Advances in pleural infection and malignancy

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.

A simple and efficient clinical prediction scoring system to identify malignant pleural effusion

BACKGROUND

Early diagnosis of malignant pleural effusion (MPE) is of great significance. Current prediction models are not simple enough to be widely used in heavy clinical work.

OBJECTIVES

We aimed to develop a simple and efficient clinical prediction scoring system to distinguish MPE from benign pleural effusion (BPE).

DESIGN

This retrospective study involved patients with MPE or BPE who were admitted in West China Hospital from December 2010 to September 2016.

METHODS

Patients were divided into training, testing, and validation set. Prediction model was developed from training set and modified to a scoring system. The diagnostic efficacy and clinical benefits of the scoring system were estimated in all three sets.

RESULTS

Finally, 598 cases of MPE and 1094 cases of BPE were included. Serum neuron-specific enolase, serum cytokeratin 19 fragment (CYFRA21-1), pleural carcinoembryonic antigen (CEA), and ratio of pleural CEA to serum CEA were selected to establish the prediction models in training set, which were modified to the scoring system with scores of 6, 8, 10, and 9 points, respectively. Patients with scores >12 points have high MPE risk while ⩽12 points have low MPE risk. The scoring system has a high predictive value and good clinical benefits to differentiate MPE from BPE or lung-specific MPE from BPE.

CONCLUSION

This study developed a simple clinical prediction scoring system and was proven to have good clinical benefits, and it may help clinicians to separate MPE from BPE.

Development and validation of a radiomics nomogram for diagnosis of malignant pleural effusion

OBJECTIVE

We aimed to develop a radiomics nomogram based on computed tomography (CT) scan features and high-throughput radiomics features for diagnosis of malignant pleural effusion (MPE).

METHODS

In this study, 507 eligible patients with PE (207 malignant and 300 benign) were collected retrospectively. Patients were divided into training (n = 355) and validation cohorts (n = 152). Radiomics features were extracted from initial unenhanced CT images. CT scan features of PE were also collected. We used the variance threshold algorithm and least absolute shrinkage and selection operator (LASSO) to select optimal features to build a radiomics model for predicting the nature of PE. Univariate and multivariable logistic regression analyzes were used to identify significant independent factors associated with MPE, which were then included in the radiomics nomogram.

RESULTS

A total of four CT features were retained as significant independent factors, including massive PE, obstructive atelectasis or pneumonia, pleural thickening > 10 mm, and pulmonary nodules and/or masses. The radiomics nomogram constructed from 13 radiomics parameters and four CT features showed good predictive efficacy in training cohort [area under the curve (AUC) = 0.926, 95% CI 0.894, 0.951] and validation cohort (AUC = 0.916, 95% CI 0.860, 0.955). The calibration curve and decision curve analysis showed that the nomogram helped differentiate MPE from benign pleural effusion (BPE) in clinical practice.

CONCLUSION

This study presents a nomogram model incorporating CT scan features and radiomics features to help physicians differentiate MPE from BPE.

Novel clinical radiomic nomogram method for differentiating malignant from non-malignant pleural effusions

Objectives

To establish a clinical radiomics nomogram that differentiates malignant and non-malignant pleural effusions.

Methods

A total of 146 patients with malignant pleural effusion (MPE) and 93 patients with non-MPE (NMPE) were included. The ROI image features of chest lesions were extracted using CT. Univariate analysis was performed, and least absolute shrinkage selection operator and multivariate logistic analysis were used to screen radiomics features and calculate the radiomics score. A nomogram was constructed by combining clinical factors with radiomics scores. ROC curve and decision curve analysis (DCA) were used to evaluate the prediction effect.

Results

After screening, 19 radiomics features and 2 clinical factors were selected as optimal predictors to establish a combined model and construct a nomogram. The AUC of the combined model was 0.968 (95% confidence interval [CI] = 0.944-0.986) in the training cohort and 0.873 (95% CI = 0.796-0.940) in the validation cohort. The AUC value of the combined model was significantly higher than those of the clinical and radiomics models (0.968 vs. 0.874 vs. 0.878, respectively). This was similar in the validation cohort (0.873, 0.764, and 0.808, respectively). DCA confirmed the clinical utility of the radiomics nomogram.

