Microbiological Characteristics and Predictive Factors for Mortality in Pleural Infection: A Single-Center Cohort Study in Korea

Unraveling the Predictive Potential of Rapid Scoring in Pleural Infection: A Critical Review

Pleural infection, or pleural empyema, is a severe medical condition associated with high morbidity and mortality rates. Timely and accurate prognostication is crucial for optimizing patient outcomes and resource allocation. Rapid scoring systems have emerged as promising tools in pleural infection prognostication, integrating various clinical and laboratory parameters to assess disease severity and quantitatively predict short-term and long-term outcomes. This review article critically evaluates existing rapid scoring systems, including CURB-65 (confusion, uremia, respiratory rate, blood pressure, age ≥ 65 years), A-DROP (age (male >70 years, female >75 years), dehydration, respiratory failure, orientation disturbance, and low blood pressure), and APACHE II (acute physiology and chronic health evaluation II), assessing their predictive accuracy and limitations. Our analysis highlights the potential clinical implications of rapid scoring, including risk stratification, treatment tailoring, and follow-up planning. We discuss practical considerations and challenges in implementing rapid scoring such as data accessibility and potential sources of bias. Furthermore, we emphasize the importance of validation, transparency, and multidisciplinary collaboration to refine and enhance the clinical applicability of these scoring systems. The prospects for rapid scoring in pleural infection management are promising, with ongoing research and data science advances offering improvement opportunities. Ultimately, the successful integration of rapid scoring into clinical practice can potentially improve patient care and outcomes in pleural infection management.

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.

ERS/ESTS statement on the management of pleural infection in adults

Pleural infection is a common condition encountered by respiratory physicians and thoracic surgeons alike. The European Respiratory Society (ERS) and European Society of Thoracic Surgeons (ESTS) established a multidisciplinary collaboration of clinicians with expertise in managing pleural infection with the aim of producing a comprehensive review of the scientific literature. Six areas of interest were identified: 1) epidemiology of pleural infection, 2) optimal antibiotic strategy, 3) diagnostic parameters for chest tube drainage, 4) status of intrapleural therapies, 5) role of surgery and 6) current place of outcome prediction in management. The literature revealed that recently updated epidemiological data continue to show an overall upwards trend in incidence, but there is an urgent need for a more comprehensive characterisation of the burden of pleural infection in specific populations such as immunocompromised hosts. There is a sparsity of regular analyses and documentation of microbiological patterns at a local level to inform geographical variation, and ongoing research efforts are needed to improve antibiotic stewardship. The evidence remains in favour of a small-bore chest tube optimally placed under image guidance as an appropriate initial intervention for most cases of pleural infection. With a growing body of data suggesting delays to treatment are key contributors to poor outcomes, this suggests that earlier consideration of combination intrapleural enzyme therapy (IET) with concurrent surgical consultation should remain a priority. Since publication of the MIST-2 study, there has been considerable data supporting safety and efficacy of IET, but further studies are needed to optimise dosing using individualised biomarkers of treatment failure. Pending further prospective evaluation, the MIST-2 regimen remains the most evidence based. Several studies have externally validated the RAPID score, but it requires incorporating into prospective intervention studies prior to adopting into clinical practice.

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.

Clinical characteristics of patients with bacterial pleuritis in the presence of Streptococcus anginosus group and obligate anaerobes detected by clone library analysis

INTRODUCTION

Bacterial pleuritis is one of the most important pleural and respiratory infectious diseases, in addition, there have been no reports describing the clinical characteristics of patients with bacterial pleuritis according to molecular methods. An accurate understanding of the clinical characteristics and etiology of bacterial pleuritis is an issue that must be addressed.

OBJECTIVES

The aim of this study was to clarify the clinical characteristics of the bacterial species in bacterial pleuritis.

METHODS

Pleural effusion samples were obtained from 29 patients with bacterial pleuritis. The microbiota of pleural effusion samples was analyzed by clone library analysis using the 16S ribosomal RNA gene.

RESULTS

The phylotypes of Fusobacterium spp. (24.1%) were most frequently the predominant phylotypes, followed by those of Streptococcus anginosus group (SAG) (20.7%) and S. aureus (17.2%). The predominant phylotypes of obligate anaerobes, including the Fusobacterium spp., were detected in 11 of 29 patients (37.9%). Patients in the SAG group were significantly older and presented lower serum albumin levels than those in the obligate anaerobe and other bacterial groups. Patients from the obligate anaerobe group took longer to present symptoms, and therefore the diagnosis of pleuritis was also delayed, in comparison to patients in the other bacterial groups.

