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

Spontaneous Pneumomediastinum: A Narrative Review Offering a New Perspective on Its Definition and Classification

Pneumomediastinum is the abnormal presence of air in the mediastinum. It is typically classified into two types: spontaneous (occurring without any underlying lung disease) and secondary (resulting from various conditions, including trauma). The most common clinical symptoms include retrosternal chest pain, difficulty breathing, subcutaneous emphysema in the neck or chest, and, in some cases, Hamman's sign, which involves crackles that occur in sync with the heartbeat. This study has two main objectives: first, to assess whether there is consistency between the definition of spontaneous pneumomediastinum presented by the authors and the description provided in their articles, and second, to evaluate whether the classification of spontaneous pneumomediastinum aligns with its definition. We conducted a literature search using PubMed, Google Scholar, and the Springer Journal Archive databases.

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.

A Case of Pneumomediastinum and Pneumorrhachis in a Patient With Multiple Risk Factors

Pneumomediastinum is the presence of gas (usually air) in the mediastinum, which is rare and typically benign. Pneumomediastinum is classified into primary and secondary based on etiology. Its pathophysiology is due to high intra-alveolar pressures causing alveolar rupture, which releases air that travels along bronchoalveolar sheaths into the mediastinum. Pneumomediastinum may also be concurrently seen with pneumorrhachis defined as air in the spinal canal, although this finding is rare. Here, we present the case of a 27-year-old male with a past medical history of polysubstance use and a one-week history of nausea, vomiting, and chest pain who presented with frostbite and was found to have pneumomediastinum and pneumorrhachis.

Pneumomediastinum and pneumothorax in coronavirus disease-2019: Description of a case series and a matched cohort study

OBJECTIVE

To describe the characteristics of COVID-19 patients with pneumothorax and pneumomediastinum (PTX/PM) and their association with patient outcomes.

PATIENTS AND METHODS

Adults admitted to five Mayo Clinic hospitals with COVID-19 between 03/2020-01/2022 were evaluated. PTX/PM was defined by imaging. Descriptive analyses and a matched (age, sex, admission month, COVID-19 severity) cohort comparison was performed. Hospital mortality, length of stay (LOS), and predisposing factors were assessed.

RESULTS

Among 6663 patients, 197 had PTX/PM (3 %) (75 PM, 40 PTX, 82 both). The median age was 59, with 71 % males. Exposure to invasive and non-invasive mechanical ventilation and high-flow nasal cannula before PTX/PM were 42 %, 17 %, and 20 %, respectively. Among isolated PTX and PM/PTX patients 70 % and 53.7 % underwent an intervention, respectively, while 96 % of the PM-only group was followed conservatively.A total of 171 patients with PTX/PM were compared to 171 matched controls. PTX/PM patients had more underlying lung disease (40.9 vs. 23.4 %, p < 0.001) and lower median body mass index (BMI) (29.5 vs. 31.3 kg/m2, p = .007) than controls. Among patients with available data, PTX/PM patients had higher median positive end-expiratory and plateau pressures than controls; however, differences were not significant (10 vs. 8 cmH2O; p = 0.38 and 28 vs. 22 cmH2O; p = 0.11, respectively). PTX/PM patients had a higher odds of mortality (adjusted odds ratio [95%CI]: 3.37 [1.61-7.07]) and longer mean LOS (percent change [95%CI]: 39 [9-77]) than controls.

CONCLUSION

In COVID-19 patients with similar severity, PTX/PM patients had more underlying lung disease and lower BMI. They had significantly increased mortality and LOS.

Spontaneous Pneumomediastinum Induced by a Combination of Flu-A Infection and E-cigarettes: A Case Report

Pneumomediastinum (PM) and subcutaneous emphysema are characterized by extra-alveolar air within the mediastinum and subcutaneous tissue. PM may occur spontaneously or due to trauma or an underlying airway disease. Spontaneous pneumomediastinum (SPM) may be caused by intractable vomiting, forceful coughing, child birthing, or performing a Valsalva maneuver. However, there are limited studies or case reports that present a combination of influenza A infection and electronic cigarette (e-cigarette)-induced SPM. This case report presents SPM in a previously healthy 20-year-old female with untreated influenza A infection and a history of e-cigarette use who presented to the emergency department with fever, cough, chest pain, dyspnea, and vomiting. Her physical examination was significant for neck tenderness, subcutaneous neck crepitus, and increased respiratory effort. Diagnostic evaluation included a chest X-ray and chest computed tomography that revealed PM with subcutaneous emphysema extending into the neck, as well as a negative Gastrografin study. She was treated conservatively and discharged after two days, with a follow-up scheduled at a pulmonary clinic. This case report highlights the need for a detailed substance use history, particularly e-cigarette use, when determining the etiology of SPM in a previously healthy patient. Management for SPM is conservative and should include addressing underlying etiologies with special attention to cessation and education of e-cigarettes and illicit substances.

