A Pilot Feasibility Study in Establishing the Role of Ultrasound-Guided Pleural Biopsies in Pleural Infection (The AUDIO Study)

Thoracic ultrasound in guiding management of respiratory disease

INTRODUCTION

The use of ultrasound in respiratory disease has evolved substantially over the past two decades. From a test done to confirm the safe site of pleural fluid drainage, thoracic ultrasound has become a point-of-care test that guides the management of patients on respiratory wards, in clinics and endoscopy.

AREAS COVERED

This review overviews the process of ultrasound examination in the chest. It then delves into specific disease areas (pleural disease, lung disease, diaphragm disease, and invasive procedures) to highlight how thoracic ultrasound is being used to refine management. The review concludes with discussion on the training curricula and assessment tools for competency in thoracic ultrasound. Being a scoping review, literature searches were conducted on PubMed using relevant search terms.

EXPERT OPINION

In addition to its current uses, there are many avenues where thoracic ultrasound will soon be beneficial. Recent studies show promising roles in areas such as patient-tailored guidance of pleurodesis and non-invasively predicting lung re-expansion after pleural fluid drainage. In addition, auxiliary tools such as contrast-enhanced ultrasound and elastography are proving useful in identifying the etiology and directing the successful sampling of pleural and lung lesions. Studies are also exploring the utility of sonographic biomarkers such as echogenicity and septations to predict outcomes in pleural disease.

Eosinophilic pleural effusion due to Staphylococcus epidermidis infection: A case report

Eosinophilic pleural effusion is rare, and the cause is often obscure. A 73-year-old man with no relevant medical history presented with exertional dyspnea. Chest imaging revealed left-sided pleural effusion, and pleural fluid examination revealed eosinophilic pleural effusion. Blood tests revealed an increased peripheral blood eosinophil count and elevated Immunoglobulin E levels. Staphylococcus epidermidis was detected in pleural specimens collected via thoracoscopy. Antimicrobial therapy targeting Staphylococcus epidermidis resolved the eosinophilic pleural effusion and elevated peripheral blood eosinophil count. Staphylococcus epidermidis infection may be considered as a cause of eosinophilic pleural effusion when the diagnosis is difficult.

Advances in the diagnosis and follow-up of pleural lesions: a scoping review

INTRODUCTION

Pleural lesions may have heterogeneous presentation and causes. In recent years, there have been significant advances in pleural lesions diagnostics. The aim of this review is to provide an overview of the state-of-the-art, and recent updates for diagnostic modalities and monitoring regimes for pleural lesions.

AREAS COVERED

A literature search was conducted through PubMed and Web of Science for relevant articles published from 1 January 2000- 1 March 2023. This article critically appraises the radiological modalities and biopsy techniques that are employed in pleural lesions diagnostics, including chest radiography, thoracic ultrasound, computed tomography, F-fluorodeoxyglycose positron emission tomography, magnetic resonance imaging, percutaneous, and thoracoscopic pleural biopsies with reference to their strengths, limitations, and clinical use. The review asserts also the available literature regarding monitoring algorithms.

EXPERT OPINION

Despite the recent advances in the field, there are several key areas for improvement, including the development and validation of minimal invasive methods and tools for risk stratification, the integration of multi-omics technologies, the implementation of standardized, evidence-based diagnostic and monitoring guidelines and increased focus on research and patient-centric approaches. The broad establishment of dedicated pleural clinics may significantly assist toward this direction.

Causes, management and treatment of empyema

Infections in the pleural space have been a significant problem since ancient times and continue to be so today, with an incidence of 52% in patients with post-pneumonia syndrome. Typically, these effusions require a combination of medical treatment and surgical drainage, including debridement and decortication. Researchers have been studying the use of intrapleural fibrinolytics in managing complicated pleural effusions and empyema, but there is still ongoing debate and controversy among clinicians. Empyema has traditionally been considered a surgical disease, with antibiotics and chest tube drainage being the initial treatment modality. However, with advances in minimally invasive procedures such as video-assisted thoracoscopic surgery (VATS) and the use of intrapleural fibrinolytics, medical management is now preferred over surgery for many cases of empyema. Surgical options, such as open thoracotomy, are reserved for patients who fail conservative management and have complicated or chronic empyema. This comprehensive review aims to explore the evolution of various management strategies for pleural space infections from ancient times to the present day and how the shift from treating empyema as a surgical condition to a medical disease continues.

