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Background: Acute respiratory failure is the predominant presentation of intensive care unit (ICU) patients with COVID-19, and lung protective strategies are recommended to mitigate additional respiratory complications such as air-leak syndrome. The aim of this study is to investigate the prevalence, type, and timing of air-leak syndrome with regards to associated factors and patient outcome in patients with COVID-19 in ICUs at a large Swedish emergency hospital., Methods: This retrospective study included all adult patients admitted to an ICU for COVID-19-related respiratory failure at Södersjukhuset between March 6, 2020, and June 6, 2021. Primary outcomes were proportion of patients diagnosed with air-leak syndrome and its different types of manifestations, and timing of diagnoses in relation to ICU admission and initiation of invasive ventilation. Secondary outcomes included the highest level of respiratory support prior to the diagnosis of air-leak syndrome, patient characteristics and treatment variables associated with air-leak syndrome, and 90-day mortality for patients with air-leak syndrome compared to those without., Results: Out of a total of 669 patients, 81 (12%) were diagnosed with air-leak syndrome. Air-leak syndrome manifested as pneumomediastinum (PMD) (n = 58, 72%), pneumothorax (PTX) (n = 43, 53%), subcutaneous emphysema (SCE) (n = 28, 35%) and pneumatocele (PC) (n = 4, 4.9%). Air-leak syndrome was diagnosed at a median of 14 days (IQR 6-22) after ICU admission and 12 days (IQR 6-19) following the initiation of invasive ventilation. The highest respiratory support prior to diagnosis was invasive ventilation (IV) in 64 patients (79%), non-invasive ventilation in two patients (2.5%), and low- or high-flow oxygen in 15 patients (19%). Multiple logistic regression showed that pulmonary disease at baseline (OR 1.87, 95% CI 1.07-3.25), a lower body mass index (OR 0.95, 95% CI 0.9-0.99), admission later compared with earlier in the pandemic (OR 3.89, 95% CI 2.14-7.08), and IV (OR 3.92, 95% CI 2.07-7.44) were associated with an increased risk of air-leak syndrome. Compared with patients not diagnosed with air-leak syndrome, patients with air-leaks had a higher mortality at 90 days after ICU admission, 46% versus 26% (p <.001). However, the mortality rate differed with different air-leak manifestations, 47% for PMD, 47% for PTX, 50% for the combination of both PMD and PTX and 0% in patients with only SCE and/or PC, respectively., Conclusion: In 669 ICU patients with COVID-19, 12% had one or more manifestations of air-leak syndrome. Notably, PMD, rather than PTX, was the most common manifestation, suggesting a potentially distinctive feature of COVID-19-related air-leak syndrome. Further research is needed to determine whether COVID-19 involves different pathophysiological or iatrogenic mechanisms compared with other critical respiratory conditions., Registration of Clinical Trial: Clinicaltrials.gov, identifying number, NCT05877443., Editorial Comment: This single-centre cohort study of air leakage into soft tissue in ventilated COVID cases presents findings for associated factors and clinical manifestations, including with different COVID-19 periods and treatments., (© 2025 The Author(s). Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.)

Objectives: To describe the prevalence, risk factors, and outcomes for neonatal air leak syndrome and its subtypes (pneumothorax, pneumomediastinum, pneumopericardium, pulmonary interstitial emphysema, and pneumoperitoneum), evaluate variables associated with the development of air leak, and analyze the national trend of neonatal air leak syndrome in the United States., Methods: A retrospective cross-sectional analysis of neonates was performed using the Kids' Inpatient Database. Univariate and multivariable analyses were used to compare neonates with and without air leak syndrome and its subtypes using the 2016 and 2019 data. Data from 1997 to 2019 were used for trend analysis., Results: Of 7.7 million neonatal discharges, 41,814 developed air leak syndrome (5.41/1,000 discharges) in 2016 and 2019, with a mortality rate of 7.2%. Pneumothorax was the most common air leak syndrome (4.3/1,000 discharges). The risk of air leak syndrome increased with decreasing gestational age on univariate analysis. On multivariable analysis, gestational age had a variable effect on developing air leaks depending on the type of air leak syndrome. The presence of meconium aspiration syndrome, congenital diaphragmatic hernia, persistent pulmonary hypertension, and the use of invasive mechanical ventilation were associated with an increased risk of air leak syndrome. There was an increased linear trend in neonatal air leak syndrome prevalence in the United States from 1997 to 2019., Conclusions: Air leak syndrome remains a serious and significant issue among the neonatal population and is associated with high morbidity and mortality. We present a national prevalence and outcomes of various neonatal air leak syndromes in the United States., Competing Interests: Conflicting interestThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Spontaneous pneumomediastinum is an uncommon condition described in veterinary medicine with concurrent respiratory disease. It can be caused by the Macklin effect, which is when gas leaks from the alveoli into the surrounding interstitial lung tissue. Pulmonary interstitial emphysema (PIE) is the presence of gas within the pulmonary vascular sheaths and indicates the presence of the Macklin effect. In the authors' experience, spontaneous pneumomediastinum and PIE are more prevalent in sighthound dogs than in other breeds and are often considered incidental findings. This retrospective, observational, cross-sectional study compared the prevalence of PIE and subsequent pneumomediastinum in sighthound with other purebred dogs. It characterized the appearance of PIE in CT and analyzed a possible association with concomitant pulmonary pathologies or with the use of general anesthesia. Medical records and thoracic CTs of sighthounds and nonsighthound dogs from two institutions were reviewed. A total of 256 dogs, comprising 127 sighthounds and 129 other purebred dogs, were included. The prevalence of PIE and pneumomediastinum was statistically higher in sighthound (14.2%) compared with other nonsighthound dogs (2.2%). There was no statistical association between the presence of PIE and pneumomediastinum with different age and weight groups or with sex. There was no statistical difference in the prevalence of PIE and pneumomediastinum between dogs with and without pulmonary pathology or in dogs undergoing CT with sedation or general anesthesia. Spontaneous pneumomediastinum in sighthounds is more prevalent than in other breeds, and its prevalence is not associated with the presence of pulmonary pathology or the use of general anesthesia., (© 2024 American College of Veterinary Radiology.)

Background: Pneumothorax, pneumomediastinum and subcutaneous emphysema are respiratory complications of Coronavirus disease 2019 occurring with noteworthy frequency in patients especially with severe disease. They can be life-threatening and often complicate patient managment., Methods: This was a retrospective, observational study of patients admitted in Nepal Armed Police Force hospital from 13/05/2020 to 28/12/2021 diagnosed with pneumothorax, pneumomediastinum or subcutaneous emphysema singly or in combination. Data were collected from clinical charts, imaging records and electronic medical records of Severe Acute Respiratory Syndrome Coronavirus-type 2 positive patients 18 years and older. The frequency and type of the defined complications, the inflammatory markers and ventilatory parameters just prior to their diagnosis, the duration of hospitalization and ICU admission and in-hospital mortality rate were studied., Results: Out of 4013 COVID-19 patients admitted in the hospital during the period, a total of 28 patients were observed to develop the complications, the overall incidence being 0.7% among hospitalized patients and 5.6% among ICU patients. The proportion of subcutaneous emphysema (64.3%) was highest followed by pneumomediastinum (46.4%) and then pneumothorax (39.3%) existing singly or in combination among the 28 patients, where four patients developed the complications spontaneously. Mean Positive End Expiratory Pressure of 12.1±2.6 cmH2O and Peak Inspiratory Pressure or Pressure Support of 30.9±10.3 cmH2O were observed for patients under positive pressure ventilation. Most of the patients who developed the complications (78.6%) died during treatment., Conclusions: Pulmonary air leak complications occur frequently in COVID-19 patients treated with or without positive pressure ventilation signifying increased disease severity, risk of ICU admission and high mortality rate. Hence, clinicians should be vigilant of these complications in all patients affected with COVID-19 and institute timely management.

Barotrauma occurs in a significant number of patients with COVID-19 interstitial pneumonia undergoing mechanical ventilation. The aim of the current study was to investigate whether the Brixia score (BS) calculated on chest-X-rays acquired at the Emergency Room was associated with barotrauma. We retrospectively evaluated 117 SARS-CoV-2 patients presented to the Emergency Department (ED) and then admitted to the intensive care unit (ICU) for mechanical ventilation between February and April 2020. Subjects were divided into two groups according to the occurrence of barotrauma during their hospitalization. CXRs performed at ED admittance were assessed using the Brixia score. Distribution of barotrauma (pneumomediastinum, pneumothorax, subcutaneous emphysema) was identified in chest CT scans. Thirty-eight subjects (32.5%) developed barotrauma (25 pneumomediastinum, 24 pneumothorax, 24 subcutaneous emphysema). In the barotrauma group we observed higher Brixia score values compared to the non-barotrauma group (mean value 12.18 vs. 9.28), and logistic regression analysis confirmed that Brixia score is associated with the risk of barotrauma. In this work, we also evaluated the relationship between barotrauma and clinical and ventilatory parameters: SOFA score calculated at ICU admittance and number of days of non-invasive ventilation (NIV) prior to intubation emerged as other potential predictors of barotrauma., Competing Interests: The authors declare no conflict of interest.

