Spontaneous pneumothorax: time to rethink management?

Medical thoracoscopy combined with argon plasma coagulation as an alternative treatment for intractable pneumothorax: a retrospective study

BACKGROUND

A significant proportion of patients with pneumothorax who do not tolerate surgery develop intractable pneumothorax after prolonged failure of conservative treatment. This significantly lengthens the duration of hospitalization and patients' quality of life. As the application of medical thoracoscopy (MT) in the management of pleural diseases is explored, MT combined with argon plasma coagulation (APC) may be an alternative option for the treatment of intractable pneumothorax.

METHODS

A retrospective analysis was conducted on thirteen patients with intractable pneumothorax whose duration of the air leak exceeded seven days and subsequently treated with MT combined with APC at West China Hospital of Sichuan University. Under MT, we first dissected the pleural adhesions with an electrocautery knife, probed for the rupture located in the pulmonary bullae or pleural and cauterised it with APC. Subsequently, all pulmonary bullae were cauterised and human fibrin sealant was sprayed locally on the cauterised surface. Preoperative, intraoperative, and more than one year of postoperative follow-up information was collected from these patients. We divided the patients into two groups with and without detected ruptures treated under MT to compare the overall efficacy and safety of this treatment.

RESULTS

All patients had pulmonary comorbidities and the median duration of the current pneumothorax episode before MT treatment was 30 days. Nine patients had a history of recurrent pneumothorax episodes, two of whom had been treated with video-assisted thoracoscopic surgery (VATS). Regarding efficacy, the overall median time of time to air leak cessation was 2.5 days, with 2 days in the group with detected ruptures treated and 5 days in the group without detected ruptures treated, and the overall median time of time to chest tube removal was 6 days, with 4 days in the group with detected ruptures treated and 7 days in the group without detected ruptures treated. Regarding safety, only 2 patients experienced postoperative adverse events of fever and chest pain.

CONCLUSIONS

For intractable pneumothorax patients with pleural adhesions that may limit lung re-expansion, who are not candidates for surgery, MT combined with APC can be an alternative treatment option.

Prevalence of Smoking Among Spontaneous Pneumothorax Patients and Its Impact on Treatment in Syria Country: A Cross-Sectional Study

Background and Aims

Spontaneous Pneumothorax (SP) is a case where air is collected in the pleural space, with smoking recognized as a major risk factor. Despite the global burden of SP, there is limited research on its prevalence and recurrence in Middle Eastern populations, particularly in Syria. This study aims to evaluate the prevalence of smoking among SP patients in Syria and investigate its impact on SP recurrence, providing insights that could guide more effective treatment strategies in regions with high smoking rates.

Methods

A cross-sectional study was conducted on patients with spontaneous pneumothorax treated at two university hospitals in Syria from January 2016 to January 2021. Data on demographics, smoking habits, treatment types (conservative, intercostal drainage, and surgical), and recurrence were collected. Pearson's Chi-square test was used to analyze the association between smoking and SP recurrence.

Results

This study included 156 patients divided into 135 males and 21 females. One hundred and twenty-five patients were smokers (80.13%), and 118 were men. A recurrence rate of 43.6% (68 patients) was observed in the complete sample. We found a relationship between recurrence and smoking (p = 0.002) and between recurrence and male gender (p = 0.015). In comparison with the three types of treatment, intercostal drainage had the highest recurrence rate (52.9%), and surgical treatment had the lowest rate (6.8%). In both surgical and conservative treatments, all recurrent cases were male smokers.

Conclusion

In Syria, the high prevalence of smoking, especially among males, significantly increases the risk and recurrence of spontaneous pneumothorax. These findings highlight the need for targeted smoking cessation programs and should inform the selection of treatment strategies for SP patients, particularly those at high risk of recurrence.

Current practice and attitudes in emergency department management of primary spontaneous pneumothorax in Australia and New Zealand: a scenario-based/survey

BACKGROUND

Management of primary spontaneous pneumothorax (PSP) has long been contentious.

AIMS

To identify the factors influencing interventional versus conservative management and to assess current practice patterns for moderate-to-large PSP in emergency department (ED) patients.

METHODS

Anonymous online survey of emergency medicine, respiratory medicine and thoracic surgery specialists and trainees in Australia and New Zealand. Data collected included rating the decision-making importance of potential drivers of interventional versus conservative management for PSP, initial management preference for stable patients with moderate-large PSP based on three X-ray-based scenarios (one moderate-large, one almost total collapse without mediastinal shift and one large with mediastinal shift) and awareness of evidence and current guidelines for the management of PSP.

RESULTS

There were 456 responses; 85.5% were from Australia. The most commonly reported factors influencing treatment decision-making were vital signs (96.7%) and patient-reported dyspnoea (84.3%). There was variation between specialty groups in initial treatment preference for all scenarios (P < 0.001) and a reduction in preference for conservative treatment as the magnitude of radiological features increased (93.8% vs 61.5% vs 32.1% respectively). Guideline recommendation awareness was low except for the 2023 British Thoracic Society guideline (60.4%).

CONCLUSION

This study demonstrates variation of opinion regarding the initial management of stable patients with moderate to large PSP and an increasing preference for intervention as the magnitude of radiological features increases. Guideline awareness was low, highlighting the need for an evidence-based approach to PSP management in the ED that is widely understood and accepted across speciality groups and that prioritises patient symptoms over X-ray findings.

Prevalence and recurrence rates of spontaneous pneumothorax in patients with diffuse cystic lung diseases in China

OBJECTIVES

To investigate the prevalence and recurrence rates of spontaneous pneumothorax (SP) in patients with diffuse cystic lung diseases (DCLDs).

METHODS

We retrospectively identified and analyzed medical records of patients with DCLDs encountered at the First Affiliated Hospital of University of Science and Technology of China from Jan 1, 2017 to December 31, 2023.

RESULTS

A total of 289 patients were identified with DCLDs; 212 females and 77 males, with a median age of 48 years (range, 18-81 years). Among them, 89 (31%) patients had experienced SP; 59% among 115 patients with Birt-Hogg-Dubé (BHD), 34% of 41 patients with lymphangioleiomyomatosis (LAM, all women), 36% of 11 patients with pulmonary Langerhans cell histiocytosis (PLCH), none of 57 patients with Sjögren's syndrome-associated diffuse cystic lung disease (SS-DCLD), and 5% of 65 patients with no identifiable underlying disease (χ² = 90.585, P < 0.001). The overall recurrence rate of SP was higher with observation or chest tube placement strategy compared to surgical intervention, 59% vs. 11% (P < 0.001, 95% CI [0.1, -0.4]), respectively. The recurrence rate after surgical management was significantly lower compared to conservative management in patients with BHD (10% vs. 69%, P < 0.001, 95% CI [0.1, 0.3]) and LAM (20% vs. 57%, P = 0.322, 95% CI [0.1, 2.1]). Among patients with BHD, LAM, and PLCH, those who had pneumothorax as the initial presentation were diagnosed of their underlying disease at a significantly younger age (42.2 ± 13.0 years) compared to those without pneumothorax (48.1 ± 11.8 years) (P = 0.032, 95% CI [-8.24, -0.36]). Notably, eight of LAM patients who were treated with sirolimus after the initial SP did not experience recurrence of SP.