CT esophagogram in the emergency setting: typical findings and suggested workflow

PURPOSE

Esophageal perforation (EP) can be a diagnostic challenge. Computed tomography (CT) and CT esophagography (CTE) are often used to rule out EP in the emergency setting with promising diagnostic performance, but the standard of care remains fluoroscopic esophagography (FE). We assess the diagnostic performance of CT and CTE when interpreted by expert and generalist radiologists and created an imaging workflow guide.

METHODS

Retrospective study of patients presenting with suspected EP. Two expert radiologists independently reviewed blinded CT/CTE studies, recorded CT findings, and assigned an esophageal injury grade. We also collected initial (general radiologist) CT findings and interpretation and FE diagnoses. We assessed inter-reader reliability and diagnostic performance.

RESULTS

EP was diagnosed in 46/139 (33%) encounters. The most common CT/CTE findings in EP were esophageal wall thickening (46/46, 100%), pneumomediastinum (42/46, 91%), and mediastinal stranding (39/46, 85%). CT and CTE sensitivity for detecting EP was 89% and 89% for expert radiologists, respectively, and 79% and 82% for general radiologists, compared with 46% for FE. Inter-reader agreement for detecting EP by CT and CTE was kappa 0.35 and 0.42 (both p < .001) between expert and generalist radiologists. We present radiographic images for key CT/CTE findings and a suggested workflow for the evaluation of possible EP.

CONCLUSION

CT and CTE are more sensitive than FE for EP in the emergency setting. Due to the rarity of EP and current wide variability in imaging interpretation, an imaging workflow and injury grading system based on esophageal and mediastinal CT findings are offered to help guide management.

A clinical review of spontaneous pneumomediastinum

Primary spontaneous pneumomediastinum is a rare, often benign and self-limited condition defined by air within the mediastinum. However, correctly distinguishing primary spontaneous pneumomediastinum from secondary causes, especially esophageal perforation, remains a diagnostic challenge. There is significant debate regarding the balance of completing a thorough but not overly invasive and costly diagnostic workup. This clinical review aims to gather the limited data regarding spontaneous pneumomediastinum management from case series and retrospective cohort studies, and presents an evaluation algorithm and treatment plan stratified by clinical history. Understanding specifically if the patient presents with coughing versus forceful vomiting is critical to help elucidate the etiology and guide management of pneumomediastinum. Patients who present with forceful vomiting or retching should be considered with higher degree of suspicion for secondary causes of pneumomediastinum, specifically esophageal perforation. However, especially in children, aggressive diagnostic workup is not warranted in every case. After ruling out other etiologies of pneumomediastinum, spontaneous pneumomediastinum can be commonly treated with symptomatic management without the aggressive use of antibiotics or diet restriction. Hospital length of stay may also be minimized on a case-by-case basis. Overall, recurrence of spontaneous pneumomediastinum is rare and outpatient follow up may be safely limited to those at highest risk of recurrence.

A Case Report of Spontaneous Pneumomediastinum From an Unusual Cause: Baritone Practice

Spontaneous pneumomediastinum (SPM) is a rare but potentially life-threatening clinical entity in which free air is introduced into the mediastinum. It most commonly presents in young males and has an incidence of approximately 0.002% of the general population. Symptoms include sudden onset chest pain, dyspnea, neck pain, vomiting, and odynophagia. Physical examination usually reveals subcutaneous emphysema, hoarse voice, tachycardia, tachypnea, and occasionally a Hamman's sign, which is a mediastinal "crunch" sound heard on cardiac auscultation. We present a case of an 18-year-old male baritone player who presented to the ED with chest pain and odynophagia shortly after waking up one morning. The patient's chest radiograph (CXR) revealed free air in the mediastinum with subcutaneous air tracking into the soft tissues of the neck and supraclavicular region. CT of the chest with contrast esophagram confirmed the diagnosis of primary SPM. The cause of his condition was likely due to barotrauma secondary to playing the baritone in his marching band. He had no evidence of esophageal injury or infectious process which further supports the diagnosis of primary SPM. After an extensive workup, the patient was discharged from the ED with instructions on rest, analgesia, and antitussives as needed. Evaluation of chest pain patients in the ED should include a CXR, in addition to other indicated tests, to rule out this potentially debilitating condition. Fortunately, though SPM is potentially life-threatening, most cases resolve spontaneously without surgical intervention.

