Search

Background: Rapid evaluation for pneumothorax is a common clinical priority. Although lung ultrasound (LUS) often is used to assess for pneumothorax, its diagnostic accuracy varies based on patient and provider factors. To enhance the performance of LUS for pulmonary pathologic features, artificial intelligence (AI)-assisted imaging has been adopted; however, the diagnostic accuracy of AI-assisted LUS (AI-LUS) deployed in real time to diagnose pneumothorax remains unknown., Research Question: In patients with suspected pneumothorax, what is the real-time diagnostic accuracy of AI-LUS to recognize the absence of lung sliding?, Study Design and Methods: We performed a prospective AI-assisted diagnostic accuracy study of AI-LUS to recognize the absence of lung sliding in a convenience sample of patients with suspected pneumothorax. After calibrating the model parameters and imaging settings for bedside deployment, we prospectively evaluated its diagnostic accuracy for lung sliding compared with a reference standard of expert consensus., Results: Two hundred forty-one lung sliding evaluations were derived from 62 patients. AI-LUS showed a sensitivity of 0.921 (95% CI, 0.792-0.973), specificity of 0.802 (95% CI, 0.735-0.856), area under the receiver operating characteristic curve of 0.885 (95% CI, 0.828-0.956), and accuracy of 0.824 (95% CI, 0.766-0.870) for the diagnosis of absent lung sliding., Interpretation: In this study, real-time AI-LUS showed high sensitivity and moderate specificity to identify the absence of lung sliding. Further research to improve model performance and optimize the integration of AI-LUS into existing diagnostic pathways is warranted., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: R. A. declares to have shares of WaveBase, Inc. None declared (H. C. F., D. S., D. W., C. D., J. T., B. W., B. V. B., R. P., R. M.)., (Copyright © 2024 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Objective: Pneumothorax is an acute thoracic disease caused by abnormal air collection between the lungs and chest wall. Recently, artificial intelligence (AI), especially deep learning (DL), has been increasingly employed for automating the diagnostic process of pneumothorax. To address the opaqueness often associated with DL models, explainable artificial intelligence (XAI) methods have been introduced to outline regions related to pneumothorax. However, these explanations sometimes diverge from actual lesion areas, highlighting the need for further improvement., Method: We propose a template-guided approach to incorporate the clinical knowledge of pneumothorax into model explanations generated by XAI methods, thereby enhancing the quality of the explanations. Utilizing one lesion delineation created by radiologists, our approach first generates a template that represents potential areas of pneumothorax occurrence. This template is then superimposed on model explanations to filter out extraneous explanations that fall outside the template's boundaries. To validate its efficacy, we carried out a comparative analysis of three XAI methods (Saliency Map, Grad-CAM, and Integrated Gradients) with and without our template guidance when explaining two DL models (VGG-19 and ResNet-50) in two real-world datasets (SIIM-ACR and ChestX-Det)., Results: The proposed approach consistently improved baseline XAI methods across twelve benchmark scenarios built on three XAI methods, two DL models, and two datasets. The average incremental percentages, calculated by the performance improvements over the baseline performance, were 97.8% in Intersection over Union (IoU) and 94.1% in Dice Similarity Coefficient (DSC) when comparing model explanations and ground-truth lesion areas. We further visualized baseline and template-guided model explanations on radiographs to showcase the performance of our approach., Conclusions: In the context of pneumothorax diagnoses, we proposed a template-guided approach for improving model explanations. Our approach not only aligns model explanations more closely with clinical insights but also exhibits extensibility to other thoracic diseases. We anticipate that our template guidance will forge a novel approach to elucidating AI models by integrating clinical domain expertise., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Pneumothorax is a common issue in the intensive care unit and emergency department, often diagnosed using lung ultrasound. The absence of lung sliding and the presence of the lung point sign are characteristic findings for pneumothorax. We describe a case of left pneumothorax diagnosed incidentally while performing a cardiac ultrasound through a new variant of the lung point sign., Case Report: A 60-year-old patient with a medical history of diabetes, stroke, and right colon cancer underwent urgent surgical treatment for intestinal sub-occlusion. In the intensive care unit, the patient required mechanical ventilation due to shock unresponsive to fluid administration, and hemodynamic monitoring was performed using echocardiography. During systole in an apical four-chamber view, the abrupt vanishing of the heart was observed. When evaluating the tricuspid annular plane systolic excursion (TAPSE) using M-mode, the interposition of the stratosphere sign during mid-systole prevented the visualization of the TAPSE peak. Lung ultrasound revealed the absence of lung sliding and the presence of the lung point sign on the left side of the thorax, confirming the diagnosis of pneumothorax. A chest x-ray study further confirmed the diagnosis, and urgent drainage was performed. The patient showed improvement in hemodynamic and respiratory conditions and was successfully weaned from mechanical ventilation, and eventually discharged home. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: By incorporating the lung ultrasound findings, including this new variant of the lung point sign, into their diagnostic approach to pneumothorax, emergency physicians can promptly initiate appropriate intervention, such as chest tube insertion, leading to improved patient outcomes., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Competing Interests: Declaration of interests We declare no competing interests.