CONCLUSION

The risk of SP secondary to DCLDs was highest in patients with BHD, followed by those with PLCH and LAM. It was extremely low in SS-DCLD. Pneumothorax as the initial presentation often facilitated diagnosis of the underlying disease. Surgical treatment was associated with a lower recurrence rate of SP compared to nonsurgical management. In addition, sirolimus therapy may reduce the risk of pneumothorax recurrence in patients with LAM.

When back pain masks a pneumothorax: Atypical presentation in a healthy young nonsmoker male

Spontaneous pneumothorax usually presents with sudden chest pain and dyspnea as cardinal symptoms, but its diagnosis may be challenging with atypical presentation. We describe here the case of an unusual presentation of spontaneous pneumothorax in a 20-year-old male nonsmoker with no past medical history, presenting to the emergency department with intense back pain accompanied by vomiting. The diagnosis of spontaneous pneumothorax should be entertained by the clinicians, even in atypical presentations, for timely management.

Recurrent Pneumothorax: A Chest Tube Complication

Chest tubes are widely used for the management of primary spontaneous pneumothorax. The most common complication of the chest tube is a nonfunctioning chest tube, which might lead to recurrent pneumothorax during hospital admission. We describe a case of a 13-year-old tall and thin-built African American male who presented to the emergency department (ED) with a large right-sided pneumothorax diagnosed with a chest X-ray (CXR). Pneumothorax was managed with the three-compartment chest tube drainage system. Serial CXR revealed improvement in pneumothorax after the chest tube insertion. The patient had recurrent pneumothorax on the right side on the second day of admission attributed to the kinking of a chest tube. Relieving the kink led to the resolution of pneumothorax. The provider needs to be aware of the common complications of chest tube insertion and their management. Alternative treatment options with fewer complications like needle tube insertion for the management of primary spontaneous pneumothorax in children and adolescents need to be considered.

Synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome as a cause of pneumothorax: A case report

BACKGROUND

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome, a rare inflammatory disease, was described in 1987 by Chamot et al, who identified its common characteristics and transitional forms through case reports. The incidence rate is now 1 in 10000 among Caucasians and 0.00144 in 10000 among Japanese. Pneumothorax occurs when gas enters the pleural cavity, typically due to lung disease or chest trauma, and is characterized as either spontaneous or traumatic. Spontaneous pneumothorax is commonly linked to congenital lung tissue abnormalities or lung conditions, such as ruptured pulmonary bullae, emphysema, and bronchial asthma. Respiratory involvement in SAPHO syndrome has historically been noted.

CASE SUMMARY

We present the case of a 44-year-old male patient who had previously been diagnosed with SAPHO syndrome. Following a two-year cessation of methotrexate therapy, he experienced recurrent anterior chest wall and joint pain accompanied by dyspnea. We conducted a comprehensive examination for the patient, which included physical examination, laboratory tests, and imaging studies. The clinical presentation and treatment outcomes suggest that his pneumothorax was related to an episode of SAPHO syndrome. We performed closed thoracic drainage surgery for the patient and treated his symptoms with etoricoxib (60 mg daily). Upon discharge, methotrexate was prescribed again. In subsequent follow-ups, there was no recurrence of joint and respiratory symptoms observed in the patient.

CONCLUSION

SAPHO syndrome has been proposed as a transitional stage between ankylosing spondylitis and psoriatic arthritis. One study reported a 0.29% incidence of spontaneous pneumothorax in patients with ankylosing spondylitis, higher than in the general population. Additionally, 30% of patients with SAPHO syndrome test positive for HLA-B27, an antigen linked to ankylosing spondylitis. Symptomatically, some patients with SAPHO syndrome meet diagnostic criteria for ankylosing spondylitis, with sternoclavicular joint involvement and paravertebral ossifications resembling syndesmophytes in ankylosing spondylitis. These features suggest a possible linked between SAPHO syndrome and ankylosing spondylitis.

Chest Tubes and Pleural Drainage: History and Current Status in Pleural Disease Management

Thoracostomy and chest tube placement are key procedures in treating pleural diseases involving the accumulation of fluids (e.g., malignant effusions, serous fluid, pus, or blood) or air (pneumothorax) in the pleural cavity. Initially described by Hippocrates and refined through the centuries, chest drainage achieved a historical milestone in the 19th century with the creation of closed drainage systems to prevent the entry of air into the pleural space and reduce infection risk. The introduction of plastic materials and the Heimlich valve further revolutionized chest tube design and function. Technological advancements led to the availability of various chest tube designs (straight, angled, and pig-tail) and drainage systems, including PVC and silicone tubes with radiopaque stripes for better radiological visualization. Modern chest drainage units can incorporate smart digital systems that monitor and graphically report pleural pressure and evacuated fluid/air, improving patient outcomes. Suction application via wall systems or portable digital devices enhances drainage efficacy, although careful regulation is needed to avoid complications such as re-expansion pulmonary edema or prolonged air leak. To prevent recurrent effusion, particularly due to malignancy, pleurodesis agents can be applied through the chest tube. In cases of non-expandable lung, maintaining a long-term chest drain may be the most appropriate approach and procedures such as the placement of an indwelling pleural catheter can significantly improve quality of life. Continued innovations and rigorous training ensure that chest tube insertion remains a cornerstone of effective pleural disease management. This review provides a comprehensive overview of the historical evolution and modern advancements in pleural drainage. By addressing both current technologies and procedural outcomes, it serves as a valuable resource for healthcare professionals aiming to optimize pleural disease management and patient care.

Predictors of surgical intervention in first episode primary spontaneous pneumothorax requiring chest drain insertion

BACKGROUND

Primary spontaneous pneumothorax occurs in patients with no underlying lung disease and guidelines recommend chest tube drainage for the first episode, with surgical intervention reserved for recurrent episodes, persistent air leak or failure of lung re-expansion. Modern surgical management is associated with reduced length of hospital stay and superior freedom from recurrence compared with chest tube drainage alone. The objective of this study was to identify risk factors for failed chest tube drainage in patients who present with first episode primary spontaneous pneumothorax.