Introduction: Coronavirus disease 2019 (COVID-19) can cause multisystem complications, with pulmonary involvement associated with the highest mortality. Pneumothorax (PT) and pneumomediastinum (PM) are uncommon complications of COVID-19 that have been reported to occur in the absence of trauma or mechanical ventilation. This study seeks to determine the incidence of these complications in patients with COVID-19 and evaluate clinical characteristics and outcomes., Methods: We identified 3375 patients admitted to our health system during March 2020 through November 2020 who tested positive for SARS-CoV-2 with a polymerase chain reaction test. Patients were screened for PT or PM and were matched to COVID-19-positive patients without PT and/or PM. Data compared demographics, clinical characteristics, and laboratory values., Results: Out of a total of 3375 COVID-19 admissions, 33 patients with PT/PM (1%) were compared to 32 matched controls without PT and/or PM. The patients with PT and/or PM demonstrated a significantly higher incidence of concomitant cancer diagnosis than those without PT and/or PM (18% vs 3%, respectively; P  = 0.05). Those with PT and/or PM required significantly more invasive mechanical ventilation than those without PT and/or PM (79% vs 47%; P  < 0.01). Mortality was significantly higher among those patients with PT and/or PM than those without PT/PM (55% vs 25%; P  < 0.05)., Discussion: A significant number of COVID-19 patients with PT and/or PM had a concomitant cancer diagnosis, required supplemental oxygen on admission, and invasive mechanical ventilation during hospitalization. Additionally, the COVID patients with PT and/or PM had significantly higher mortality compared to those without PT and/or PM. However, with all retrospective studies, there are limitations., (Copyright© Board of Regents of the University of Wisconsin System and The Medical College of Wisconsin, Inc.)

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.

Background: Various complications have been reported in patients with COVID-19 including pneumomediastinum., Methods: The primary objective of the study was to determine the incidence of pneumomediastinum in COVID-19 positive patients who underwent CT pulmonary angiography (CTPA). The secondary objectives were to analyse if the incidence of pneumomediastinum changed between March and May 2020 (peak of the first wave in the UK) and January 2021 (peak of the second wave in the UK) and to determine the mortality rate in patients with pneumomediastinum. We undertook an observational, retrospective, single-centre, cohort study of patients with COVID-19 admitted to Northwick Park Hospital., Results: 74 patients in the first wave and 220 patients in the second wave met the study criteria. Two patients during the first wave and eleven patients during the second wave developed pneumomediastinum., Conclusions: The incidence of pneumomediastinum changed from 2.7% during the first wave to 5% during the second wave and this change was not statistically significant (p value 0.4057). The difference in mortality rates of patients with pneumomediastinum in both waves of COVID-19 (69.23%) versus patients without pneumomediastinum in both waves of COVID-19 (25.62%) was statistically significant (p value 0.0005). Many patients with pneumomediastinum were ventilated, which could be a confounding factor. When controlling for ventilation, there was no statistically significant difference in the mortality rates of ventilated patients with pneumomediastinum (81.81%) versus ventilated patients without pneumomediastinum (59.30%) (p value 0.14)., (© The Author(s) 2022. Published by Oxford University Press on behalf of Postgraduate Medical Journal. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: Patients with COVID-19 infection are frequently found to have pulmonary barotrauma. Recent work has identified the Macklin effect as a radiographic sign that often occurs in patients with COVID-19 and may correlate with barotrauma., Methods: We evaluated chest CT scans in COVID-19 positive mechanically ventilated patients for the Macklin effect and any type of pulmonary barotrauma. Patient charts were reviewed to identify demographic and clinical characteristics., Results: The Macklin effect on chest CT scan was identified in a total of 10/75 (13.3%) COVID-19 positive mechanically ventilated patients; 9 developed barotrauma. Patients with the Macklin effect on chest CT scan had a 90% rate of pneumomediastinum (p < 0.001) and a trend toward a higher rate of pneumothorax (60%, p = 0.09). Pneumothorax was most frequently omolateral to the site of the Macklin effect (83.3%)., Conclusion: The Macklin effect may be a strong radiographic biomarker for pulmonary barotrauma, most strongly correlating with pneumomediastinum. Studies in ARDS patients without COVID-19 are needed to validate this sign in a broader population. If validated in a broad population, future critical care treatment algorithms may include the Macklin sign for clinical decision making and prognostication., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: During the novel coronavirus disease-2019 pandemic, a considerable number of pneumothorax (PNX)/pneumomediastinum (PNM) associated with COVID-19 have been reported, and the incidence is higher in critically ill patients. Despite using a protective ventilation strategy, PNX/PNM still occurs in patients on invasive mechanical ventilation (IMV). This matched case-control study aims to identify the risk factors and clinical characteristics of PNX/PNM in COVID-19., Methods: This retrospective study enrolled adult patients with COVID-19, admitted to a critical care unit from March 1, 2020, to January 31, 2022. COVID-19 patients with PNX/PNM were compared, in a 1-2 ratio, to COVID-19 patients without PNX/PNM, matched for age, gender, and worst National Institute of Allergy and Infectious Diseases ordinal scale. Conditional logistic regression analysis was performed to assess the risk factors for PNX/PNM in COVID-19., Results: 427 patients with COVID-19 were admitted during the period, and 24 patients were diagnosed with PNX/PNM. Body mass index (BMI) was significantly lower in the case group (22.8 kg/m 2 and 24.7 kg/m 2 ; P = 0.048). BMI was statistically significant risk factor for PNX/PNM in univariate conditional logistic regression analysis [odds ratio (OR), 0.85; confidence interval (CI), 0.72-0.996; P = 0.044]. For patients on IMV support, univariate conditional logistic regression analysis showed the statistical significance of the duration from symptom onset to intubation (OR, 1.14; CI, 1.006-1.293; P = 0.041)., Conclusions: Higher BMI tended to show a protective effect against PNX/PNM due to COVID-19 and delayed application of IMV might be a contributive factor for this complication., (© 2023. The Author(s).)

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., (Copyright © 2022 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Objectives: Pneumomediastinum (PNM) is a rare complication of mechanical ventilation, but its reported occurrence in patients with acute respiratory distress syndrome secondary to COVID-19 is significant. The objective is to determine the incidence, risk factors, and outcome of PNM in non-ICU hospitalized patients with severe-to-critical COVID-19 pneumonia., Design: Retrospective observational study., Setting: Population-based, single-setting, tertiary-care level COVID treatment center., Patients: Individuals hospitalized with a diagnosis of COVID-19 pneumonia and severe to critical illness were included. Those hospitalized without respiratory failure, observed for less than 24 hours, or admitted from an ICU were excluded., Interventions: None., Measurements and Main Results: All patients underwent a complete clinical assessment and chest CT scan, and were followed up from hospitalization to discharge or death. The outcome was the number of cases of PNM, defined as the presence of free air in the mediastinal tissues diagnosed by chest CT scan, in non-ICU hospitalized patients and the subsequent risk of intubation and mortality. PNM occurred in 48 out of 331 participants. The incidence was 14.5% (95% CI, 10.9-18.8%). A CT-Scan Severity score greater than 15 was positively associated with PNM (odds ratio [OR], 4.09; p = 0.002) and was observed in 35.2% of the participants (95% CI, 26.2-44.9%). Noninvasive ventilation was also positively associated with PNM (OR, 4.46; p = 0.005), but there was no positive association with airway pressures. Fifty patients (15%) were intubated, and 88 (27%) died. Both the risk for intubation and mortality were higher in patients with PNM, with a hazard ratio of 3.72 ( p < 0.001) and 3.27 ( p < 0.001), respectively., Conclusions: Non-ICU hospitalized patients with COVID-19 have a high incidence of PNM, increasing the risk for intubation and mortality three- to four-fold, particularly in those with extensive lung damage. These findings help define the risk and outcome of PNM in severe-to-critical COVID-19 pneumonia in a non-ICU setting., Competing Interests: The authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2022 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Spontaneous pneumomediastinum (SP) has been described early during the COVID-19 pandemic in large series of patients with severe pneumonia, but most patients were receiving invasive mechanical ventilation (IMV) at the time of SP diagnosis. In this retrospective multicenter observational study, we aimed at describing the prevalence and outcomes of SP during severe COVID-19 with pneumonia before any IMV, to rule out mechanisms induced by IMV in the development of pneumomediastinum.Among 549 patients, 21 patients (4%) developed a SP while receiving non-invasive respiratory support, after a median of 6 days [4-12] from ICU admission. The proportion of patients requiring IMV was similar. However, the time to tracheal intubation was longer in patients with SP (6 days [5-13] vs. 2 days [1-4]; P = 0.00002), with a higher first-line use of non-invasive ventilation (n = 11; 52% vs. n = 150; 28%; P = 0.02). The 21 patients who developed a SP had persisting signs of severe lung disease and respiratory failure with lower ROX index between ICU admission and occurrence of SP (3.94 [3.15-5.55] at admission vs. 3.25 [2.73-4.02] the day preceding SP; P = 0.1), which may underline potential indirect signals of Patient-self inflicted lung injury (P-SILI).In this series of critically ill COVID-19 patients, the prevalence of SP without IMV was not uncommon, affecting 4% of patients. They received more often vasopressors and had a longer ICU length of stay, as compared with their counterparts. One pathophysiological mechanism may potentially be carried out by P-SILI related to a prolonged respiratory failure, as underlined by a delayed use of IMV and the evolution of the ROX index between ICU admission and the day preceding SP., (© 2022. The Author(s).)