Objective: To describe the clinical and transport characteristics of patients diagnosed with a suspected traumatic pneumothorax and managed conservatively by prehospital medical teams including secondary deterioration during transfer and the subsequent rate of in-hospital tube thoracostomy., Methods: Retrospective observational study of all adult trauma patients diagnosed with a suspected pneumothorax on ultrasound and managed conservatively by their treating prehospital medical team between 2018 and 2020. Descriptive analysis was performed comparing patients who did and did not receive in-hospital tube thoracostomy., Results: In total, 181 patients were diagnosed with suspected traumatic pneumothoraces on prehospital ultrasound of which 75 (41.4%) were managed conservatively by their treating medical team whilst 106 (58.6%) underwent pleural decompression. There were no recorded cases of emergent pleural decompression required in transit. Of the 75 conservatively managed patients, 42 (56%) had an intercostal catheter (ICC) placed within four hours of hospital arrival and another nine (17.6%) had an ICC placed between four- and 24-hours post-hospital arrival. There was no significant difference in prehospital clinical characteristics between patients who did and did not receive an in-hospital ICC. The detection of a pneumothorax on the initial chest x-ray and larger pneumothorax volume visualised on computed tomography imaging were significantly more common in patients receiving in-hospital ICCs. Aviation factors including flight altitude and duration of flight were not associated with subsequent in-hospital tube thoracostomy., Conclusion: Prehospital medical teams can safely identify patients who have a traumatic pneumothorax and can be transported to hospital without pleural decompression. Patient characteristics at the time of hospital arrival combined with the size of pneumothorax identified on imaging appear most likely to influence subsequent urgent in-hospital tube thoracostomy placement., Competing Interests: Declaration of Competing Interest The authors report no conflict of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Large chest X-rays (CXR) datasets have been collected to train deep learning models to detect thorax pathology on CXR. However, most CXR datasets are from single-center studies and the collected pathologies are often imbalanced. The aim of this study was to automatically construct a public, weakly-labeled CXR database from articles in PubMed Central Open Access (PMC-OA) and to assess model performance on CXR pathology classification by using this database as additional training data. Our framework includes text extraction, CXR pathology verification, subfigure separation, and image modality classification. We have extensively validated the utility of the automatically generated image database on thoracic disease detection tasks, including Hernia, Lung Lesion, Pneumonia, and pneumothorax. We pick these diseases due to their historically poor performance in existing datasets: the NIH-CXR dataset (112,120 CXR) and the MIMIC-CXR dataset (243,324 CXR). We find that classifiers fine-tuned with additional PMC-CXR extracted by the proposed framework consistently and significantly achieved better performance than those without (e.g., Hernia: 0.9335 vs 0.9154; Lung Lesion: 0.7394 vs. 0.7207; Pneumonia: 0.7074 vs. 0.6709; Pneumothorax 0.8185 vs. 0.7517, all in AUC with p< 0.0001) for CXR pathology detection. In contrast to previous approaches that manually submit the medical images to the repository, our framework can automatically collect figures and their accompanied figure legends. Compared to previous studies, the proposed framework improved subfigure segmentation and incorporates our advanced self-developed NLP technique for CXR pathology verification. We hope it complements existing resources and improves our ability to make biomedical image data findable, accessible, interoperable, and reusable., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Introduction: Thoracic trauma is an important cause of morbidity and mortality in children exposed to blast and early recognition of these injuries is vital. While numerous studies have investigated the sensitivity of chest X-ray (CXR) for the detection of chest injury in blunt trauma, none have evaluated its performance in paediatric blast injury., Methods: CXR and Computed Tomography (CT) thorax findings were compared for 105 children who were injured by blast and presented to the UK Role 3 Hospital, Camp Bastion, Helmand Province, during the recent conflict in Afghanistan from 2011 to 2013. CXR performance was evaluated compared to the 'gold standard' of CT for the detection of significant thoracic injuries, defined as pneumothorax, haemothorax, aortic or great vessel injury, 2 or more rib fractures, ruptured diaphragm, sternal fracture, penetrating fragments and pulmonary contusion or laceration., Results: The sensitivity of CXR for the detection of significant injuries was: pneumothorax 43%, haemothorax 40%, contusion 44%, laceration 100%, blast lung 80% and subdermal metallic fragments 75%. CXR missed all cases of diaphragm injury, ≥2 rib fractures, clavicle fracture and pleural effusion, although numbers of each were small. Specificity for CXR injury detection was 94% for contusion and 93% for fragment, and 100% otherwise. The