METHODS

A retrospective analysis of patients who presented to Royal Prince Alfred Hospital, Australia with first episode PSP and underwent chest tube insertion was performed. Patient demographics and size of pneumothorax were examined in relation to the primary outcome, a composite of failed chest tube drainage and recurrent ipsilateral pneumothorax.

RESULTS

Fifty-five patients underwent chest tube drainage for first episode primary spontaneous pneumothorax between 1st January 2017 and 31st December 2020. Complete lung collapse on admission chest x-ray was associated with an increased risk of the primary outcome (63% versus 19%, OR 7.3 [96% CI 2.0-27.4), P = 0.004).

CONCLUSION

This small retrospective study found that patients that undergo chest drain insertion for first episode primary spontaneous pneumothorax who present with complete lung collapse on admission are at high risk of requiring pleurodesis and therefore may benefit from early surgical referral.

The Medical Management of Spontaneous Pneumothorax: A Concise Review

Spontaneous pneumothorax is an increasingly common clinical presentation, the management of which, until recent years, had remained unchanged for decades. A recent surge in pneumothorax research has produced the largest randomised controlled trials in the field yet and has revolutionised the management of spontaneous pneumothorax. The body of evidence supporting the introduction of conservative and ambulatory care in appropriate patients in recent guidelines now allows these patients, many of whom would otherwise have been admitted to hospital, to be managed in the outpatient setting and reduces their risk of complications compared to conventional chest drain insertion. In this review, we discuss recent advances in the management of pneumothorax and the evidence underpinning contemporary guidelines. We aim to equip physicians with the knowledge to engage their patients in the decision-making process regarding their pneumothorax, whilst keeping patient safety and patients' own preferences at the centre of their care.

Simple aspiration for spontaneous pneumothorax in adults: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Spontaneous pneumothorax (SP) is a widespread clinical entity, and methods of managing adult SP remain controversial. The aim of this meta-analysis was to further determine the clinical efficacy and safety of simple aspiration (SA) in comparison to intercostal tube drainage (ITD) during the management of adult SP.

METHODS

EMBASE, Medline and the Cochrane Central Register of Controlled Trials via Ovid SP were searched (to June 2023) to identify randomized controlled trials (RCT) that reported outcomes of interest after comparing SA with ITD for the management of adult SP.

RESULTS

The search strategy yielded 1447 citations, of which 10 RCTs enrolling 1044 subjects were included. Compared with the ITD group, the SA group had a significantly lower the initial success rate of the procedure for the management of SP (OR 0.63, 95% CI [0.47-0.86]; P = 0.004). Moreover, SA was associated with a decreased duration of hospitalization (mean difference-2.05 days, 95% CI [-2.66 - -1.44]; P < 0.001) and a decreased need for operation (P = 0.03). For frequently reported adverse events such as subcutaneous emphysema (P = 0.32), bleeding (P = 0.0.26) and wound infection (P = 0.07), no significant difference between the SA and ITD groups was found. There was no significant difference for other outcomes. Subgroup analysis found that there was no significant difference between SA and ITD in terms of the initial success rate, 1-week success rate or any type of adverse event for PSP patients.

CONCLUSIONS

In the management of adult SP, the use of SA decreased the initial success rate but also decreased the duration of hospitalization and the need for operation compared with ITD. The incidence of adverse events did not differ between the two approaches. The research plan was registered at PROSPERO, and the registration number was CRD42023436770.

Hypoxemia in School-age Children Undergoing One-lung Ventilation: A Retrospective Cohort Study from the Multicenter Perioperative Outcomes Group

BACKGROUND

Risk factors for hypoxemia in school-age children undergoing one-lung ventilation remain poorly understood. The hypothesis was that certain modifiable and nonmodifiable factors may be associated with increased risk of hypoxemia in school-age children undergoing one-lung ventilation and thoracic surgery.

METHODS

The Multicenter Perioperative Outcomes Group database was queried for children 4 to 17 yr of age undergoing one-lung ventilation. Patients undergoing vascular or cardiac procedures were excluded. The original cohort was divided into two cohorts: 4 to 9 and 10 to 17 yr of age inclusive. All records were reviewed electronically for the primary outcome of hypoxemia during one-lung ventilation, which was defined as an oxygen saturation measured by pulse oximetry (Spo2) less than 90% for 3 min or longer continuously, while severe hypoxemia was defined as Spo2 less than 90% for 5 min or longer. Potential modifiable and nonmodifiable risk factors associated with these outcomes were evaluated using separate multivariable least absolute shrinkage and selection operator regression analyses for each cohort. The covariates evaluated included age, extremes of weight, American Society of Anesthesiologists Physical Status of III or higher, duration of one-lung ventilation, preoperative Spo2 less than 98%, approach to one-lung ventilation, right operative side, video-assisted thoracoscopic surgery, lower tidal volume ventilation (defined as tidal volume of 6 ml/kg or less and positive end-expiratory pressure of 4 cm H2O or greater for more than 80% of the duration of one-lung ventilation), and procedure type.

RESULTS

The prevalence of hypoxemia in the 4- to 9-yr-old cohort and the 10- to 17-yr-old cohort was 24 of 228 (10.5% [95% CI, 6.5 to 14.5%]) and 76 of 1,012 (7.5% [95% CI, 5.9 to 9.1%]), respectively. The prevalence of severe hypoxemia in both cohorts was 14 of 228 (6.1% [95% CI, 3.0 to 9.3%]) and 47 of 1,012 (4.6% [95% CI, 3.3 to 5.8%]). Initial Spo2 less than 98% was associated with hypoxemia in the 4- to 9-yr-old cohort (odds ratio, 4.20 [95% CI, 1.61 to 6.29]). Initial Spo2 less than 98% (odds ratio, 2.76 [95% CI, 1.69 to 4.48]), extremes of weight (odds ratio, 2.18 [95% CI, 1.29 to 3.61]), and right-sided cases (odds ratio, 2.33 [95% CI, 1.41 to 3.92]) were associated with an increased risk of hypoxemia in the older cohort. Increasing age (1-yr increment; odds ratio, 0.88 [95% CI, 0.80 to 0.97]) was associated with a decreased risk of hypoxemia.

CONCLUSIONS

An initial room air oxygen saturation of less than 98% was associated with an increased risk of hypoxemia in all children 4 to 17 yr of age. Extremes of weight, right-sided cases, and decreasing age were associated with an increased risk of hypoxemia in children 10 to 17 yr of age.