Diagnosis and management of pleural infection

Pleural infection remains a medical challenge. Although closed tube drainage revolutionised treatment in the 19th century, pleural infection still poses a significant health burden with increasing incidence. Diagnosis presents challenges due to non-specific clinical presenting features. Imaging techniques such as chest radiographs, thoracic ultrasound and computed tomography scans aid diagnosis. Pleural fluid analysis, the gold standard, involves assessing gross appearance, biochemical markers and microbiology. Novel biomarkers such as suPAR (soluble urokinase plasminogen activator receptor) and PAI-1 (plasminogen activator inhibitor-1) show promise in diagnosis and prognosis, and microbiology demonstrates complex microbial diversity and is associated with outcomes. The management of pleural infection involves antibiotic therapy, chest drain insertion, intrapleural fibrinolytic therapy and surgery. Antibiotic therapy relies on empirical broad-spectrum antibiotics based on local policies, infection setting and resistance patterns. Chest drain insertion is the mainstay of management, and use of intrapleural fibrinolytics facilitates effective drainage. Surgical interventions such as video-assisted thoracoscopic surgery and decortication are considered in cases not responding to medical therapy. Risk stratification tools such as the RAPID (renal, age, purulence, infection source and dietary factors) score may help guide tailored management. The roles of other modalities such as local anaesthetic medical thoracoscopy and intrapleural antibiotics are debated. Ongoing research aims to improve outcomes by matching interventions with risk profile and to better understand the development of disease.

The clinical features and prognosis of fungal pleural infection: A case series and literature review

Fungal pleural infections are infrequent and insidious, for which there are neither large clinical studies nor targeted guidelines to provide standardized treatment options. We reported 4 cases of fungal pleural infection and reviewed the cases of fungal pleural infections in previous studies to provide a basis for the diagnosis and treatment of fungal pleural infections. There were 2 females and 2 males with a mean age of 58.5 years in our data. The average time from onset to diagnosis was 30.25 days. Risk factors most frequently included pulmonary diseases (n = 4) and malignancy (n = 1). Two patients underwent pleural biopsy through a thoracoscope, and no pathogens were detected. Pleural fluid culture was positive in 2 out of 3 cases. The diagnoses were "possible" (n = 1), "probable" (n = 1), and "proven" (n = 2). All patients received systemic antifungal therapy, and 3 received combined thoracic drainage. The outcomes were cured (n = 1), improved (n = 2) and lost to follow-up (n = 1). We reviewed 12 cases of fungal pleural infection in previous studies. The diagnosis was confirmed via culture in 7 cases and via biopsy in 8 cases. The pathogen was Aspergillus in 7 cases. After a combination of systemic antifungal (n = 12) and local treatment (n = 11), 10 patients improved and 2 patients died. Diagnosis of fungal pleural infection should incorporate risk factors, clinical presentation and fungal evidence, with pleural fluid culture being an important and feasible mean of confirming the diagnosis; and treatment should be based on systemic antifungal therapy supplemented by topical therapy.

Expert Review on Nonsurgical Management of Parapneumonic Effusion: Advances, Controversies, and New Directions

Parapneumonic effusion and empyema are rising in incidence worldwide, particularly in association with comorbidities in an aging population. Also driving this change is the widespread uptake of pneumococcal vaccines, leading to the emergence of nonvaccine-type pneumococci and other bacteria. Early treatment with systemic antibiotics is essential but should be guided by local microbial guidelines and antimicrobial resistance patterns due to significant geographical variation. Thoracic ultrasound has emerged as a leading imaging technique in parapneumonic effusion, enabling physicians to characterize effusions, assess the underlying parenchyma, and safely guide pleural procedures. Drainage decisions remain based on longstanding criteria including the size of the effusion and fluid gram stain and biochemistry results. Small-bore chest drains appear to be as effective as large bore and are adequate for the delivery of intrapleural enzyme therapy (IET), which is now supported by a large body of evidence. The IET dosing regimen used in the UK Multicenter Sepsis Trial -2 has the most evidence available but data surrounding alternative dosing, concurrent and once-daily instillations, and novel fibrinolytic agents are promising. Prognostic scores used in pneumonia (e.g., CURB-65) tend to underestimate mortality in parapneumonic effusion/empyema. Scores specifically based on pleural infection have been developed but require validation in prospective cohorts.

Phenotyping empyema by pleural fluid culture results and macroscopic appearance: an 8-year retrospective study

Background

The clinical impact of phenotyping empyema is poorly described. This study was designed to evaluate clinical characteristics and outcomes based on the two readily available parameters, pleural fluid culture status and macroscopic fluid appearance.

Methods

A retrospective study was conducted on patients with empyema hospitalised between 2013 and 2020. Empyema was classified into culture-positive empyema (CPE) or culture-negative empyema (CNE) and pus-appearing empyema (PAE) or non-pus-appearing empyema (non-PAE) based on the pleural fluid culture status and macroscopic fluid appearance, respectively.

