Subcutaneous emphysema and preexisting lung diseases were identified in 11 (85%) patients each. Post-tubercular pulmonary sequelae (5 patients) and asthma (4 patients) were the most common underlying lung diseases. Pneumothorax was identified in 6 (46%) patients; 4 required tube thoracostomy. Chest radiography was diagnostic in 92% of patients. The median length of hospital stay was 9 days (interquartile range 6-12 days). No recurrence was reported in 11 patients followed up for a median of 1550 days (interquartile range 691-1909 days).

CONCLUSIONS

Spontaneous pneumomediastinum is a benign disorder, but underlying lung diseases and concomitant pneumothorax are likely to complicate the disease course. Exacerbation of post-tubercular obstructive airway disease is a common risk factor for spontaneous pneumomediastinum in a tuberculosis endemic country.

Spontaneous Pneumomediastinum: A Rare Disease Associated with Chest Pain in Adolescents

PURPOSE

Spontaneous pneumomediastinum (SPM) is a rare entity, with only a few cases reported, especially in adolescents. We aimed to analyze the clinical characteristics of SPM in adolescents and the diagnostic implications of computed tomography (CT) and esophagography therein.

MATERIALS AND METHODS

This retrospective descriptive study was conducted as a review of medical records of 416 adolescents (10-18 years of age) with chest pain from March 2005 to June 2013. Information on clinical presentation, methods of diagnosis, hospital stay, and outcomes were collected and analyzed.

RESULTS

Among adolescents complaining of chest pain, 11 patients had SPM (11/416, 2.64%). All patients presented with pleuritic chest pain, and 54.5% reported neck pain as the most common associated complaint. Clinical findings were nonspecific, and initial chest X-ray assessment was diagnostic only in three of 11 patients. However, reassessment of chest X-ray revealed diagnostic findings of SPM in five of the remaining eight patients. CT was diagnostic in all patients, while esophagography and echocardiogram were uninformative. Symptomatic improvement was noted within 2.45±1.2 hours (range, 0.5 to 4) after supportive care; mean hospital stay was 4.54±0.99 days (range, 2 to 6). No recurrence was observed.

CONCLUSION

SPM is a rare disease that should be considered in adolescent patients with pleuritic chest pain. Careful reading of initial chest X-rays is important to avoiding further unnecessary investigations. SPM is self-limited and treatment is supportive; nevertheless, if there are no indications of esophageal rupture, urgent esophagography is not recommended.

Pneumomediastinum as a complication of critical pertussis

BACKGROUND AND AIMS

Pertussis is a common and potentially serious disease affecting mainly infants and young children. In its non-classic presentation, pertussis can be clinically indistinguishable from other respiratory illnesses. Pertussis today often remains underdiagnosed in adults. Our aims was to report a complicated cases of pertussis.

RESULTS

A case of serologically confirmed pertussis occurred in an 18-year-old man presenting with pneumomediastinum, subcutaneous emphysema in the neck and chest, and persistent attacks of coughing with apnea that required treatment in the intensive care unit.

CONCLUSION

Pneumomediastinum and subcutaneous emphysema have never been described in adult patients with pertussis. Physicians should be aware that patients presenting with persistent cough and pneumomediastinum may have pertussis and include this in their differential diagnosis.

Pneumomediastinum

Pneumomediastinum is a condition in which air is present in the mediastinum. This condition can result from physical trauma or other situations that lead to air escaping from the lungs, airways or bowel into the chest cavity. Pneumomediastinum is a rare situation and occurs when air leaks into the mediastinum. The diagnosis can be confirmed via chest X-ray or CT scanning of the thorax. The main symptom is usually severe central chest pain. Other symptoms include laboured breathing, voice distortion (as with helium) and subcutaneous emphysema, specifically affecting the face, neck, and chest. Pneumomediastinum can also be characterized by the shortness of breath that is typical of a respiratory system problem. It is often recognized on auscultation by a "crunching" sound timed with the cardiac cycle (Hamman's crunch). Pnemomediastinum may also present with symptoms mimicking cardiac tamponade as a result of the increased intrapulmonary pressure on venous flow to the heart. The tissues in the mediastinum will slowly resorb the air in the cavity so most pneumomediastinums are treated conservatively.

