Macklin Effect: From Pathophysiology to Clinical Implication.

Air leak syndromes (such as pneumomediastinum, pneumothorax, or subcutaneous emphysema) are frequent complications of acute respiratory distress syndrome (ARDS). Unfortunately, the development of air leaks is associated with worse outcomes. In addition, it has been hypothesized that the development of pneumomediastinum could be a marker of disease severity in patients with respiratory failure receiving noninvasive respiratory support or assisted ventilation. The so-called Macklin effect (or pulmonary interstitial emphysema) is the air dissection of the lung bronchovascular tree from peripheral to central airways following injury to distal alveoli. Ultimately, the progression of the Macklin effect leads to the development of pneumomediastinum, subcutaneous emphysema, or pneumothorax. The Macklin effect is identifiable on a chest computed tomography (CT) scan. The Macklin effect could be an accurate predictor of barotrauma in patients with ARDS (sensitivity = 89.2% [95% CI: 74.6-96.9]; specificity = 95.6% [95% CI: 90.6-98.4]), and may be a marker of disease severity. Accordingly, the detection of the Macklin effect on a chest CT scan could be used to select which patients with ARDS might benefit from different treatment algorithms, including advanced respiratory monitoring, early intubation, or, potentially, the institution of early extracorporeal support with or without invasive ventilation. In this video, the authors summarize the pathophysiology and potential clinical significance and applications of the Macklin effect in patients with acute respiratory failure.

Conservative Approach For The Management Of Bilateral Pneumothorax And Pneumomediastinum After Laparoscopic Totally Extraperitoneal Inguinal Hernia Repair.

Laparoscopic totally extraperitoneal inguinal hernia repair is considered a common and safe procedure. Here, we present the case of a 31-year-old male with right indirect inguinal hernia and no medical history. The patient underwent laparoscopic totally extraperitoneal inguinal hernia repair and the operation was completed successfully. During extubation, subcutaneous emphysema was noted at the neck, chest, and above the nipples. Tracheal injury was excluded by the anaesthesiologists and otorhinolaryngologists. On arterial blood gas, the patient's oxygen saturation was 95% with nasal oxygen support. The patient was followed-up closely in the general surgery inpatient clinic. Computed tomography was performed, on which bilateral pneumothorax and pneumomediastinum were noted. Conservative management was planned and the patient was discharged on the fourth postoperative day. Laparoscopic totally extraperitoneal inguinal hernia repair is considered a routinely applied safe procedure, however, appropriate care should be taken to avoid possible complications.

Spontaneous pneumomediastinum and macklin effect: Three rare case reports with computed tomography findings.

Spontaneous pneumomediastinum (SPM) is defined as free air or gas in the mediastinum that is not associated with an obvious cause such as chest trauma. The SPM results from acutely elevated intra-alveolar pressure: The high-pressure gradient between the distal alveoli and the pulmonary interstitium leads to alveolar rupture. This causes free gas to separate through the peribronchovascular fascial sheaths (interstitial emphysema) into the hilum and then into the mediastinum. Once the gas is in the mediastinum, it can travel up to the cervical soft tissues (even the retroperitoneum) producing subcutaneous emphysema. The Macklin effect appears on thoracic computed tomography (CT) as linear air collections adjacent to bronchovascular sheaths. This case report presents CT findings of SPM due to the Macklin effect in three cases and a brief literature review on this subject.

Angiocatheter Decompression on a Covid-19 Patient with severe Pneumonia, Pneumothorax, and Subcutaneous Emphysema.