Results

Altogether, 212 patients had confirmed empyema (CPE: n=188, CNE: n=24; PAE: n=118, non-PAE: n=94). The cohort was predominantly male (n=163, 76.9%) with a mean age of 65.0±13.6 years. Most patients (n=180, 84.9%) had at least one comorbidity. Patients with CPE had higher rates of in-hospital mortality (19.1% versus 0.0%, p=0.017) and 90-day mortality (18.6% versus 0.0%, p=0.017) and more extrapulmonary sources of infection (29.8% versus 8.3%, p=0.026) when compared with patients with CNE. No significant difference in mortality rate was found between PAE and non-PAE during the in-hospital stay and at 30 days and 90 days. Patients with PAE had less extrapulmonary sources of infection (20.3% versus 36.2%, p=0.010) and more anaerobic infection (40.9% versus 24.5%, p=0.017) than those with non-PAE. The median RAPID (renal, age, purulence, infection source, and dietary factors) scores were higher in the CPE and non-PAE groups. After adjusting for covariates, culture positivity was not independently associated with mortality on multivariable analysis.

Conclusion

Empyema is a heterogeneous disease with different clinical characteristics. Phenotyping empyema into different subclasses based on pleural fluid microbiological results and macroscopic fluid appearance provides insight into the underlying bacteriology, source of infection and subsequent clinical outcomes.

Pleural Space Infections

Pleural space infections have been a well-recognized clinical syndrome for over 4000 years and continue to cause significant morbidity and mortality worldwide. However, our collective understanding of the causative pathophysiology has greatly expanded over the last few decades, as have our treatment options. The aim of this paper is to review recent updates in our understanding of this troublesome disease and to provide updates on established and emerging treatment modalities for patients suffering from pleural space infections. With that, we present a review and discussion synthesizing the recent pertinent literature surrounding the history, epidemiology, pathophysiology, diagnosis, and management of these challenging infections.

Optimal diagnostic strategies for pleural diseases and identifying high-risk patients

INTRODUCTION

Pleural diseases encompass a broad range of conditions with diverse and heterogenous etiologies. Diagnostics in pleural diseases thus represents a challenging field with a wide array of available testing to distinguish between the numerous causes of pleural disease. Nonetheless, deploying best practice diagnostics in this area is essential in reducing both duration o the investigation pathway and symptom burden.

AREAS COVERED

This article critically appraises the optimal diagnostic strategies and pathway in patients with pleural disease, reviewing the latest evidence and key practice points in achieving a treatable diagnosis in patients with pleural disease. We also cover future and novel directions that are likely to influence pleural diagnostics in the near future. PubMed was searched for articles related to pleural diagnostics (search terms below), with the date ranges including June 2012 to June 2022.

EXPERT OPINION

No single test will ever be sufficient to provide a diagnosis in pleural conditions. The key to reducing procedure burden and duration to diagnosis lies in personalizing the investigation pathway to patients and deploying tests with the highest diagnostic yield early (such as pleural biopsy in infection and malignancy). Novel biomarkers may also allow earlier diagnostic precision in the near future.

Highlights del 55.° Congreso SEPAR

The 55th SEPAR Congress was held in Pamplona from 2 to 4 of June 2022. Once again, it was the referral scientific meeting for specialists in pulmonology, thoracic surgery, nursing, physiotherapy, paediatric respiratory diseases and other disciplines involved in respiratory care. The Spanish Society of Pulmonology and Thoracic Surgery showed its national and international leadership in the management of respiratory diseases, which was reflected in a program with an excellent content and a high scientific level. In this review, we offer a summary of some notable aspects covered in six selected areas of interest: pulmonary vascular diseases, non-invasive mechanical ventilation and sleep disorders, asthma, chronic obstructive pulmonary disease (COPD), interstitial lung diseases (ILD), and interventional pulmonolgy and lung transplant.

Diagnosis and Treatment of Pleural Effusion. Recommendations of the Spanish Society of Pulmonology and Thoracic Surgery. Update 2022

Pleural effusion (PE) is a common yet complex disease that requires specialized, multidisciplinary management. Recent advances, novel diagnostic techniques, and innovative patient-centered therapeutic proposals have prompted an update of the current guidelines. This document provides recommendations and protocols based on a critical review of the literature on the epidemiology, etiology, diagnosis, prognosis, and new therapeutic options in PE, and addresses some cost-effectiveness issues related to the main types of PE.