EDITOR’S PERSPECTIVE

Trends in recurrence of primary spontaneous pneumothorax in young population after treatment for first episode based on a nationwide population data

The aim of this study is to identifying post treatment recurrence rates in pneumothorax patients under 35 and without any comorbidities according to the treatment types, gender, and age categories based on nationwide population data. Clinical information of pneumothorax patients was extracted from the Korean National Health Insurance Service (NHIS) database between January 2002 and December 2020. Enrolled patients were categorized into two groups; (1) Group I, those who underwent conservative management including pain relief, oxygen therapy, and closed thoracostomy, and (2) Group II, surgical intervention. Recurrence rates were compared according to age, gender, and type of treatment. Surgical intervention was performed in 25.6% patients as first treatment. The overall recurrence rate was 20.3%. Male patients showed a higher 5-year recurrence rate than female (20.8% vs. 10.9%, p < 0.001). Those with conservative management showed lower 5-year recurrence rates than those with surgical treatment (7.9% vs. 23.7%, p < 0.001). The 5-year recurrence rates of patients aged 14≤, and < 20 was higher than other age groups (29.2% vs. 4.5 and 11.9%, p < 0.001). Surgical intervention, male gender and aged under 20 showed association with higher recurrence rates.

Probability of sporadic lymphangioleiomyomatosis in women presenting with spontaneous pneumothorax

BACKGROUND

Sporadic lymphangioleiomyomatosis (S-LAM) is a rare low-grade neoplasm of young women characterized by multiple pulmonary cysts leading to progressive dyspnea and recurrent spontaneous pneumothorax (SP). The diagnosis of S-LAM may be delayed by several years. To reduce this delay, chest computed tomography (CT) screening has been proposed to uncover cystic lung disease in women presenting with SP. However, the probability to discover S-LAM in this population has not been determined precisely. The aim of this study was to calculate the probability of finding S-LAM in women presenting with (a) SP, and (b) apparent primary SP (PSP) as first manifestation of S-LAM.

METHODS

Calculations were made by applying the Bayes theorem to published epidemiological data on S-LAM, SP and PSP. Each term of the Bayes equation was determined by meta-analysis, and included: (1) the prevalence of S-LAM in the general female population, (2) the incidence rate of SP and PSP in the general female population, and (3) the incidence rate of SP and apparent PSP in women with S-LAM.

RESULTS

The prevalence of S-LAM in the general female population was 3.03 per million (95% confidence interval 2.48, 3.62). The incidence rate of SP in the general female population was 9.54 (8.15, 11.17) per 100,000 person-years (p-y). The incidence rate of SP in women with S-LAM was 0.13 (0.08, 0.20). By combining these data in the Bayes theorem, the probability of finding S-LAM in women presenting with SP was 0.0036 (0.0025, 0.0051). For PSP, the incidence rate in the general female population was 2.70 (1.95, 3.74) per 100,000 p-y. The incidence rate of apparent PSP in women with S-LAM was 0.041 (0.030, 0.055). With the Bayes theorem, the probability of finding S-LAM in women presenting with apparent PSP as first disease manifestation was 0.0030 (0.0020, 0.0046). The number of CT scans to perform in women to find one case of S-LAM was 279 for SP and 331 for PSP.

CONCLUSION

The probability of discovering S-LAM at chest CT in women presenting with apparent PSP as first disease manifestation was low (0.3%). Recommending chest CT screening in this population should be reconsidered.

Use of Video-Assisted Thoracoscopic Surgery (VATS) in the Treatment of Primary Spontaneous Pneumothorax (PSP) in Children

INTRODUCTION

This study aims to review the primary spontaneous pneumothorax (PSP) patients we have treated and to discuss the results in terms of PSP treatment management and video-assisted thoracoscopic surgery (VATS) use in the light of the literature.

METHODS

The study was designed retrospectively and conducted at a tertiary referral university hospital between January 1, 2015 and May 1, 2021. Patients under the age of 18 years with a diagnosis of pneumothorax (PTX) were included in the study. Medical records were analyzed in terms of clinical characteristics, demographic data, findings from imaging data, procedures performed, and course of the disease at hospital. Patients with no evidence of PTX on radiologic imaging (direct postero-anterior chest X-ray (PACXR) or thoracic computed tomography (TCT)), incomplete medical records for follow-up, history of trauma, and neonatal PTX were excluded from the study.

RESULTS

The study was conducted on a total of 98 PTX cases in 69 patients, 61 (88.4%) males and eight (11.6%) females. The ages of the patients ranged between 13 and 17 years with a mean of 16.59 ± 0.95 years. While 48 (49%) PTX cases were treated with tube thoracostomy, 19 (19.4%) were treated with medical follow-up (nonsurgical treatment) and 31 (31.6%) were treated with VATS. A total of 31 VATS procedures were performed on 28 patients. The follow-up period after VATS ranged from tthree to 78 months, with a mean of 31.5 ± 20.3 months and a median of 28 months.

CONCLUSION

 Our retrospective study showed that TCT scanning did not provide additional benefit when PSP was detected on PACXR in patients presenting with chest pain and respiratory distress. According to the findings of our study, it was thought that the probability of undergoing an invasive procedure and surgical intervention increased as the percentage of PTX detected in PACXR increased. Tube thoracostomy may be required in a patient with PSP if PTX does not start to decrease and lung expansion does not increase after an average of 60 hours after the decision for medical follow-up, and if PTX is progressive in the follow-up. VATS can be performed on a patient with PSP when lung expansion does not increase after an average of 18 hours after tube thoracostomy, when PTX progresses, when air leakage continues for more than 10 days despite increased lung expansion, and when recurrent PTX occurs.

Evaluation and management of persistent air leak

INTRODUCTION

Persistent air leaks (PAL) represent a challenging clinical problem for which there is not a clear consensus to guide optimal management. PAL is associated with significant morbidity, mortality, and increased length of hospital stay. There are a variety of surgical and non-surgical management options available.

AREAS COVERED

This narrative review describes the current evidence for PAL management including surgical approach, autologous blood patch pleurodesis, chemical pleurodesis, endobronchial valves, and one-way valves. Additionally, emerging topics such as drainage-dependent air leak and intensive care unit management are described.

EXPERT OPINION

There has been considerable progress in understanding the pathophysiology of PAL and growing evidence to support the various non-surgical treatment modalities. Increased recognition of drainage-dependent persistent air leaks offers the opportunity to decrease the number of patients requiring additional invasive treatment. Randomized control trials are needed to guide optimal management.