Objectives: To investigate the incidence, risk factors, and outcomes of barotrauma (pneumomediastinum and subcutaneous emphysema) in mechanically ventilated COVID-19 patients. To describe the chest radiography patterns of barotrauma and understand the development in relation to mechanical ventilation and patient mortality., Methods: We performed a retrospective study of 363 patients with COVID-19 from March 1 to April 8, 2020. Primary outcomes were pneumomediastinum or subcutaneous emphysema with or without pneumothorax, pneumoperitoneum, or pneumoretroperitoneum. The secondary outcomes were length of intubation and death. In patients with pneumomediastinum and/or subcutaneous emphysema, we conducted an imaging review to determine the timeline of barotrauma development., Results: Forty three out of 363 (12%) patients developed barotrauma radiographically. The median time to development of either pneumomediastinum or subcutaneous emphysema was 2 days (IQR 1.0-4.5) after intubation and the median time to pneumothorax was 7 days (IQR 2.0-10.0). The overall incidence of pneumothorax was 28/363 (8%) with an incidence of 17/43 (40%) in the barotrauma cohort and 11/320 (3%) in those without barotrauma (p ≤ 0.001). In total, 257/363 (71%) patients died with an increase in mortality in those with barotrauma 33/43 (77%) vs. 224/320 (70%). When adjusting for covariates, barotrauma was associated with increased odds of death (OR 2.99, 95% CI 1.25-7.17)., Conclusion: Barotrauma is a frequent complication of mechanically ventilated COVID-19 patients. In comparison to intubated COVID-19 patients without barotrauma, there is a higher rate of pneumothorax and an increased risk of death., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Pneumothorax (PTX) and pneumomediastinum (PM), collectively termed here "air leak", are now well described complications of severe COVID-19 pneumonia across several case series. The incidence is thought to be approximately 1% but is not definitively known., Objectives: To report the incidence and describe the demographic features, risk factors and outcomes of patients with air leak as a complication of COVID-19., Methods: A retrospective observational study on all adult patients with COVID-19 admitted to Watford General Hospital, West Hertfordshire NHS Trust between March 1st 2020 and Feb 28 th 2021. Patients with air leak were identified after reviewing both chest radiographs (CXRs) and axial imaging (CT Thorax) with confirmatory radiology reports inclusive of the terms PTX and/or PM., Results: Air leak occurred with an incidence of 0.56%. Patients with air leak were younger and had evidence of more severe disease at presentation, including a higher median CRP and number of abnormal zones affected on chest radiograph. Asthma was a significant risk factor in the development of air leak (OR 13.4 [4.7-36.4]), both spontaneously and following positive pressure ventilation. CPAP and IMV were also associated with a greater than six fold increase in the risk of air leak (OR 6.4 [2.5-16.6] and 9.8 [3.7-27.8] respectively). PTX, with or without PM, in the context of COVID-19 pneumonia was almost universally fatal whereas those with alone PM had a lower risk of death., Conclusion: Despite the global vaccination programme, patients continue to develop severe COVID-19 disease and may require respiratory support. This study demonstrates the importance of identifying that deterioration in such patients may be resultant from PTX or PM, particularly in asthmatics and those managed with positive pressure ventilation.

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

Introduction: Mechanical ventilation is a last resort solution for patients presenting with acute respiratory distress syndrome produced by SARS-CoV-2. Spontaneous pneumomediastinum is a rare pathology associated with invasive mechanical ventilation. The objective of our research was to highlight the increased incidence of spontaneous pneumomediastinum during the COVID-19 pandemics in our hospital. Material and method: A retrospective review of the cases in our hospital requiring surgical evaluation was performed. Electronic health records from our institution were searched for nontraumatic pneumomediastinum from October to November 2021. All patients that were identified with pneumomediastinum were included in the review. Results: We identified 12 mechanical ventilated patients that presented with free air in the mediastinum on a computed tomography during the study period. All of the patients had SARS-CoV-2 bronchopneumonia with extensive pulmonary involvement. The mortality rate among these patients was 58.33%. Conclusions: The main take-home message of our study is that the incidence of mechanically ventilation-associated pneumomediastinum was exponentially higher during the fourth wave of COVID-19. There is a need for multicenter data in this pathology for a better approach and to define surgical management options for these patients., (Celsius.)

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., (Celsius.)

Purpose: To validate the role of Macklin effect on chest CT imaging in predicting subsequent occurrence of pneumomediastinum/pneumothorax (PMD/PNX) in COVID-19 patients., Materials and Methods: This is an observational, case-control study. Consecutive COVID-19 patients who underwent chest CT scan at hospital admission during the study time period (October 1st, 2020-April 31st, 2021) were identified. Macklin effect accuracy for prediction of spontaneous barotrauma was measured in terms of sensitivity, specificity, positive (PPV) and negative predictive values (NPV)., Results: Overall, 981 COVID-19 patients underwent chest CT scan at hospital arrival during the study time period; 698 patients had radiological signs of interstitial pneumonia and were considered for further evaluation. Among these, Macklin effect was found in 33 (4.7%), including all 32 patients who suffered from barotrauma lately during hospital stay (true positive rate: 96.9%); only 1/33 with Macklin effect did not develop barotrauma (false positive rate: 3.1%). No barotrauma event was recorded in patients without Macklin effect on baseline chest CT scan. Macklin effect yielded a sensitivity of 100% (95% CI: 89.1-100), a specificity of 99.85% (95% CI: 99.2-100), a PPV of 96.7% (95% CI: 80.8-99.5), a NPV of 100% and an accuracy of 99.8% (95% CI: 99.2-100) in predicting PMD/PNX, with a mean advance of 3.2 ± 2.5 days. Moreover, all Macklin-positive patients developed ARDS requiring ICU admission and, in 90.1% of cases, invasive mechanical ventilation., Conclusions: Macklin effect has high accuracy in predicting PMD/PNX in COVID-19 patients; it is also an excellent predictor of disease severity., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objectives: In this study, we aimed to establish risk factors for primary spontaneous pneumomediastinum associated with Coronavirus disease 2019 (COVID-19) and reveal those which are significant., Methods: The study included 62 patients with primary spontaneous pneumomediastinum who presented to our hospital between 11 March 2020, the date of the first-reported COVID-19 case in our country, and 3 January 2021. Of these, 14 patients (22.6%) had COVID-19 and 48 patients (77.4%) did not have COVID-19., Results: Of the 62 patients included in the study, 41 (66.1%) were male and 21 (33.9%) were female. The mean age was 28.90 ± 16.86 (range, 16-84) years. The most common symptom at admission was chest pain (54.8%). The mean age of the patients with COVID-19 was 39.35 ± 23.04 years and that of the patients without COVID-19 was 25.85 ± 13.45 years (P < 0.001). In receiver-operating characteristic curve analysis, the area under the curve for age was 0.785 (95% confidence interval: 0.648-0.922) and the optimal cut-off value was 24 years for COVID-19-positive patients. The highest sensitivity and specificity values were 0.857 and 0.729. Twelve (85.79%) of the COVID-19-positive primary spontaneous pneumomediastinum patients were aged 24 years or older (P < 0.001). Five patients (8.1%) had positive severe acute respiratory syndrome coronavirus 2 polymerase chain reaction test but no abnormal findings on computed tomography., Conclusions: Having an age of more than 24 years was associated with a higher prevalence of pneumomediastinum in COVID-19 patients and emerged as an important risk factor. Multicentre studies with more cases are needed to determine whether pneumomediastinum is associated with additional other risk factors related to COVID-19., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.)