Nonmalignant Pleural Effusions

Although the potential causes of nonmalignant pleural effusions are many, the management of a few, including complicated pleural infections and refractory heart failure and hepatic hydrothoraces, can be challenging and requires the assistance of interventional pulmonologists. A pragmatic approach to complicated parapneumonic effusions or empyemas is the insertion of a small-bore chest tube (e.g., 14-16 Fr) through which fibrinolytics (e.g., urokinase and alteplase) and DNase are administered in combination. Therapeutic thoracenteses are usually reserved for small to moderate effusions that are expected to be completely aspirated at a single time, whereas video-assisted thoracic surgery should be considered after failure of intrapleural enzyme therapy. Refractory cardiac and liver-induced pleural effusions portend a poor prognosis. In cases of heart failure-related effusions, therapeutic thoracentesis is the first-line palliative therapy. However, if it is frequently needed, an indwelling pleural catheter (IPC) is recommended. In patients with hepatic hydrothorax, repeated therapeutic thoracenteses are commonly performed while a multidisciplinary decision on the most appropriate definitive management is taken. The percutaneous creation of a portosystemic shunt may be used as a bridge to liver transplantation or as a potential definitive therapy in nontransplant candidates. In general, an IPC should be avoided because of the high risk of complications, particularly infections, that may jeopardize candidacy for liver transplantation. Even so, in noncandidates for liver transplant or surgical correction of diaphragmatic defects, IPC is a therapeutic option as valid as serial thoracenteses.

Mycoplasma pneumoniae Pleural Effusion in Adults

Parapneumonic effusions often complicate Mycoplasma pneumoniae (MP) pneumonia, contrary to the notion that they are a rare feature of MP infection. Increased research and evidence on MP parapneumonic effusions (MPPE) can help elucidate its clinical significance as one of the variable manifestations of MP infection. This article aims to summarize the existing literature about the clinical characteristics of MPPE in adults and discuss its diagnostic implications from the perspective of pleural fluid analysis. Approximately 20–25% of adult patients with MP pneumonia develop MPPE, and its frequency in children and adults seems to be similar. Although the pathogenesis of MPPE remains to be elucidated, MP-induced cell-mediated immune mechanisms might be partially associated with the development of MPPE. MPPE usually shows mononuclear leukocyte predominance with elevated adenosine deaminase (ADA) activity, similar to tuberculous pleural effusion (TPE). The degree of increase in pleural fluid ADA levels and serum inflammatory biomarkers may help differentiate between MPPE and TPE. During the acute phase, a single positive IgM and positive polymerase chain reaction results allow for a precise and reliable MP infection diagnosis. The mainstay of treatment is the selection of adequate anti-mycoplasma antibiotics with or without corticosteroid, based on the local epidemiologic data on macrolide resistance.

From Chest Wall Resection to Medical Management: The Continued Saga of Parapneumonic Effusion Management and Future Directions

Pleural space infections have been described since the time of Hippocrates and to this day remains a significant pathology. Every year in the USA approximately there are one million hospital admissions for pneumonia with 20%-40% associated with some form of pleural space infections leading to pleural effusions with increased morbidity and mortality. Often, management of these effusions mandate combination of medical treatment and surgical drainage with debridement and decortication. There has been a lot of ongoing research regarding the safety and efficacy of intrapleural fibrinolytics in the management of complicated pleural effusions and empyema. Till this day, areas of debate and controversies exist among clinicians treating pleural space infection. Empyema is historically considered a surgical disease. There have been societies and guidelines for the management of infected parapneumonic effusions with antibiotics and chest tube drainage as an initial empiric treatment modality. With the advances in the use of Intrapleural fibrinolytics and minimally invasive procedures such as video-assisted thoracoscopic surgery (VATS), empyema a surgical disease is now more favoring medical management. Surgical option, such as open thoracotomy, is reserved for patients who failed conservative management and chronic empyema. The aim of this comprehensive review is to shed light on the evolution of various management strategies from the era of Hippocrates to current day practice and how there continues to be a paradigm shift in treating empyema as a surgical condition to a medical disease.

Ultrasound-Guided Pleural Investigations: Fluid, Air, and Biopsy

Pleural diseases are frequently encountered across multiple inpatient and outpatient settings, making pleural drainage and sampling one of the most common medical procedures. With the widespread adoption of bedside ultrasound examination, ultrasound machines are now readily available in many clinical settings, providing both diagnostic and procedural guidance. The modern management of pleural disease is dominated by ultrasound assessment with strong evidence supporting its use to guide pleural interventions. Here, we review the current landscape of ultrasound use to guide pleural drainage, pneumothorax management, and pleural biopsy.

Parapneumonic Effusion and Empyema

The rising incidence and high morbidity of pleural infection remain a significant challenge to health care systems worldwide. With distinct microbiology and treatment paradigms from pneumonia, pleural infection is an area in which the evidence base has been rapidly evolving. Progress in recent years has revolved around characterizing the microbiome of pleural infection and the addition of new strategies such as intrapleural enzyme therapy to the established treatment pathway of drainage and antibiotics. The future of improving outcomes lies with personalizing treatment, establishing optimal timing of intrapleural agents and surgery, alongside wider use of risk stratification to guide treatment.

Setting up a Pleural Disease Service

Pleural disease incidence is continuing to rise internationally and management is becoming increasingly complex. There are now many more options for patients, with access to thoracic ultrasound, image-guided biopsies, indwelling pleural catheters, and local-anesthetic pleuroscopy (thoracoscopy). Safety reports have also highlighted the need for specialist operator knowledge and skill. Consequently, the development of a specialized pleural service can manage patients entirely as an outpatient, limit the number of procedures, and improve patient safety, it also fosters opportunities to enhance specialist procedural skills, engage in clinical research, and reduce the costs of care.

