Childhood Parapneumonic Effusions

Diagnostic value of soluble biomarkers for parapneumonic pleural effusion

Parapneumonic pleural effusion (PPE) is a common complication in patients with pneumonia. Timely and accurate diagnosis of PPE is of great value for its management. Measurement of biomarkers in circulating and pleural fluid have the advantages of easy accessibility, short turn-around time, objectiveness and low cost and thus have utility for PPE diagnosis and stratification. To date, many biomarkers have been reported to be of value for the management of PPE. Here, we review the values of pleural fluid and circulating biomarkers for the diagnosis and stratification PPE. The biomarkers discussed are C-reactive protein, procalcitonin, presepsin, soluble triggering receptor expressed on myeloid cells 1, lipopolysaccharide-binding protein, inflammatory markers, serum amyloid A, soluble urokinase plasminogen activator receptor, matrix metalloproteinases, pentraxin-3 and cell-free DNA. We found that none of the available biomarkers has adequate performance for diagnosing and stratifying PPE. Therefore, further work is needed to identify and validate novel biomarkers, and their combinations, for the management of PPE.

Elevated Nitrite/Nitrate Ratio as a Potential Biomarker for the Differential Diagnosis of Pleural Effusions

Pleural effusions (PEs) are common in clinical practice and can be due to many different underlying diseases such as cancer, congestive heart failure, or pneumonia. An accurate differential diagnostic categorization is essential, as the treatment and prognosis of PEs largely depend on its cause. In this study, we tested the hypothesis that nitrite and nitrate concentrations in PEs are associated with the inflammation and infection conditions. We therefore measured the nitrite and nitrate levels in 143 PE samples using a sensitive liquid chromatography-tandem mass spectrometry method and investigated their diagnostic potential in differentiating PEs. The results showed that nitrite concentrations and nitrite/nitrate ratios were higher in exudates than in transudates (NO₂^-: 2.12 vs. 1.49 μM; NO₂^-/NO₃^-: 23.3 vs. 14.0). Both the nitrite concentrations and the nitrite/nitrate ratios were positively correlated with the three Light's criteria. Moreover, the receiver operating characteristic curve analysis revealed that the nitrite/nitrate ratio with an area under the curve of 0.71 could be a potential diagnostic biomarker in separating infectious PEs (IPEs) from other types of PEs. Taken together, the nitrite/nitrate ratio not only reflected the statuses of inflammation, but also the nitrate reduction by pathogenic bacteria infection in the pleural cavity. The nitrite/nitrate ratio could be a better biomarker in the differential diagnosis of PEs than the nitrite concentration alone.

Factors Associated With the Presence of Tuberculous Empyema in Children With Pleural Tuberculosis

Background: Until now, the factor of tuberculous empyema (TE) in children with pleural tuberculosis (TB) remains unclear. Therefore, a retrospective study was conducted to assess the factors associated with the presence of TE in children. Methods: Between January 2006 and December 2019, consecutive children patients (≤ 15 years old) with suspected pleural TB were selected for further analysis. Empyema was defined as grossly purulent pleural fluid. The demographic, clinical, laboratory, and radiographic features were collected from the electrical medical records retrospectively. Univariate and multivariate logistic regressions were used to explore the factors associated with the presence of TE in children with pleural TB. Results: A total of 154 children with pleural TB (definite, 123 cases; possible, 31 cases) were included in our study and then were classified as TE (n = 27) and Non-TE (n = 127) groups. Multivariate analysis revealed that surgical treatment (age- and sex-adjusted OR = 92.0, 95% CI: 11.7, 721.3), cavity (age- and sex-adjusted OR = 39.2, 95% CI: 3.2, 476.3), pleural LDH (>941 U/L, age- and sex-adjusted OR = 14.8, 95% CI: 2.4, 90.4), and temperature (>37.2°C, age- and sex-adjusted OR = 0.08, 95% CI: 0.01, 0.53) were associated with the presence of TE in children with pleural TB. Conclusion: Early detection of the presence of TE in children remains a challenge and several characteristics, such as surgical treatment, lung cavitation, high pleural LDH level, and low temperature, were identified as factors of the presence of TE in children with pleural TB. These findings may improve the management of childhood TE.