Pneumomediastinum and pneumothorax are recognised complications encountered in COVID-19 before or during invasive mechanical ventilation (IMV). The clinical course of patients developing pneumomediastinum before IMV is yet to be evaluated.Four-thousand, one-hundred and thirty-one patients hospitalised with COVID-19 over a 12-month period were retrospectively reviewed to evaluate for incidence, clinical characteristics and outcomes. A subgroup analysis was done to identify any clinical traits between survivors and non-survivors. The overall incidence of pneumomediastinum prior to IMV was 0.92% (n=38) and was seen at admission or during non-invasive respiratory support. Thirty-seven per cent had associated pneumothorax most commonly unilateral (right side). The median (interquartile range (IQR)) duration from admission to developing pneumomediastinum was 7 days (3-11) and complete resolution was seen in 53% of patients; median (IQR) duration to resolution was 8 days (4-17). The in-hospital mortality associated with pneumomediastinum in patients with SARS-CoV-2 (PneumoCoV) was 55%. Increasing age (68 ± 12 years vs 56 ± 14 years; p=0.01), higher body mass index (31 ± 5 kg/m 2 vs 28 ± 5 kg/m 2 ; p=0.04), lack of resolution of pneumomediastinum (67% vs 24%; p=0.01; odds ratio (OR) 6.5; 95% confidence interval (CI) 1.5-27.5), presence of concurrent pneumothorax (65% vs 14%; p=0.002; OR 11; 95% CI 2.2-53.1) and elevated procalcitonin levels (>0.5 ng/mL; 81% vs 41%; p=0.01; OR 6; 95% CI 1.4-26) were significant features in those who did not survive.The incidence of PneumoCoV, despite being low, is associated with increased mortality. It is a hallmark of moderate to severe disease with multifaceted contributory factors. Both demographic and clinical factors predict survival., (© Royal College of Physicians 2022. All rights reserved.)

Objectives: The incidence of pneumomediastinum (PNMD), its causes of development and its effect on prognosis in the coronavirus disease 2019 (COVID-19) are not clear., Methods: Between March 2020 and December 2020, 427 patients with real-time reverse transcriptase-polymerase chain reaction-confirmed COVID-19 admitted to the intensive care unit were analysed retrospectively. Using receiver operating characteristic analysis, the area under the curve (AUC) for initial invasive mechanical ventilation (MV) variables such as initial peak inspiratory pressure (PIP), PaO2/FiO2 (P/F ratio), tidal volume, compliance and positive end-expiratory pressure was evaluated regarding PNMD development., Results: The incidence of PNMD was 5.6% (n = 24). PNMD development rate was 2.7% in non-invasive MV and 6.2% in MV [odds ratio (OR) 2.352, 95% confidence interval (CI) 0.541-10.232; P = 0.400]. In the multivariate analysis, the independent risk factors affecting the development of PNMD were PIP (OR 1.238, 95% CI 1.091-1.378; P < 0.001) and P/F ratio (OR 0.982, 95% CI 0.971-0.994; P = 0.004). P/F ratio (AUC 0.815, 95% CI 0.771-0.854), PIP (AUC 0.780, 95% CI 0.734-0.822), compliance (AUC 0.735, 95% CI 0.677-0.774) and positive end-expiratory pressure (AUC 0.718, 95% CI 0.668-0.764) were the best predictors for PNMD development. Regarding the multivariate analysis, independent risk factors affecting mortality were detected as age (OR 1.015, 95% CI 0.999-1.031; P = 0.04), comorbidity (OR 1.940, 95% CI 1.100-3.419; P = 0.02), mode of breathing (OR 48.345, 95% CI 14.666-159.360; P < 0.001), PNMD (OR 5.234, 95% CI 1.379-19.857; P = 0.01), positive end-expiratory pressure (OR 1.305, 95% CI 1.062-1.603; P = 0.01) and tidal volume (OR 0.995, 95% CI 0.992-0.998; P = 0.004)., Conclusions: PNMD development was associated with the initial P/F ratio and PIP. Therefore, it was considered to be related to both the patient and barotrauma. PNMD is a poor prognostic factor for COVID-19., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.)

Background: Since the beginning of the ongoing Coronavirus Disease 2019 (COVID-19) pandemic, pneumomediastinum has been reported in patients with COVID-19 pneumonia and acute respiratory distress syndrome. It has been suggested that pneumomediastinum may portend a worse outcome in such patients although no investigation has established this association definitively. Research Question: We hypothesized that the finding of pneumomediastinum in the setting of COVID-19 disease may be associated with a worse clinical outcome. The purpose of this study was to determine if the presence of pneumomediastinum was predictive of increased mortality in patients with COVID-19. Study Design and Methods: A retrospective case-control study utilizing clinical data and imaging for COVID-19 patients seen at our institution from 3/7/2020 to 5/20/2020 was performed. 87 COVID-19 positive patients with pneumomediastinum were compared to 87 COVID-19 positive patients without pneumomediastinum and to a historical group of patients with pneumomediastinum during the same time frame in 2019. Results: The incidence of pneumomediastinum was increased more than 6-fold during the COVID-19 pandemic compared to 2019 ( P  = <.001). 1.5% of all COVID-19 patients and 11% of mechanically ventilated COVID-19 patients at our institution developed pneumomediastinum. Patients who developed pneumomediastinum had a significantly higher PEEP and lower P/F ratio than those who did not ( P  = .002 and .033, respectively). Pneumomediastinum was not found to be associated with increased mortality ( P  = .16, confidence interval [CI]: 0.89-2.09, 1.37). The presence of concurrent pneumothorax at the time of pneumomediastinum diagnosis was associated with increased mortality ( P  = .013 CI: 1.15-3.17, 1.91). Conclusion: Pneumomediastinum is not independently associated with a worse clinical prognosis in COVID-19 positive patients. The presence of concurrent pneumothorax was associated with increased mortality.

Background: Pneumomediastinum, an uncommon entity, has been on the rise with increasing cases of COVID-Acute respiratory distress syndrome. It has been unclear whether this entity represents an indicator of poor clinical outcome or not. The aims of this study were to find out the incidence of pneumomediastinum in COVID-Acute respiratory distress syndrome patients, describe their clinical characteristics and try to explain its plausible mechanisms.., Methods: A descriptive, cross-sectional study was carried out in the ICU of our hospital among 280 patients admitted with COVID-Acute respiratory distress syndrome over a period of 6 months. Demographics along with various clinical, laboratory, and radiological parameters were analyzed. Relevant statistical analyses were done to summarize our findings., Results: The incidence of pneumomediastinum in COVID-ARDS patients was 2.8%. All patients were male, none had pulmonary co-morbidities and six of them (60%) were on invasive mechanical ventilation. All intubated patients were on lung protective mechanical ventilation. The median PEEP, peak airway pressure and plateau pressure were 10 (IQR: 4), 29 (IQR: 8) and 28 (IQR: 4) respectively. The mean CT severity score was 22.7 (SD: 1.64). Five patients died after 6.8 days (SD: 4.8) of diagnosis. The average hospital stay was of 34 days., Conclusions: Pneumomediastinum is a possible complication of COVID-Acute respiratory distress syndrome which could signify the disease severity and vice versa. Furthermore, it could be an indicator of relatively poor prognosis and therefore requires larger studies to establish the association.