Management of complex pleural disease in the critically ill patient

Disorders of the pleural space are quite common in the critically ill patient. They are generally associated with the underlying illness. It is sometimes difficult to assess for pleural space disorders in the ICU given the instability of some patients. Although the portable chest X-ray remains the primary modality of diagnosis for pleural disorders in the ICU. It can be nonspecific and may miss subtle findings. Ultrasound has become a useful tool to the bedside clinician to aid in diagnosis and management of pleural disease. The majority of pleural space disorders resolve as the patient’s illness improves. There remain a few pleural processes that need specific therapies. While uncomplicated parapneumonic effusions do not have their own treatments. Those that progress to become a complex infected pleural space can have its individual complexity in therapy. Chest tube drainage remains the cornerstone in therapy. The use of intrapleural fibrinolytics has decreased the need for surgical referral. A large hemothorax or pneumothorax in patients admitted to the ICU represent medical emergencies and require emergent action. In this review we focus on the management of commonly encountered complex pleural space disorders in critically ill patients such as complicated pleural space infections, hemothoraces and pneumothoraces.

Medical thoracoscopy in intensive care unit

During the last decade, there has been a tremendous effort towards making procedures less invasive, which could reduce complications, decrease hospital stay and minimize overall health care cost. Medical thoracoscopy (MT) or pleuroscopy is a minimally invasive procedure commonly performed by interventional pulmonologist in United States. It has a favorable safety profile allowing access to the pleural cavity with a thoracoscope via a small chest wall incision to perform diagnostic or therapeutic interventions under direct visualization. MT allows the physician to perform pleural biopsy with high accuracy, drain loculated pleural effusion, guide chest tube placement and perform pleurodesis. As compared to video-assisted thoracoscopic surgery (VATS), MT is less invasive, does not require single lung ventilation, has a comparable diagnostic yield, and better tolerated in high-risk patients. MT can also be performed at bedside in critically ill patients. Although MT is generally safe, a multi-disciplinary discussion between the interventional pulmonologist, intensive care team, anesthesiologist and thoracic team is necessary to ensure best clinical practice as well as minimize complications for such high-risk patients. The purpose of this article is to review technique, diagnostic and therapeutic indications, as well as contraindications of performing bedside MT in intensive care unit. It aims to review both advantages and limitations of performing MT in intensive care unit.

Recent Insights into the Management of Pleural Infection

Pleural infection in adults has considerable morbidity and continues to be a life-threatening condition. The term “pleural infection” encompasses complicated parapneumonic effusions and primary pleural infections, and includes but is not limited to empyema, which refers to collection of pus in the pleural cavity. The incidence of pleural infection in adults has been continuously increasing over the past two decades, particularly in older adults, and most of such patients have comorbidities. Management of pleural infection requires prolonged duration of hospitalization (average 14 days). There are recognized differences in microbial etiology of pleural infection depending on whether the infection was acquired in the community or in a health-care setting. Anaerobic bacteria are acknowledged as a major cause of pleural infection, and thus anaerobic coverage in antibiotic regimens for pleural infection is mandatory. The key components of managing pleural infection are appropriate antimicrobial therapy and chest-tube drainage. In patients who fail medical therapy by manifesting persistent sepsis despite standard measures, surgical intervention to clear the infected space or intrapleural fibrinolytic therapy (in poor surgical candidates) are recommended. Recent studies have explored the role of early intrapleural fibrinolytics or first-line surgery, but due to considerable costs of such interventions and the lack of convincing evidence of improved outcomes with early use, early intervention cannot be recommended, and further evidence is awaited from ongoing studies. Other areas of research include the role of routine molecular testing of infected pleural fluid in improving the rate of identification of causative organisms. Other research topics include the benefit of such interventions as medical thoracoscopy, high-volume pleural irrigation with saline/antiseptic solution, and repeated thoracentesis (as opposed to chest-tube drainage) in reducing morbidity and improving outcomes of pleural infection. This review summarizes current knowledge and practice in managing pleural infection and future research directions.

Contrast-enhanced ultrasound guided pleural biopsy improves diagnostic confidence for pleural based lesions: a 3-year prospective study

Objective

To evaluate the accuracy and safety of contrast-enhanced ultrasound (CEUS) guided biopsy in the diagnosis of radiologically determined pleural based lesions.

Method

A prospective study was conducted on patients with radiologically determined pleural based lesions. Patients who met the inclusion criteria received pleural biopsy guided by CEUS to obtain specimens, followed by histomathological and microbiological examinations. After treatment and follow-up, surgical thoracoscopy was performed on cases with undefinite diagnosis.