Spontaneous pneumomediastinum and Macklin effect: Overview and appearance on computed tomography

Spontaneous pneumomediastinum (SPM) is described as free air or gas located within the mediastinum that is not associated with any noticeable cause such as chest trauma. SPM has been associated with many conditions and triggers, including bronchial asthma, diabetic ketoacidosis, forceful straining during exercise, inhalation of drugs, as well as other activities associated with the Valsalva maneuver. The Macklin effect appears on thoracic computed tomography (CT) as linear collections of air contiguous to the bronchovascular sheaths. With the recent availability of multidetector-row CT, the Macklin effect has been seen in the clinical setting more frequently than expected. The aim of this review article is to describe the CT imaging spectrum of the Macklin effect in patients with SPM, focusing on the common appearance of the Macklin effect, pneumorrhachis, and persistent SPM with pneumatocele.

Is primary spontaneous pneumomediastinum a truly benign entity?

OBJECTIVE

This study aimed to investigate the benignancy of primary spontaneous pneumomediastinum (PSP), and to establish an appropriate management strategy.

METHODS

Patients diagnosed with PSP between January 2003 and December 2013 were analysed retrospectively. From January 2013 onwards, a simplified protocol, with consensus for the management of PSP, was applied in our hospital.

RESULTS

In total, 37 patients were identified as having PSP during the study period. Among them, 27 were enrolled prior to applying the new protocol. Among these patients, extra diagnostic tests, in addition to chest radiography (CXR) and chest computed tomography (CT), were performed in 15 patients (55.5%). In the pre-protocol decade, a total of 15 patients (55.5%) were initially fasted and 16 (59.3%) were administered antibiotics. Mean hospital stay was 2.9 days (range, 0-5 days). No patient developed complications during the hospital stay and outpatient follow up. Since the revised protocol was in practical use, 10 consecutive patients with PSP were enrolled and reviewed. No additional diagnostic imaging studies or procedures (except for CXR and chest CT) were performed in these patients; furthermore, diet was not restricted and prophylactic antibiotics were not prescribed. Mean hospital stay was 14.5 h (range, 1-34 h). No complications were observed in any of the patients.

CONCLUSIONS

Our management protocol (i.e. routine check of chest CT without any additional diagnostic tests, no special treatment, and early discharge with short-term follow up) may be safe and feasible for the treatment of PSP.

Fatal pneumomediastinum associated with use of noninvasive mechanical ventilation

We present a case of fatal pneumomediastinum in a patient with acute respiratory failure caused by acute exacerbated chronic obstructive pulmonary disease (AECOPD) and interstitial lung disease (ILD) precipitated by noninvasive mechanical ventilation (NIMV). To our knowledge, this is the first case reported in the literature. NIMV is very useful to treat acute respiratory failure due to AECOPD improving survival and avoiding endotracheal intubation. Use of NIMV in end stage ILD is not standardized and efficacy is to be proven. No data are reported to manage patient with concomitant COPD and ILD. Pathophysiological mechanisms underlying this fatal complication are explained and suggestions to treat this subgroup of patients discussed.

Pneumothorax and asthma

This review is focused on the relationship between asthma, pneumothorax and pneumomediastinum while presenting a number of case reports that include these conditions. The association between pneumothorax and asthma is not widely known. While asthma includes a common disorder and is prevalent worldwide, its morbidity and mortality is high when is associated with pneumothorax. Furthermore, the delayed diagnosis of pneumothorax while focusing on asthma includes the higher risk of coincidental pneumothorax in asthmatic patients. In addition, pneumomediastinum is considered benign and self-limiting condition that responds to conservative therapy. Although it is rare, the concurrence of pneumomediastinum with pneumothorax may prove fatal during a serious asthma attack. In conclusion, the symptoms of chest pain, dyspnea or focal chest findings when presented in asthmatic patients, must always create suspicion of pneumothorax or pneumomediastinum to the physician.

Pneumomediastinum: etiology and a guide to diagnosis and treatment

BACKGROUND

Pneumomediastinum may be associated with mediastinal organ injury. The aim of this study was to identify predictive factors of mediastinal organ injury in patients with pneumomediastinum to guide diagnosis and treatment.