Simple Aspiration versus Drainage for Complete Pneumothorax: A Randomized Noninferiority Trial

Rationale: Management of first episodes of primary spontaneous pneumothorax remains the subject of debate. Objectives: To determine whether first-line simple aspiration is noninferior to first-line chest tube drainage for lung expansion in patients with complete primary spontaneous pneumothorax. Methods: We conducted a prospective, open-label, randomized noninferiority trial. Adults aged 18-50 years with complete primary spontaneous pneumothorax (total separation of the lung from the chest wall), recruited at 31 French hospitals from 2009 to 2015, received simple aspiration (n = 200) or chest tube drainage (n = 202) as first-line treatment. The primary outcome was pulmonary expansion 24 hours after the procedure. Secondary outcomes were tolerance of treatment, occurrence of adverse events, and recurrence of pneumothorax within 1 year. Substantial discordance in the numerical inputs used for trial planning and the actual trial rates of the primary outcome resulted in a reevaluation of the trial analysis plan. Measurement and Main Results: Treatment failure occurred in 29% in the aspiration group and 18% in the chest tube drainage group (difference in failure rate, 0.113; 95% confidence interval [CI], 0.026-0.200). The aspiration group experienced less pain overall (mean difference, -1.4; 95% CI, -1.89, -0.91), less pain limiting breathing (frequency difference, -0.18; 95% CI, -0.27, -0.09), and less kinking of the device (frequency difference, -0.05; 95% CI, -0.09, -0.01). Recurrence of pneumothorax was 20% in this group versus 27% in the drainage group (frequency difference, -0.07; 95% CI, -0.16, +0.02). Conclusions: First-line management of complete primary spontaneous pneumothorax with simple aspiration had a higher failure rate than chest tube drainage but was better tolerated with fewer adverse events. Clinical trial registered with www.clinicaltrials.gov (NCT01008228).

Natural History of Contralateral Bullae/Blebs After Ipsilateral Video-Assisted Thoracoscopic Surgery for Primary Spontaneous Pneumothorax: A Retrospective Cohort Study

BACKGROUND

Contralateral bullae/blebs are frequently found in patients who are scheduled to undergo ipsilateral video-assisted thoracoscopic surgery (VATS) for primary spontaneous pneumothorax (PSP).

RESEARCH QUESTION

Should visible contralateral bullae/blebs be simultaneously resected when ipsilateral VATS bullectomy is performed?

STUDY DESIGN AND METHODS

In this single-center, retrospective cohort study, we included patients aged ≤ 30 years who underwent ipsilateral VATS for PSP from April 2009 to December 2019. Electronic medical records, radiograph images, and preoperative high-resolution CT images were reviewed. The primary end point was recurrence-free survival (no contralateral pneumothorax) after discharge of ipsilateral VATS for PSP, determined via Kaplan-Meier analysis. Recurrence was compared between the group with and that without contralateral bullae/blebs by using the log-rank test. A multivariable Cox proportional hazards model was constructed to investigate risk factors for contralateral pneumothorax.

RESULTS

Among 567 patients, contralateral pneumothorax occurred in 86 of them after ipsilateral VATS (15.2%) during a median follow-up period of 51.3 (interquartile range, 67.2) months. The 1-, 5-, and 10-year recurrence-free survival rates were 92.2%, 83.7%, and 79.9%, respectively. Contralateral recurrence was higher in the group with (82/455, 18.0%) than in that without (4/112, 3.6%) contralateral bullae/blebs (P < .001). Age (hazard ratio [HR], 0.701; 95% CI, 0.629-0.780; P < .001), current smoking (HR, 2.106; 95% CI, 1.158-3.831; P = .015), and the presence of bullae/blebs (increasing with size, HR, 4.818-8.980; all P < .05) were independent risk factors for contralateral pneumothorax. The annual rates of contralateral pneumothorax in the group with (4.0%) and in that without (0.7%) contralateral bullae/blebs declined over time.

INTERPRETATION

Although contralateral bullae/blebs were common in patients who underwent ipsilateral VATS for PSP and were statistically significantly associated with future pneumothorax, the annual rate of pneumothorax was 4.0% in such patients, and it decreased over time. Therefore, a conservative approach on unruptured contralateral bullae/blebs is recommended.

Comparison of clinical utility between digital and analog drainage systems in patients with spontaneous pneumothorax

BACKGROUND

Digital drainage systems can continuously and numerically monitor air leakage, which may lead to a shorter duration of drainage and hospitalization; however, the usefulness of digital drainage systems compared to that of analog drainage systems for patients with primary or secondary spontaneous pneumothorax remains unclear.

METHODS

This retrospective study included 108 patients with spontaneous pneumothorax who were successfully treated with chest drainage alone at our institution. We compared the clinical efficacy of digital and analog chest drainage systems.

RESULTS

From the study population, 68 patients were diagnosed with primary and the other 40 with secondary spontaneous pneumothorax. The analog drainage system was used in 44 patients, and the digital drainage system in 64 patients. Among patients with primary spontaneous pneumothorax, the digital group had a significantly shorter duration of chest drainage than the analog group (median 2 vs. 4 days; p = 0.001), but there was no significant difference in those with secondary spontaneous pneumothorax. Additionally, the length and cost of hospitalization in the digital group were significantly lower than those in the analog group for both patients with primary and secondary spontaneous pneumothorax. There was no significant difference in recurrence within 1 week after chest tube removal between the two groups, neither among patients with primary nor among those with secondary pneumothorax.

CONCLUSIONS

Digital drainage system may be better than analog drainage system for patients with primary spontaneous pneumothorax who need chest drainage, but further research is needed on drainage system selection for those with secondary disease.

Quantitative Measurement of Pneumothorax Using Artificial Intelligence Management Model and Clinical Application

Artificial intelligence (AI) techniques can be a solution for delayed or misdiagnosed pneumothorax. This study developed, a deep-learning-based AI model to estimate the pneumothorax amount on a chest radiograph and applied it to a treatment algorithm developed by experienced thoracic surgeons. U-net performed semantic segmentation and classification of pneumothorax and non-pneumothorax areas. The pneumothorax amount was measured using chest computed tomography (volume ratio, gold standard) and chest radiographs (area ratio, true label) and calculated using the AI model (area ratio, predicted label). Each value was compared and analyzed based on clinical outcomes. The study included 96 patients, of which 67 comprised the training set and the others the test set. The AI model showed an accuracy of 97.8%, sensitivity of 69.2%, a negative predictive value of 99.1%, and a dice similarity coefficient of 61.8%. In the test set, the average amount of pneumothorax was 15%, 16%, and 13% in the gold standard, predicted, and true labels, respectively. The predicted label was not significantly different from the gold standard (p = 0.11) but inferior to the true label (difference in MAE: 3.03%). The amount of pneumothorax in thoracostomy patients was 21.6% in predicted cases and 18.5% in true cases.

Acute Respiratory Failure

Respiratory failure is one of the most common reasons for hospitalization and intensive care unit (ICU) admissions, and a diverse range of etiologies can precipitate it. Respiratory failure can result from various mechanisms such as hypoventilation, diffusion impairment, shunting, ventilation-perfusion mismatch, or a combination of those mentioned earlier. Hence, an accurate understanding of different pathophysiologic mechanisms is required for appropriate patient care. Prompt identification and treatment of various respiratory emergencies such as tension pneumothorax, massive hemoptysis, and high-risk pulmonary embolism lead to fewer complications, shorter ICU and hospital stay, and improved survival. This review article entails common respiratory failure pathologies encountered in the ICU and addresses their epidemiology, pathophysiology, clinical presentation, and management.