Result

A total of 460 patients were finally included. CEUS showed internal necrosis in 72.17% cases and obvious peripheral vessels in 55.43% cases, both of which were significantly higher than the conventional ultrasound imaged (p < 0.05). The diagnostic accuracy through CEUS guided biopsy sampling was 98.91% (455/460). The microbiological diagnostic yield achieved 71.88% (225/313) in infectious lesions. In 330 cases combined pleural effusion, CEUS guided biopsy increased the diagnostic yield from 60.30% (199 /330) to 98.36% (325 /330) in all cases (p < 0.05), from 15.56% (14/90) to 94.44% (85/90) in malignant lesions (p < 0.01) and from 77.08% (185/240) to 100% (240/240) in infectious lesions (p < 0.05). No serious adverse events occurred.

Conclusion

CEUS guided biopsy provides a minimally invasive, effective and safe diagnostic biopsy method for pleural lesions.

Clinical Trials Registration: Chinese Clinical Trial Registry ChiCTR2000029749 (ChiCTR, www.chictr.org.cn).

Intrapleural Fibrinolytic Therapy versus Early Medical Thoracoscopy for Treatment of Pleural Infection. Randomized Controlled Clinical Trial

Rationale: Pleural infection is frequently encountered in clinical practice and is associated with high morbidity and mortality. Limited evidence exists regarding the optimal treatment. Although both early medical thoracoscopy (MT) and tube thoracostomy with intrapleural instillation of tissue plasminogen activator and human recombinant deoxyribonuclease are acceptable treatments for patients with complicated pleural infection, there is a lack of comparative data for these modes of management.Objectives: The aim of this study was to compare the safety and efficacy of early MT versus intrapleural fibrinolytic therapy (IPFT) in selected patients with multiloculated pleural infection and empyema.Methods: This was a prospective multicenter, randomized controlled trial involving patients who underwent MT or IPFT for pleural infection. The primary outcome was the length of hospital stay after either intervention. Secondary outcomes included the total length of hospital stay, treatment failure, 30-day mortality, and adverse events.Results: Thirty-two patients with pleural infection were included in the study. The median length of stay after an intervention was 4 days in the IPFT arm and 2 days in the MT arm (P = 0.026). The total length of hospital stay was 6 days in the IPFT arm and 3.5 days in MT arm (P = 0.12). There was no difference in treatment failure, mortality, or adverse events between the treatment groups, and no serious complications related to either intervention were recorded.Conclusions: When used early in the course of a complicated parapneumonic effusion or empyema, MT is safe and might shorten hospital stays for selected patients as compared with IPFT therapy. A multicenter trial with a larger sample size is needed to confirm these findings.Clinical trial registered with ClinicalTrials.gov (NCT02973139).

Advances in pleural infection and malignancy

Pleural infection and malignancy are among the most common causes of pleural disease and form the mainstay of pleural practice. There has been significant research and increase in scientific understanding in these areas in the past decade. With regard to pleural infection, the rising incidence remains worrying. An increased awareness allowing earlier diagnosis, earlier escalation of therapy and the use of validated risk stratification measures may improve outcomes. In pleural malignancy, research has enabled clinicians to streamline patient pathways with focus on reducing time to diagnosis, definitive management of malignant pleural effusion and achieving these with the minimum number of pleural interventions. Trials comparing treatment modalities of malignant pleural effusion continue to highlight the importance of patient choice in clinical decision-making. This article aims to summarise some of the most recent literature informing current practice in these two areas.

Bacteriology, antibiotic resistance and risk stratification of patients with culture-positive, community-acquired pleural infection

Background

Community-acquired pleural infection (CAPI) is a growing health problem worldwide. Although most CAPI patients recover with antibiotics and pleural drainage, 20% require surgical intervention. The use of inappropriate antibiotics is a common cause of treatment failure. Awareness of the common causative bacteria along with their patterns of antibiotic resistance is critical in the selection of antibiotics in CAPI-patients. This study aimed to define CAPI bacteriology from the positive pleural fluid cultures, determine effective antibiotic regimens and investigate for associations between clinical features and risk for death or antibiotic-resistance, in order to advocate with more invasive techniques in the optimal timing.

Methods

We examined 158 patients with culture positive, CAPI collected both retrospectively (2012-2013) and prospectively (2014-2018). Culture-positive, CAPI patients hospitalized in six tertiary hospitals in Greece were prospectively recruited (N=113). Bacteriological data from retrospectively detected patients were also used (N=45). Logistic regression analysis was performed to identify clinical features related to mortality, presence of certain bacteria and antibiotic resistance.