METHODS

A retrospective review was conducted including patients aged ≥18 years with Current Procedural Terminology code 518.1 (interstitial emphysema) from 2005-2011.

RESULTS

There were 279 of 343 patients (81%) with and 64 of 343 (19%) without history of trauma. In the trauma population, 13 patients (5%) were found to have mediastinal organ injuries, 10 (4%) had airway injuries, and 3 (1%) had esophageal injuries. In the nontrauma population, 36 patients (56%) had spontaneous pneumomediastinum, esophageal injuries were seen in 17 (27%), pneumothorax in 9 (14%), and airway injuries in 2 (3%). The predictors of esophageal injury were instrumentation (odds ratio [OR], 45.7; P < .0001), pleural effusion (OR, 10.5; P < .0001), and vomiting (OR, 9.3; P < .0001). Previous instrumentation was the most significant predictor of airway injury (OR, 9.05; P < .02).

CONCLUSIONS

Mediastinal organ injury in patients with pneumomediastinum is uncommon. Patients presenting with pneumomediastinum without a history of instrumentation, pleural effusion, or vomiting most commonly do not have mediastinal organ injuries.

Systematic review of spontaneous pneumomediastinum: a survey of 22 years' data

OBJECTIVE

To describe and clarify management protocols in relation to spontaneous pneumomediastinum, and try to integrate criteria on this subject.

BACKGROUND

Thoracic physicians are faced with patients who present with gas in the mediastinum, frequently without an obvious etiologic factor. Published material contains heterogeneous information from which different conclusions can be drawn.

METHODS

In a Medline search from 1990 to 2012, we collected data on mortality, morbidity, signs, symptoms, etiologic factors, and diagnostic methods. Standardized mean differences were calculated.

RESULTS

We identified 600 patients in 27 papers with series of >5 patients without precipitating or etiologic factors previous to the clinical presentation, but athletic activity, drug abuse, and history of asthma played an apparent role in the disease process. Most patients complained of thoracic pain and dyspnea, with subcutaneous emphysema and Hamman's sign. The most common complication was tension pneumothorax. Morbidity was seen in 2.8%; no mortality has been reported so far.

CONCLUSION

Spontaneous pneumomediastinum is a rare disease with a benign course, which should be treated conservatively unless a complication mandates an invasive procedure. An algorithm for diagnosis and treatment is offered, based on the available evidence.

Pneumomediastinum, pneumorachis, subcutaneous emphysema: An unusual complication of leukemia in a child

Pneumorrhachis (PR), or epidural emphysema, denotes the presence of air in the spinal epidural space. It can be associated with a variety of etiologies, including trauma; recent iatrogenic manipulations during surgical, anesthesiological and diagnostic interventions; malignancy and its associated therapy. It usually represents an asymptomatic epiphenomenon but also can be symptomatic by itself, as well as by its underlying pathology, and rarely can be fatal. The pathogenesis and etiology of PR are varied and can sometimes be a diagnostic challenge. As such, there are no standard guidelines for the management of symptomatic PR and its treatment is often individualized. Here, we present a case of a 14-year-old boy treated for leukemia who developed this complication and whether chemotherapy related or not, it proved to be fatal for him. To our knowledge, this is the first case in the literature of this complication with acute lymphoblastic leukemia.

Imaging presentation of complicated diabetic ketoacidosis: a case report

Spontaneous pneumomediastinum is a fairly uncommon complication of diabetic ketoacidosis. Knowledge of the clinical and radiographic manifestation is important for the proper management of patients since the disease usually follows a benign evolution. We report a case of a 20-year-old soldier who presented with a pneumomediastinum that was initially falsely attributed to a motor vehicular crash.

Head and neck manifestations of spontaneous pneumomediastinum

OBJECTIVE

Spontaneous pneumomediastinum (SPM) is a rare disease entity that often manifests localized signs in the head and neck region. The thoracic features of SPM have been well described; however, there is a paucity of information on its otolaryngological characteristics. The authors describe the clinical management among SPM patients having primarily head and neck symptoms.

STUDY DESIGN

Case series with chart review.