Objective: To determine the incidence, predictors, and outcome of pneumothorax (PNX)/pneumomediastinum (PMD) in coronavirus disease 2019 (COVID-19) acute respiratory distress syndrome (ARDS)., Design: Observational study., Setting: Tertiary-care university hospital., Participants: One hundred sixteen consecutive critically ill, invasively ventilated patients with COVID-19 ARDS., Interventions: The authors collected demographic, mechanical ventilation, imaging, laboratory, and outcome data. Primary outcome was the incidence of PNX/PMD. Multiple logistic regression analyses were performed to identify predictors of PNX/PMD., Measurements and Main Results: PNX/PMD occurred in a total of 28 patients (24.1%), with 22 patients developing PNX (19.0%) and 13 developing PMD (11.2%). Mean time to development of PNX/PMD was 14 ± 11 days from intubation. The authors found no significant difference in mechanical ventilation parameters between patients who developed PNX/PMD and those who did not. Mechanical ventilation parameters were within recommended limits for protective ventilation in both groups. Ninety-five percent of patients with PNX/PMD had the Macklin effect (linear collections of air contiguous to the bronchovascular sheaths) on a baseline computed tomography scan, and tended to have a higher lung involvement at intensive care unit (ICU) admission (Radiographic Assessment of Lung Edema score 32.2 ± 13.4 v 18.7 ± 9.8 in patients without PNX/PMD, p = 0.08). Time from symptom onset to intubation and time from total bilirubin on day two after ICU admission were the only independent predictors of PNX/PMD. Mortality was 60.7% in patients who developed PNX/PMD versus 38.6% in those who did not (p = 0.04)., Conclusion: PNX/PMD occurs frequently in COVID-19 patients with ARDS requiring mechanical ventilation, and is associated with increased mortality. Development of PNX/PMD seems to occur despite use of protective mechanical ventilation and has a radiologic predictor sign., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: There are limited data regarding the incidence of pneumothorax in COVID-19 patients as well as the impact of the same on patient outcomes., Methods: A retrospective review of the medical records at three large tertiary care hospitals in Mumbai was performed to identify patients hospitalised with COVID-19 from March 2020 to October 2020. The presence of pneumothorax and/or pneumomediastinum was noted when chest radiographs or CT scans were performed. Demographic and clinical characteristics of patients who developed air leak were recorded., Results: 4,906 patients with COVID-19 were admitted, with 1,324 (27%) having severe COVID-19 disease. The overall incidence of pneumothorax and/or pneumomediastinum in patients with severe disease was 3.2% (42/1,324). Eighteen patients had pneumothorax, 16 had pneumomediastinum and 8 patients had both. Fourteen patients (33.3%) developed this complication breathing spontaneously, 28 patients (66.6%) developed it during mechanical ventilation. Overall mortality in this cohort was 74%, compared with 17% in the COVID-19 patients without pneumothorax (p<0.001)., Conclusions: Our study demonstrates that air leaks occur with a higher frequency in patients with COVID-19 than in other ICU patients. When present, such air leaks contributed to poor outcomes with almost 74% mortality rates in these patients., (© Royal College of Physicians 2021. All rights reserved.)

Objectives: To evaluate the presentation characteristics and disease course of seven patients with COVID-19 who spontaneously developed pneumomediastinum without a history of mechanical ventilation., Methods: A total of seven non-intubated patients with COVID-19, of age ranging from 18-67 years, who developed spontaneous pneumomediastinum between 01 April and 01 October 2020 were included in the study. Patients' demographic data, clinical variables, and laboratory values were examined. Spontaneous pneumomediastinum was evaluated using posteroanterior chest radiography and thorax computed tomography., Results: During the research period, 38,492 patients reported to the emergency department of our hospital with COVID-19 symptoms. Of these, spontaneous pneumomediastinum was detected in seven patients who had no previous history of intubation. Chronic obstructive pulmonary disease (2/7) and asthma bronchiale (2/7) were determined as the most common causes of comorbidity., Conclusions: In our study, the frequency of spontaneous pneumomediastinum developing without pneumothorax was found to be high in non-intubated patients. Whether this is related to the nature of the disease or it is a result of the increase in cases diagnosed incidentally owing to the increasing use of low-dose computed tomography should be explored in further studies.

In this study, we compared the incidence of pneumomediastinum in coronavirus disease (COVID-19) patients during the ascending phases of the 1st and 2nd epidemic waves. Crude incidence was higher during the 2nd wave at a quasi-significant level (0.68/1000 vs. 2.05/1000 patient-days, p = 0.05). When restricting the analysis to patients who developed pneumomediastinum during noninvasive ventilation, the difference became clearly significant (0.17/1000 vs 1.36/1000 patient-days, p = 0.039). At logistic regression, predisposing factors (p = 0.031), and COVID-19 radiological severity (p = 0.019) were independently associated with pneumomediastinum. Mortality in patients with pneumomediastinum was 87.5%. However, pneumomediastinum seemed to be related to a generally worse disease presentation in hospitalized patients during the 2nd wave, rather than to a separate pattern of disease., Competing Interests: Conflict of Interest None of the author has any relevant conflict of interest of any nature to disclose. Prof. Paola Rogliani has received research grants from a few pharmaceutical companies, outside of the present study., (Copyright © 2021 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.)

Background: Spontaneous pneumomediastinum is characterized by the presence of interstitial air in the mediastinum without any underlying disease. Some cases of spontaneous pneumomediastinum have been reported in the past, although only few reports are available, and its management remains uncertain. This study reviewed our experience in the diagnosis and treatment of spontaneous pneumomediastinum., Methods: A retrospective study of 71 cases treated for spontaneous pneumomediastinum at the Yodogawa Christian Hospital between April 2005 and March 2020 was conducted., Results: The patients' mean age was 19.3 years (range, 7-48 years). A triggering event was noted in 69% of the cases. Seventy-six percent of the patients were admitted to the hospital, and 24% were outpatients. Treatment included analgesia, rest, antibiotics, and/or oxygen therapy. Thirty-six patients (51%) were treated with antibiotics. None of the cases presented any complications, including mediastinitis or worsening respiratory condition. Two patients (3%) had a recurrence of spontaneous pneumomediastinum., Conclusions: All the patients, with or without antimicrobial treatment and hospitalization, had favorable outcomes. We should therefore reconsider the need for hospitalization and antimicrobial therapy for patients with mediastinitis prophylaxis., Competing Interests: Conflict of Interest All authors have no conflicts of interest to declare., (Copyright © 2021 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.)

Aim: Pneumomediastinum (PM) is associated with several etiologies and mechanisms. Although it has been described more than 100 years ago, the literature is limited to small retrospective studies. This study aimed to follow patients with coronavirus disease (COVID-19) that developed PM during hospitalization and describe their clinical and radiological evolution., Methods: A prospective cohort was developed with patients with PM, excluding those with aerodigestive trauma, inside a hospital COVID-19 dedicated hospital. Clinical variables including onset of symptoms, hemodynamic instability, associated complications, the need of interventions, and disease course were all recorded. Also, radiological findings such as the presence of the Macklin effect, extension of lung involvement by COVID-19, and characteristics of the PM were analyzed., Results: Twenty-one patients with non-traumatic PM were followed, resulting in an overall incidence of 0.5% during the study period. Seven (33%) patients had associated pneumothorax and malignant/tension PM was observed in three (14%) cases. The Macklin effect could be found in 11 patients (52%) and the majority of them had more than 50% of lung involvement due to COVID-19. The mortality rate was 49%; however, no deaths were directly related to the PM., Conclusions: PM incidence is probably increased in the severe acute respiratory syndrome caused by COVID-19, especially in those with greater involvement of the lungs, and the Macklin effect may be an important underlying mechanism of this complication. Usually, PM has a benign course, but complications like tension/malignant PM may occur requiring prompt detection and intervention.

The novel coronavirus identified as severe acute respiratory syndrome-coronavirus-2 causes acute respiratory distress syndrome (ARDS). Our aim in this study is to assess the incidence of life-threatening complications like pneumothorax, haemothorax, pneumomediastinum and subcutaneous emphysema, probable risk factors and effect on mortality in coronavirus disease-2019 (COVID-19) ARDS patients treated with mechanical ventilation (MV). Data from 96 adult patients admitted to the intensive care unit with COVID-19 ARDS diagnosis from 11 March to 31 July 2020 were retrospectively assessed. A total of 75 patients abiding by the study criteria were divided into two groups as the group developing ventilator-related barotrauma (BG) (N = 10) and the group not developing ventilator-related barotrauma (NBG) (N = 65). In 10 patients (13%), barotrauma findings occurred 22 ± 3.6 days after the onset of symptoms. The mortality rate was 40% in the BG-group, while it was 29% in the NBG-group with no statistical difference identified. The BG-group had longer intensive care admission duration, duration of time in prone position and total MV duration, with higher max positive end-expiratory pressure (PEEP) levels and lower min pO2/FiO2 levels. The peak lactate dehydrogenase levels in blood were higher by statistically significant level in the BG-group (P < 0.05). The contribution of MV to alveolar injury caused by infection in COVID-19 ARDS patients may cause more frequent barotrauma compared to classic ARDS and this situation significantly increases the MV and intensive care admission durations of patients. In terms of reducing mortality and morbidity in these patients, MV treatment should be carefully maintained within the framework of lung-protective strategies and the studies researching barotrauma pathophysiology should be increased.

