Management of infectious processes of the pleural space: a review

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.

Analysis of clinical characteristics and risk factors of community-acquired pneumonia complicated by parapneumonic pleural effusion in elderly patients

BACKGROUND

Community-acquired pneumonia (CAP) patients usually present with parapneumonic pleural effusion (PPE), which complicates the treatment of pneumonia. This study aims to investigate the clinical characteristics and risk factors of elderly CAP patients hospitalised with PPE.

METHODS

The clinical data of 132 elderly patients with CAP were retrospectively analysed. A total of 54 patients with PPE (PPE group) and 78 patients without PPE (NPPE group) were included in this study. Clinical data, laboratory examinations, treatments and other relevant indicators were collected. Univariate analysis and multivariate logistic regression analysis will be used to explore the possible risk factors for PPE.

RESULTS

The proportion of PPE in elderly patients with CAP was 40.9%. PPE patients were significantly more likely to be older, have comorbid neurological diseases, experience chest tightness, and have a lasting fever (P < 0.05). In contrast to NPPE patients, the total number of lymphocytes, serum albumin and blood sodium levels in the PPE group were significantly lower (P < 0.05). The blood D-dimer, C-reactive protein and CURB-65 score of PPE patients were significantly higher (P < 0.05) than those of NPPE patients. Multivariate logistic regression identified chest tightness (OR = 3.964, 95% CI: 1.254-12.537, P = 0.019), long duration of fever (OR = 1.108, 95%CI: 1.009-1.217, P = 0.03), low serum albumin (OR = 0.876, 95%CI: 0.790- 0.971, P = 0.012) or low blood sodium (OR = 0.896, 95%CI: 0.828-0.969, P = 0.006) as independently associated with the development of parapneumonic pleural effusion in the elderly.

CONCLUSION

This study has identified several clinical factors, such as chest tightness, long duration of fever, low serum albumin, and low blood sodium, as risk factors for the development of pleural effusion in elderly patients with CAP. Early identification and prompt management of these patients can prevent inappropriate treatment and reduce morbidity and mortality.

Predictors of outcome of chest tube drainage of non-purulent exudative pleural effusions

Background

Although chest tube drainage is the primary management method for many pleural effusions, it has a failure rate of 9.4–48%. In this study, we examined the factors that predict the outcome of management of nonpurulent exudative effusions. The aim of this study was to determine the predictors of outcomes of chest tube drainage of pleural effusions.

Methodology

Consecutive patients who had a chest tube drainage of nonpurulent exudative pleural effusions were followed up in a prospective observational cohort study until extubation and discharge. Data on the management of the patients were recorded, analysed and compared between groups of patients with good and poor outcomes.

Results

Of the 52 patients studied, 38 had good outcomes, while 14 had poor outcomes. The mean±sd age was 39.7±15.9 years. Multivariate analysis demonstrated that empyema thoracis complicating drainage was an independent predictor of a poor outcome, while the duration of drainage ≤14 days and duration of illness before presentation <30 days were predictive of a good outcome.

Conclusion

Our results show that the development of empyema thoracis during drainage, a long duration of drainage and a prolonged period of illness before presentation are predictive of the outcome of chest tube drainage.

This study of predictors of outcome of chest drainage of nonpurulent pleural effusions found that the development of empyema, a prolonged duration of drainage and a prolonged duration of illness are predictive of a poor outcome of drainagehttps://bit.ly/3tpK39Y

Neutrophils in Extravascular Body Fluids: Cytological-Energy Analysis Enables Rapid, Reliable and Inexpensive Detection of Purulent Inflammation and Tissue Damage