SETTING

Cathay General Hospital, Taiwan.

RESULTS

The study included 13 men and 1 woman, with a mean age of 18.8 years (range, 14-29 years). The primary initial symptoms were neck swelling (11), neck pain (10), and odynophagia (9). Neck soft tissue and chest radiography was diagnostic of SPM in all patients. Conservative treatment consisted of bed rest and analgesics, which led to rapid resolution of SPM.

CONCLUSIONS

SPM is a benign entity that responds well to conservative treatment. The results of our investigation highlight the importance of an ear, nose, and throat (ENT) clinical examination as a guide for diagnosing SPM because of the high percentage of ENT manifestations in the initial clinical profiles. Secondary causes of SPM must be ruled out to avoid an unfavorable outcome.

Spontaneous pneumomediastinum after kidney transplantation: case report

Spontaneous pneumomediastinum is a rare condition with nonspecific signs and symptoms. A 39-year-old underwent cadaver kidney transplantation. After an uncomplicated operation, progressive dyspnea of unknown origin developed. Findings at chest radiography suggested pneumomediastinum, which was confirmed at computed tomography. Esophageal or tracheal injury was ruled out. The rapidly developing atelectasis of the left lung necessitated urgent bronchoscopy, which revealed occlusion of the left main bronchus. After removal of the occluding mucus plug, the clinical symptoms immediately improved, and the spontaneous pneumomediastinum resolved within 3 days. Asymptomatic increase in airway secretions in patients receiving peritoneal dialysis may result in mucus plug formation during general anesthesia, which can cause spontaneous pneumomediastinum.

Spontaneous pneumomediastinum: a report of 2 cases

We report 2 cases of spontaneous pneumomediastinum (SPM) with clinical presentations similar to pericarditis, including positional chest pain, tachycardia, a precordial rub, and electrocardiographic changes. Chest radiography is the most commonly used imaging modality for diagnosis, but the findings may be subtle. In select patients, a more extensive diagnostic approach is warranted. Spontaneous pneumomediastinum is self-limiting, and the risk of recurrence is negligible. These cases serve to illustrate the need to include spontaneous pneumomediastinum in the differential diagnosis of pericarditis.

Spontaneous pneumomediastinum in adolescents and children

Pneumomediastinum, the leakage of air or gas into the mediastinum, can be a primary or secondary diagnosis. Although spontaneous pneumomediastinum (SPM) is uncommon in pediatric respiratory disorders, it is potentially life-threatening. In this study, we investigated the associations between various etiologies and clinical presentations, hospital length-of-stay, and clinical outcomes of SPM. From January 2004 to December 2007, we collected medical records and chest films from 23 pediatric patients with SPM. Results showed that increased hospital length-of-stay was significantly associated with asthma (p = 0.035), dyspnea/tachypnea (p = 0.01), and emergent visit (p = 0.04). Dysphagia was associated with shorter hospital stay (p = 0.058). Besides, the disorder was misdiagnosed initially in 21% of patients. In conclusion, there may be close relationships between the predisposing factors of SPM and its clinical manifestations. The high rate of misdiagnosis highlights the importance of careful examination and history taking in pediatric patients with chest pain.

Spontaneous pneumomediastinum (Hamman's syndrome)

INTRODUCTION

Spontaneous pneumomediastinum is defined as the presence of free air in the mediastium in the absence of any obvious precipitating cause. The purpose of this study was to review our experience with this condition, discuss mechanisms and provide a management algorithm.

METHODS

A retrospective audit of patients admitted with spontaneous pneumomediastinum between 2003 and 2008 was performed. A total of 17 patients were identified.

RESULTS

Common predisposing factors for spontaneous pneumomediastinum were alcohol excess, asthma and illicit drug use. Vomiting and coughing were common precipitating factors. There was no morbidity, mortality or recurrence. Patients were admitted under a number of different specialties.

DISCUSSION

Spontaneous pneumomediastinum is a benign self-limiting condition that requires early differentiation from more serious causes, in particular Boerhaave's syndrome.