Introduction: Pneumomediastinum (PM) is characterized by the presence of air within the mediastinum. The association between PM and coronavirus 2019 (COVID-19) has not been well established in the current literature. We sought to summarize the limited body of literature regarding PM in patients with COVID-19 and characterize the presentation and clinical outcomes of PM in patients with severe acute respiratory syndrome (SARS)-COV-2 pneumonia at our institution to better define the incidence, prognosis, and available treatment for this condition. Materials and Methods: All patients with a proven diagnosis of COVID-19 and PM between March 18, 2020 and May 5, 2020 were identified through hospital records. Retrospective analysis of radiology records and chart review were conducted. Clinical characteristics and outcomes were collected and descriptive statistics was analyzed. Results: Thirty-six patients met inclusion criteria. Out of the 346 intubated COVID-19 patients, 34 (10%) had PM. The incidence of PM increased for the first 4 weeks of the pandemic, and then began to decrease by week 5. At the endpoint of the study, 12 (33.33%) patients were alive and 24 patients (66.67%) had died. Conclusion: PM, although a rare phenomenon, was more prevalent in COVID-19 patients compared with historical patients with adult respiratory distress syndrome. The etiology of this condition may be attributed to higher susceptibility of patients infected with SARS-CoV-2 to a combination of barotrauma and airway injury.

Since December 2019, the clinical symptoms of coronavirus disease 2019 (COVID-19) and its complications are evolving. As the number of COVID patients requiring positive pressure ventilation is increasing, so is the incidence of subcutaneous emphysema (SE). We report 10 patients of COVID-19, with SE and pneumomediastinum. The mean age of the patients was 59 ± 8 years (range, 23-75). Majority of them were men (80%), and common symptoms were dyspnoea (100%), fever (80%) and cough (80%). None of them had any underlying lung disorder. All patients had acute respiratory distress syndrome on admission, with a median PaO2/FiO2 ratio of 122.5. Eight out of ten patients had spontaneous pneumomediastinum on their initial chest x-ray in the emergency department. The median duration of assisted ventilation before the development of SE was 5.5 days (interquartile range, 5-10 days). The highest positive end-expiratory pressure (PEEP) was 10 cmH2O for patients recieving invasive mechanical ventilation, while 8 cmH2O was the average PEEP in patients who had developed subcutaneous emphysema on non-invasive ventilation. All patients received corticosteroids while six also received tocilizumab, and seven received convalescent plasma therapy, respectively. Seven patients died during their hospital stay. All patients either survivor or non-survivor had prolonged hospital stay with an average of 14 days (range 8-25 days). Our findings suggest that it is lung damage secondary to inflammatory response due to COVID-19 triggered by the use of positive pressure ventilation which resulted in this complication. We conclude that the development of spontaneous pneumomediastinum and SE whenever present, is associated with poor outcome in critically ill COVID-19 ARDS patients.

COVID-19 is associated with rarer extra-parenchymal manifestations, namely pneumothorax (PTX) and pneumomediastinum (PM) leading to complications and increased mortality. The study aims to describe the prevalence, risk factors for mortality, radiological characteristics and outcome of PTX/PM in patients admitted with COVID-19. This was a retrospective, single-centre, observational study in patients with confirmed COVID-19 presenting with non-iatrogenic PTX/PM from April 2020 to May 2021. Details pertaining to demographics, presentation, radiological characteristics, management and outcome were collected. Cases were classified into spontaneous and barotraumatic PTX/PM and a between-group comparison was performed using Chi-square and t-test. A total of 45 cases (mean age: 53.2 years, 82% males) out of 8,294 confirmed COVID-19 patients developed PTX/PM, the calculated incidence being 0.54%. 29 cases had spontaneous PTX/PM and the remaining 17 cases were attributed to barotrauma. The most common comorbidities were diabetes-mellitus (65.3%) and hypertension (42.3%). The majority of the cases had large PTX (62.1%) with tension in 8 cases (27.5%). There were predominant right-sided pneumothoraces and five were diagnosed with bronchopleural fistula. 37.7% of cases had associated subcutaneous emphysema. The median duration of PTX/PM from symptom onset was delayed at 22.5 and 17.6 days respectively. The mean CT severity score (CTSS) was 20.5 (± 4.9) with fibrosis (53.8%), bronchiectatic changes (50%) and cystic-cavitary changes (23%). There was no statistically significant difference between the spontaneous and barotrauma cohort. 71% of cases died and the majority belonged to the barotrauma cohort. It is imperative to consider the possibility of PTX/PM in patients having COVID-19, especially in those with deterioration in the disease course, both in spontaneously breathing and mechanically ventilated patients. These patients may also have a high incidence of death, reflecting the gravity of COVID-19.

Objective: To determine the optimal management of pneumomediastinum in patients with a novel coronavirus infection (COVID-19)., Material and Methods: There were 14 patients with pneumomediastinum and COVID-19 infection without mechanical ventilation. We discussed the world data on pneumomediastinum in patients with coronavirus infection., Results: Before the COVID-19 pandemic, the annual number of own observations of spontaneous pneumomediastinum did not exceed 1-2 patients. The mechanism of pneumomediastinum is explained by the Macklin effect. COVID-19 pandemic in the Russian Federation was followed by increase of the number of patients with pneumomediastinum up to 2.4% of the total number of patients in the thoracic department. In this sample, pneumomediastinum occurred at all variants of the course of coronavirus infection. The timing of pneumomediastinum ranged from 2 to 18 (median 14) days after clinical manifestation of COVID-19. In 2 out of 14 cases, pneumomediastinum was the main symptom of coronavirus infection at admission. One patient had a combination of pneumomediastinum and pneumothorax. In 6 cases, pneumomediastinum was stable and regressed under conservative therapy. Eight patients underwent Razumovsky suprajugular mediastinotomy. There were no postoperative deaths. Recurrent pneumomediastinum was noted in one patient., Conclusion: The causes of pneumomediastinum in some patients with coronavirus infection, peculiarities of diagnosis and treatment and clarification of indications for invasive interventions require further study.

Introduction: Pneumothorax and pneumomediastinum have both been noted to complicate cases of coronavirus disease 2019 (COVID-19) requiring hospital admission. We report the largest case series yet described of patients with both these pathologies (including nonventilated patients)., Methods: Cases were collected retrospectively from UK hospitals with inclusion criteria limited to a diagnosis of COVID-19 and the presence of either pneumothorax or pneumomediastinum. Patients included in the study presented between March and June 2020. Details obtained from the medical record included demographics, radiology, laboratory investigations, clinical management and survival., Results: 71 patients from 16 centres were included in the study, of whom 60 had pneumothoraces (six with pneumomediastinum in addition) and 11 had pneumomediastinum alone. Two of these patients had two distinct episodes of pneumothorax, occurring bilaterally in sequential fashion, bringing the total number of pneumothoraces included to 62. Clinical scenarios included patients who had presented to hospital with pneumothorax, patients who had developed pneumothorax or pneumomediastinum during their inpatient admission with COVID-19 and patients who developed their complication while intubated and ventilated, either with or without concurrent extracorporeal membrane oxygenation. Survival at 28 days was not significantly different following pneumothorax (63.1±6.5%) or isolated pneumomediastinum (53.0±18.7%; p=0.854). The incidence of pneumothorax was higher in males. 28-day survival was not different between the sexes (males 62.5±7.7% versus females 68.4±10.7%; p=0.619). Patients aged ≥70 years had a significantly lower 28-day survival than younger individuals (≥70 years 41.7±13.5% survival versus <70 years 70.9±6.8% survival; p=0.018 log-rank)., Conclusion: These cases suggest that pneumothorax is a complication of COVID-19. Pneumothorax does not seem to be an independent marker of poor prognosis and we encourage continuation of active treatment where clinically possible., Competing Interests: Conflict of interest: A.W. Martinelli has nothing to disclose. Conflict of interest: T. Ingle has nothing to disclose. Conflict of interest: J. Newman has nothing to disclose. Conflict of interest: I. Nadeem has nothing to disclose. Conflict of interest: K. Jackson has nothing to disclose. Conflict of interest: N.D. Lane reports non-financial support from Chiesi, outside the submitted work. Conflict of interest: J. Melhorn has nothing to disclose. Conflict of interest: H.E. Davies has nothing to disclose. Conflict of interest: A.J. Rostron has nothing to disclose. Conflict of interest: A. Adeni has nothing to disclose. Conflict of interest: K. Conroy has nothing to disclose. Conflict of interest: N. Woznitza reports grants from Cancer Research UK and Roy Castle Lung Cancer Foundation, and personal fees from InHealth, outside the submitted work. Conflict of interest: M. Matson has nothing to disclose. Conflict of interest: S.E. Brill has nothing to disclose. Conflict of interest: J. Murray has nothing to disclose. Conflict of interest: A. Shah has nothing to disclose. Conflict of interest: R. Naran has nothing to disclose. Conflict of interest: S.S. Hare has nothing to disclose. Conflict of interest: O. Collas has nothing to disclose. Conflict of interest: S. Bigham has nothing to disclose. Conflict of interest: M. Spiro has nothing to disclose. Conflict of interest: M.M. Huang has nothing to disclose. Conflict of interest: B. Iqbal has nothing to disclose. Conflict of interest: S. Trenfield has nothing to disclose. Conflict of interest: S. Ledot has nothing to disclose. Conflict of interest: S. Desai has nothing to disclose. Conflict of interest: L. Standing has nothing to disclose. Conflict of interest: J. Babar has nothing to disclose. Conflict of interest: R. Mahroof has nothing to disclose. Conflict of interest: I. Smith has nothing to disclose. Conflict of interest: K. Lee has nothing to disclose. Conflict of interest: N. Tchrakain Nothing to declare. Conflict of interest: S. Uys has nothing to disclose. Conflict of interest: W. Ricketts has nothing to disclose. Conflict of interest: A.R.C. Patel has nothing to disclose. Conflict of interest: A. Aujayeb has nothing to disclose. Conflict of interest: M. Kokosi has nothing to disclose. Conflict of interest: A.J.K. Wilkinson has nothing to disclose. Conflict of interest: S.J. Marciniak has nothing to disclose., (Copyright ©ERS 2020.)