BACKGROUND: A novel coronavirus, currently known as Severe Acute Respiratory Syndrome Coronavirus 2, causes Coronavirus disease 2019 (Covid-19). Its most significant complication is a kind of pneumonia known as of 2019 New Coronavirus-Infected Pneumonia (NCIP). Covid-19 pneumonia can have unusual complications that affect both lungs in a widespread manner. Acute lung damage and Acute Respiratory Distress Syndrome (ARDS) are typical in severe Covid-19 cases. Several potential risk factors cause the pneumonia associated with this disease, such as age over 65, diabetes, hypertension, chronic obstructive pulmonary disease, immunosuppression, and pregnancy. Furthermore, various laboratory markers like high levels of C-reactive protein (CRP), D-dimers, ferritin, interleukin-6 (IL-6), and LDH, as well as a low lymphocyte and thrombocyte count, have been linked to increased disease severity and a poor prognosis. METHODS: In this study, we present a case of a 45-year-old patient with a rare evolution of the disease, who made a full recovery against all odds. We highlight the atypical presentation of Covid-19 in this patient, who developed some unusual complications, such as pneumonia, pneumothorax, pneumomediastinum, and subcutaneous emphysema. RESULTS: There is a scarcity of information on patient-related variables linked to pneumothorax in severely sick Covid-19 patients. This study adds to the existing research, reinforcing that spontaneous pneumothorax can be caused by the infection itself, in addition to ventilator-induced trauma in mechanically ventilated patients. CONCLUSIONS: We conclude that patients with Covid-19 pneumonia may develop a more robust and systemic illness characterized by acute lung injury, acute respiratory distress syndrome (ARDS), shock, coagulopathy, and nu¬merous organ dysfunctions, all of which are linked with a high risk of death.

Spontaneous prevertebral emphysema following weight training in a 21-year-old female.

Subcutaneous emphysema (SCE) of the head, neck and mediastinum most commonly arises due to penetrating trauma and iatrogenic events facilitating air entry into these spaces [1]. Spontaneous SCE can emerge due to a pressure gradient between the intra-alveolar air and surrounding structures, causing alveolar rupture and dissection of the peribronchovascular sheath. This is known as the Macklin effect. Potential consequences include pneumomediastinum, pneumothorax, facial emphysema and pneumoracchis [1]. We aim to describe a case of SCE in a 21-year-old female presenting to the emergency department (ED) after weight training. A 21-year-old female presented to the ED with a sore throat and dysphagia after weight lifting in the gym 6 h earlier. Training involved repeat Valsalva manoeuvres. She experienced sharp pain with onset over an hour, worse with swallowing. She had a history of gastro-oesophageal reflux disease. Vital signs, local examination and systemic examination were unremarkable. The diagnosis was made with soft tissue neck X-ray, demonstrating emphysema within the prevertebral space extending from the skull base to the first thoracic vertebra (Fig. 1). Her chest X-ray showed no pneumothorax or pneumomediastinum. No intervention was required beyond analgesia, and she was discharged from the ED. She was advised to avoid heavy lifting and diving. A follow-up radiograph showed resolution of the SCE. This case is an important rare entity and highlights for clinicians that pain after physical exercise may involve injuries extending beyond the area directly trained.

Cervical tracheal rupture with persistence of a pseudotrachea in a dog.

A dog was examined because of acute onset of respiratory distress following a cervical dog bite. Physical examination revealed a deep ventral cervical bite wound associated with localized mild subcutaneous emphysema. Thoracic radiographs showed moderate pneumomediastinum. Medical management consisting of oxygen therapy, antibiotics, and anti-inflammatories was initiated. After 2 days, respiratory distress suddenly worsened. Tracheoscopy showed a discontinuity between the tracheal rings of the cervical trachea; however, the inner tracheal wall appeared intact. Computed tomography scan revealed a ~3-cm complete rupture of all layers of the trachea. Surgical resection and anastomosis of the trachea were performed successfully. Follow-up 15 days after surgery showed complete resolution of respiratory signs, as well as subcutaneous emphysema. A mild ventral angulation of the trachea at the surgical site was noticed on thoracic radiographs. This is the first case report of a pseudotrachea in a dog. Persistence of a pseudotrachea may initially result in only minor clinical signs responsive to medical therapy despite tracheal rupture. In the presence of a pseudotrachea, tracheal rupture may be difficult to identify with tracheoscopy alone. Therefore, CT scan should be proposed in every patient with suspected tracheal trauma. Key clinical message: This case report highlights the importance of including a tracheal rupture in the differential diagnosis of cervical subcutaneous emphysema, even if the amount is small and not associated with significant respiratory signs. The presence of a pseudotrachea may result in less severe clinical signs than expected based on the actual degree of tracheal injury; however, the clinical status may rapidly deteriorate and become life-threatening. This case report also underlines the importance of a CT scan as a complement to tracheoscopy, which may not be sufficient to identify a tracheal rupture in the presence of a pseudotrachea.

