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.

BACKGROUND: With the prevalence of coronavirus disease 2019 (COVID-19), many severe cases have been discovered worldwide. Here, a case of concurrent pneumomediastinum, pneumoretroperitoneum, and intestinal perforation was reported. This case was the first report on COVID-19-induced related complications.
METHODS: A 74-year-old female patient was hospitalized for COVID-19. Air leakage was unexpectedly found during imaging reexamination. Considering the unobvious subjective feeling of the patient, a conservative treatment was given at the early stage, and finally, sigmoid colon perforation was surgically confirmed. The family gave up the treatment at last, because the patient could not be taken off the ventilator. Coincidentally, the patient also had abnormal renal anatomical position. This situation led to an abnormal air leakage direction and the atypical manifestations of peritonitis. It was also one of the important reasons for the delayed diagnosis and treatment of the disease.
CONCLUSIONS: Clinicians should be vigilant for spontaneous gastrointestinal perforation in patients with COVID-19, particularly those undergoing treatment with glucocorticoids and tocilizumab. The case is shared to highlight this rare and fatal extrapulmonary manifestation of COVID-19 and further assist clinicians to raise their awareness and timely implement imaging investigation and multidisciplinary intervention so as to facilitate early discovery, diagnosis and treatment and reduce the mortality.

UNASSIGNED: To investigate the short-term changes in chest CT images of low-altitude populations after entering a high-altitude environment.
UNASSIGNED: Chest CT images of 3,587 people from low-altitude areas were obtained within one month of entering a high-altitude environment. Abnormal CT features and clinical symptoms were analyzed.
UNASSIGNED: Besides acute high-altitude pulmonary edema, the incidence of soft tissue space pneumatosis was significantly higher than that in low-altitude areas. Pneumatosis was observed in the mediastinum, cervical muscle space, abdominal cavity, and spinal cord epidural space, especially the mediastinum.
UNASSIGNED: In addition to acute high-altitude pulmonary edema, spontaneous mediastinal emphysema often occurs when individuals in low-altitude areas adapt to the high-altitude environment of cold, low-pressure, and hypoxia. When the gas escapes to the abdominal cavity, it is easy to be misdiagnosed as gastrointestinal perforation. It is also not uncommon for gas accumulation to escape into the epidural space of the spinal cord. The phenomenon of gas diffusion into distant tissue space and the mechanism of gas escape needs to be further studied.

We aimed to determine the clinical characteristics of patient self-inflicted lung injury (P-SILI)-associated pneumothorax/pneumomediastinum, to reveal its risk factors, and to assess its impact on severe COVID-19 cases. In total, 229 patients were included in this case-control study. They were randomly divided into either the case group or the control group as per the inclusion and exclusion criteria. The two groups were further analyzed to reveal the risk factors of spontaneous pneumothorax/pneumomediastinum (SP/P). Finally, risk factors for death were analyzed in the case group and the relationship between death and SP/P was also analyzed among all patients. The mean age of patients was 59.69 ± 17.01 years, most of them were male (74.2%), and 62.0% of them had comorbidities upon admission. A respiratory rate higher than 30 BPM was a risk factor for SP/P (OR 7.186, 95% CI 2.414-21.391, P < 0.001). Patients with delayed intubation due to early application of HFNC or NIV had a higher mortality rate when they developed SP/P (P < 0.05). Additionally, advanced age increased the risk of death (P < 0.05). Finally, SP/P may be a risk factor for death among patients with severe COVID-19 (OR 2.047). P-SILI occurs in severe COVID-19 with acute respiratory failure. It is necessary to identify the risk factors of P-SILI, the indicators of severe P-SILI, and the preventive measures.