sensitivity and specificity of CXR for identifying an abnormality that would prompt CT imaging was 72% (95% CI 55-85%) and 82% (95% CI 70-90%)., Conclusions: CXR has a poor sensitivity for the identification of significant thoracic injury in children exposed to blast. We argue that, given the challenge of clinical assessment of injured children and the potential for serious adverse consequences of missed thoracic injuries, there should be a low threshold for the use of CT chest in the evaluation of children exposed to blast., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to declare, (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Introduction: A chest radiograph (CXR) is routinely obtained in trauma patients following tube thoracostomy (TT) removal to assess for residual pneumothorax (PTX). New literature supports the deference of a radiograph after routine removal procedure. However, many surgeons have hesitated to adopt this practice due to concern for patient welfare and medicolegal implications. Ultrasound (US) is a portable imaging modality which may be performed rapidly, without radiation exposure, and at minimal cost. We hypothesized that transitioning from CXR to US following TT removal in trauma patients would prove safe and provide superior detection of residual PTX., Materials and Methods: A practice management guideline was established calling for the performance of a CXR and bedside US 2 h after TT removal in all adult trauma patients diagnosed with PTX at a level 1 trauma center. Surgical interns completed a 30-minute, US training course utilizing a handheld US device. US findings were interpreted and documented by the surgical interns. CXRs were interpreted by staff radiologists blinded to US findings. Data was retrospectively collected and analyzed., Results: Eighty-nine patients met inclusion criteria. Thirteen (15%) post removal PTX were identified on both US and CXR. An additional 11 (12%) PTX were identified on CXR, and 5 (6%) were identified via US, for a total of 29 PTX (33%). One patient required re-intervention; the recurrent PTX was detected by both US and CXR. For all patients, using CXR as the standard, US displayed a sensitivity of 54.2%, specificity of 92.3%, negative predictive value of 84.5%, and positive predictive value of 72.2%. The cost of care for the study cohort may have been reduced over $9,000 should US alone have been employed., Conclusion: Bedside US may be an acceptable alternative to CXR to assess for recurrent PTX following trauma TT removal., Competing Interests: Conflicts of interest The authors declare no conflicts of interest., (Copyright © 2022. Published by Elsevier Ltd.)

Background: Chest roentgenograms after chest tube removal are common practice in postoperative thoracic surgery patients. Whether these roentgenograms change clinical management is debatable. We investigated prevalence and management of post-pull pneumothoraces after lung resection., Methods: Patients undergoing minimally invasive wedge resections, segmentectomies, and lobectomies between March 2018 and September 2018 were retrospectively reviewed. Baseline factors, operative technique, chest tube management, and outcomes after post-pull chest roentgenograms, and factors associated with post-pull pneumothoraces were analyzed., Results: The study analyzed 200 consecutive patients comprising 117 wedge resections (59%), 24 segmentectomies (12%), and 59 lobectomies (30%). Wedge resections compared with segmentectomy or lobectomy had lower rates of chest tube use, drain duration, air leaks, and need for a clamp trial, with Blake drains most often removed last compared with segmentectomy or lobectomy (all P < .001). Post-pull pneumothoraces, which were largely small/tiny/trace (96%), occurred in 110 patients (55%). Five patients experienced symptoms, and no patients required intervention. Resection type was associated with the pneumothorax rate, need for additional imaging, and discharge timing (all P < .05). Those with pneumothoraces compared with those without differed in type of resection and chest drain, presence of air leak within 24 hours of removal, need for clamp trial, order of tube removal, and hospital length of stay (all P < .05). Multivariable regression showed only clamp trial was associated with post-pull pneumothorax development (odds ratio, 2.48; 95% CI, 1.13-5.45; P = .024)., Conclusions: Although routine use of post-pull chest roentgenograms identified a high prevalence of pneumothorax, no intervention was required. Our study demonstrates post-pull imaging may not be indicated in asymptomatic patients without prior air leak or clamp trial., (Copyright © 2022 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

An air leak lasting more than 5-7 days (persistent air leak, PAL) can complicate up to 40% of patients with secondary spontaneous pneumothorax. Chronic obstructive pulmonary disease is the most common cause of secondary spontaneous pneumothorax, and early surgical intervention has been recommended for patients with PAL. Bullectomy or blebectomy with concomitant mechanical pleurodesis by medical thoracoscopy or video assisted thoracoscopic surgery is considered definitive therapy. Unfortunately, the perioperative course following lung resection can also be complicated by air leaks leading to worse clinical outcomes. Post lung resection air leak can be pressure independent or pressure dependent (also known as drainage-related air leak). The distinction between these two entities is crucial as the management varies drastically. Pleural manometry may play an important role in the early diagnosis of pressure-dependent PAL preventing further unnecessary surgical procedures from being performed., Competing Interests: Conflicts of interest The author has no financial or other conflicts of interest to disclose., (Copyright © 2022 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