Rupture trachéale cervicale avec persistance d'une pseudotrachée chez un chien. Un chien a été présenté pour une dyspnée aiguë modérée consécutive à des morsures cervicales par un autre chien. L'examen clinique révéla une plaie cervicale ventrale profonde associée à un emphysème sous-cutané localisé léger. Les radiographies thoraciques ont montré un pneumomédiastin modéré. Un traitement médical consistant en une oxygénothérapie, des antibiotiques et des anti-inflammatoires a été initié. Après deux jours, la dyspnée s'aggrava brutalement. Une trachéoscopie révéla une discontinuité entre les anneaux trachéaux malgré la persistance d'une paroi trachéale interne intègre. L'examen par tomodensitométrie montra une rupture trachéale cervicale complète dans toute son épaisseur, sur 3 cm de long. Une chirurgie de résection-anastomose de la trachée a été réalisée avec succès.Il s'agit de la première description de pseudotrachée chez un chien. La persistance d'une pseudotrachée peut initialement ne provoquer que des signes cliniques mineurs, notamment un emphysème sous-cutané léger et une dyspnée répondant au traitement médical, malgré une lésion trachéale en réalité importante. Par conséquent, un examen par tomodensitométrie de la trachée doit être envisagé chez tous les patients pour lesquels un traumatisme trachéal est suspecté.Message clinique clé :Ce cas souligne l'importance d'inclure une rupture trachéale dans le diagnostic différentiel de l'emphysème souscutané cervical, et cela même s'il n'est présent qu'en petite quantité et associé à faibles signes cliniques respiratoires. La persistance d'une pseudotrachée peut entraîner des signes cliniques moins importants qu'une rupture trachéale complète, cependant l'état respiratoire de l'animal peut rapidement s'aggraver et devenir une urgence vitale.Ce cas souligne de plus l'importance de l'examen par tomodensitométrie en complément de la trachéoscopie, qui peut parfois s'avérer insuffisante pour le diagnostic des ruptures trachéales, en particulier en présence d'une pseudotrachée.(Traduit par les auteurs).

Successful Management Foreign Body Aspiration Associated with Severe Respiratory Distress and Subcutaneous Emphysema: Case Report and Literature Review.

The presence of a foreign body in the airway is a potentially life-threatening clinical condition that requires urgent medical attention. We present a case of a 12-year-old boy who presented in the emergency room with a history of an episode of choking after aspiration of a foreign body, followed by severe respiratory distress and subcutaneous emphysema. Chest radiography revealed hyperinflation data, pneumothorax, and subcutaneous emphysema data. The flexible bronchoscope examination showed the presence of an inorganic foreign body impacted on the carina with tracheal lesions and laryngeal edema. It was necessary to perform a tracheostomy for its definitive extraction. The gold standard in the treatment of foreign body aspiration is bronchoscopy; although, in children, the technique adopted continues to be controversial, flexible bronchoscopy can be effective and very useful.

Massive Spontaneous Pneumomediastinum-A Form of Presentation for Severe COVID-19 Pneumonia.

For COVID-19 pneumonia, many manifestations such as fever, dyspnea, dry cough, anosmia and tiredness have been described, but differences have been observed from person to person according to age, pulmonary function, damage and severity. In clinical practice, it has been found that patients with severe forms of infection with COVID-19 develop serious complications, including pneumomediastinum. Although two years have passed since the beginning of the pandemic with the SARS-CoV-2 virus and progress has been made in understanding the pathophysiological mechanisms underlying the COVID-19 infection, there are also unknown factors that contribute to the evolution of the disease and can lead to the emergence some complications. In this case report, we present a patient with COVID-19 infection who developed a massive spontaneous pneumomediastinum and subcutaneous emphysema during hospitalization, with no pre-existing lung pathology and no history of smoking. The patient did not get mechanical ventilation or chest trauma, but the possible cause could be severe alveolar inflammation. The CT results highlighted pneumonia in context with SARS-CoV-2 infection affecting about 50% of the pulmonary area. During hospitalization, lung lesions evolved 80% pulmonary damage associated with pneumomediastinum and subcutaneous emphysema. After three months, the patient completely recovered and the pneumomediastinum fully recovered with the complete disappearance of the lesions. Pneumomediastinum is a severe and rare complication in COVID-19 pneumonia, especially in male patients, without risk factors, and an early diagnosis can increase the chances of survival.