Which pneumothorax volume/size measurement method can best predict surgical indication in primary spontaneous pneumothorax patients? A comparison of six different methods

OBJECTIVES

We determined whether patients requiring surgery could be identified using pneumothorax volume/size in the first episode of primary spontaneous pneumothorax (PSP) and confirmed which of six different measurement methods of pneumothorax volume/size best predicted surgical indication (prolonged air leak, PAL, or ipsilateral recurrence).

METHODS

Between 2013 and 2017, 282 patients with PSP were analysed. The volume of the pneumothorax (%) was calculated using volumetric methods (Collins, Rhea, Kircher, Light), while its size (large or small) was determined using the British Thoracic Society (BTS) and American College of Chest Physicians (ACCP) guidelines for the first PSP episode. The optimal cut-off points of pneumothorax volume in patients requiring surgery were based on the most sensitive and specific scores, calculated using receiver operating characteristic analysis.

RESULTS

Surgery was indicated in 162 patients (57.4%) because of PAL (n = 92) or ipsilateral recurrence (n = 70). Kircher's method had a better area under the curve (AUC) value than the others (AUC = 0.731, 95% confidence interval [CI] 0.676-0.782). Comparing the calculated cut-off points for each volumetric method and the known thresholds from the BTS/ACCP, the best predictor for surgical indications (for both PAL and ipsilateral recurrence) was Kircher's method (odds ratio = 5.636, 95% CI 3.338-9.516, p < 0.001). The four volumetric methods were significantly correlated with pneumothorax volume (rho ≥ 0.8, p < 0.001, for all comparisons).

CONCLUSIONS

Pneumothorax volume/size calculated in the first PSP episode may help predict surgical candidates, with Kircher's method being the best predictor. There was a correlation between all the volumetric methods of the pneumothorax volume.

Ambulant treatment with a digital chest tube for prolonged air leak is safe and effective

Background

Outpatient or ambulatory treatment for prolonged air leak (PAL) has been reported previously in various studies. Evidence regarding efficiency and safety is nevertheless poor. This report describes the experience of 10 years ambulatory care with a digital chest drain system monitored by specialized nurses in our centre. The aim of the study is to give further insights in the effectiveness and safety of this treatment.

Methods

Retrospective data of 10 years ambulatory care for PAL were examined. One hundred and forty patients with PAL after pneumothorax or pulmonary surgery were included.

Results

A total of 140 patients with PAL were included. Treatment was successful in 112 patients (80.0%). Hospital readmission was necessary in 33 patients (23.6%) and 28 (20.0%) of them received additional treatment. Additional treatment consisted of video-assisted thoracoscopic surgery (VATS) in 19 patients (13.6%), new chest tube placement in 8 patients (5.7%) and pleurodesis (with talc slurry) in 1 patient (0.7%). Minor complications occurred in 10 patients (7.1%), major complications requiring readmission occurred in 14 patients (10.0%).

Conclusions

Ambulatory treatment of PAL with a digital monitoring device resulted in a high success rate with a limited complication rate.

Aetiology of Primary Spontaneous Pneumothorax

Air in the pleural cavity is termed pneumothorax. When this occurs in the absence of trauma or medical intervention, it is called spontaneous pneumothorax. Primary spontaneous pneumothorax typically occurs in young patients without known lung disease. However, the idea that these patients have “normal” lungs is outdated. This article will review evidence of inflammation and respiratory bronchiolitis on surgical specimens, discuss the identification of emphysema-like change (i.e., blebs and bullae), the concept of pleural porosity and review recent data on the overexpression of matrix metalloproteinases in the lungs of patients who have had pneumothorax.

Management of pneumothorax in the setting of chronic non-invasive positive pressure ventilation: A case series

There is a growing population of patients who require chronic noninvasive ventilation. While these patients often have no parenchymal lung disease, the use of positive pressure ventilation itself predisposes to both initial and recurrent pneumothoraces. Furthermore, generally accepted pneumothorax management strategies, such as removing a chest tube after liberation from positive pressure ventilation, are not possible in this population. Despite this, there is a lack of clear guidance on management of pneumothorax in the chronically ventilated patient. In this case series, we discuss the management of pneumothoraces in patients requiring chronic noninvasive mechanical ventilation in our Assisted Ventilation Clinic (AVC). Our experience suggests a potential role of definitive treatment of the initial pneumothorax to prevent reoccurrence.

Deep multi-instance transfer learning for pneumothorax classification in chest X-ray images

PURPOSE

Pneumothorax is a life-threatening emergency that requires immediate treatment. Frontal-view chest X-ray images are typically used for pneumothorax detection in clinical practice. However, manual review of radiographs is time-consuming, labor-intensive, and highly dependent on the experience of radiologists, which may lead to misdiagnosis. Here, we aim to develop a reliable automatic classification method to assist radiologists in rapidly and accurately diagnosing pneumothorax in frontal chest radiographs.

METHODS

A novel residual neural network (ResNet)-based two-stage deep-learning strategy is proposed for pneumothorax identification: local feature learning (LFL) followed by global multi-instance learning (GMIL). Most of the nonlesion regions in the images are removed for learning discriminative features. Two datasets are used for large-scale validation: a private dataset (27 955 frontal-view chest X-ray images) and a public dataset (the National Institutes of Health [NIH] ChestX-ray14; 112 120 frontal-view X-ray images). The model performance of the identification was evaluated using the accuracy, precision, recall, specificity, F1-score, receiver operating characteristic (ROC), and area under ROC curve (AUC). Fivefold cross-validation is conducted on the datasets, and then the mean and standard deviation of the above-mentioned metrics are calculated to assess the overall performance of the model.

RESULTS

The experimental results demonstrate that the proposed learning strategy can achieve state-of-the-art performance on the NIH dataset with an accuracy, AUC, precision, recall, specificity, and F1-score of 94.4% ± 0.7%, 97.3% ± 0.5%, 94.2% ± 0.3%, 94.6% ± 1.5%, 94.2% ± 0.4%, and 94.4% ± 0.7%, respectively.

CONCLUSIONS

The experimental results demonstrate that our proposed CAD system is an efficient assistive tool in the identification of pneumothorax.