Cerebral gas embolism is an unusual but extremely serious condition that occurs when air is introduced into the arterial or venous circulation of the brain. Although rare, it can lead to significant neurological deficits and even the death of the patient.
76-year-old patient with pre-existing diffuse interstitial lung disease, who experienced a massive stroke due to spontaneous pneumomediastinum. Her presentation included confusion, seizures, and motor weakness. Imaging tests revealed air bubbles in the cerebral sulci and hypodense areas in the cerebellum and parietooccipitals. In addition, pneumothorax and air in the upper mediastinum were noted on chest radiographs and chest CT scan. Despite therapeutic measures such as hyperbaric oxygen, the patient unfortunately died due to multiple organ failure.
The diagnosis of cerebral gas embolism generally involves performing a cerebral computed tomography, which is highly sensitive for detecting the presence of air in the cerebral vessels. Management includes monitoring of vital and neurological signs, as well as specific measures such as airway closure, venous catheter aspiration, Trendelenburg positioning, and hyperbaric oxygen.
Cerebral gas embolism is a potentially fatal condition that requires a brain computed tomography for diagnosis and it is vitally important to know the prevention measures to avoid the appearance of this complication and also to know the general measures to adopt when it occurs.
La embolia gaseosa cerebral es una afección inusual pero extremadamente grave que se produce cuando se introduce aire en la circulación arterial o venosa del cerebro. Aunque poco común, puede derivar en déficits neurológicos significativos e incluso la muerte del paciente.
Paciente de 76 años con una enfermedad pulmonar intersticial difusa preexistente, que experimentó un ictus masivo debido a un neumomediastino espontáneo. Su presentación incluyó confusión, convulsiones y debilidad motora. Las pruebas de imagen revelaron burbujas de aire en los surcos cerebrales y áreas hipodensas en el cerebelo y parietooccipitales. Además, se observó neumotórax y aire en el mediastino superior en las radiografías de tórax y la tomografía torácica. A pesar de las medidas terapéuticas como el oxígeno hiperbárico, la paciente lamentablemente falleció debido al fallo multiorgánico.
El diagnóstico de embolia gaseosa cerebral generalmente implica la realización de una tomografía computarizada cerebral, que es altamente sensible para detectar la presencia de aire en los vasos cerebrales. El manejo incluye el control de las constantes vitales y neurológicas, así como medidas específicas como cierre de la entrada de aire, aspiración de catéteres venosos, posicionamiento de Trendelenburg y oxígeno hiperbárico.
La embolia gaseosa cerebral es una afección potencialmente mortal que requiere una tomografía computarizada cerebral para el diagnóstico y de vital importancia conocer las medidas de prevención para evitar la aparición de esta complicación y así mismo conocer las medidas generales a adoptar cuando ésta se presenta.

BACKGROUND: We present a unique case of rhinolalia as the first recognizable sign of spontaneous pneumomediastinum and surgical emphysema following drug use.
METHODS: This case presents a 17-year-old white male experiencing rhinolalia following ecstasy ingestion at a rave. Subsequent chest X-ray revealed extensive surgical emphysema, along with a continuous diaphragm sign indicative of pneumomediastinum. Computed tomography confirmed the diagnosis. The patient was managed conservatively with strict monitoring and 6 hourly electrocardiograms. Follow-up computed tomography on day 3 showed resolution of pneumomediastinum and surgical emphysema, and the patient was safely discharged. Notably, the patient experienced a temporary rhinolalia during the acute phase, which resolved spontaneously as his condition improved.
CONCLUSIONS: This case underscores the importance of considering spontaneous pneumomediastinum and surgical emphysema in the differential diagnosis of young individuals presenting with acute symptoms after drug use.

BACKGROUND: Pneumomediastinum and pneumorrachis are rare complications following epidural analgesia, that can either be asymptomatic or rarely can produce mild to moderate severity symptoms. Most reported cases regarding the presentation of these two entities with epidural analgesia concern asymptomatic patients, however there are cases reporting post-dural puncture headache and respiratory manifestations.
METHODS: We present a case where a combined lumbar epidural and spinal anesthesia was performed using the loss of resistance to air technique (LOR), on a 78-year-old Greek (Caucasian) male undergoing a total hip replacement. Despite being hemodynamically stable throughout the operation, two hours following epidural analgesia the patient manifested a sudden drop in blood pressure and heart rate that required the administration of adrenaline to counter. Pneumomediastinum, pneumorrachis and paravertebral soft tissue emphysema were demonstrated in a Computed Tomography scan. We believe that injected air from the epidural space and surrounding tissues slowly moved towards the mediastinum, stimulating the para-aortic ganglia causing parasympathetic stimulation and therefore hypotension and bradycardia.
CONCLUSIONS: Anesthesiologists should be aware that epidural analgesia using the LOR to technique injecting air could produce a pneumomediastinum and pneumorrachis, which in turn could produce hemodynamic instability via parasympathetic stimulation.