[Traumatic subcutaneous emphysema of the face: the hazard of holding a sneeze]. / L'image du mois. Emphysème sous-cutané traumatique de la face : le danger de retenir un éternuement.

In this period of pandemic, protective measures and social distancing, sneezing might not be well received and trying to suppress a sneeze is tempting. It's not always a good idea. We here report the case of a patient suffering from minor facial trauma. The next day after the accident, while trying to hold back a sneeze, the patient caused sudden swelling of the right cheek, associated with subcutaneous emphysema and disturbances in sensitivity, revealing an unrecognized fracture of the right maxillary sinus. Post-traumatic subcutaneous emphysema of the face, caused by suppressed sneezing, is rarely described.

En cette période de pandémie, de gestes barrières et de distanciation sociale, éternuer peut être mal perçu et chercher à réprimer un éternuement est tentant. Ce n'est pas toujours une bonne idée. Nous rapportons ici le cas d'un patient victime d'un traumatisme facial mineur. Le lendemain de l'accident, en essayant de retenir un éternuement, le patient provoqua un brusque gonflement de la joue droite, associé à un emphysème sous-cutané et à des troubles de la sensibilité, révélant ainsi une fracture méconnue du sinus maxillaire droit. L'emphysème sous-cutané post-traumatique de la face, provoqué par un éternuement réprimé, est rarement décrit.

[Subcutaneous emphysema after dental or stomatological treatment, rare complications or consequences of malpractice ?] / Emphysèmes sous-cutanés après soins dentaires ou stomatologiques, rares complications ou conséquences d'une mauvaise pratique ?

The occurrence of pneumomediastinum and subcutaneous emphysema following oral treatment is the result of the inappropriate use of dental equipment using pressurised air. However, their use in oral surgery, including dental extractions, continues nowadays. In addition to being a source of subcutaneous and pneumomediastinum emphysema at risk of infection, pneumatic instrumentation can also be a source of potentially serious gas embolisms. A thorough knowledge of this type of complication by the practitioners and the proper use of the instrumentation will enable a significant reduction of the incidence of theses complications.

La survenue de pneumomédiastins et d'emphysèmes sous-cutanés à la suite de traitements buccaux est le résultat d'une utilisation inadéquate de matériels dentaires utilisant l'air pressurisé. Leur usage dans des soins de chirurgie orale, dont les extractions dentaires, persiste néanmoins à l'heure actuelle. En plus d'être pourvoyeur d'emphysèmes sous-cutanés et pneumomédiastin à risque de surinfection, l'instrumentation pneumatique peut également être la source d'embolies gazeuses potentiellement graves. Une connaissance approfondie de ce type de complications par les praticiens ainsi que la bonne utilisation de l'instrumentation permettront une réduction significative de leur incidence.

[Pneumothorax, pneumomediastinum and subcutaneous emphysema as complica-tions of COVID-19].