Pneumothorax: Classification and Etiology

Pneumothorax is a common problem worldwide. Pneumothorax develops secondary to diverse aetiologies; in many cases, there may be no recognizable lung abnormality. The pathogenetic mechanism(s) causing spontaneous pneumothorax may be related to an interplay between lung-related abnormalities and environmental factors such as smoking. Tobacco smoking is a major risk factor for primary spontaneous pneumothorax; chronic obstructive pulmonary disease is most frequently associated with secondary spontaneous pneumothorax. This review article provides an overview of the historical perspective, epidemiology, classification, and aetiology of pneumothorax. It also aims to highlight current knowledge and understanding of underlying risks and pathophysiological mechanisms in pneumothorax development.

A Rare Case of Interlobar Pneumothorax

BACKGROUND: Pneumothorax is a severe medical condition characterized by the collection of air in one or several spaces of the pleura. A rare subtype of pneumothorax where air is restricted in interlobar pleural space, mostly due to the previous fibrous pleural adhesions, is known as interlobar pneumothorax. CASE PRESENTATION: We present a rare case of a 58-year-old female admitted to the emergency department due to difficulty on breathing, hemoptysis, and discomfort in the right anterior axillary line, which worsened with inspiration and was associated with breathlessness during physical activity. The diagnosis was confirmed by thoracic multi slice computed tomography (MSCT), showing that air was located between the middle and lower lobes of the right lung , measuring 7 × 5 × 2.5 cm (transversal × oblique cranio-caudal × antero-posterior), representing interlobar pneumothorax. DISCUSSION: Cases of interlobar pneumothorax need to be carefully differentiated and evaluated, while skin folds, overlapping breast margin, interlobar fissure, bullae in the apices, pneumomediastinum, pneumopericardium, inferior pulmonary ligament air collection, pneumatocele, and air collection in the intrathoracic extrapleural space, can mimic pneumothorax and make diagnosing very challenging.

Secondary spontaneous pneumothorax: a time to re-evaluate management

Spontaneous pneumothorax (SP) is defined as the presence of air in the pleural cavity and remains a significant health problem. Secondary SP (SSP) is associated with underlying lung diseases, such as cystic fibrosis, chronic obstructive pulmonary disease (COPD), and interstitial lung disease (ILD), and is associated with poor outcomes. The current guidelines in the management of SSP have not been updated since the last decade; therefore, new protocols focused on the management of SSP should be evaluated. We present two cases of patients admitted with SSP who were treated conservatively due to haemodynamic stability. In both cases, the pneumothoraces resolved without further complications.

End-Tidal Carbon Dioxide Monitoring for Spontaneous Pneumothorax

Background

Spontaneous pneumothorax should be classified as primary spontaneous pneumothorax (PSP) or secondary spontaneous pneumothorax (SSP) because treatment strategies may differ depending on underlying lung conditions and clinical course. The pulmonary dysfunction can lead to changes in end-tidal carbon dioxide (ETCO₂). The aim of this study was to investigate the difference in ETCO₂ between PSP and SSP.

Methods

This retrospective observational study included adult patients diagnosed with spontaneous pneumothorax in the emergency room from April 2019 to September 2020. We divided patients into PSP and SSP groups and compared ETCO₂ variables between the two groups.

Results

There were 33 (66%) patients in the PSP group and 17 (34%) patients in the SSP group. Initial ETCO₂ was lower in the SSP group than in the PSP group (30 (23–33) vs. 35 (33–38) mmHg, p=0.002). Multivariate analysis revealed that respiratory gas associated with SSP was initial ETCO₂ (OR: 0.824; 95% CI: 0.697–0.974, p=0.023). The optimal cutoff for initial ETCO₂ to detection of SSP was 32 mmHg (area under curve, 0.754), with 76.5% sensitivity and 72.7% specificity.

Conclusion

ETCO₂ monitoring is a reliable noninvasive indicator of differentiating between PSP and SSP. Initial ETCO₂ lower than 32 mmHg is a predictor of SSP.

Recommendation for management of patients with their first episode of primary spontaneous pneumothorax, using video-assisted thoracoscopic surgery or conservative treatment

International guidelines do not recommend surgery for the first episode of primary spontaneous pneumothorax (PSP), except in cases of persistent air leak, hemopneumothorax, bilateral pneumothorax, or occupations at risk. However, these recommendations have been challenged because of a significant reduction in the recurrence rate in emerging studies. We evaluated the rationale of recommendations by systematically reviewing RCTs and observational studies by using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) system. We searched articles in PubMed, EMBASE, and Cochrane databases up to August 15, 2020. The primary outcomes were the recurrence rate and complication rate. The secondary outcomes were hospital stay and drainage duration. Nine eligible studies with 1121 patients were retrieved and analyzed. The recurrence rate was lower in the VATS than in conservative treatment with moderate evidence (OR 0.13, 95% CI 0.09 to 0.19, P < 0.001, I² = 0%). We did not find significant differences in complication rate (Peto OR 1.17, 95% CI 0.33 to 4.12, P = 0.80), hospital stay duration (MD − 0.48 days, 95% CI − 2.84 to 1.87, P = 0.69, very low evidence), and in drainage duration (MD − 3.99 days, 95% CI − 9.06 to 1.08, P = 0.12, very low evidence) between the two groups. Our results would suggest VATS treatment as a weak recommendation for patients with the first episode of PSP, based on our systematic review of the current evidence by using the GRADE system, indicating that different treatments will be appropriate for different patients and that patients’ values and preferences should be incorporated through shared decision making.

Trial REGISTRY: PROSPERO; No.: CRD42020162267.

Spontaneous pneumothorax-When do we need to intervene?

BACKGROUND

Pneumothorax can be classified as traumatic, iatrogenic or spontaneous (SP), which can be subdivided into primary spontaneous pneumothorax (PSP), a condition without preexisting lung disease, or secondary spontaneous pneumothorax (SSP) a complication of a preexisting lung disease. Recurrence rate of PSP is 30% whereas for SSP rate is unknown. This article explores the experience of a tertiary center over 20 years.

METHODS

A retrospective case review of patients hospitalized with pneumothorax to investigate the natural history and treatment of SP in a young population in a single tertiary center was conducted. A search of the digital archive (going back to 01/01/1995) of Sheba Medical Center identified hospitalized patients below the age of 40.

RESULTS

The database was composed of the records of 750 patients (612 males, 138 females) who were hospitalized. The recurrence risk for SP after nonoperative treatment was significantly higher. Women were found to have an increased risk of SSP when having SP (OR 2.78). Asthma was the most prevalent disease causing SSP in young people.

CONCLUSIONS

In this large cohort, we found that operative procedure has clear protective effect from recurrence in SP, so surgery should be positively considered when treating SP in hospitalized patients. Among young people and particularly in pediatric patients, when females have a SP, we strongly recommend looking for primary lung disease. More studies are needed to determine the risk factors and produce clear guidelines regarding surgery as first treatment.