Results

Streptococci, especially the non-pneumococcal ones, were the most common bacteria among the isolates, which were mostly sensitive to commonly used antibiotic combinations. RAPID score (i.e., clinical score for the stratification of mortality risk in patients with pleural infection; parameters: renal, age, purulence, infection source, and dietary factors), diabetes and CRP were independent predictors of mortality while several patient co-morbidities (e.g., diabetes, malignancy, chronic renal failure, etc.) were related to the presence of certain bacteria or antibiotic resistance.

Conclusions

The dominance of streptococci among pleural fluid isolates from culture-positive, CAPI patients was demonstrated. Common antibiotic regimens were found highly effective in CAPI treatment. The predictive strength of RAPID score for CAPI mortality was confirmed while additional risk factors for mortality and antibiotic resistance were detected.

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 efficacy of metagenomic next-generation sequencing for rapid detection of Mycobacterium tuberculosis in smear-negative extrapulmonary specimens in a high tuberculosis burden area

OBJECTIVE

The aim of this study was to assess the clinical utility of metagenomic next-generation sequencing (mNGS) on smear-negative extrapulmonary specimens collected in China.

METHODS

Specimens were tested by mNGS and other routine tests for tuberculosis (TB). The diagnostic accuracy of mNGS was calculated and compared with the final clinical diagnosis.

RESULTS

The sensitivity of mNGS was found to be significantly higher than the sensitivities of the other routine TB tests. Receiver operating characteristic curve analysis showed that mNGS achieved the highest area under the curve (AUC) value of 0.79. The mNGS positive rate was highest for tuberculous meningitis. All non-tuberculous extrapulmonary pathogens were directly and simultaneously detected.

CONCLUSIONS

mNGS appeared to be superior to all previous etiological tests for TB on smear-negative extrapulmonary specimens and could identify all possible pathogens at once within 48 h.

Prospective validation of the RAPID clinical risk prediction score in adult patients with pleural infection: the PILOT study

BACKGROUND

Over 30% of adult patients with pleural infection either die and/or require surgery. There is no robust means of predicting at baseline presentation which patients will suffer a poor clinical outcome. A validated risk prediction score would allow early identification of high-risk patients, potentially directing more aggressive treatment thereafter.

OBJECTIVES

To prospectively assess a previously described risk score (the RAPID (Renal (urea), Age, fluid Purulence, Infection source, Dietary (albumin)) score) in adults with pleural infection.

METHODS

Prospective observational cohort study that recruited patients undergoing treatment for pleural infection. RAPID score and risk category were calculated at baseline presentation. The primary outcome was mortality at 3 months; secondary outcomes were mortality at 12 months, length of hospital stay, need for thoracic surgery, failure of medical treatment and lung function at 3 months.

RESULTS

Mortality data were available in 542 out of 546 patients recruited (99.3%). Overall mortality was 10% at 3 months (54 out of 542) and 19% at 12 months (102 out of 542). The RAPID risk category predicted mortality at 3 months. Low-risk mortality (RAPID score 0-2): five out of 222 (2.3%, 95% CI 0.9 to 5.7%); medium-risk mortality (RAPID score 3-4): 21 out of 228 (9.2%, 95% CI 6.0 to 13.7%); and high-risk mortality (RAPID score 5-7): 27 out of 92 (29.3%, 95% CI 21.0 to 39.2%). C-statistics for the scores at 3 months and 12 months were 0.78 (95% CI 0.71-0.83) and 0.77 (95% CI 0.72-0.82), respectively.

CONCLUSIONS

The RAPID score stratifies adults with pleural infection according to increasing risk of mortality and should inform future research directed at improving outcomes in this patient population.

Osler Centenary Papers: Management of pleural infection: Osler's final illness and recent advances

Sir William Osler's great work and achievements are extensively documented. Less well known is his prolonged battle with postinfluenza pneumonia, lung abscess and pleural infection that eventually led to his demise. At the age of 70, he was a victim of the global Spanish influenza epidemic, and subsequently developed pneumonia. In the era before antibiotics, he received supportive care and opium for symptom control. The infection extended to the pleura and he required repeated thoracentesis which failed to halt his deterioration. He proceeded to open surgical drainage involving rib resection. Unfortunately, he died shortly after the operation from massive pleuropulmonary haemorrhage. In this article, we review the events leading up to Osler's death and contrast his care 100 years ago with contemporary state-of-the-art management in pleural infection.

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.

Routine Microbiologic Studies of Pleural Fluid Specimens in Cancer Patients

BACKGROUND

Patients who have pleural effusions typically undergo thoracentesis with examination of pleural fluid in their initial assessment. However, limited data are available on the diagnostic yield of pleural fluid bacterial cultures and fungal and acid-fast bacilli (AFB) smear and cultures in patients with cancer.

METHODS

We performed a retrospective cohort study of consecutive patients who had new onset pleural effusions and underwent an initial thoracentesis. The primary outcome was diagnostic yield of pleural fluid bacterial cultures and fungal and AFB smear and cultures.