Spontaneous pneumothorax, pneumomediastinum and subcutaneous emphysema are serious complications of COVID-19 infection caused by SARS-CoV-2, occurring in approximately 1% of hospitalized patients. The risk increases with the accumulation of risk factors, namely moderate or severe illness, high-flow oxygen therapy and noninvasive ventilation. The pathophysiology may be contributed to by patient self-inflicted lung injury. Hypoxia-induced respiratory effort in patients with pneumonia puts an enormous load on certain parts of their lungs, leading to subsequent progression of lung tissue damage. These complications start with destruction of the alveolar membrane, accompanied by emergence of a pulmonary bulla. Rupture of the bulla results in air leaking to the pleural space (pneumothorax). In the case of pneumomediastinum, the air spreads within the peribronchial interstitium along the airways to the mediastinum and subcutaneous tissues (Macklin effect). While pneumomediastinum and subcutaneous emphysema resolve spontaneously in most cases, pneumothorax treatment depends on its magnitude. While small pneumothorax may be managed conservatively, large pneumothorax usually requires active treatment with an acute chest drain; the latter is also associated with worse prognosis and a higher chance of death. We report air-leak complications in nine COVID-19 patients, of whom seven had spontaneous pneumothorax and four of them died. Three patients developed spontaneous pneumomediastinum together with subcutaneous emphysema, with two of them surviving. One patient with combination of pneumothorax, pneumomediastinum and subcutaneous emphysema died. These complications may accompany moderate or severe COVID-19-associated pneumonia, mostly the late phase of the disease. They should be considered when patients complain of sudden chest or back pain or worsening respiratory insufficiency.

Cervico-Thoracic Air Collections in COVID-19 Pneumonia Patients - Our Experience and Brief Review.

Introduction: Abstract COVID-19 (Coronavirus-19 disease), a new clinical entity caused by SARS-COV-2 infection, could explain the physiopathology of cervicothoracic air collections (pneumothorax, pneumomediastinum, and subcutaneous emphysema). Material and Methods: We conducted an 8-months retrospective analysis of a single-center SARS-CoV-2 cases associating pneumothorax, pneumomediastinum, and subcutaneous emphysema, either alone or combined. Results: All non-intubated patients with the complications cited above had a favorable outcome after pleural drainage, percutaneous drainage, and/or conservative treatment, while the intubated patients, with multiple comorbidities, have had an unfavorable outcome, regardless the chosen treatment. Pleural drainage was used for pneumothorax cases; pneumomediastinum with subcutaneous emphysema required insertion of subcutaneous needles or angio-catheters with manual decompressive massage. Conservative methods of treatment were used for patients with pneumomediastinum and medium or severe respiratory disfunction. Conclusions: Etiopathogenic classification of pneumothorax should include SARS-CoV-2 infection as a possible cause of secondary spontaneous pneumothorax due to COVID-19 pneumonia. Survival rate after the occurrence of these complications was small (18,75%), 4 of the patients were cured, 2 had a favorable outcome and 26 have died. Pleural drainage which is mandatory to do for patients with pneumothorax complication in COVID -19 pneumonia, doesn't change the prognosis for those with severe affecting lungs, because the prolonged ventilation and the other comorbidities have led to death in most of these cases.

Getting the wind knocked out of him - Report of a broncho-cutaneous fistula caused by staphylococcal pneumonia, and review of literature.

A broncho-cutaneous fistula (BCF) refers to the formation of an abnormal fistulous connection between the tracheobronchial tree and the cutaneous surface of skin. A rare occurrence in and of itself, the disease entity may have varied etiologies, and may or may not be associated with a broncho-pleural fistula. We describe a case of a young patient who developed a BCF as a complication of a necrotizing pneumonic process, and his subsequent clinical course. In so doing, we review the clinical features of this peculiar disease entity, analyzing the available medical literature similarities in etiology and variations in management strategies described in the literature thus far.

[Restrictive respiratory distress caused by major subcutaneous emphysema]. / Détresse respiratoire restrictive sur un emphysème sous-cutané majeur.

We describe the case of subcutaneous emphysema that resulted in major respiratory distress. Drainage was performed thanks to the insertion of subcutaneous catheters. This technique has already been described and involves few complications. It represents a potentially easy and lifesaving procedure.

Nous décrivons un cas d'emphysème sous-cutané ayant entraîné une détresse respiratoire majeure. Un drainage décompressif a été réalisé grâce à l'insertion de cathéters sous-cutanés. Cette technique a déjà été décrite et comporte peu de risques et de complications. Elle représente potentiellement un geste simple et salvateur.

Squamous cell carcinoma of the perineum masquerading as necrotizing hidradenitis suppurativa.