Introduction/background: Primary spontaneous pneumothorax (PSP) is characterised by the onset of pneumothorax with no evidence of trauma or associated co-morbidities. Several clinical practice guidelines (CPGs) have been published regarding the management of PSP. Inconsistency in imaging protocols across clinics globally may indicate variability in the recommendations within these guidelines. We aimed to support clinical decision making with an assessment of CPGs regarding PSP diagnosis., Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews was utilised. A systematic search of databases Medline, Embase, and Scopus was conducted. Manual searches of the grey literature and guideline-focused databases was undertaken Inclusion criteria included English-language CPGs pertaining to the management of PSP. Publications were independently extracted and critically appraised by two reviewers using the AGREE-II tool. Recommendations were assessed and tabulated., Results: Eight CPGs met the eligibility criteria. 16 recommendations were identified relating to assessment of medical history, physical examination, assessment of clinical stability, posterior-anterior chest X-ray (CXR) on held inspiration, computed tomography following inconclusive CXR, and ultrasound to complement other imaging modalities., Conclusion: There is universal agreement on the exclusion of expiratory and lateral images in the conventional radiographic series, suggesting that these clinical behaviours may be influenced by local preferences or inhibitors to knowledge translation. This scoping review has summarised the key recommendations of CPGs regarding PSP diagnosis and assessed the methodological quality of the current evidence-base., (Copyright © 2022. Published by Elsevier Inc.)

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.)

COVID- 19 has become a major pandemic affecting more than 11 million people worldwide. Common radiological manifestations of COVID-19 include peripheral based ground-glass or consolidative opacities; however, pneumothorax and pneumo-mediastinum are very rare manifestations; even more so within patients not on mechanical ventilation. We present a case series of 5 patients with COVID-19 who either presented with or developed spontaneous pneumothorax or pneumo-mediastinum within the course of hospitalization. With the exception of one patient, all other patients developed pneumothorax as a late manifestation in their illness; more than 10 days after initial symptom onset in COVID-19. From within this case series, all patients who developed spontaneous pneumothorax or pneumo-mediastinum during hospitalization subsequently succumbed to the illness. Spontaneous pneumothorax or pneumo-mediastinum may be an important late manifestation in COVID-19; even in spontaneously breathing patients. This may be related to development of cystic changes within the lung parenchyma. Although the clinical relevance of this finding is unknown; in our series, it portended a worse prognosis in the majority of patients., (Copyright © 2020 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

Case Presentation: A 19-year-old, previously healthy man presented with 3 days of cough, high-grade fevers (40 °C), and dyspnea. Apart from a resolved history of seizures not requiring medications, he had no medical or surgical history. He had no known drug allergies. He took montelukast for allergies and trimethoprim-sulfamethoxazole (TMP-SMX) for 2 weeks before admission for acne, but no other medications, including over-the-counter medications and supplements. He had animal exposures to a new puppy and a friend's bird. He had no history of smoking, vaping, or recreational drug use. His paternal grandmother had rheumatoid arthritis., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Although interest in artificial intelligence (AI) has exploded in recent years and led to the development of numerous commercial and noncommercial algorithms, the process of implementing such tools into day-to-day clinical practice is rarely described in the burgeoning AI literature. In this report, we describe our experience with the successful integration of an AI-enabled mobile x-ray scanner with an FDA-approved algorithm for detecting pneumothoraces into an end-to-end solution capable of extracting, delivering, and prioritizing positive studies within our thoracic radiology clinical workflow. We also detail several sample cases from our AI algorithm and associated PACS workflow in action to highlight key insights from our experience. We hope this report can help inform other radiology enterprises seeking to evaluate and implement AI-related workflow solutions into daily clinical practice., (Copyright © 2021 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