Spontaneous Pneumomediastinum: A Rare Cause of Chest Pain

Spontaneous pneumomediastinum is a rare medical condition characterized by the presence of free air in the mediastinum, not preceded by trauma, surgery, or another medical procedure. It predominantly affects young adult males and usually has a benign course, and in most cases, it is not possible to identify the precipitating factor. There are some conditions that predispose to its occurrence, namely those that lead to an increase in intrapleural pressure, such as coughing, vomiting, or vigorous exercise. We report a case of a 21-year-old male who presented with acute-onset shortness of breath after an episode of coughing and was found to have mediastinal and subcutaneous emphysema. Clinical, laboratory, and radiological studies did not demonstrate any predisposing factor, and the case was classified as spontaneous pneumomediastinum.

Pneumomediastinum: Experience with 87 Patients

OBJECTIVE

The aim of the present series was first to present our experience in the management of 37 patients with spontaneous pneumomediastinum (SPM), and further to indicate the necessity of identifying true SPM cases as they are currently inadequately defined.

METHODS

This is a single-center, retrospective study, conducted in a university hospital. Consecutive adult patients with pneumomediastinum (PM) between January 2009 and March 2020 were involved in the series. The data about age, gender, symptoms, signs, treatment, length of hospital stay (LOS), and in-hospital mortality were evaluated.

RESULTS

In total, 87 cases with pneumomediastinum (37 with spontaneous and 50 with secondary PM) were analyzed. Patients in both groups were of similar ages (P=0.4). Sufferers with secondary PM were more likely to have: an associated pneumothorax (19% vs 58%, P<0.05), a chest tube placed (18.9% vs 58%, P<0.05), an associated pleural effusion (0% vs 18%, P<0.05). They presented with a longer LOS (3.9 vs 5.3 days, P<0.05), and were more likely to die (0% vs 10%, P<0.05). Additionally they showed a higher prevalence of radiologic subcutaneous emphysema (49% vs 74%, P<0.05).

CONCLUSION

Spontaneous pneumomediastinum is an onset of clinical importance with a low mortality rate, short LOS and good longterm prognosis. It often presents with chest pain, dyspnea and/or subcutaneous emphysema. However, secondary causes of mediastinal air must be ruled out, due to their potential devastating outcome if not diagnosed promptly. A consensus aimed at an update of the classification guidelines is more than indispensable.

Primary spontaneous pneumomediastinum: 237 cases in a single-center experience over a 10-year period and assessment of factors related with recurrence

OBJECTIVE

To evaluate the precipitating factors and symptoms of primary spontaneous pneumomediastinum (PSPM) and to assess the factors related with recurrent spontaneous pneumomediastinum (RSPM).

METHODS

From 2010 to 2021, 237 PSPM patients were included in this retrospective study. Clinical information including in-hospital periods, morbidity, mortality, presenting symptoms, precipitating events, smoking, and asthma history was obtained. The patients with smoking history were subdivided into "ex-smoker" or "current smoker". The severity of asthma was categorized into "mild intermittent", "mild persistent", "moderate persistent", or "severe persistent". During follow-up, patients with RSPM were classified into "recurrence" group and the others were into "no recurrence" group. Multivariate regression analysis was used to elucidate the associated factors with RSPM.

RESULTS

The mean age of study patients (men: women = 222: 15) was 23.4 years and mean period of hospital stay was 7.5 days. There was no mortality and morbidity. Most frequent symptom and precipitating factor were acute chest pain (n = 211, 89.0%) and cough (n = 72, 30.4%), respectively. RSPM occurred in 11 patients (4.6%). The proportion of patients with smoking (72.8% vs. 37.1%, p = 0.010) or asthma (81.8% vs. 39.8%, p<0.001) was significantly higher in "recurrence" group than "no recurrence" group. On multivariate analysis, asthma was the only factor associated with RSPM (mild intermittent/persistent, OR = 7.092, p = 0.047; moderate persistent, OR = 8.000, p = 0.011).

CONCLUSION

PSPM is a benign disease with no morbidity and mortality. Asthma may be the associated factor with RSPM; thus, despite the low rate of recurrence, patients with asthma should be informed about the chance of RSPM.

Utility of fluoroscopic oesophagography in the setting of spontaneous and blunt traumatic pneumomediastinum

AIM

To determine the incidence of positive fluoroscopic oesophagography in patients presenting with spontaneous or blunt traumatic pneumomediastinum.

MATERIALS AND METHODS

Retrospective chart review was performed on patients who underwent fluoroscopic oesophagography for spontaneous or blunt traumatic pneumomediastinum between 2001-2019. Patients were excluded for history of oesophageal surgery, penetrating trauma, oesophageal cancer, or tracheal/oesophageal instrumentation.