UNASSIGNED: Tracheal rupture is a very rare but life-threatening complication of endotracheal intubation. It is more common in women and patients older than 50 years old. Overinflation of endotracheal tube cuff and tracheal wall weakening are the most important pathogenetic mechanisms. Laceration sites are located in the posterior membranous wall in most cases. Subcutaneous and mediastinal emphysema and respiratory distress are the most common manifestations. A 55-year-old female presented with postoperative subcutaneous and mediastinal emphysema without dyspnea because of a tear in the posterior tracheal wall. The diagnosis was based on clinical manifestation, chest computer tomography scans (CT), and endoscopic findings. A conservative approach by broad-spectrum antibiotic therapy was decided because of patients\' vital signs stability and the absence of esophageal injury. The follow-up showed that there was no lesion in the posterior tracheal wall. Our case showed that in clinically stable patients without mediastinitis and with spontaneous breathing, conservative management of tracheal tears is a safe procedure.

A man in his 30s presented to the emergency department with a history of injury to the face with a crowbar. He was discharged from the department, in the absence of any facial bone fractures and given normal examination findings, except for a puncture wound on the mentum. The patient then re-presented within 24 hours with extensive cervical emphysema extending into the mediastinal cavity.He was referred to ear, nose and throat team for further management. CT scan of the chest and neck showed extensive surgical emphysema and a pneumomediastinum. The patient was managed conservatively and recovered well with no significant sequelae.Even in the absence of facial bone fractures, it is imperative to understand the force of impact which should prompt a consideration of imaging of the chest. Appropriate advice regarding avoidance of Valsalva manoeuvres will help prevent extensive propagation of air through the fascial planes that can result in a pneumomediastinum.

BACKGROUND: Gas extravasation complications arising from perforated diverticulitis are common but manifestations such as pneumoperitoneum, pneumoretroperitoneum, and pneumomediastinum happening at the same time are exceedingly rare. This case report explores the unique presentation of these 3 complications occurring simultaneously, their diagnosis and their management, emphasizing the importance of interdisciplinary collaboration for accurate diagnosis and effective management.
METHODS: A 74-year-old North African female, with a medical history including hypertension, dyslipidemia, type 2 diabetes, goiter, prior cholecystectomy, and bilateral total knee replacement, presented with sudden-onset pelvic pain, chronic constipation, and rectal bleeding. Clinical examination revealed hemodynamic instability, hypoxemia, and diffuse tenderness. After appropriate fluid resuscitation with norepinephrine and saline serum, the patient was stable enough to undergo computed tomography scan. Emergency computed tomography scan confirmed perforated diverticulitis at the rectosigmoid junction, accompanied by the unprecedented presence of pneumoperitoneum, pneumoretroperitoneum, and pneumomediastinum. The patient underwent prompt surgical intervention with colo-rectal resection and a Hartmann colostomy. The postoperative course was favorable, leading to discharge one week after admission.
CONCLUSIONS: This case report highlights the clinical novelty of gas extravasation complications in perforated diverticulitis. The unique triad of pneumoperitoneum, pneumoretroperitoneum, and pneumomediastinum in a 74-year-old female underscores the diagnostic challenges and the importance of advanced imaging techniques. The successful collaboration between radiologists and surgeons facilitated a timely and accurate diagnosis, enabling a minimally invasive surgical approach. This case contributes to the understanding of atypical presentations of diverticulitis and emphasizes the significance of interdisciplinary teamwork in managing such rare manifestations.