The Biological Role of Pleural Fluid PAI-1 and Sonographic Septations in Pleural Infection: Analysis of a Prospectively Collected Clinical Outcome Study.

Rationale: Sonographic septations are assumed to be important clinical predictors of outcome in pleural infection, but the evidence for this is sparse. The inflammatory and fibrinolysis-associated intrapleural pathway(s) leading to septation formation have not been studied in a large cohort of pleural fluid (PF) samples with confirmed pleural infection matched with ultrasound and clinical outcome data. Objectives: To assess the presence and severity of septations against baseline PF PAI-1 (Plasminogen-Activator Inhibitor-1) and other inflammatory and fibrinolysis-associated proteins as well as to correlate these with clinically important outcomes. Methods: We analyzed 214 pleural fluid samples from PILOT (Pleural Infection Longitudinal Outcome Study), a prospective observational pleural infection study, for inflammatory and fibrinolysis-associated proteins using the Luminex platform. Multivariate regression analyses were used to assess the association of pleural biological markers with septation presence and severity (on ultrasound) and clinical outcomes. Measurements and Main Results: PF PAI-1 was the only protein independently associated with septation presence (P < 0.001) and septation severity (P = 0.003). PF PAI-1 concentrations were associated with increased length of stay (P = 0.048) and increased 12-month mortality (P = 0.003). Sonographic septations alone had no relation to clinical outcomes. Conclusions: In a large and well-characterized cohort, this is the first study to associate pleural biological parameters with a validated sonographic septation outcome in pleural infection. PF PAI-1 is the first biomarker to demonstrate an independent association with mortality. Although PF PAI-1 plays an integral role in driving septation formation, septations themselves are not associated with clinically important outcomes. These novel findings now require prospective validation.

Early Video-assisted Thoracoscopic Surgery or Intrapleural Enzyme Therapy in Pleural Infection: A Feasibility Randomized Controlled Trial. The Third Multicenter Intrapleural Sepsis Trial-MIST-3.

Rationale: Assessing the early use of video-assisted thoracoscopic surgery (VATS) or intrapleural enzyme therapy (IET) in pleural infection requires a phase III randomized controlled trial (RCT). Objectives: To establish the feasibility of randomization in a surgery-versus-nonsurgery trial as well as the key outcome measures that are important to identify relevant patient-centered outcomes in a subsequent RCT. Methods: The MIST-3 (third Multicenter Intrapleural Sepsis Trial) was a prospective multicenter RCT involving eight U.K. centers combining on-site and off-site surgical services. The study enrolled all patients with a confirmed diagnosis of pleural infection and randomized those with ongoing pleural sepsis after an initial period (as long as 24 h) of standard care to one of three treatment arms: continued standard care, early IET, or a surgical opinion with regard to early VATS. The primary outcome was feasibility based on >50% of eligible patients being successfully randomized, >95% of randomized participants retained to discharge, and >80% of randomized participants retained to 2 weeks of follow-up. The analysis was performed per intention to treat. Measurements and Main Results: Of 97 eligible patients, 60 (62%) were randomized, with 100% retained to discharge and 84% retained to 2 weeks. Baseline demographic, clinical, and microbiological characteristics of the patients were similar across groups. Median times to intervention were 1.0 and 3.5 days in the IET and surgery groups, respectively (P = 0.02). Despite the difference in time to intervention, length of stay (from randomization to discharge) was similar in both intervention arms (7 d) compared with standard care (10 d) (P = 0.70). There were no significant intergroup differences in 2-month readmission and further intervention, although the study was not adequately powered for this outcome. Compared with VATS, IET demonstrated a larger improvement in mean EuroQol five-dimension health utility index (five-level edition) from baseline (0.35) to 2 months (0.83) (P = 0.023). One serious adverse event was reported in the VATS arm. Conclusions: This is the first multicenter RCT of early IET versus early surgery in pleural infection. Despite the logistical challenges posed by the coronavirus disease (COVID-19) pandemic, the study met its predefined feasibility criteria, demonstrated potential shortening of length of stay with early surgery, and signals toward earlier resolution of pain and a shortened recovery with IET. The study findings suggest that a definitive phase III study is feasible but highlights important considerations and significant modifications to the design that would be required to adequately assess optimal initial management in pleural infection.The trial was registered on ISRCTN (number 18,192,121).