The simultaneous cytological and metabolic investigation of various extravascular body fluids (EBFs) provides clinically relevant information about the type and intensity of the immune response in particular organ systems. The oxidative burst of professional phagocytes with the concomitant production of reactive oxygen species consumes a large amount of oxygen and is the cause of switch to the development of anaerobic metabolism. We assessed the relationships between percentages of neutrophils, aerobic and anaerobic metabolism, and tissue damage via the determination of aspartate aminotransferase catalytic activities (AST) in cerebrospinal fluid (CSF), pleural effusions (PE), abdominal effusions (AE), and synovial fluids (SF). EBFs with 0.0–20.0% neutrophils: 83.0% aerobic and 1.3% strongly anaerobic cases with median of AST = 13.8 IU/L in CSF; 68.0% aerobic and 9.0% strongly anaerobic cases with median of AST = 20.4 IU/L in PE; 77.5% aerobic and 10.5% strongly anaerobic cases with median of AST = 18.0 IU/L in AE; 64.1% aerobic and 7.7% strongly anaerobic cases with median of AST = 13.8 IU/L in SF. EBFs with 80.0–100.0% neutrophils: 4.2% aerobic and 73.7% strongly anaerobic cases with median of AST = 19.2 IU/L in CSF; 7.4% aerobic and 77.3% strongly anaerobic cases with median of AST = 145.2 IU/L in PE; 11.8% aerobic and 73.7% strongly anaerobic cases with median of AST = 61.8 IU/L in AE; 25.5% aerobic and 38.2% strongly anaerobic cases with median of AST = 37.2 IU/L in SF. The significant presence of neutrophils, concomitant strong anaerobic metabolism, and elevated AST in various EBFs are reliable signs of damaging purulent inflammation.

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 for Pleural Disease. Beyond a Pocket of Pleural Fluid

The evolution of pleural disease imaging modalities through the years has helped the scientific community understand and treat various disease states. Ultrasound (US) has been an image modality that has reigned superior to those used in the past such as chest X-ray and computed tomographic scan in terms of cost effectiveness, portability, and reduction in unwarranted radiation exposure to patients. Here we provide a succinct review of US use in pleural disease including imaging techniques, identifying safe pleural space for access, and predicting pleural fluid volume and etiology along with specificities regarding trapped lung identification and pleural mass biopsy. We believe bedside chest US is an adjunct to the physical exam adding superior diagnostic abilities. Further research is warranted in more specific aspects of sonographic use such as in fibrinolytic therapy management, evaluation for trapped lung, and the utility of specific modes like the color flow Doppler.

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.

Features of Parapneumonic Effusions

Introduction: Parapneumonic effusions, as a complication of community-acquired pneumonia (CAP), usually have a good course, but they sometimes progress into complicated parapneumonic effusion (CPPE) and empyema, thus becoming a significant clinical problem.

Aim: To review clinical and radiological features, as well as diagnostic and therapeutic options in parapneumonic effusions.

Material and methods: The analysis included 94 patients with parapneumonic effusion hospitalized at the University Infectious Diseases Clinic in Skopje during a 4 year period. Out of 755 patients with CAP, 175 (23.18%), had parapneumonic effusion. Thoracentesis was performed in 94 (53.71%) patients, 50 patients were with uncomplicated parapneumonic effusions (UCPPE) and 44 with complicated parapneumonic effusions (CPPE).

Results: More patients (59.57%) were male; the average age was 53.82±17.5 years. The most common symptoms included: fever (91; 96.81%), cough (80; 85.11%), pleuritic chest pain (68; 72.34%), dyspnea (65; 69.15%). Alcoholism was the most common comorbidity registered in 12 (12.77%) patients. Macroscopically, effusion was yellow and clear in most cases (36; 38.29%). Localization of pleural effusion was often in the left costophrenic angle (53; 56.38%) and ultrasonographic non-septated complex. Between the two groups of effusions there was a significant difference between the ERS, WBC and CRP in serum and CRP in pleural fluid. Statistical difference existed in terms of days of hospitalization with a longer hospital stay for patients with CPPE (p <0.0001).

Conclusion: Patients with parapneumonic effusion have the symptoms of acute respiratory infection and frequent accompanying diseases. Future diagnostic and therapeutic treatment depends on pleural fluid features and imaging lung findings.