CONCLUSIONS

Our results demonstrated that there were characteristic differences between patients in SAG, obligate anaerobe and other bacterial groups. Physicians may need to consider treatment strategy options based on the clinical characteristics of patients with bacterial pleuritis.

The microbiology of pleural infection in adults: a systematic review

BACKGROUND AND OBJECTIVES

Pleural infection is a major cause of morbidity and mortality among adults. Identification of the offending organism is key to appropriate antimicrobial therapy. It is not known whether the microbiological pattern of pleural infection is variable temporally or geographically. This systematic review aimed to investigate available literature to understand the worldwide pattern of microbiology and the factors that might affect such pattern.

DATA SOURCES AND ELIGIBILITY CRITERIA

Ovid MEDLINE and Embase were searched between 2000 and 2018 for publications that reported on the microbiology of pleural infection in adults. Both observational and interventional studies were included. Studies were excluded if the main focus of the report was paediatric population, tuberculous empyema or post-operative empyema.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies of ≥20 patients with clear reporting of microbial isolates were included. The numbers of isolates of each specific organism/group were collated from the included studies. Besides the overall presentation of data, subgroup analyses by geographical distribution, infection setting (community versus hospital) and time of the report were performed.

RESULTS

From 20 980 reports returned by the initial search, 75 articles reporting on 10 241 patients were included in the data synthesis. The most common organism reported worldwide was Staphylococcus aureus. Geographically, pneumococci and viridans streptococci were the most commonly reported isolates from tropical and temperate regions, respectively. The microbiological pattern was considerably different between community- and hospital-acquired infections, where more Gram-negative and drug-resistant isolates were reported in the hospital-acquired infections. The main limitations of this systematic review were the heterogeneity in the method of reporting of certain bacteria and the predominance of reports from Europe and South East Asia.

CONCLUSIONS

In pleural infection, the geographical location and the setting of infection have considerable bearing on the expected causative organisms. This should be reflected in the choice of empirical antimicrobial treatment.

A systematic review of comorbidities and outcomes of adult patients with pleural infection

Background

Pleural infection remains an important cause of mortality. This study aimed to investigate worldwide patterns of pre-existing comorbidities and clinical outcomes of patients with pleural infection.

Methods

Studies reporting on adults with pleural infection between 2000 and 2017 were identified from a search of Embase and MEDLINE. Articles reporting exclusively on tuberculous, fungal or post-pneumonectomy infection were excluded. Two reviewers assessed 20 980 records for eligibility.

Results

211 studies met the inclusion criteria. 134 articles (227 898 patients, mean age 52.8 years) reported comorbidity and/or outcome data. The majority of studies were retrospective observational cohorts (n=104, 78%) and the most common region of reporting was East Asia (n=33, 24%) followed by North America (n=27, 20%). 85 articles (50 756 patients) reported comorbidity. The median (interquartile range (IQR)) percentage prevalence of any comorbidity was 72% (58–83%), with respiratory illness (20%, 16–32%) and cardiac illness (19%, 15–27%) most commonly reported. 125 papers (192 298 patients) reported outcome data. The median (IQR) length of stay was 19 days (13–27 days) and median in-hospital or 30-day mortality was 4% (IQR 1–11%). In regions with high-income economies (n=100, 74%) patients were older (mean 56.5 versus 42.5 years, p<0.0001), but there were no significant differences in prevalence of pre-existing comorbidity nor in length of hospital stay or mortality.

Conclusion

Patients with pleural infection have high levels of comorbidity and long hospital stays. Most reported data are from high-income economy settings. Data from lower-income regions is needed to better understand regional trends and enable optimal resource provision going forward.

In pleural infection, patients from higher-income countries tend to be older with more comorbidities and are more likely to be referred for fibrinolytic treatment in comparison to patients from lower-income countrieshttp://bit.ly/2K2M5HL

Emerging concepts in pleural infection

PURPOSE OF REVIEW

Pleural infection remains an important pulmonary disease, causing significant morbidity and mortality. There is a resurgence of disease burden despite introduction of antibiotics and pneumococcal vaccines. A revisit of the pathogenesis and update on intervention may improve the care of pleural infection.