Efficacy of Small versus Large-Bore Chest Drain in Pleural Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: Pleural infection represents a significant clinical challenge worldwide. Although prompt drainage of pleural fluid is thought to play a key role in pleural infection management, the optimal size of intrapleural catheter has yet to be defined. OBJECTIVES: The aim of this systematic review and meta-analysis was to summarize data on efficacy and complications of small-bore drain (SBD), defined as ≤14F, in comparison to large-bore drain (LBD) in patients with pleural infection. METHOD: We searched MEDLINE and Embase for all studies reporting outcomes of interest published up to October 2021. Two authors reviewed selected full text to identify studies according to predefined eligibility criteria. Summary estimates were derived using the random-effects model. RESULTS: Twelve original studies were included for qualitative analysis and 7 of these for quantitative analysis. The surgical referral rate of SBD and LBD were, respectively, 0.16 (95% confidence interval [CI], 0.12-0.21) and 0.20 (95% CI, 0.10-0.32), the pooled mortality were 0.12 (95% CI, 0.05-0.21) and 0.20 (95% CI, 0.10-0.32), and the length of hospital stay was 24 days in both groups. Data on complications suggest similar proportions of tube dislodgement. Intensity of pain was evaluated in one study only, reporting higher scores for LBD. CONCLUSIONS: This systematic review and meta-analysis provide the first synthesis of data on performance of SBD and LBD in management of pleural infection, and, overall, clinical outcomes and complications did not substantially differ, although the limited number of studies and the absence of dedicated randomized trials does limit the reliability of results.

Objective Thoracoscopic Criteria in Differentiation between Benign and Malignant Pleural Effusions.

BACKGROUND: Thoracoscopy is the "gold standard" diagnostic modality for investigation of suspected pleural malignancy. It is postulated that meticulous assessment of the pleural cavity may be adequate to indicate malignancy through the macroscopic findings of nodules, pleural thickening, and lymphangitis. We attempted to critically assess this practice, by precisely defining objective macroscopic criteria which might differentiate benign from malignant pleural diseases according to intrapleural pattern and anatomical location, and thereby to explore the predilection of abnormalities to specific sites on pleural surfaces. METHODS: A structured review of recorded video footage from medical thoracoscopy procedures in 96 patients was conducted by 2 independent assessors. Abnormalities were scored on agreed, objective criteria for the presence of nodules, lymphangitis and inflammation on each of the costoparietal, visceral and diaphragmatic surfaces. The costoparietal pleura was divided into 6 levels (apical, middle, and inferior surfaces of the lateral and posterior parietal pleura). The anterior surface of the costoparietal pleura was excluded from analysis after interim review as this surface was rarely seen. RESULTS: In the benign group, inflammation was the predominant finding in 65% (n = 33; costoparietal), 44% (n = 21; visceral), and 42% (n = 15; diaphragmatic). Nodules were detected in 24% (n = 12; costoparietal), 8% (n = 4; visceral), and 8% (n = 3; diaphragmatic). The most affected surfaces with inflammation were the middle lateral (60%) and the inferior lateral (57.8%) parts of the costoparietal pleura. In the malignant group, nodules were the predominant finding according to surface in 73% (n = 33; costoparietal), 32% (n = 13; visceral) and 48% (n = 17; diaphragmatic). Inflammation was detected in 44% (n = 20; costoparietal), 25% (n = 10; visceral), and 29% (n = 10; diaphragmatic). The most affected surfaces with nodules were the middle lateral (67.4%) and inferior lateral (66.7%) costoparietal pleural surfaces. CONCLUSION: This is the first detailed, anatomical description of abnormalities in the pleural space during thoracoscopy. While nodules were the predominant pattern in malignant pleural effusion, they were detected in 24% of benign diagnoses. Detection of nodules in >1 area of the costoparietal pleura was in favor of a malignant diagnosis. Inflammation was the predominant pattern in benign pleural effusion. Our results suggest that macroscopic nodules in malignant diagnoses have a predilection for the middle and inferior surfaces of the lateral costoparietal pleura.

The randomised thoracoscopic talc poudrage+indwelling pleural catheters versus thoracoscopic talc poudrage only in malignant pleural effusion trial (TACTIC): study protocol for a randomised controlled trial.