Spontaneous pneumomediastinum: an algorithm for diagnosis and management

Spontaneous pneumomediastinum (SPM) is a rare disorder most often affecting young males which is generally self-limiting. Despite the benign prognosis with few complications and little morbidity, it frequently confuses clinicians in primary settings, who may have difficulty differentiating SPM from other serious organ ruptures, especially oesophageal rupture (the so-called Boerhaave syndrome), which may lead to mediastinitis and may be fatal, even with appropriate interventions. An overview of adult SPM is provided, reviewing 17 studies (414 patients), including our clinical experience, and finally an algorithm for diagnosis and management of SPM is proposed, based on the characteristics of SPM.

Secondary pneumomediastinum: a retrospective comparative analysis

Pneumomediastinum is an uncommon radiographic finding of potential clinical significance. Secondary pneumomediastinum (SPM) has a variety of etiologies that can lead to potentially morbid outcomes. There are limited data regarding the etiologies, diagnosis, and outcomes of this entity. A retrospective comparative study was conducted over an 11-year period of patients developing pneumomediastinum secondary to a specific pathologic or traumatic event. Forty-five patients were identified with an underlying condition resulting in SPM. Demographic data, radiologic findings, length of hospital stay, and mortality were recorded. Statistical comparison was conducted between patients with blunt thoracic trauma- and barotrauma-induced pneumomediastinum. Logistic and multiple linear regression analyses were performed to discover factors predictive of mortality and length of hospital stay. Median age of the patients was 40 years and 69% were men. Subcutaneous emphysema was identified in 44%, pneumothorax in 47%, and pleural effusion in 11%. Pneumomediastinum was identified by plain radiograph (CXR) in only 47% compared to 100% by computed tomogram (CT scan). Average length of hospital stay was 19 days and mortality was 38%. Patients with blunt thoracic trauma had a lower sensitivity for CXR to discover pneumomediastinum, were more likely to develop subcutaneous emphysema or pneumothorax, and had lower mortality and length of hospital stay compared with those with barotrauma-induced pneumomediastinum. Barotrauma was an independent predictor for hospital mortality. Secondary pneumomediastinum is a morbid condition with distinctive etiologies, radiologic findings, and outcomes. Barotrauma-induced pneumomediastinum is associated with a prolonged recovery and high mortality rate.

Spontaneous pneumomediastinum: analysis of 62 consecutive adult patients

OBJECTIVE

To clarify the clinical presentation and course of patients with spontaneous pneumomediastinum (SP) and to determine the usefulness of diagnostic testing in these patients.

PATIENTS AND METHODS

We conducted a retrospective review of 62 consecutive adult patients (age >or=18 years) diagnosed as having SP during an 11-year period from July 1, 1997, to June 30, 2008. The study cohort included 41 men and 21 women (median age, 30 years; interquartile range, 20-69 years).

RESULTS

Among the 62 study patients, the most common presenting symptoms were chest pain (39 patients [63%]), cough (28 [45%]), and dyspnea (27 [44%]). Preexisting lung diseases were identified in 27 patients (44%) and included interstitial lung disease, asthma, lung malignancies, bronchiolitis obliterans syndrome, chronic obstructive pulmonary disease, bronchiectasis, and cystic lung lesions. The initial diagnosis of SP was achieved by chest radiography in 52 patients (84%); the remaining cases were diagnosed by computed tomography. Forty-seven patients (76%) were hospitalized for a median duration of 2.5 days. Additional diagnostic procedures were performed in 27 patients (44%) and included contrast esophagography, bronchoscopy, and esophagogastroduodenoscopy; however, they did not yield a pathologic cause in any patient. Pneumothorax was identified in 20 patients (32%), but less than one-third of these patients underwent chest tube thoracostomy. No episodes of mediastinitis or sepsis occurred. Recurrence of SP was seen in 1 patient, and thoracoscopic surgery was performed in 1 patient for persistent air leak (pneumothorax).

CONCLUSION

Spontaneous pneumomediastinum was associated with a relatively benign clinical course; however, pneumothorax was seen in 32% of cases. Diagnostic testing to determine a pathologic cause yielded little clinically relevant information in these patients.

Spontaneous pneumomediastinum: diagnostic and therapeutic interventions

OBJECTIVES

The objective of this case series is to review our experience with spontaneous pneumomediastinum, review the available literature, and refine the current clinical approach to this uncommon condition.