RESULTS

Of 1637 patients, 1547 (94%) had evidence of active malignancy and 1359 (83%) had evidence of metastatic disease. Of the 1637 patients, 542 (33%) had high clinical suspicion of pneumonia within 14 days prior to thoracentesis. Only 14 patients (1.1%) had positive pleural fluid bacterial cultures, and only 6 of these positive cultures met the criteria for true pleural space infection.

CONCLUSIONS

The incidence of positive results from pleural fluid bacterial, fungal, and AFB in cancer populations is very low. Unless there is a suspicion for infection, microbiological analysis should be ordered selectively.

Advances in pleural effusion diagnostics

Introduction: Pleural effusion is a common clinical problem. Yet, in a significant proportion of patients (~20%), the cause of pleural effusion remains unknown. Understanding the diagnostic value of pleural fluid tests is crucial for the development of accurate diagnostic models.Areas covered: This paper provides an overview of latest advances in the diagnosis of pleural effusion based on the best evidence available.Expert opinion: For pleural fluid tests to have a good diagnostic value, it is necessary that data obtained from clinical history, physical examination, and radiological studies are correctly interpreted. Thoracentesis and pleural biopsy should always be performed under image guidance to improve its diagnostic sensitivity and prevent complications. Nucleic acid amplification tests, pleural tissue cultures, and collection of pleural fluid in blood culture bottles improve the diagnostic yield of pleural fluid cultures. Although undiagnosed pleural effusions generally have a favorable prognosis, follow-up is recommended to prevent the development of a malignant pleural effusion.

Biological effect of tissue plasminogen activator (t-PA) and DNase intrapleural delivery in pleural infection patients

Background

Pleural infection (PI) is a major global disease with an increasing incidence, and pleural fluid (PF) drainage is essential for the successful treatment. The MIST2 study demonstrated that intrapleural administration of tissue plasminogen activator (t-PA) and DNase, or t-PA alone increased the volume of drained PF. Mouse model studies have suggested that the volume increase is due to the interaction of the pleura with the t-PA via the monocyte chemoattractant protein 1 (MCP-1) pathway. We designed a study to determine the time frame of drained PF volume induction on intrapleural delivery of t-PA±DNase in humans, and to test the hypothesis that the induction is mediated by the MCP-1 pathway.

Methods

Data and samples from the MIST2 study were used (210 PI patients randomised to receive for 3 days either: t-PA and DNase, t-PA and placebo, DNase and placebo or double placebo). PF MCP-1 levels were measured by ELISA. One-way and two-way analysis of variance (ANOVA) with Tukey's post hoc tests were used to estimate statistical significance. Pearson's correlation coefficient was used to assess linear correlation.

Results

Intrapleural administration of t-PA±DNase stimulated a statistically significant rise in the volume of drained PF during the treatment period (days 1-3). No significant difference was detected between any groups during the post-treatment period (days 5-7). Intrapleural administration of t-PA increased MCP-1 PF levels during treatment; however, no statistically significant difference was detected between patients who received t-PA and those who did not. PF MCP-1 expression was not correlated to the drug given nor the volume of drained PF.

Conclusions

We conclude that the PF volume drainage increment seen with the administration of t-PA does not appear to act solely via activation of the MCP-1 pathway.

Interpreting pleural fluid results

Interpreting pleural fluid results correctly requires an awareness of the possible aetiologies of a pleural effusion and an understanding of the reliability of the outcome of each investigation. All results must be interpreted within each different clinical context and knowledge of the pitfalls for each test is necessary when the diagnosis is unclear. This review aims to discuss the common aetiologies of a pleural effusion and some of the pitfalls in interpretation that can occur when the diagnosis is unclear.

Pleural infection: a closer look at the etiopathogenesis, microbiology and role of antibiotics

INTRODUCTION

Pleural infection is a condition that continues to pose a significant challenge to respiratory physicians. We hypothesize that the main barriers to progress include limited understanding of the etiopathogenesis, microbiology,and role of antibiotics in the pleural space. Areas covered: PubMed was searched for articles related to adult pleural infection using the terms 'pleural infection', 'empyema' and 'parapneumonic'. The search focused on relevant literature within the last 10 years, with any older citations used only to display context or lack of progress. Tuberculous pleural infection was excluded. We chose to give specific attention to the etiopathogenesis of pleural infection, including recent advances in diagnostics and biomarkers. We discuss our understanding of the pleural microbiome and rationalize the current use of antibiotics in treating this condition. Expert commentary: Understanding of key events in the development of this condition remains limited. The microbiology is unique compared to the lung, and highly variable. Higher culture yields from pleural biopsy may add new insights into the etiopathogenesis. There is little evidence into achievable effective antibiotic concentration within the pleura. Research into issues including the relevance of biofilm formation and significance of pleural thickening is necessary for treatment progress.