In this article, we present a case of leptomeningeal pneumocephalus and pneumorrhachis secondary to pneumothorax that occurred six years after syringopleural shunting., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The positions of nodules can change because of intraoperative lung deflation, and the modeling of pneumothorax-associated deformation remains a challenging issue for intraoperative tumor localization. In this study, we introduce spatial and geometric analysis methods for inflated/deflated lungs and discuss heterogeneity in pneumothorax-associated lung deformation. Contrast-enhanced CT images simulating intraoperative conditions were acquired from live Beagle dogs. The images contain the overall shape of the lungs, including all lobes and internal bronchial structures, and were analyzed to provide a statistical deformation model that could be used as prior knowledge to predict pneumothorax. To address the difficulties of mapping pneumothorax CT images with topological changes and CT intensity shifts, we designed deformable mesh registration techniques for mixed data structures including the lobe surfaces and the bronchial centerlines. Three global-to-local registration steps were performed under the constraint that the deformation was spatially continuous and smooth, while matching visible bronchial tree structures as much as possible. The developed framework achieved stable registration with a Hausdorff distance of less than 1 mm and a target registration error of less than 5 mm, and visualized deformation fields that demonstrate per-lobe contractions and rotations with high variability between subjects. The deformation analysis results show that the strain of lung parenchyma was 35% higher than that of bronchi, and that deformation in the deflated lung is heterogeneous., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: To determine safety of shortened observation time without follow-up chest x-ray (CXR) after CT-guided transthoracic procedures (lung biopsy or fiducial placement) in patients without immediate postprocedural pneumothorax (PTX)., Methods: Consecutive patients that underwent CT-guided procedures between January 5, 2015, and June 19, 2017, were included in this retrospective institutional review board-approved HIPAA-compliant study. Data regarding postprocedural course, complications, and clinical follow-up of the patients were obtained through a review of electronic medical records. Descriptive statistics were used., Results: There were 441 procedures for 409 patients performed; 82 procedures were excluded because of predefined criteria. In 312 of 336 asymptomatic procedures (92.9%), asymptomatic patients did not undergo CXR after procedure, with 7 of 312 of these patients (2.2%) diagnosed with delayed PTX 2 to 10 days after the procedure. In 24 of 336 procedures (7.1%), asymptomatic patients underwent CXR within 4 hours with no PTX detected, and despite that 1 of 24 of these patients (4.2%) presented with delayed PTX 7 days after procedure. When no immediate postprocedural PTX was present, rate of observation PTX and delayed PTX was 1 of 359 (0.3%) and 8 of 359 (2.2%), respectively. Average duration of monitoring for outpatients (n = 295) was 2.0 hours with median of 1.8 hours. In 23 of 359 (6.4%) procedures, the patient became symptomatic during postprocedural observation with 1 of 23 (4%) developing PTX., Conclusions: Obtaining routine postprocedural CXRs in asymptomatic patients without immediate postprocedural PTX after CT-guided transthoracic procedures is likely not necessary given the low likelihood of PTX., (Copyright © 2021 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Background: The treatment of primary spontaneous pneumothorax (PSP) remains controversial. We aimed to examine the role of chest computed tomography (CT), the advantages of pigtail catheter versus chest tube regarding duration of drainage or hospitalization period, and the impact of small PSP and surgical treatment on recurrence rate., Methods: We retrospectively reviewed the medical records of 109 children with PSP (20 years' period). Patients with recurrent and those with non-recurrent PSP were compared., Results: We recorded 183 episodes of PSP (45% recurrences), 89 patients (97%) were male, and the median age at presentation was 16 years. There were no significant differences between recurrence and non-recurrence PSP regarding age, gender, medical background, presentation symptoms, type of chest drain, median hospitalization length and median follow-up period. Recurrences were less frequent among patients who presented with small PSP and were treated conservatively (P = 0.029). PSP was almost always unilateral and the recurrence was observed ipsilateral in almost 80% of the cases. CT was more frequently used and blebs/bullae were more frequently found among patients with recurrent PSP. Pigtail use had no advantage in reducing hospitalization period and surgical procedures prevented recurrences., Conclusion: The size of pneumothorax at presentation helps to predict recurrences. There are no differences regarding duration of drainage or hospitalization period in the use of pigtail compared to chest tube. CT helps evaluate findings in the lungs in recurrent cases of PSP and surgery prevents recurrences effectively., Competing Interests: Declaration of competing interest Not applicable., (Copyright © 2021. Published by Elsevier Taiwan LLC.)