METHODS

The case notes of all patients admitted to the George Washington University Medical Center with spontaneous pneumomediastinum from April 2005 to June 2008 were retrospectively reviewed, indentifying seventeen patients on whom various data was collected and analyzed.

RESULTS

The typical patient is a young man. The commonest presenting complaint is chest pain. Odynophagia and subcutaneous emphysema are common. Leucocytosis is uncommon. The need for swallow studies, antibiotics, and prolonged hospitalization is uncommon. Most patients have no recurrences or sequelae on long-term follow-up.

CONCLUSION

Spontaneous pneumomediastinum is an uncommon, self-limiting condition. Due to concerns for the integrity of the aero-digestive tract, the finding of spontaneous pneumomediastinum usually results in unnecessary radiological investigations, dietary restriction and antibiotic administration with prolonged hospitalization.

Spontaneous pneumomediastinum: a comparative study and review of the literature

BACKGROUND

Spontaneous pneumomediastinum (SPM) is an unusual occurrence with few cases reported. It is seen after intrathoracic pressure changes leading to alveolar rupture and dissection of air along the tracheobronchial tree. This study was undertaken to provide a thorough clinical and radiologic analysis of this patient population.

METHODS

A retrospective comparative analysis was performed on patients with SPM over 12 years. Patient demographics, clinical presentation, and radiographic and diagnostic studies were recorded. A clinical and radiologic comparison was performed with secondary pneumomediastinum.

RESULTS

Seventy-four patients were identified with a diagnosis of pneumomediastinum. A total of 28 patients with SPM were identified. The major initial complaints were chest pain (54%), shortness of breath (39%), and subcutaneous emphysema (32%). The main triggering events were emesis (36%) and asthma flare-ups (21%). No apparent triggering event was noted in 21% of patients. Chest radiograph was diagnostic in 69%; computed tomography was required in 31%. Esophagram, esophagoscopy, and bronchoscopy were performed on an individual basis and were invariably negative. When compared with secondary pneumomediastinum, SPM is more likely to be discovered by chest radiography, has a lower incidence of pneumothorax and pleural effusion, requires a shorter hospital stay, and has no associated mortality.

CONCLUSIONS

Spontaneous pneumomediastinum is a benign condition that often presents with chest pain or dyspnea. It can develop without a triggering event and with no findings on chest radiography. Treatment is expectant and recurrence is low. Secondary causes must be ruled out to avoid an unfavorable outcome.

Management of spontaneous pneumomediastinum based on clinical experience of 25 cases

STUDY OBJECTIVES

Spontaneous pneumomediastinum (SPM) is a rare disorder that usually occurs in young individuals and has a self-limiting course and no recurrence in most cases. But actually in many cases, patients are undergo some examinations or some limitations. The purpose of this study was to evaluate the clinical characteristics and recommend appropriate management of SPM.

DESIGN

Retrospective research of clinical records of a single institution.

RESULTS

Over 11 years, we diagnosed 25 patients (18 males) with SPM. Their average age was 20.1 years (range 13-28 years). Chest pain or neck symptoms were most frequent, and 17 patients (68%) had subcutaneous emphysema. In all cases, blood counts and C-reactive protein (CRP) were measured, and their mean values were 10,100+/-4600/mm(3) and 1.0+/-1.5 mg/dL, respectively. In 20 patients (80%), either leucocytosis or elevated CRP was observed. Twenty-four patients (96%) were admitted (average 7.8+/-4.1 days) and 20 of them were prescribed antibiotics or limited oral intake. The symptoms were self-limiting in all cases and disappeared on average 1.8+/-0.9 days after diagnosis. No recurrence was noted in the approximately 2 years follow-up period.

CONCLUSION

SPM is a self-limiting disease with mild inflammatory signs. For patients suspicious of SPM, shortened hospitalization for about 2 days with observation alone may be feasible, if their symptoms improve gradually. Otherwise, less invasive procedures, such as esophagram, should be performed immediately. Long-term follow-up is usually unnecessary. We propose a new algorithm for management of SPM based on clinical experience.