Purpose: We describe the presenting characteristics and hospital course of 11 novel coronavirus (COVID-19) patients who developed spontaneous subcutaneous emphysema (SE) with or without pneumomediastinum (SPM) in the absence of prior mechanical ventilation., Materials and Methods: A total of 11 non-intubated COVID-19 patients (8 male and 3 female, median age 61 years) developed SE and SPM between March 15 and April 30, 2020 at a multi-center urban health system in New York City. Demographics (age, gender, smoking status, comorbid conditions, and body-mass index), clinical variables (temperature, oxygen saturation, and symptoms), and laboratory values (white blood cell count, C-reactive protein, D-dimer, and peak interleukin-6) were collected. Chest radiography (CXR) and computed tomography (CT) were analyzed for SE, SPM, and pneumothorax by a board-certified cardiothoracic-fellowship trained radiologist., Results: Eleven non-intubated patients developed SE, 36% (4/11) of whom had SE on their initial CXR. Concomitant SPM was apparent in 91% (10/11) of patients, and 45% (5/11) also developed pneumothorax. Patients developed SE on average 13.3 days (SD: 6.3) following symptom onset. No patients reported a history of smoking. The most common comorbidities included hypertension (6/11), diabetes mellitus (5/11), asthma (3/11), dyslipidemia (3/11), and renal disease (2/11). Four (36%) patients expired during hospitalization., Conclusion: SE and SPM were observed in a cohort of 11 non-intubated COVID-19 patients without any known cause or history of invasive ventilation. Further investigation is required to elucidate the underlying mechanism in this patient population., Competing Interests: Declaration of competing interest The authors have no conflicts of interests to disclose. No financial or material support was received for this work., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Spontaneous pneumomediastinum is a benign entity but can worsen the underlying condition with which it is associated. We evaluated the incidence and the clinical relevance of spontaneous pneumomediastinum in a consecutive series of 102 patients with COVID-19 pneumonia. Six cases of pneumomediastinum were identified by high-resolution chest CT-scan. Three patients required early intubation, and one of them died, while in in the remaining subjects the clinical course was benign. The presence of pneumomediastinum required some changes in the management of mechanical ventilation. In conclusion, spontaneous pneumomediastinum is a possible complication of severe COVID-19 pneumonia that can affect patient management and clinical outcomes.

Objective: To get a clear view of the current state of treatment for esophageal perforation in Japan. Esophagus perforations are the most serious gastrointestinal tract perforations and are associated with high morbidity and mortality. The optimal treatment choice remains unknown., Methods: We conducted a retrospective clinical review of 182 esophageal perforation cases at 108 hospitals accredited by the Japanese Esophageal Society between January 2010 and December 2015., Results: We found that 20.9% of patients were incorrectly diagnosed initially. We observed mediastinum emphysema in 83.5% of patients, and serious abscess formations of the mediastinum and intrathoracic cavity in 38.6% and 29.6%, respectively. The lower esophagus was the most commonly perforated site (77.7%). Management of esophageal perforations included nonoperative treatment in 20 patients (11%) and operative treatment in 162 patients (89%). The overall mortality rate was 6.9%. The survivors had significantly shorter times from symptom appearance to visit (p = 0.0016), and from time to visit to diagnosis confirmation (p = 0.0011). Moreover, patients older than 65 years, white blood cells less than 3000/mm 3 , C-reactive protein > 10 mg/L, or abscesses in the thoracic cavity showed significantly higher mortality than others., Conclusion: Shortening the time from onset to the start of treatment contributes to reduce mortality in patients with esophageal perforation. Moreover, strict medical treatment is necessary to lower the mortality rate of elderly patients with strong inflammation and abscesses in the thoracic cavity.

Background: Extremely preterm infants are peculiar in regard to their risk of retinopathy of prematurity (ROP). In this study, we aim to study insults that may affect extremely preterm infants, including prenatal, at birth, and postnatal insults and their effect on the development of ROP., Methods: This study used the data from Prematurity and Respiratory Outcomes Program (PROP). All included infants with a gestational age of 23 0/7 to 28 6/7 weeks using best obstetrical estimate. We included stressful events and/or modifiable variables that may affect the normal development. We used multiple regression analysis in our statistical analysis., Results: We included a total of 751 infants in our study. The mean birth weight for the included sample was 915.1 (±232.94) grams. 391 (52.1%) Infants were diagnosed with ROP. We found a significant negative correlation between ROP development and birth weight (p < 0.001), with a correlation coefficient of - 0.374. We found that the need for prophylactic indomethacin (OR 1.67), the occurrence of air leaks (OR: 2.35), ventilator-associated pneumonia (OR: 2.01), isolated bowel perforations (OR: 3.7), blood culture-proven sepsis (OR: 1.5), other infections (OR: 1.44), and receiving ventricular shunt (OR: 2.9) are significantly associated with the development of ROP., Conclusions: We believe this study included the largest number of factors studied in the largest sample of extremely premature infants. We recommend a screening program for extremely preterm infants that takes into account a scoring system with higher scores for complicated condition.

Background/aims: Recently, postendoscopic submucosal dissection electrocoagulation syndrome (PEECS) has attracted attention. However, the criteria for computed tomography (CT) scanning following esophageal endoscopic submucosal dissection (ESD) are unclear. In this study, we aimed to identify the predictive factors of PEECS and the usefulness of CT scanning after esophageal ESD., Methods: A total of 245 lesions in 223 patients who underwent esophageal ESD between February 2008 and October 2018 were retrospectively analyzed. Patients with double cancers, those who experienced procedural accidents, such as aspiration pneumonitis or perforation, and those who were unable to undergo CT were excluded from the study. PEECS evaluation items included body temperature (≤37.7°C = 1 point, ≥37.8°C = 2 points), white blood cell count (<10,800/μL = 1 point, ≥10,800/μL = 2 points), and chest pain (numerical rating scale [NRS] ≤4 = 1 point, NRS ≥5 = 2 points). Scores of ≥5 points were categorized as the PEECS-positive group, and scores of ≤4 points were categorized as the PEECS-negative group. The degree of mediastinal emphysema on CT was stratified into 5 grades, in which grades 0 and 1 were considered as the "low-grade" group, and grades 2, 3, and 4 were considered as the "high-grade" group. We analyzed the prognostic factors of high-grade mediastinal emphysema, including the presence or absence of PEECS., Results: The PEECS-positive group comprised 18 out of the 163 patients (11.0%), and mediastinal emphysema was stratified into grades 0 (94), 1 (51), 2 (12), 3 (5), and 4 (1 patient). Three independent risk factors for the onset of PEECS were identified, as follows: resected area ≥750 mm2 (OR 7.28, 95% CI 1.42-37.33, p = 0.017), treatment duration ≥75 min (OR 10.26, 95% CI 1.20-87.77, p = 0.034), and muscle layer exposure (OR 10.92, 95% CI 2.22-53.74, p = 0.003). Two independent predictive factors of high-grade mediastinal emphysema were identified, which were PEECS positivity (OR 4.31, 95% CI 1.29-14.41, p = 0.018), and muscle layer exposure (OR 4.08, 95% CI 1.18-14.06, p = 0.026)., Conclusions: A large resected area, prolonged treatment duration, and muscle layer exposure are risk factors for the onset of PEECS. Mediastinal emphysema was observed in 43% of patients following ESD. When marked clinical symptoms of PEECS appear, high-grade mediastinal emphysema may be observed, and therefore CT should be performed in these cases., (© 2019 S. Karger AG, Basel.)