Background: With the advancement of cardiorespiratory interventions, the survival rate among patients with Duchenne muscular dystrophy (DMD) has increased. Subsequently, pneumothorax has become a significant problem in patients with prolonged ventilatory support., Research Question: What are the frequency, recurrence rate, risk factors, and prognosis of pneumothorax in patients with DMD requiring noninvasive ventilation (NIV)? Also, are there known risk factors of pneumothorax on chest CT scans?, Study Design and Methods: This retrospective longitudinal cohort study included 176 patients treated between 2006 and 2019. We collected information regarding location, severity, treatment methods, recurrence frequency, abnormal findings on CT scanning, and date of death. We compared the pneumothorax and nonpneumothorax groups. We calculated the estimated survival probabilities from the age at NIV application according to pneumothorax occurrence., Results: Sixteen of the 176 patients (9.0%) experienced pneumothorax (median age at diagnosis, 24.6 years; range, 20.7-33.7 years). Among the 16 patients, 15 demonstrated pneumothorax after NIV application (median time between diagnosis and initial NIV application, 5.6 years; range, 3 days-9.6 years). Sixteen patients experienced 31 episodes of pneumothoraces (range, one-five episodes); among them, seven episodes (22.6%) were asymptomatic. Known risk factors not clearly visible by radiography scans were found in chest CT scan in 11 patients (68.8%). Seven of 16 patients (43.8%) eventually sustained severe lung damage with pulmonary fibrosis. No significant between-group differences were found in body weight, BMI, and age at NIV application; however, the pneumothorax group showed a significantly higher mortality rate after NIV application., Interpretation: On pneumothorax occurrence in patients with DMD, recurrences and severe lung damage are common; moreover, these patients show higher mortality rates than patients without pneumothorax. Chest CT scans should be performed to identify risk factors, and treatment should be initiated accordingly. In addition, physicians should consider chest CT scanning in the case of suspected pneumothorax, even if no radiographic abnormality is found., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Real-Time-reverse-transcription-Polymerase-Chain-Reaction from nasopharyngeal swabs and chest computed tomography (CT) depicting typically bilateral ground-glass opacities with a peripheral and/or posterior distribution are mandatory in the diagnosis of COVID-19. COVID-19 pneumonia may present though with atypical features such as pleural and pericardial effusions, lymphadenopathy, cavitations, and CT halo sign. In these two case-reports, COVID-19 presented as pneumothorax, pneumomediastinum and subcutaneous emphysema in critically ill patients. These disorders may require treatment or can be even self-limiting. Clinicians should be aware of their potential effects on the cardiorespiratory status of critically ill COVID-19 patients. Finally, pneumothorax can be promptly diagnosed by means of lung ultrasound. Although operator dependent, lung ultrasound is a useful bedside diagnostic tool that could alleviate the risk of cross-infection related to COVID-19 patient transport., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Recent reports of patients with coronavirus disease 2019 (COVID-19) developing pneumothorax correspond mainly to case reports describing mechanically ventilated patients. The real incidence, clinical characteristics, and outcome of spontaneous pneumothorax (SP) as a form of COVID-19 presentation remain to be defined., Research Question: Do the incidence, risk factors, clinical characteristics, and outcomes of SP in patients with COVID-19 attending EDs differ compared with COVID-19 patients without SP and non-COVID-19 patients with SP?, Study Design and Methods: This case-control study retrospectively reviewed all patients with COVID-19 diagnosed with SP (case group) in 61 Spanish EDs (20% of Spanish EDs) and compared them with two control groups: COVID-19 patients without SP and non-COVID-19 patients with SP. The relative frequencies of SP were estimated in COVID-19 and non-COVID-19 patients in the ED, and annual standardized incidences were estimated for both populations. Comparisons between case subjects and control subjects included 52 clinical, analytical, and radiologic characteristics and four outcomes., Results: We identified 40 occurrences of SP in 71,904 patients with COVID-19 attending EDs (0.56‰; 95% CI, 0.40‰-0.76‰). This relative frequency was higher than that among non-COVID-19 patients (387 of 1,358,134, 0.28‰; 95% CI, 0.26‰-0.32‰; OR, 1.93; 95% CI, 1.41-2.71). The standardized incidence of SP was also higher in patients with COVID-19 (34.2 vs 8.2/100,000/year; OR, 4.19; 95% CI, 3.64-4.81). Compared with COVID-19 patients without SP, COVID-19 patients developing SP more frequently had dyspnea and chest pain, low pulse oximetry readings, tachypnea, and increased leukocyte count. Compared with non-COVID-19 patients with SP, case subjects differed in 19 clinical variables, the most prominent being a higher frequency of dysgeusia/anosmia, headache, diarrhea, fever, and lymphopenia (all with OR > 10). All the outcomes measured, including in-hospital death, were worse in case subjects than in both control groups., Interpretation: SP as a form of COVID-19 presentation at the ED is unusual (< 1‰ cases) but is more frequent than in the non-COVID-19 population and could be associated with worse outcomes than SP in non-COVID-19 patients and COVID-19 patients without SP., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background: Following placement of tube thoracostomy (TT) for