Cytological-energy analysis of pleural effusions

Background

Simultaneous cytological and metabolic investigation of the pleural effusion provides clinically relevant information about the type and intensity of immune response in the pleural cavity.

Methods

We investigated 1329 pleural effusions from patients with different pathological changes in the pleural cavity. Evaluated parameters were differential cell count of neutrophils, eosinophils, lymphocytes and monocytes, and values of the coefficient of energy balance.

Results

We found the lowest numbers of cells and the highest coefficient of energy balance values in patients with heart failure and sepsis; relatively high frequency of eosinophils and slightly decreased coefficient of energy balance values in patients with pneumothorax and haemothorax; the predominance of lymphocytes and low coefficient of energy balance values in patients with tuberculous pleuritis; the predominance of neutrophils and variable coefficient of energy balance values in patients after chest surgery; the highest presence of neutrophils and very low coefficient of energy balance values in patients with chest empyema and the predominance of lymphocytes and normal to low coefficient of energy balance values in patients with pleural malignancy.

Conclusions

Our findings in patients with heart failure and sepsis suggest the absence of inflammation in the pleural cavity. We observed the manifestation of tissue repair in patients with pneumothorax and haemothorax. Patients with tuberculous pleuritis were predominantly characterized by T cell-driven immune response and oxidative burst of macrophages. We found different intensities of immune responses to the chest surgery. The typical finding in patients with empyema was oxidative burst of neutrophils. In patients with pleural malignancy, weak cytotoxic inflammation predominates together with the intensive inflammation characterized by oxidative burst of macrophages.

Inhibition of Glycogen Synthase Kinase 3β Blocks Mesomesenchymal Transition and Attenuates Streptococcus pneumonia-Mediated Pleural Injury in Mice

Pleural loculation affects about 30,000 patients annually in the United States and in severe cases can resolve with restrictive lung disease and pleural fibrosis. Pleural mesothelial cells contribute to pleural rind formation by undergoing mesothelial mesenchymal transition (MesoMT), whereby they acquire a profibrotic phenotype characterized by increased expression of α-smooth muscle actin and collagen 1. Components of the fibrinolytic pathway (urokinase plasminogen activator and plasmin) are elaborated in pleural injury and strongly induce MesoMT in vitro. These same stimuli enhance glycogen synthase kinase (GSK)-3β activity through increased phosphorylation of Tyr-216 in pleural mesothelial cells and GSK-3β mobilization from the cytoplasm to the nucleus. GSK-3β down-regulation blocked induction of MesoMT. Likewise, GSK-3β inhibitor 9ING41 blocked induction of MesoMT and reversed established MesoMT. Similar results were demonstrated in a mouse model of Streptococcus pneumoniae-induced empyema. Intraperitoneal administration of 9ING41, after the induction of pleural injury, attenuated injury progression and improved lung function (lung volume and compliance; P < 0.05 compared with untreated and vehicle controls). MesoMT marker α-smooth muscle actin was reduced in 9ING41-treated mice. Pleural thickening was also notably reduced in 9ING41-treated mice (P < 0.05). Collectively, these studies identify GSK-3β as a newly identified target for amelioration of empyema-related pleural fibrosis and provide a strong rationale for further investigation of GSK-3β signaling in the control of MesoMT and pleural injury.

Clinical, Laboratory and Radiographic Features of Patients with Pneumonia and Parapneumonic Effusions

BACKGROUND:

Parapneumonic effusions complicating pneumonia are associated with increased morbidity and mortality.

AIM:

To determine the role of the clinical, laboratory and radiographic features to the differential diagnosis of patients with community- acquired pneumonia (CAP) without effusion, uncomplicated parapneumonic effusion (UCPPE) and complicated parapneumonic effusion (CPPE).

MATERIAL AND METHODS:

We analysed 148 patients with CAP without effusion, 50 with UCPPE and 44 with CPPE. In three groups of patients, the majority was male patients (58.11%, 58%, 61.36%) consequently.