INTRODUCTION: Malignant pleural effusion (MPE) is common, with 50 000 new cases per year in the UK. MPE causes disabling breathlessness and indicates advanced disease with a poor prognosis. Treatment approaches focus on symptom relief and optimising quality of life (QoL). Patients who newly present with MPE commonly require procedural intervention for both diagnosis and therapeutic benefit.Thoracoscopic pleural biopsies are highly sensitive in diagnosing pleural malignancy. Talc poudrage may be delivered at thoracoscopy (TTP) to prevent effusion recurrence by effecting pleurodesis. Indwelling pleural catheters (IPCs) offer an alternative strategy for fluid control, enabling outpatient management and are often used as 'rescue' therapy following pleurodesis failure or in cases of 'trapped lung'. It is unknown whether combining a TTP with IPC insertion will improve patient symptoms or reduce time spent in the hospital.The randomised thoracoscopic talc poudrage + indwelling pleural catheters versus thoracoscopic talc poudrage only in malignant pleural effusion trial (TACTIC) is the first randomised controlled trial (RCT) to examine the benefit of a combined TTP and IPC procedure, evaluating cost-effectiveness and patient-centred outcomes such as symptoms and QoL. The study remains in active recruitment and has the potential to radically transform the pathway for all patients presenting with MPE. METHODS AND ANALYSIS: TACTIC is an unblinded, multicentre, RCT comparing the combination of TTP with an IPC to TTP alone. Co-primary outcomes are time spent in the hospital and mean breathlessness score over 4 weeks postprocedure. The study will recruit 124 patients and aims to define the optimal pathway for patients presenting with symptomatic MPE. ETHICS AND DISSEMINATION: TACTIC is sponsored by North Bristol NHS Trust and has been granted ethical approval by the London-Brent Research Ethics Committee (REC ref: 21/LO/0495). Publication of results in a peer-reviewed journal and conference presentations are anticipated. TRIAL REGISTRATION: ISRCTN 11058680.

Achieving Molecular Profiling in Pleural Biopsies: A Multicenter, Retrospective Cohort Study.

BACKGROUND: Pleural biopsy findings offer greater diagnostic sensitivity in malignant pleural effusions compared with pleural fluid. The adequacy of pleural biopsy techniques in achieving molecular marker status has not been studied, and such information (termed "actionable" histology) is critical in providing a rational, efficient, and evidence-based approach to diagnostic investigation. RESEARCH QUESTION: What is the adequacy of various pleural biopsy techniques at providing adequate molecular diagnostic information to guide treatment in malignant pleural effusions? STUDY DESIGN AND METHODS: This study analyzed anonymized data on 183 patients from four sites across three countries in whom pleural biopsy results had confirmed a malignant diagnosis and molecular profiling was relevant for the diagnosed cancer type. The primary outcome measure was adequacy of pleural biopsy for achieving molecular marker status. Secondary outcomes included clinical factors predictive of achieving a molecular diagnosis. RESULTS: The median age of patients was 71 years (interquartile range, 63-78 years), with 92 of 183 (50%) male. Of the 183 procedures, 105 (57%) were local anesthetic thoracoscopies (LAT), 12 (7%) were CT scan guided, and 66 (36%) were ultrasound guided. Successful molecular marker analysis was associated with mode of biopsy, with LAT having the highest yield and ultrasound-guided biopsy the lowest (LAT vs CT scan guided vs ultrasound guided: LAT yield, 95%; CT scan guided, 86%; and ultrasound guided, 77% [P = .004]). Biopsy technique and size of biopsy sample were independently associated with successful molecular marker analysis. LAT had an adjusted OR for successful diagnosis of 30.16 (95% CI, 3.15-288.56; P = .003) and biopsy sample size an OR of 1.18 (95% CI, 1.02-1.37) per millimeter increase in tissue sample size (P < .03). INTERPRETATION: Although previous studies have shown comparable overall diagnostic yields, in the modern era of targeted therapies, this study found that LAT offers far superior results to image-guided techniques at achieving molecular profiling and remains the optimal diagnostic tool.

Investigation and outcomes in patients with nonspecific pleuritis: results from the International Collaborative Effusion database.

Introduction: We present findings from the International Collaborative Effusion database, a European Respiratory Society clinical research collaboration. Nonspecific pleuritis (NSP) is a broad term that describes chronic pleural inflammation. Various aetiologies lead to NSP, which poses a diagnostic challenge for clinicians. A significant proportion of patients with this finding eventually develop a malignant diagnosis. Methods: 12 sites across nine countries contributed anonymised data on 187 patients. 175 records were suitable for analysis. Results: The commonest aetiology for NSP was recorded as idiopathic (80 out of 175, 44%). This was followed by pleural infection (15%), benign asbestos disease (12%), malignancy (6%) and cardiac failure (6%). The malignant diagnoses were predominantly mesothelioma (six out of 175, 3.4%) and lung adenocarcinoma (four out of 175, 2.3%). The median time to malignant diagnosis was 12.2 months (range 0.8-32 months). There was a signal towards greater asbestos exposure in the malignant NSP group compared to the benign group (0.63 versus 0.27, p=0.07). Neither recurrence of effusion requiring further therapeutic intervention nor initial biopsy approach were associated with a false-negative biopsy. A computed tomography finding of a mass lesion was the only imaging feature to demonstrate a significant association (0.18 versus 0.01, p=0.02), although sonographic pleural thickening also suggested an association (0.27 versus 0.09, p=0.09). Discussion: This is the first multicentre study of NSP and its associated outcomes. While some of our findings are reflected by the established body of literature, other findings have highlighted important areas for future research, not previously studied in NSP.

