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.

Spontaneous pneumomediastinum associated with subcutaneous emphysema, pneumopericardium and pneumothorax: a rare association complicating measles.

A unique case of severe measles complicated by multiple features of gas accumulation is described, on the ground of the available literature evidences. Complications from measles have been reported in every organ system and they may vary by age and underlying conditions. Pneumomediastinum is usually associated with subcutaneous emphysema and pneumopericardium, but rarely associated with pneumothorax. We report extremely rare simultaneous occurrence of self-limiting pneumomediastinum, pneumopericardium, subcutaneous neck and chest region emphysema, and pneumothorax, in a 19-year-old girl with measles. A review of the literature has documented only one previous report of spontaneous pneumomediastinum, subcutaneous emphysema and pneumothorax in the course of measles, and no previous cases reported the association of pneumomediastinum, subcutaneous emphysema, pneumopericardium and pneumothorax complicating measles.

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.

Pneumothorax, pneumomediastinum, and subcutaneous emphysema in hospitalized COVID-19 patients: incidence, clinical characteristics, and outcomes.

BACKGROUND: Limited data is available on the incidence and outcomes of pneumothorax (PTX), pneumomediastinum (PNM), and subcutaneous emphysema (SCE) in COVID-19 patients. This study aimed to investigate the characteristics of these complications in hospitalized COVID-19 patients. RESEARCH DESIGN AND METHODS: A retrospective study was conducted, involving adult COVID-19 patients admitted to Mayo Clinic Florida from 03/2020-06/2022. Patients were divided into two groups based on the presence or absence of PTX/PNM/SCE. RESULTS: 1926 hospitalized patients with COVID-19 were included, of which 518 were admitted to the ICU. The incidence of PTX/PNM/SCE was 6.3%. Patients with these complications were more likely to be male, Asian, and unvaccinated. Conversely, they were less likely to have chronic obstructive pulmonary disease. Patients who developed PTX/PNM/SCE after 72 hours of admission were more likely to receive high-dose corticosteroids and for an extended duration. The affected group had an adjusted odds ratio for in-hospital mortality of 13.32 (95%CI, 8.19-21.59) and ICU admission of 9.14 (95%CI, 5.3-12.78) compared to the unaffected group. CONCLUSION: Although the occurrence of PTX/PNM/SCE in hospitalized COVID-19 patients was rare, it was associated with worse outcomes. Corticosteroids may contribute to the pathogenesis of these complications; however, further studies are needed to investigate this relationship in more detail.

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.

Use of an equine compression suit to manage a deep axillary wound in a horse.

PURPOSE: To describe the use of an equine compression suit to manage a deep axillary wound in a Thoroughbred filly with bilateral pneumothorax. CASE SUMMARY: A 2-year-old Thoroughbred filly was referred for management of a deep wound to the left axilla. Packing and bandaging of the area were initially attempted, but this became repeatedly dislodged, and bandaging was discontinued. The filly subsequently developed widespread subcutaneous emphysema, and the wound was slow to granulate. Acute onset respiratory distress occurred 11 days after admission, secondary to bilateral worsening pneumothorax, and required placement of a chest drain. A commercially available equine compression suit was then successfully used to hold a primary dressing in place. This resulted in a marked improvement in the subcutaneous emphysema and pneumothorax. Wound granulation subsequently progressed well, and the filly was discharged from the clinic on day 36. UNIQUE INFORMATION PROVIDED: This case report highlights the potential applicability of a compression suit as an alternative to a stent to effectively prevent entry of air and successfully manage axillary wounds in the horse. It was also noted how delayed the progression of a pneumothorax can be after inadequate bandaging of a deep wound in the axillary region. The compression suit provided an alternative means of securing a dressing onto an awkwardly placed wound and may be useful in locations other than the axilla.

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.

Spontaneous pneumorrhachis with pneumomediastinum, scrotal emphysema, and extensive subcutaneous emphysema in a patient with pneumonia: A case report and literature review.

BACKGROUND: Spontaneous pneumorrhachis with pneumomediastinum, scrotal emphysema, and extensive subcutaneous emphysema caused by acute pneumonia are rarely observed in clinical practice. CASE PRESENTATION: Herein, we report a case of a 12-year-old boy with spontaneous pneumorrhachis with pneumomediastinum, scrotal emphysema, and extensive subcutaneous emphysema caused by a severe cough due to mycoplasma pneumonia. This patient neither received invasive or noninvasive ventilator treatment nor surgical treatment before the onset of the disease. After treatment, the patient recovered smoothly and was discharged from the hospital. LITERATURE REVIEW: We reviewed all cases of spontaneous pneumorrhachis in children and adolescents between 1988 and 2022 in the PubMed database. Twenty-seven cases met our inclusion criteria, and the data on demographic information, triggers, comorbidities, symptoms, imaging findings, treatment, and prognosis were extracted and analyzed. CONCLUSION: Although spontaneous pneumorrhachis is a rare condition, it has been reported in children. Computed tomography scanning is the gold standard for its detection. Spontaneous pneumorrhachis is typically a benign disease. This condition usually does not require any special treatment and should be monitored as common types of air leaks, such as pneumothorax and pneumomediastinum.