Conclusion

CT-based radiomics showed better diagnostic accuracy and model fit than clinical and radiological features in distinguishing MPE from NMPE. The combination of both achieved better diagnostic performance. These findings support the clinical application of the nomogram in diagnosing MPE using chest CT.

DNase inhibits early biofilm formation in Pseudomonas aeruginosa- or Staphylococcus aureus-induced empyema models

Anti-infection strategies against pleural empyema include the use of antibiotics and drainage treatments, but bacterial eradication rates remain low. A major challenge is the formation of biofilms in the pleural cavity. DNase has antibiofilm efficacy in vitro, and intrapleural therapy with DNase is recommended to treat pleural empyema, but the relevant mechanisms remain limited. Our aim was to investigate whether DNase I inhibit the early biofilm formation in Pseudomonas aeruginosa- or Staphylococcus aureus-induced empyema models. We used various assays, such as crystal violet staining, confocal laser scanning microscopy (CLSM) analysis, peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH), and scanning electron microscopy (SEM) analysis. Our results suggested that DNase I significantly inhibited early biofilm formation in a dose-dependent manner, without affecting the growth of P. aeruginosa or S. aureus in vitro. CLSM analysis confirmed that DNase I decreased the biomass and thickness of both bacterial biofilms. The PNA-FISH and SEM analyses also revealed that DNase I inhibited early (24h) biofilm formation in two empyema models. Thus, the results indicated that DNase inhibited early (24h) biofilm formation in P. aeruginosa- or S. aureus-induced rabbit empyema models and showed its therapeutic potential against empyema biofilms.

Predictors of lung entrapment in malignant pleural effusion

INTRODUCTION

Malignant pleural effusion (MPE) is a common complication in advanced stages of malignancy and is associated with poor prognosis. Non-expandable lung (NEL) often occurs and its presence influences the MPE approach. Our main objective was to assess risk factors for malignant NEL.

METHODS

Patients diagnosed with pathologically confirmed MPE between January 2012 and December 2018 in our institution were retrospectively analyzed. Demographic and clinical data of patients were reviewed and compared according to the presence or absence of NEL. A univariate and multivariate binary logistic regression analysis were used to determine predictors of the development of NEL.

RESULTS

Of 365 patients included, 68 (18.6%) had NEL. After multivariate analysis, we found that loculated MPE (OR 8.63, 95%CI 4.30-17.33, p<0.001), complete hemithorax opacification (OR 2.81, 95%CI 1.17-6.76, p<0.021), lung cancer (OR 2.09, 95%CI 1.01-4.31, p=0.047) and higher effusion-serum LDH ratio (OR 1.09, 95%CI 1.00-1.17, p=0.039) were independent predictors of malignant NEL. There were no significant differences compared with expandable lung group regarding time from primary malignancy diagnosis to MPE diagnosis (3.0, IQR 0.0-75.8 vs 2.0, IQR 0.0-75.5 weeks, p=0.942) or MPE symptoms onset to MPE diagnosis (4.0, IQR 1.0-9.0 vs 3.0, IQR 1.0-9.0 weeks, p=0.497). Patients with NEL had a higher number of therapeutic pleural drainages (3.0, IQR 2.0-6.0 vs 2.0, IQR 1.0-3.0; p<0.001) and longer hospital stay (32.5, IQR 15.5-46.3 vs 21.0, IQR 11.0-36.0, p=0.007), measured in hospitalization days until the end of life, than patients with expandable lung. The rate of recurrence of pleural effusion was not significantly different between groups (p=0.291). Overall survival (OS) was 3.0 (95%CI, 2.3-3.7) months, regardless of lung expandability (p=0.923).

CONCLUSION

Loculated MPE, complete hemithorax opacification, lung cancer and a higher effusion-serum LDH ratio were found to be independent predictors for NEL. These patients underwent thoracocenteses more frequently and had longer hospitalization days, although without significant impact in the OS.

Hepatic Hydrothorax: A Narrative Review

Hepatic hydrothorax (HH) represents a distinct clinical entity within the broader classification of pleural effusion that is associated with significant morbidity and mortality. The median survival of patients with cirrhosis who develop HH is 8-12 months. The diagnosis is typically made in the context of advanced liver disease and ascites, in the absence of underlying cardio-pulmonary pathology. A multi-disciplinary approach to management, involving respiratory physicians, hepatologists, and palliative care specialists is crucial to ensuring optimal patient-centered care. However, the majority of accepted therapeutic options are based on expert opinion rather than large, adequately powered randomized controlled trials. In this narrative review, we discuss the epidemiology, pathophysiology, clinical characteristics, and management of HH, highlighting the use of salt restriction and diuretic therapy, porto-systemic shunts, and liver transplantation. We include specific sections focusing on the role of pleural interventions and palliative care, respectively.