RESULTS

Two hundred and fifty-two patients met the inclusion criteria; 170 presented with spontaneous pneumomediastinum and 82 presented with blunt traumatic pneumomediastinum. Fluoroscopic oesophagography was positive in eight patients with spontaneous pneumomediastinum, for a positivity rate of 4.7% (8/170). There was one false-negative case in a patient who presented with spontaneous pneumomediastinum and was found to have a non-full-thickness oesophageal injury on endoscopy. Fluoroscopic oesophagography was negative in all patients with blunt traumatic pneumomediastinum (0/82). The sensitivity and specificity of fluoroscopic oesophagography were 88.9% (8/9) and 100% (243/243), respectively. Oesophageal injury was more common in patients with spontaneous pneumomediastinum and a pleural effusion (5/11, 45.4%) than in patients with spontaneous pneumomediastinum and no pleural effusion (4/159, 2.5%, p<0.001).

CONCLUSION

The present findings do not support routine oesophagography in patients with blunt traumatic pneumomediastinum. Conversely, a positivity rate of 4.7% in patients with spontaneous pneumomediastinum suggests oesophagography may be warranted in this population, particularly if an associated pleural effusion is present.

Dedicated esophageal imaging may be unnecessary in marijuana-associated spontaneous pneumomediastinum: Findings from a retrospective cohort study

Background

Marijuana use has become more common since its legalization, as have reports of marijuana-associated spontaneous pneumomediastinum. Non-spontaneous causes such as esophageal perforation are often ruled out on presentation due to the severe consequences of untreated disease. Here we seek to characterize the presentation of marijuana-associated spontaneous pneumomediastinum and explore whether esophageal imaging is necessary in the setting of an often benign course and rising healthcare costs.

Materials and Methods

Retrospective review was performed for all 18-55 year old patients evaluated at a tertiary care hospital between 1/1/2008 and 12/31/2018 for pneumomediastinum. Iatrogenic and traumatic causes were excluded. Patients were divided into marijuana and control groups.

Results

30 patients met criteria, with 13 patients in the marijuana group. The most common presenting symptoms were chest pain/discomfort and shortness of breath. Other symptoms included neck/throat pain, wheezing, and back pain. Emesis was more common in the control group but cough was equally prevalent. Leukocytosis was present in most patients. Four out of eight of computed tomography esophagarams in the control group showed a leak requiring intervention, while only one out of five in the marijuana group showed even a possible subtle extravasation of contrast but this patient ultimately was managed conservatively given the clinical picture. All standard esophagrams were negative. All marijuana patients were managed without intervention.

Discussion

Marijuana-associated spontaneous pneumomediastinum appears to have a more benign clinical course compared to non-spontaneous pneumomediastinum. Esophageal imaging did not change management for any marijuana cases. Perhaps such imaging could be deferred if clinical presentation of pneumomediastinum in the setting of marijuana use is not suggestive of esophageal perforation. Further research into this area is certainly worth pursuing.

Spontaneous pneumomediastinum in a young adult female

Spontaneous pneumomediastinum is characterized by the accumulation of air in the mediastinum with no identified cause. It is a rare and self-limiting condition. We report the case of a 32-year-old female patient with controlled bronchial asthma, who presented with spontaneous pneumomediastinum, with no precipitating event. The evolution is generally benign and the treatment is conservative. Symptomatic medication may be instituted.

Spontaneous pneumomediastinum and subcutaneous emphysema after masturbation

Spontaneous pneumomediastinum is a rare condition that mostly affects young men and generally follows a benign and self-limiting course. In contrast to secondary pneumomediastinum, which is caused by trauma, iatrogenic intervention or esophageal perforation, spontaneous pneumomediastinum is triggered by violent coughing, excessive vomiting, strenuous physical exercise or Valsalva maneuver. It results from an abrupt increase in intrathoracic pressure leading to alveolar rupture and air leak along the tracheobronchial tree into the mediastinal cavity. Extended spontaneous pneumomediastinum goes along with subcutaneous emphysema of the chest, neck or head. We present a case of a healthy young man who developed pneumomediastinum and profound subcutaneous emphysema with onset during masturbation. Since there is no literature on spontaneous pneumomediastinum associated with autoerotic experiences, we consider our case an unusual presentation of this entity.

[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.

Cycling-induced recurrent spontaneous pneumomediastinum and pneumopericardium in a young female patient

We present an exceptional case of recurrent cycling-induced spontaneous pneumomediastinum and pneumopericardium in a female patient without any trauma. Radiological and endoscopic examinations were carried out to exclude other differential diagnoses. Decision for in-hospital observation and conservative treatment was made. No symptoms were reported 12 months after return to sports activity.