evacuation of traumatic hemopneumothorax (HPTX), controversy persists over the need for routine post-TT removal chest radiograph (CXR). Current research demonstrates routine CXR may offer no advantage over clinical observation alone while simultaneously increasing hospital resource utilization. As such, we hypothesized that in resolved traumatic HPTXs routine post-TT removal CXR to assess recurrent PTX compared to clinical observation is not cost-effective., Methods: We performed a decision-analytic model to evaluate the cost-effectiveness of routine CXR compared to clinical observation following TT removal. Our base case was a patient that sustained thoracic trauma with radiographic and clinical resolution of HPTX following TT evacuation. Cost, utility and probability estimates were generated from published literature, with costs represented in 2019 US dollars and utilities in Quality-Adjusted Life Years (QALYs). Deterministic and probabilistic sensitivity analyses were performed., Results: Decision-analytic model identified that clinical observation after TT removal was the dominant strategy with increased benefit at less cost, when compared to routine CXR, with a net cost of $194.92, QALYs of 0.44. In comparison, routine CXR demonstrated an increase of $821.42 in cost with 0.43 QALYs. On probabilistic sensitivity analysis the clinical observation strategy was found cost-effective in 99.5% of 10,000 iterations., Conclusion: In trauma patients with clinical and radiographic evidence of a resolved HPTX, the adoption of clinical observation in lieu of post-TT removal CXR is cost-effective. Routine CXR following TT removal accrues more cost without additional benefit. The practice of routinely obtaining a CXR following TT removal should be scrutinized., Competing Interests: Declaration of Competing Interest All authors of this manuscript have no financial and/or personal relationships with other people or organizations that could inappropriately influence their work. This includes employment, consultancies, stock ownership, honoraria, paid expert testimony, patent applications/registrations, and grants or other funding sources., (Copyright © 2020. Published by Elsevier Ltd.)

Purpose: To validate a machine learning model trained on an open source dataset and subsequently optimize it to chest X-rays with large pneumothoraces from our institution., Methods: The study was retrospective in nature. The open-source chest X-ray (CXR8) dataset was dichotomized to cases with pneumothorax (PTX) and all other cases (non-PTX), resulting in 41,946 non-PTX and 4696 PTX cases for the training set and 11,120 non-PTX and 541 PTX cases for the validation set. A limited supervision machine learning model was constructed to incorporate both localized and unlocalized pathology. Cases were then queried from our health system from 2013 to 2017. A total of 159 pneumothorax and 682 non-pneumothorax cases were available for the training set. For the validation set, 48 pneumothorax and 1287 non-pneumothorax cases were available. The model was trained, a receiver operator curve (ROC) was created, and output metrics, including area under the curve (AUC), sensitivity and specificity were calculated., Results: Initial training of the model using the CXR8 dataset resulted in an AUC of 0.90 for pneumothorax detection. Naively inferring our own validation dataset on the CXR8 trained model output an AUC of 0.59. After re-training the model with our own training dataset, the validation dataset inference output an AUC of 0.90., Conclusion: Our study showed that even though you may get great results on open-source datasets, those models may not translate well to real world data without an intervening retraining process., (Copyright © 2020 Elsevier Inc. All rights reserved.)

We describe the case of a 35-year-old man who presented in respiratory failure after influenza B infection requiring initiation of venovenous extracorporeal membrane oxygenation and eventual pulmonary resection for necrotizing pneumonia. Following a successful wean off venovenous extracorporeal membrane oxygenation, and once hemodynamically stable, he was taken to the operating room for decortication and left pulmonary resection. Recovery was complicated by persistent airleak requiring placement of endobronchial valves, but otherwise he recovered very well. This case demonstrates the benefits of lung resection for necrotizing pneumonia., (Copyright © 2019 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Probe based confocal laser endomicroscopy (pCLE) is a new optical endoscopic technique, generating fluorescent light emission from the tissue of interest and allowing in vivo live imaging at a cellular level ("optical biopsies"). To the best of our knowledge, this article is the first to present pCLE images during medical thoracoscopy. We present here 3 different patients referred for various health problems. A precise description of pleural cavity pCLE images after intravenous fluorescein injection (a fluorophore) together with corresponding macroscopical and histological studies is performed. This led to the diagnosis of normal pleura in one case, carcinomatous pleuritis in another case and a malignant mesothelioma in the third case. We believe that optical biopsies could help clinicians to make an early diagnosis, thereby allowing rapid therapeutic intervention (talc pleurodesis for example). Furthermore, it could help to guide biopsies when affected zones are not obvious to macroscopic examination. In a near future, new fluorophores could be developed to stain some pathophysiological processes, therapeutic targets, or enzymes activities bringing new insights in endoscopic pleural disease work-up., (Copyright © 2019. Published by Elsevier Ltd.)