RESULTS:

The chronic heart failure was the most common comorbidity in a group with CAP (28; 18.92%) and UCPPE (7; 14%), alcoholism (12;12.77%) in a group with CPPE. Patients with CPPE had significantly longer fever compared to patients with CAP without effusion (p = 0.003). Pleuritic chest pain (86.36%) and dyspnea (88.64%) were the most common symptoms in CPPE, then to group with UCPPE (60%; 52%), and in CAP without effusion (25.68%; 47,97%). Diffuse pulmonary changes were detected more frequently in the group with CAP without effusion compared with the group with CPPE (64.86 % vs. 27.27 %), while the segment lung changes were more common in patients with CPPE (50% vs. 20.27%). Patients with CPPE were significant with higher erythrocytes sedimentation rate (ESR), white blood cells (WBC) and serum C- reactive protein (CRP) than it the other two groups (p = 0.00090, p = 0.01, p= 0.000065).

CONCLUSION:

Proper analysis of clinical, laboratory and radiographic features of patients with CAP and parapneumonic effusion can prevent mismanagement in these patients and will reduce morbidity and mortality.

[The management of complicated parapneumonic effusions in France]

INTRODUCTION

There are no French guidelines for the management of complicated parapneumonic effusions. A national observational study was carried out to assess the main features of current clinical practice for this condition.

MATERIAL AND METHODS

A questionnaire was sent by email to the 1500 members of the Société de Pneumologie de Langue Française (SPLF) between 15th November and 15th December 2012.

RESULTS

There were 92 responders, i.e. a response rate of 6%. Of these, 87 physicians mentioned that they were involved in the management of patients with complicated parapneumonic effusions with a median number of cases of 10 per year (IQR: 5-20). Chest tube drainage was the main approach used for pleural fluid aspiration (n=51/87), followed by repeated thoracentesis (n=29/87) and early surgery (1/87). Five physicians answered both chest tube drainage or repeated thoracentesis and one physician either chest tube drainage or early surgery. Pleural fibrinolytics were never used by 20% of physicians, only in case of loculations by 70% and by 10% of respondents in all cases. Only 3 physicians combined fibrinolytics with DNAse. A double antibiotic dose was used by one third of physicians. All the physicians used respiratory physiotherapy during hospitalization and to aid recovery. Follow-up practices were heterogeneous.

CONCLUSIONS

The management of complicated parapneumonic effusions varies significantly in France. National guidelines may be helpful to define best practice and aid in its implementation.

[Parapneumonic pleural effusions: Epidemiology, diagnosis, classification and management]

Parapneumonic pleural effusions represent the main cause of pleural infections. Their incidence is constantly increasing. Although by definition they are considered to be a "parapneumonic" phenomenon, the microbial epidemiology of these effusions differs from pneumonia with a higher prevalence of anaerobic bacteria. The first thoracentesis is the most important diagnostic stage because it allows for a distinction between complicated and non-complicated parapneumonic effusions. Only complicated parapneumonic effusions need to be drained. Therapeutic evacuation modalities include repeated therapeutic thoracentesis, chest tube drainage or thoracic surgery. The choice of the first-line evacuation treatment is still controversial and there are few prospective controlled studies. The effectiveness of fibrinolytic agents is not established except when they are combined with DNase. Antibiotics are mandatory; they should be initiated as quickly as possible and should be active against anaerobic bacteria except for in the context of pneumococcal infections. There are few data on the use of chest physiotherapy, which remains widely used. Mortality is still high and is influenced by underlying comorbidities.

Utility of measurement of interleukin-1ß and interleukin-8 in the diagnosis of complicated parapneumonic pleural effusions

OBJECTIVES

Thirty percent of patients with pneumonia develop pleural effusion, and of these, 20% have complicated effusion (CPPE), which may require a chest tube or surgery for resolution. The objective of the study is to compare the diagnostic yield of determining interleukin-1β and interleukin-8 in pleural fluid (PF) (PFIL-1β and PFIL-8) with respect to classic criteria (pH <7.2, lactate dehydrogenase [LD] >1,000 IU/mL, and/or glucose <60 mg/dL) in the early diagnosis of CPPE.