Co-creation in a digital health living lab: A case study.

Co-creation in healthcare, especially in developing digital health solutions, has been widely identified as a fundamental principle for person-centered technologies that could accelerate the adaptation of innovation. A Digital Health Living Lab based on community offers a sustainable and real-life environment to ideate, develop, and evaluate digital health solutions addressing the needs of multiple stakeholders. This article presents the experience of the School of Sport and Health Sciences at the University of Brighton in establishing a Digital Health Living Lab. In addition, we share a proposed step-by-step approach to establishing such a living lab in the community, supplemented by a case study of product development.

Inflammation of the Pleural Cavity: A Review on Pathogenesis, Diagnosis and Implications in Tumor Pathophysiology.

Pleural effusions are a common respiratory condition with many etiologies. Nonmalignant etiologies explain most pleural effusions and despite being nonmalignant, they can be associated with poor survival; thus, it is important to understand their pathophysiology. Furthermore, diagnosing a benign pleural pathology always harbors the uncertainty of a false-negative diagnosis for physicians and pathologists, especially for the group of non-specific pleuritis. This review aims to present the role of the inflammation in the development of benign pleural effusions, with a special interest in their pathophysiology and their association with malignancy.

The Frequency, Risk Factors, and Management of Complications From Pleural Procedures.

Pleural disease is a common presentation and spans a heterogeneous population across broad disease entities; a common feature is the requirement for interventional procedures. Despite the frequency of such procedures, there is little consensus on rates of complications and risk factors associated with such complications. This narrative review was based on a structured search of the literature. Searches were limited to 2010 onward, in recognition of the transformation in procedural complications following the mainstream use of thoracic ultrasound. Procedures of interest were limited to thoracocentesis, intercostal drains, indwelling pleural catheters (IPCs), and local anesthetic thoracoscopy. A total of 4,308 studies were screened, and 48 studies were identified for inclusion. Iatrogenic pneumothorax remains the most common complication following thoracocentesis (3.3%; 95% CI, 3.2-3.4), although pneumothorax requiring intervention was rare (0.3%; 95% CI, 0.2-0.4) when the procedure was ultrasound guided. Drain blockage and displacement were the most common complications following intercostal drain insertion (6.3% and 6.8%, respectively). IPC-related infections can be a significant problem (5.8%; 95% CI, 5.1-6.7). However, most cases can be managed without removal of the IPC. Local anesthetic thoracoscopy has an overall mortality of 0.1% (95% CI, 0.03-0.3). Data on safety and complication rates in procedural interventions are limited by methodologic problems, and novel methods to study this topic should be considered. Although complications remain rare events, once encountered, they have the potential to rapidly escalate. It is of paramount importance for operators to prepare and have in place plans for such events to ensure high quality and, above all, safe care.

The bacteriology of pleural infection (TORPIDS): an exploratory metagenomics analysis through next generation sequencing.