Many cases of superinfected hidradenitis suppurativa (HS) involve multiple species of bacteria, but gas-producing infections are rare and can complicate the clinical picture. Additionally, recognizing squamous cell carcinoma (SCC) as a complication of longstanding HS is imperative. Herein, we present a unique case of a severe emphysematous HS that was initially mistaken for Fournier gangrene and eventually diagnosed as superinfected SCC.

Pediatric Spontaneous Pneumomediastinum: Narrative Literature Review.

INTRODUCTION: Described since 1939 in the adult population, spontaneous pneumomediastinum is less known in children. Because of its symptoms and a generally benign evolution, it is probably an underestimated diagnosis. However, it has to be considered in the differential diagnosis of acute thoracic pain. METHODS: The incidence being low, we conducted a narrative literature review to identify the circumstances leading to a spontaneous pneumomediastinum, the most relevant signs and symptoms, investigations, as well as treatment recommendations. RESULTS: Of 216 patients, 66.2% are boys, and mean ages range from 6.9 to 14 years. The most frequent comorbidity in children is asthma (22.2%), and the most common trigger factors are bronchospasm (49%), cough (45.6%), various respiratory tract infections, vomiting (10.3%), and foreign body aspiration (8.3%). It remains idiopathic in 33.3%. Relevant signs are chest pain (54.6%), neck pain and/or sore throat (53.3%), and dyspnea (41.2%). The most relevant sign is palpation of subcutaneous emphysema (66.4%). The classically described Hamman crunch is only present in 11.6%. Chest x-ray provides the right diagnosis in 99.5% of the patients. Pneumothorax is associated in 11.6%. Most patients are hospitalized (88.3%); treatment is based on oxygen therapy, painkillers, and rest. In some series, there can be up to 25.8% of patients requiring intensive care and 5.5% requiring drainage of associated pneumothorax. Survival rate is 92.5%, and long-term follow-up shows normal x-rays after 4 days and no recurrence. CONCLUSIONS: Spontaneous pneumomediastinum is uncommon in children but must be considered in pediatric patients with acute chest and/or neck pain. History taking, physical examination, and standard chest x-ray are most often diagnostic, and there is rarely a need for other investigation.Hospitalization is not always indispensable; ambulatory management can be considered. Outcome is good, and follow-up can be clinical, therefore avoiding further x-rays.

Teenager with chest pain and swollen neck: a leave-it-alone condition.

A 19-year-old boy with shortness of breath and chest pain after strenuous exercise presented to emergency department . On physical examination, the neck and shoulders appeared to be swollen. There was crepitus on skin palpation. Chest X-ray disclosed diffuse subcutaneous emphysema and pneumomediastinum. CT showed additional finding of air in epidural space. The patient was discharged after 2 days of hospitalisation with conservative treatment uneventfully. Pneumorrhachis is usually caused by abrupt increase in intrathoracic pressure in instance of forceful vomiting, cough or asthma attack in an otherwise healthy young adult. It is usually accompanied with pneumomediastinum. The management of epidural pneumatosis should be tailored according to its primary cause. For most patients with pneumorrhachis associated to a spontaneous pneumomediastinum without neurological symptoms, this condition is generally self-limited. For epidural free air of large volume that causes neurological deficits, surgical laminectomy may be indicated.

[A Case of Emphysematous Pyelonephritis with Pneumoderma Treated by Open Surgical Drainage].

Emphysematous pyelonephritis (EPN) is an acute, severe necrotizing infection of the renal parenchyma and perirenal tissue. A 72-year-old female patient with uncontrolled diabetes mellitus was admitted to a hospital with loss of consciousness and, fever. Laboratory data suggested acute inflammation and hyperosmolar hyperglycemic syndrome. The left EPN was accurately diagnosed after abdominal computed tomographic (CT) scan revealed renal parenchymal gas and fluid within the subcutaneous tissue and mediastinum. The patient was transferred to our institution and underwent emergent open surgical drainage. However, a CT scan performed 3 days after the drainage revealed the presence of fluid in the left perinephric space. CT-guided drainage of the left perinephric fluid was performed. The patient was finally discharged after complete recovery from severe inflammation.