METHODS

Of the 559 patients studied, 40 had CPPE. All underwent PF analysis: pH, glucose (PFGLUC), LD (PFLD), PFIL-1β and PFIL-8, and PF/serum ratios (PF/SIL-1β and PF/SIL-8).

RESULTS

The diagnostic criterion that showed the best area under the curve was the combination of PF/SIL-8 and PFIL-1β (0.906), with a statistically significant difference (P < .05) compared with the classic criterion of pH and PFGLUC or PFLD (0.826). The combination of PF/SIL-8 and PFIL-1β (cutoffs >5.73 and >9.14 pg/mL, respectively) was significantly more sensitive (72.7%) and more specific (97.9%) (P < .05) than the rest of the parameters used.

CONCLUSIONS

Measurement of IL-1β and IL-8 in pleural fluid may be useful in the early diagnosis of CPPE, although individually, it may not improve the results obtained with the PFLD. Further studies are needed to more firmly establish what role these new parameters can play in the diagnosis of CPPE.

Optimal timing of thoracoscopic drainage and decortication for empyema

BACKGROUND

Although video-assisted thoracic surgery (VATS) pleural drainage and decortication have been proven to be effective treatments in the early stages of empyema, the optimal timing of VATS is still not clear. To assess the effectiveness of early VATS drainage and decortication, we reviewed the records of patients who underwent VATS and open decortication for empyema.

METHODS

One hundred twenty-eight patients with empyema were treated with VATS and open decortication over 8 years at Korea University Anam Hospital. The VATS patients (120 patients) were divided into 3 groups based on the interval between the onset of chest symptoms and the time of operation (group 1: <2 weeks; group 2: 2 to 4 weeks; group 3: >4 weeks). Additional 8 open decortication patients with symptom durations greater than 4 weeks were compared with group 3 patients.

RESULTS

Groups 1 and 2 showed shorter chest tube duration, postoperative hospital stay, surgical procedure time, and fewer prolonged air leaks than group 3. No significant difference was noted between groups 1 and 2; and no difference was noted in the length of postoperative intensive care unit stays or the reintervention and reoperation rates among the 3 groups. In chronic empyema patients, group 3 showed shorter chest tube duration than the open decortication group.

CONCLUSIONS

Patients with symptom durations of less than 4 weeks showed better early results than those with symptom durations greater than 4 weeks. Thus, symptom duration can be considered a reliable preoperative factor in deciding the surgical management of empyema or cases involving loculated pleural effusion.

Potential implication of new torque teno mini viruses in parapneumonic empyema in children

An unexplained increase in the incidence of parapneumonic empyema (PPE) in pneumonia cases has been reported in recent years. The present study investigated the genetic and biological specifications of new isolates of torque teno mini virus (TTMV) detected in pleural effusion samples from children hospitalised for severe pneumonia with PPE.

A pathogen discovery protocol was applied in undiagnosed pleural effusion samples and led to the identification of three new isolates of TTMV (TTMV-LY). Isolated TTMV-LY genomes were transfected into A549 and human embryonic kidney 293T cells and viral replication was assessed by quantitative real-time PCR and full-length genome amplification. A549 cells were further infected with released TTMV-LY virions and the induced-innate immune response was measured by multiplex immunoassays.

Genetic analyses of the three TTMV-LY genomes revealed a classic genomic organisation but a weak identity (<64%) with known sequences. We demonstrated the in vitro replication of TTMV-LY in alveolar epithelial cells and the effective release of infectious viral particles. We also showed a selective production of inflammatory mediators in response to TTMV infection.

This study reports the description of replicative TTMV-LY isolated from parapneumonic effusions of children hospitalised with PPE, suggesting a potential role of the virus in the pathogenesis of pneumonia.