RECENT FINDINGS

Recent studies have uncovered the prognostic implication of the presence of a pleural effusion in patients with pneumonia. Identifying where the bacteria lives may have diagnostic and therapeutic implications. Over-exaggerated pleural inflammation may underlie development of parapneumonic effusion as indirect evidence and a randomized study in children raised a role of corticosteroids in parapneumonic pleural effusions, but data are lacking for adults. Optimization of the delivery regimen of intrapleural fibrinolytic and deoxyribonuclease therapy is ongoing.

SUMMARY

The review aims to review the current practice and explore new directions of treatment on pleural infection.

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.

Recent developments in the management of pleural infection: A comprehensive review

OBJECTIVES

Pleural infection is a condition commonly encountered by the respiratory physician. This review aims to provide the reader with an update on the most recent data regarding the epidemiology, microbiology, and the management of pleural infection.

DATA SOURCE

Medline was searched for articles related to pleural infection using the terms "pleural infection," "empyema," and "parapneumonic." The search was limited to the years 1997-2017. Only human studies and reports in English were included.

RESULTS

A rise in the incidence of pleural infection is seen worldwide. Despite the improvement in healthcare practices, the mortality from pleural infection remains high. The role of oral microflora in the etiology of pleural infection is firmly established. A concise review of the recent insights on the pathogenesis of pleural infections is presented. A particular focus is made on the role of tPA, DNAse and similar substances and their interaction with inflammatory cells and how this affects the pathogenesis and treatment of pleural infection.

CONCLUSION

Pleural infection is a common disease with significant morbidity and mortality, as well as a considerable economic burden. The role of medical management is expanding thanks to the widespread use of newer treatments.

Risk Stratification in Patients with Complicated Parapneumonic Effusions and Empyema Using the RAPID Score

PURPOSE

Complicated parapneumonic effusions and empyema are a leading cause of morbidity in the United States with over 1 million admissions annually and a mortality rate that remains high in spite of recent advances in diagnosis and treatment. The identification of high risk patients is crucial for improved management and the provision of cost-effective care. The RAPID score is a scoring system comprised of the following variables: renal function, age, purulence, infection source, and dietary factors and has been shown to predict outcomes in patients with pleural space infections.

METHODS

In a single center retrospective study, we evaluated 98 patients with complicated parapneumonic effusions and empyema who had tube thoracostomy (with or without Intrapleural fibrinolytic therapy) and assessed treatment success rates, mortality, length of hospital stay, and direct hospitalization costs stratified by three RAPID score categories: low-risk (0-2), medium risk (3-4), and high-risk (5-7) groups.

RESULTS

Treatment success rate was 71%, and the 90 day mortality rate was 12%. There was a positive-graded association between the low, medium and high RAPID score categories and mortality, (5.3%, 8.3% and 22.6%, respectively), length of hospital stay (10, 21, 19 days, respectively), and direct hospitalization costs ($19,909, $36,317 and $43,384, respectively).

CONCLUSION

Our findings suggest that the RAPID score is a robust tool which could be used to identify patients with complicated parapneumonic effusions and empyema who may be at an increased risk of mortality, prolonged hospitalization, and who may incur a higher cost of treatment. Randomized controlled trials identifying the most effective initial treatment modality for medium- and high-risk patients are needed.

Chest imaging for the diagnosis of complicated parapneumonic effusions

PURPOSE OF REVIEW

To provide an overview of the contribution of thoracic ultrasound (TUS) and computed tomography (CT) in the identification of complicated parapneumonic effusions (CPPE), defined as those which need chest tube drainage for resolution.

RECENT FINDINGS

A recent retrospective study found that visualization of complex (nonanechoic) effusions on TUS (likelihood ratio positive = 6.92) outperformed the recognition of loculated/septated effusions on CT (likelihood ratio = 2.20) or chest radiographs (likelihood ratio = 1.54) for predicting a CPPE. In another retrospective study, a weighted CT scoring system consisting of pleural contrast enhancement (three points), pleural microbubbles, increased extrapleural fat attenuation, and fluid volume at least 400 ml (one point each) had relatively good accuracy for labeling CPPE (likelihood ratio positive = 3.4; likelihood ratio negative = 0.22) when four or more points were achieved.

SUMMARY

Although a gold standard for CPPE diagnosis is lacking, bedside TUS primarily, and CT scan in certain circumstances, may help to drive clinical decisions regarding chest tube placement in parapneumonic effusions (PPE). However, recommendations are limited by the absence of prospective trials.