A 46-year-old woman arrived at our ED for the worsening of a thoracic pain localized in the left interscapulo-vertebral region that she had been commenting on for the past few days. Anamnestic data were collected; vital parameters, blood tests, and ECG were normal., (Copyright © 2018 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine whether routine postprocedure chest radiography is indicated to exclude pneumothorax after outpatient right heart catheterization with or without endomyocardial biopsy., Methods: This HIPAA-compliant retrospective quality improvement cohort study was approved by the institutional review board. All outpatients from January 1, 2010, to July 1, 2017, who underwent routine postprocedure chest radiography after right heart catheterization with or without endomyocardial biopsy formed the study population (n = 6,036). Subjects were identified by electronic medical record query using Current Procedural Terminology codes. Pneumothorax prevalence was calculated by coded review of chest radiography reports. Size of pneumothorax (if present) and clinical outcome were determined, and 95% confidence intervals (CIs) were calculated., Results: Most (99%) right heart catheterizations were performed using an internal jugular vein approach, as determined by a random sample of 100 subjects. The prevalence of pneumothorax on postprocedure chest radiography reports was 0.1% (7 of 6,036; 95% CI: 0.05%-0.24%). Three of these seven pneumothoraces were confirmed by repeat imaging within 1 hour to be false-positives (ie, no pneumothorax), resulting in a corrected pneumothorax rate of 0.07% (4 of 6,036; 95% CI: 0.00%-0.2%). The remaining four that reported pneumothoraces were less than 1 cm. No chest tubes were placed, and all subjects were discharged home without an unexpected escalation in the level of care., Conclusion: In a large cohort of over 6,000 subjects, pneumothorax after right heart catheterization utilizing an internal jugular vein approach was rare and when found was clinically insignificant. False-positives were common. Routine postprocedure chest radiography in this setting is not warranted and is being discontinued at the study institution., (Copyright © 2018 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Background: Complications related to incorrect positioning of tube thoracostomy (TT) have been reported to be as high as 30%. The aim of this study was to assess the feasibility of flexible videoscope guided placement of a pre-loaded chest tube, permitting direct intrapleural visualization and placement (Video-Tube Thoracostomy [V-TT])., Methods: A prospective, single centre, phase 1 pilot study with a parallel control group was undertaken. The population studied were adult thoracic trauma patients requiring emergency TT who were haemodynamically stable. The intervention performed was VTT. Patients in the control group underwent conventional TT. The primary outcome was tube position as defined by a consultant radiologist's interpretation of chest x-ray (CXR) or CT. The trial was registered with ANZCTR.org.au (ACTRN: 12,615,000,870,550)., Results: There were 37 patients enrolled in the study - 12 patients allocated to the VTT intervention group and 25 patients allocated to conventional TT. Mean age of participants was 48 years (SD 15) in intervention group and 46 years (SD 15) years in the control group. In the VTT group all patients were male; the indications were pneumothorax (83%), haemothorax (8%) and haemopneumothorax (8%). The median injury severity score was 23 (16-28). There were 1 positional and 1 insertional complications. In the control group 72% of patients were male, the indications were pneumothorax (56%), haemothorax (4%) and haemopneumothorax (40%). The median injury severity score was 24 (14-36). There were 8 (32%) positional complications and no insertional complications., Conclusion: V-TT was demonstrated to be a feasible alternative to conventional thoracostomy and merits further investigation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Video-assisted thoracoscopic surgery is the standard procedure for treatment of spontaneous pneumothorax. However, postoperative recurrence is relatively common even if an absorbable covering sheet is used for reinforcement of the visceral pleura. Injection of a high concentration glucose solution to the thoracic cavity was recently reported to be effective in stopping postoperative air leakage or as a prophylactic procedure to prevent postoperative recurrence of spontaneous pneumothorax. Therefore, we used 50 mL of a 50% glucose solution for pleural coating (GPC) on an absorbable sheet intraoperatively to prevent postoperative recurrence of spontaneous pneumothorax. This is a retrospective study, and patient backgrounds are heterogeneous. We evaluated the feasibility of GPC using propensity scores to adjust for heterogeneity in their backgrounds., Methods: Between January 2010 and December 2017, 376 patients who underwent video-assisted thoracoscopic surgery, with or without GPC, were evaluated. The GPC group consisted of 106 patients, and the non-GPC group consisted of 270. We analyzed the factors preventing postoperative recurrence of spontaneous pneumothorax by univariate analysis and Cox regression analysis with or without propensity score matching., Results: Univariate analysis revealed age of 25 or older, smoking habit, no history of an ipsilateral operation, and GPC were significant factors preventing postoperative recurrence. GPC significantly prevented postoperative recurrence as shown by Cox regression analysis with propensity score matching (hazard ratio, 0.15; p = 0.014) and the inverse-probability of treatment weighted method (hazard ratio, 0.23; p = 0.0038)., Conclusions: Intraoperative GPC significantly reduced the postoperative recurrence rate of spontaneous pneumothorax., (Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)