Prevalence of Birt-Hogg-Dubé Syndrome Determined Through Epidemiological Data on Spontaneous Pneumothorax and Bayes Theorem

Background: Birt-Hogg-Dubé syndrome (BHD) is a rare inherited disorder characterized by cutaneous fibrofolliculomas, multiple pulmonary cysts, recurrent spontaneous pneumothorax (SP), and renal tumors. More than 40 years after its description, the prevalence of BHD in the general population remains unknown. This study aimed at determining the prevalence of BHD by applying the Bayes theorem of conditional probability to epidemiological data on SP. Methods: We performed a meta-analysis of published data on: (1) the probability of having BHD among patients with apparent primary SP (4 studies), (2) the incidence rate of primary SP in the general population (9 studies), and (3) the probability of experiencing a SP in BHD (16 studies). Results were corrected for SP relapses, stratified by gender and year of study publication (before and after 2000), and computed with the Bayes equation. Results: The probability of having BHD among patients with apparent primary SP was 0.09 (95% confidence interval: 0.07, 0.11) or 9%. It was 0.20 (0.14, 0.27) in women and 0.05 (0.04, 0.07) in men. The incidence rate of primary SP in the general population was 8.69 (6.58, 11.46) per 100,000 person-years (p-y). It was 3.44 (2.36, 4.99) per 100,000 p-y in women and 13.96 (10.72, 18.18) per 100,000 p-y in men, and was about 2 times higher in studies published after 2000 than in those published before 2000. The probability of experiencing at least one SP among patients with BHD was 0.43 (0.31, 0.54) or 43%, without gender difference. By combining these data in the Bayes equation, we found a prevalence of BHD in the general population of 1.86 (1.16, 3.00) per million, with values of 1.86 (1.02, 3.39) per million in men, and 1.88 (0.97, 3.63) per million in women. Conclusion: The prevalence of BHD in the general population is about 2 cases per million, without difference between genders.

Pneumothorax detection in chest radiographs: optimizing artificial intelligence system for accuracy and confounding bias reduction using in-image annotations in algorithm training

OBJECTIVES

Diagnostic accuracy of artificial intelligence (AI) pneumothorax (PTX) detection in chest radiographs (CXR) is limited by the noisy annotation quality of public training data and confounding thoracic tubes (TT). We hypothesize that in-image annotations of the dehiscent visceral pleura for algorithm training boosts algorithm's performance and suppresses confounders.

METHODS

Our single-center evaluation cohort of 3062 supine CXRs includes 760 PTX-positive cases with radiological annotations of PTX size and inserted TTs. Three step-by-step improved algorithms (differing in algorithm architecture, training data from public datasets/clinical sites, and in-image annotations included in algorithm training) were characterized by area under the receiver operating characteristics (AUROC) in detailed subgroup analyses and referenced to the well-established "CheXNet" algorithm.

RESULTS

Performances of established algorithms exclusively trained on publicly available data without in-image annotations are limited to AUROCs of 0.778 and strongly biased towards TTs that can completely eliminate algorithm's discriminative power in individual subgroups. Contrarily, our final "algorithm 2" which was trained on a lower number of images but additionally with in-image annotations of the dehiscent pleura achieved an overall AUROC of 0.877 for unilateral PTX detection with a significantly reduced TT-related confounding bias.

CONCLUSIONS

We demonstrated strong limitations of an established PTX-detecting AI algorithm that can be significantly reduced by designing an AI system capable of learning to both classify and localize PTX. Our results are aimed at drawing attention to the necessity of high-quality in-image localization in training data to reduce the risks of unintentionally biasing the training process of pathology-detecting AI algorithms.

KEY POINTS

• Established pneumothorax-detecting artificial intelligence algorithms trained on public training data are strongly limited and biased by confounding thoracic tubes. • We used high-quality in-image annotated training data to effectively boost algorithm performance and suppress the impact of confounding thoracic tubes. • Based on our results, we hypothesize that even hidden confounders might be effectively addressed by in-image annotations of pathology-related image features.

Spontaneous Pneumothorax: New Horizons

Spontaneous pneumothorax can be divided into two categories: primary and secondary. The management of each one depends on resource availability, physician preference, and procedural capability, and is broadly based on guidelines that are over a decade old. Emerging evidence from three recent randomized controlled trials on ambulatory pneumothorax pathways are exciting and herald a new era for management of spontaneous pneumothorax. These three trials and their implications are discussed.

A novel finding related to bulla and bleb formation in patients with primary spontaneous pneumothorax

BACKGROUND

Spontaneous pneumothorax is a common problem globally. Bullas and blebs have been implicated in this problem, but the etiology of their formation is unknown. We aim to show the relation between a novel clinical finding, the pulmonary delayed inflation (PDI) sign, and the etiology of bulla and bleb formation in young patients.

METHODS

We retrospectively analyzed data from 111 patients with pneumothorax and a control group of 27 patients. We evaluated the relation between the PDI sign and other clinical factors.

RESULTS

The PDI sign was observed in 78 patients. Of these, 75 exhibited the PDI sign in only the upper lobe. Regardless of smoking status, patients 34 years of age or younger had a significantly higher incidence of the PDI sign than, patients 55 years of age or older and control patients. The inflation time in patients 34 years of age or younger, regardless of smoking status, was significantly longer than in patients 55 years of age or older and patients in the control group. There was no significant association between inflation time and the presence of asthma.

CONCLUSIONS

The novel PDI sign is seen in patients 34 years of age or younger. Because this sign may indicate a peripheral bronchial abnormality and may be related to the formation of blebs and bullae in young patients with spontaneous pneumothorax, it is possible that it can be used to develop effective treatments for pneumothorax in young patients.

Analysis of Pneumothorax in Noninvasive Ventilator Users With Duchenne Muscular Dystrophy

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.

Pleural effusions and pneumothorax: Beyond simple plumbing: Expert opinions on knowledge gaps and essential next steps

Pleural diseases affect millions of people worldwide. Pleural infection, malignant pleural diseases and pneumothorax are common clinical challenges. A large number of recent clinical trials have provided an evidence-based platform to evaluate conventional and novel methods to drain pleural effusions/air which reduce morbidity and unnecessary interventions. These successes have generated significant enthusiasm and raised the profile of pleural medicine as a new subspecialty. The ultimate goal of pleural research is to prevent/stop development of pleural effusions/pneumothorax. Current research studies mainly focus on the technical aspects of pleural drainage. Significant knowledge gaps exist in many aspects such as understanding of the pathobiology of the underlying pleural diseases, pharmacokinetics of pleural drug delivery, etc. Answers to these important questions are needed to move the field forward. This article collates opinions of leading experts in the field in highlighting major knowledge gaps in common pleural diseases to provoke thinking beyond pleural drainage. Recognizing the key barriers will help prioritize future research in the quest to ultimately cure (rather than just drain) these pleural conditions.