Background: Pneumomediastinum (PM) is the term which defines the presence of air in the mediastinum. PM has also been described as mediastinal emphysema. PM is divided into two subgroups called as Spontaneous PM (SPM) and Secondary PM (ScPM)., Methods: A retrospective comparative study of the PM diagnosed between February 2010 and July 2018 is presented. Forty patients were compared. Clinical data on patient history, physical characteristics, symptoms, findings of examinations, length of the hospital stay, treatments, clinical time course, recurrence and complications were investigated carefully. Patients with SPM, Traumatic PM (TPM) and Iatrogenic PM (IPM) were compared., Results: SPM was identified in 14 patients (35%). In ScPM group, TPM was identified in 16 patients (40%), and IPM was identified in 10 patients (25%). On the SPM group, the most frequently reported symptoms were chest pain, dyspnea, subcutaneous emphysema and cough. CT was performed to all patients to confirm the diagnosis and to assess the possible findings. All patients prescribed prophylactic antibiotics to prevent mediastinitis., Conclusion: The present study aimed to evaluate the clinical differences and managements of PMs in trauma and non-trauma patients. The clinical spectrum of pneumomediastinum may vary from benign mediastinal emphysema to a fatal mediastinitis due to perforation of mediastinal structures. In most series, only the SPM was evaluated in many aspects, but there are fewer studies comparing the evaluation and management of traumatic and non-traumatic PMs. The patients with TPM who have limited trauma to the thorax and who do not have mediastinal organ injury in their imaging studies can be followed up and treated like SPM patients who do not have mediastinal organ injury, and both have good clinical course.

Objectives : The real incidence of pneumomediastinum (PNM) in adult patients with severe acute asthma exacerbation continues to be unknown. The current study aims to investigate the occurrence of PNM in an adult population of patients presenting a severe asthma attack and to evaluate the risk factors associated to its development. Methods : The 45 consecutive subjects who were admitted to our Division between January 1, 2015 and December 31, 2016 for severe acute asthma exacerbation underwent a diagnostic protocol including a standard chest X-ray and continuous monitoring of arterial oxygen saturation (SaO 2 ) during the first 24 hours following admission. The patients showing persistence or deterioration of oxyhemoglobin desaturation were prescribed a chest Computed Tomographic (CT) scan. Results : Five out of the 45 patients (11.1%) with severe acute asthma exacerbation were diagnosed with PNM, in one case on the basis of an X-ray image and in four on the basis of a chest CT scan. Data analysis showed that the PNM patients were younger [21 (17-21) vs 49.5 (20-73) yrs; p < 0.001] and more likely to show sensitization to Alternaria (2/5 vs 0/40; p = 0.0101) with respect to their non-PNM counterparts. The duration of hospital stay was similar in the two groups [8 (4-12) vs 7 (3-15) days; p = 0.6939]. Conclusions : PNM is a common clinical entity in young adults with severe acute asthma exacerbation, particularly in those with unsatisfactory response to initial medical therapy. Although generally benign, patients with suspected PNM should be closely monitored because of the risk of developing severe hypoxemia.

Objective: The purposes of this study were to determine the incidence of pneumorrhachis among patients with pneumomediastinum, determine whether its proportion correlates with the extent of pneumomediastinum, and ascertain its clinical relevance., Materials and Methods: The radiologic database was searched for CT reports between January 2009 and September 2013 containing the term "pneumomediastinum" or "mediastinal air." Scans were examined for pneumomediastinum, pneumorrhachis, pneumothorax, sternotomy, and distribution of pneumomediastinum. The age and sex of the patient and probable cause of the abnormality were recorded. Cases that might have had another cause were excluded., Results: The search yielded 422 CT scans. Among these, 242 instances of pneumomediastinum in 241 patients were found. Fifteen of these patients had pneumorrhachis. One was excluded because of recent traumatic spinal penetration. There was no significant difference in age or sex between patients with and those without pneumorrhachis. After application of the exclusion criteria, there were 14 cases of pneumorrhachis, yielding a proportion of 5.8%. Pneumorrhachis was observed more frequently in cases of the most severe grade (grade C) of pneumomediastinum; however, that relationship was not statistically significant (11 cases [8.2%]; p = 0.304). Pneumorrhachis was found significantly more frequently in patients with distribution of air in all three mediastinal compartments (13 cases, 16.2%, p < 0.001). Pneumorrhachis was overrepresented among subjects with spontaneous compared with those with secondary pneumomediastinum, although the trend did not reach statistical significance., Conclusion: Pneumorrhachis was present in 5.8% of patients. It is significantly more common in patients with the broadest distributions of mediastinal air and nonsignificantly more common in association with spontaneous as opposed to secondary pneumomediastinum. Pneumorrhachis in patients with pneumomediastinum is a generally benign, self-resolving condition.

Background: Aim of this study is to report and to analyze the incidence, clinical impact and treatment options of ectopic air localizations after transanal procedures., Methods: A systematic literature review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The research was carried out using the PubMed database, identifying 40 articles with the following keywords: "transanal" AND "emphysema"; "transanal" AND "subcutaneous emphysema"; "transanal" AND "pneumomediastinum"; "transanal" AND "pneumothoraces"; "transanal" AND "pneumopericardium"; "transanal" AND "retropneumoperitoneum"., Results: Nineteen articles, published between 1993 and 2017, were included in the study for a total of 29 patients. The most frequent air localization was in the retroperitoneum, followed by subcutaneous tissues, mediastinum and neck. This condition was treated conservatively in 20 patients, with colostomy in 4 patients, with bowel resection and negative diagnostic laparoscopy in one patient each. In three cases the treatment was not specified. Ectopic air location resolved in all cases., Conclusions: Pneumo-mediastinum and pneumo-retroperitoneum after transanal procedures are unusual complications with a dramatic radiological appearance but can be managed successfully with a completely benign course in most cases. Initially, a conservative approach is recommended. Surgical treatment should be reserved only in case of fluid collection or suture dehiscence., (Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

Per-oral endoscopic myotomy (POEM) has surfaced as an effective endoscopic treatment modality for achalasia cardia (AC). Promising results in short- and mid-term follow-up studies have increased the use of POEM for the management of AC. POEM can be safely performed in an endoscopy suit, and major adverse events (AEs) are uncommon. AEs encountered during POEM or during the perioperative period principally include insufflation-related AEs, mucosal injuries, bleeding, pain, and aspiration pneumonia. Most insufflation-related AEs do not require an active intervention and therefore should not be considered as AEs in the true sense. When management of AEs is required, most intraoperative AEs can be managed at the same time without untoward consequences. Occurrences of AEs lessen after completion of the learning curve. However, experience alone does not ensure "zero" incidence of AEs, and early recognition remains essential. Postoperative AEs, like leaks, delayed bleeding, and delayed mucosal perforations, may pose special challenges for diagnosis and management. There is no standardized classification system for grading the severity of AEs associated with POEM, resulting in wide variation in their reported occurrences. Uniform reporting of AEs is not only crucial to comprehensively analyze the safety of POEM but also for comparison with other established treatment modalities like Heller's myotomy. GERD is an important long-term AE after POEM. Unlike the perioperative AEs, little is known regarding the intraoperative or patient-related factors that influence the occurrence of post-POEM GERD. Large prospective studies with long-term follow-up are required to determine the procedural factors associated with GERD after POEM., (Copyright © 2018. Published by Elsevier Inc.)

Purpose: Balloon Eustachian tuboplasty (BET) is a new treatment modality addressing chronic obstructive dysfunction of the Eustachian tube (ET). So far, BET has been deemed a safe procedure under general anesthesia with only minor adverse effects. However, individual cases of postoperative emphysema have been reported. In the present retrospective multicenter analysis we determined the incidence rate of this potentially life threatening complication after BET., Methods: In total we collected data from 3,670 BET procedures performed on 2,272 patients in four tertiary care ENT departments., Results: Ten cases of postoperative cervicofacial emphysema were documented, whereas only in 3 of them a pneumomediastinum was developed. None of the affected patients developed at any time serious clinical signs or symptoms besides cutaneous crepitations. A complete resolution and recovery of the emphysema occurred in all patients under antibiotic prophylaxis and abstinence from Valsalva maneuver within the first 2-6 postoperative days., Conclusions: Possible causes for the development of these postinterventional emphysemas are considered to be mucosal injuries of the ET during manipulations for the correct position of the insertion instrument, through a "kinking" of the balloon catheter or even due to the relative rigid catheter itself, although its form is regarded to be atraumatic. The complication rate of postoperative emphysema was 0.27% (95% CI 0.13-0.50%). The above facts in addition to only minor and transient overall complications after BET reported in literature, can label this procedure as a safe treatment with a low risk profile.