Integrated Chinese herbal medicine and Western medicine successfully resolves spontaneous subcutaneous emphysema and pneumomediastinum in a patient with severe COVID-19 in Taiwan: A case report.

CASE: Serious complications of severe coronavirus disease 2019 (COVID-19) include subcutaneous emphysema (SE) and pneumomediastinum, which are complicated to treat with conventional Western medicine. We report how combining Chinese herbal medicine (CHM) with Western medicine quickly resolved a patient's COVID-19-associated pulmonary complications, shortened hospital stay and improved quality of life. CLINICAL FEATURES AND OUTCOME: A 59-year-old male with a history of smoking and tumors was diagnosed with COVID-19 in May 2021. At hospitalization, his oxygen saturation (SpO2) was 80%, he had a continuous severe cough, rapid shallow breathing, spontaneous SE and pneumomediastinum. By Day 4 of hospitalization, his condition was worsening despite standard care, so CHM was added. After 3-5 days, his coughing had lessened and supplementary oxygen therapy was de-escalated. Nine days after starting CHM, the SE had completely resolved and the patient avoided intubation. His WHO OS 10-point Scale score had fallen from 6 to 3 points and the modified Medical Research Council Dyspnea Scale score from 4 to 2 points. He was hospitalized for 19 days. At 1 week post-discharge, the patient could handle most of his daily activities and experienced minor shortness of breath only when performing labor-intensive tasks. At 1 month, his work output was restored to pre-COVID-19 levels. CONCLUSION: CHM combined with standard Western medicine improved pulmonary function, respiratory rate, blood oxygen saturation and shortened the hospital stay of a patient with severe COVID-19 complicated by SE and pneumomediastinum.

Perioperative Management of a Patient With Tongue Cancer Who Developed Pneumomediastinum Following Tracheostomy Performed to Secure the Airway.

Prior to a scheduled operation for a 45-year-old male patient with tongue cancer, a tracheotomy performed under intravenous sedation to prevent asphyxia due to extensive bleeding resulted in pneumomediastinum and subcutaneous emphysema. The planned operations were postponed until reduction of the pneumomediastinum was confirmed. During operation, airway pressure was kept low to prevent tension pneumomediastinum along with a sufficient depth of anesthesia, controlled analgesia, and continuous administration of muscle relaxants. Postoperatively, sedation was used to avoid stress and complications with the vascular anastomosis site. In this case, air leakage into the soft tissues was one of the possible causes of the event associated with increased airway pressure. Although the incidence of such complications is relatively low, caution should be exercised after tracheostomy.

[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.

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.

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.

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.

[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.

[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.

A Case of Spontaneous Mediastinal and Subcutaneous Emphysema in a Patient with HIV-Infected Pneumonia.

BACKGROUND: Acquired immunodeficiency syndrome is a chronic infectious disease with high mortality and is caused by the Human Immunodeficiency Virus (HIV). Pneumonia caused by HIV is common, but it rarely causes spontaneous mediastinal and subcutaneous emphysema. CASE PRESENTATION: A 21-year-old man with severe pneumonia was hospitalized owing to dyspnea that had been persisting for 1 day; blood test results confirmed HIV infection. Initial chest Computed Tomography (CT) did not reveal mediastinal or subcutaneous emphysema. However, after 21 days of treatment, the patient experienced discomfort in the neck region and experienced the feeling of snowflakes on applying pressure. Chest CT showed mediastinal and subcutaneous emphysema, located in the bilateral cervical roots, anterior upper chest wall, left axillary chest wall, mediastinum, and other parts. Metagenomic Next Generation Sequencing (mNGS) of the sputum and blood samples suggested multiple pathogenic infections. Antiinfection treatment was initiated, and changes in the patient's condition were monitored. The patient's subcutaneous emphysema improved during the follow-up. CONCLUSION: In HIV-infected patients with sudden mediastinal and subcutaneous emphysema, mNGS can be used to determine the etiological agent during symptomatic treatment. Targeted antipathogen therapy is helpful in improving the condition of patients with subcutaneous emphysema.