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.

Development and Validation of a Scoring System for Early Diagnosis of Malignant Pleural Effusion Based on a Nomogram

Background

The diagnostic value of clinical and laboratory features to differentiate between malignant pleural effusion (MPE) and benign pleural effusion (BPE) has not yet been established.

Objectives

The present study aimed to develop and validate the diagnostic accuracy of a scoring system based on a nomogram to distinguish MPE from BPE.

Methods

A total of 1,239 eligible patients with PE were recruited in this study and randomly divided into a training set and an internal validation set at a ratio of 7:3. Logistic regression analysis was performed in the training set, and a nomogram was developed using selected predictors. The diagnostic accuracy of an innovative scoring system based on the nomogram was established and validated in the training, internal validation, and external validation sets (n = 217). The discriminatory power and the calibration and clinical values of the prediction model were evaluated.

Results

Seven variables [effusion carcinoembryonic antigen (CEA), effusion adenosine deaminase (ADA), erythrocyte sedimentation rate (ESR), PE/serum CEA ratio (CEA ratio), effusion carbohydrate antigen 19-9 (CA19-9), effusion cytokeratin 19 fragment (CYFRA 21-1), and serum lactate dehydrogenase (LDH)/effusion ADA ratio (cancer ratio, CR)] were validated and used to develop a nomogram. The prediction model showed both good discrimination and calibration capabilities for all sets. A scoring system was established based on the nomogram scores to distinguish MPE from BPE. The scoring system showed favorable diagnostic performance in the training set [area under the curve (AUC) = 0.955, 95% confidence interval (CI) = 0.942-0.968], the internal validation set (AUC = 0.952, 95% CI = 0.932-0.973), and the external validation set (AUC = 0.973, 95% CI = 0.956-0.990). In addition, the scoring system achieved satisfactory discriminative abilities at separating lung cancer-associated MPE from tuberculous pleurisy effusion (TPE) in the combined training and validation sets.

Conclusions

The present study developed and validated a scoring system based on seven parameters. The scoring system exhibited a reliable diagnostic performance in distinguishing MPE from BPE and might guide clinical decision-making.

An international survey on the use of intrapleural tissue plasminogen activator/DNase therapy for pleural infection

Introduction

Intrapleural tissue plasminogen activator (tPA) combined with human recombinant DNase (DNase) could be an effective alternative to surgery in managing pleural infection, as demonstrated in the Multi-centre Intrapleural Sepsis Trial (MIST)-2. However, the optimal delivery regimen is still unknown. The aim of this survey was to identify the current practice of tPA/DNase use by physicians with published interests in pleural infection, and their opinions on dose de-escalation of tPA/DNase therapy.

Methods

Potential participants were identified using four search strategies. Only practising physicians who were managing patients with pleural infections and either actively involved in pleural research and publications, or were members of relevant pleural disease guideline panels at the time of survey were included.

Results

An invitation email with the questionnaire was sent to 102 participants, of whom 49 (48%) responded. Most respondents (90%, n=44) have used tPA/DNase to manage pleural infection, but the dosing and delivery regimens employed varied. Many (86%, 38 out of 44) respondents have used 10 mg tPA, while 73% (n=32), 16% (n=7) and 9% (n=4) have used 5 mg, 2.5 mg and 1 mg doses, respectively. Most respondents instilled tPA/DNase concurrently (61%, n=27) and routinely administered six doses of tPA/DNase (52%, n=23) twice daily (82%, n=36). Respondents would consider using a lower starting dose of tPA (with the possibility of escalation if clinically needed) if a median 80% (interquartile range 50–80%) of patients could be successfully treated at that dose.

Conclusion

This survey observed a large variation in the current treatment protocol of intrapleural tPA/DNase therapy worldwide and the need for more data on this subject.

This international survey observed a large variation in the delivery of tPA/DNase therapy for pleural infection. Respondents were open to the concept of starting with a lower (<10 mg) dose of tPA (with the possibility of escalation) if evidence accumulates.https://bit.ly/2ZfPRrL