BACKGROUND: Pleural infection is a common and severe disease with high morbidity and mortality worldwide. The knowledge of pleural infection bacteriology remains incomplete, as pathogen detection methods based on culture have insufficient sensitivity and are biased to selected microbes. We designed a study with the aim to discover and investigate the total microbiome of pleural infection and assess the correlation between bacterial patterns and 1-year survival of patients. METHODS: We assessed 243 pleural fluid samples from the PILOT study, a prospective observational study on pleural infection, with 16S rRNA next generation sequencing. 20 pleural fluid samples from patients with pleural effusion due to a non-infectious cause and ten PCR-grade water samples were used as controls. Downstream analysis was done with the DADA2 pipeline. We applied multivariate Cox regression analyses to investigate the association between bacterial patterns and 1-year survival of patients with pleural infection. FINDINGS: Pleural infection was predominately polymicrobial (192 [79%] of 243 samples), with diverse bacterial frequencies observed in monomicrobial and polymicrobial disease and in both community-acquired and hospital-acquired infection. Mixed anaerobes and other Gram-negative bacteria predominated in community-acquired polymicrobial infection whereas Streptococcus pneumoniae prevailed in monomicrobial cases. The presence of anaerobes (hazard ratio 0·46, 95% CI 0·24-0·86, p=0·015) or bacteria of the Streptococcus anginosus group (0·43, 0·19-0·97, p=0·043) was associated with better patient survival, whereas the presence (5·80, 2·37-14·21, p<0·0001) or dominance (3·97, 1·20-13·08, p=0·024) of Staphylococcus aureus was linked with lower survival. Moreover, dominance of Enterobacteriaceae was associated with higher risk of death (2·26, 1·03-4·93, p=0·041). INTERPRETATION: Pleural infection is a predominantly polymicrobial infection, explaining the requirement for broad spectrum antibiotic cover in most individuals. High mortality infection associated with S aureus and Enterobacteriaceae favours more aggressive, with a narrower spectrum, antibiotic strategies. FUNDING: UK Medical Research Council, National Institute for Health Research Oxford Biomedical Research Centre, Wellcome Trust, Oxfordshire Health Services Research Committee, Chinese Academy of Medical Sciences, and John Fell Fund.

Management of Pleural Infection.

Pleural infection is a millennia-spanning condition that has proved challenging to treat over many years. Fourteen percent of cases of pneumonia are reported to present with a pleural effusion on chest X-ray (CXR), which rises to 44% on ultrasound but many will resolve with prompt antibiotic therapy. To guide treatment, parapneumonic effusions have been separated into distinct categories according to their biochemical, microbiological and radiological characteristics. There is wide variation in causative organisms according to geographical location and healthcare setting. Positive cultures are only obtained in 56% of cases; therefore, empirical antibiotics should provide Gram-positive, Gram-negative and anaerobic cover whilst providing adequate pleural penetrance. With the advent of next-generation sequencing techniques, yields are expected to improve. Complicated parapneumonic effusions and empyema necessitate prompt tube thoracostomy. It is reported that 16-27% treated in this way will fail on this therapy and require some form of escalation. The now seminal Multi-centre Intrapleural Sepsis Trials (MIST) demonstrated the use of combination fibrinolysin and DNase as more effective in the treatment of empyema compared to either agent alone or placebo, and success rates of 90% are reported with this technique. The focus is now on dose adjustments according to the patient's specific 'fibrinolytic potential', in order to deliver personalised therapy. Surgery has remained a cornerstone in the management of pleural infection and is certainly required in late-stage manifestations of the disease. However, its role in early-stage disease and optimal patient selection is being re-explored. A number of adjunct and exploratory therapies are also discussed in this review, including the use of local anaesthetic thoracoscopy, indwelling pleural catheters, intrapleural antibiotics, pleural irrigation and steroid therapy.

Diagnostics in Pleural Disease.

Pleural disease diagnostics represent a sprawling topic that has enjoyed a renaissance in recent years from humble beginnings. Whilst pleural patients are heterogeneous as a population and in the aetiology of the disease with which they present, we provide an overview of the typical diagnostic approach. Pleural fluid analysis is the cornerstone of the diagnostic pathway; however, it has many shortcomings. Strong cases have been made for more invasive upfront investigations, including image-guided biopsies or local anaesthetic thoracoscopy, in selected populations. Imaging can guide the diagnostic process as well as act as a vehicle to facilitate therapies, and this is never truer than with the recent advances in thoracic ultrasound.

Clinical perspective and practices on pleural effusions in chronic systemic inflammatory diseases.

Systemic inflammatory diseases are a heterogeneous family of autoimmune chronic inflammatory disorders that affect multiple systems within the human body. Connective tissue disease (CTD) is a large group within this family characterised by immune-mediated inflammation of the connective tissue. This group of disorders are often associated with pleural manifestations. CTD-induced pleuritis exhibits a wide variety of symptoms and signs including exudative pleural effusions and chest pain. Accurate estimation of prevalence for CTD-related pleuritis is challenging as small effusions are asymptomatic and remain undetected. Rheumatoid arthritis and systemic lupus erythematosus are frequent CTDs and present with pleural pathology in approximately 5-20% and 17-60% of cases, respectively. By contrast, pleural involvement in systemic sclerosis, eosinophilia-myalgia syndrome, mixed connective tissue disease, ankylosing spondylitis, polymyositis and dermatomyositis syndrome is rare. Clinical management depends on the severity of symptoms; however, most effusions resolve spontaneously. In this review we discuss the pathophysiological mechanisms and the clinical considerations of CTD-induced pleuritis.