Systemic cytokines/chemokines associated to radiographic abnormalities in pneumonia in children

Community-acquired pneumonia (CAP) diagnosis remains a challenge in paediatrics. Chest radiography is considered gold standard for definition of pneumonia, however no previous study assessed the relationship between immune response and radiographic-confirmed-pneumonia. We assessed association between cytokines/chemokines levels and radiographic abnormalities in children with CAP. Children < 5-years-old hospitalized with CAP were investigated in a prospective study at the Federal University of Bahia Hospital, Brazil. On admission, clinical data and biological samples were collected to investigate 20 aetiological agents and determine serum cytokines/chemokines levels; chest radiographs were performed. Among 158 patients, radiographic diagnosis of pneumonia was confirmed in 126(79.7%) and 17(10.8%) had pleural effusion. Viral, bacterial and pneumococcal infection were detected in 80(50.6%), 78(49.4%) and 37(23.4%) cases. By comparing the median concentrations of serum cytokines/chemokines between children with or without pleural effusion, interleukin(IL)-6 was higher (26.6[18.6-103.7] vs 3.0[0.0-19.8]; p < 0.001) among those with pleural effusion; and between children with or without radiographic-confirmed-pneumonia, IL-6 was higher in the first subgroup (4.5[0.0-23.4] vs 0.0[0.0-3.6]; p = 0.02) after having excluded cases with pleural effusion. Stratified analyses according to aetiology showed IL-6 increase in the radiographic-confirmed-pneumonia subgroup inside the pneumococcal infection (28.2[5.9-64.1] vs 0.0[0.0-0.0]; p = 0.03) subgroup. By multivariable analysis, with IL-6 as dependent variable, pneumococcal infection and pleural effusion showed independent association with IL-6 elevation [respective OR: 5.071 (95%CI = 2.226-11.548; p < 0.001) and 13.604 (95%CI = 3.463-53.449; p = 0.0001)]. Considering the cases without pleural effusion, the area under the curve of IL-6 to predict pneumococcal infection was 0.76 (95%CI = 0.66-0.86; p < 0.001). IL-6 increase is a potential biomarker of pneumococcal infection among children with CAP without pleural effusion upon admission.

Metabolomics Reveals Anaerobic Bacterial Fermentation and Hypoxanthine Accumulation for Fibrinous Pleural Effusions in Children with Pneumonia

Fibrin formation in infectious parapneumonic effusion (IPE) characterizes complicated parapneumonic effusion and is important for providing guidelines for the management of IPEs that require aggressive interventions. We aim to identify metabolic mechanisms associated with bacterial invasion, inflammatory cytokines, and biochemical markers in cases of fibrinous infectious pleural effusions in children with pneumonia. Pleural fluid metabolites were determined by ¹H nuclear magnetic resonance spectroscopy. Metabolites that contributed to the separation between fibrinous and nonfibrinous IPEs were identified using supervised partial least squares discriminant analysis ( Q²/ R² = 0.84; P_permutation < 0.01). IL-1β in the inflammatory cytokines and glucose in the biochemical markers were significantly correlated with 11 and 9 pleural fluid metabolites, respectively, and exhibited significant overlaps. Four metabolites, including glucose, lactic acid, 3-hydroxybutyric acid, and hypoxanthine, were significantly correlated with plasminogen activator inhibitor type 1 in the fibrinolytic system enzymes. Metabolic pathway analysis revealed that anaerobic bacterial fermentation with increased lactic acid and butyric acid via glucose consumption and adenosine triphosphate hydrolysis with increased hypoxanthine appeared to be associated with fibrinous IPE. Our results demonstrate that an increase in lactic acid anaerobic fermentation and hypoxanthine accumulation under hypoxic conditions are associated with fibrin formation in IPE, representing advanced pleural inflammatory progress in children with pneumonia.

When should parapneumonic pleural effusions be drained in children?

Pneumonia is an important health problem in children, and parapneumonic pleural effusion (PPE) is a frequent complication. There is no standard strategy for treating PPE, reflected in the few international guidelines that have been published on the issue. Compared to adults, there is no consensus on the utility of pleural fluid analysis in paediatric PPE. This is because of the lack of good evidence either in favour or against it and the risks of procedural sedation for acquiring pleural fluid for analysis to guide management. In this paper we provide a succinct review of the different approaches to the management of PPE, including diagnosis, pleural fluid analysis (Light's criteria) and treatment, both medical and surgical.

Metabolomic Profiling of Infectious Parapneumonic Effusions Reveals Biomarkers for Guiding Management of Children with Streptococcus pneumoniae Pneumonia

Metabolic markers in biofluids represent an attractive tool for guiding clinical management. The aim of this study was to identify metabolic mechanisms during the progress of pleural infection in children with Streptococcus pneumoniae pneumonia. Forty children diagnosed with pneumococcal pneumonia were enrolled and analysis of pleural fluid metabolites categorized by complicated parapneumonic effusions (CPE) and non-CPE was assessed by using ¹H-NMR spectroscopy. Multivariate statistical analysis including principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were performed. Metabolites identified were studied in relation to subsequent intervention procedures by receiver operating characteristic (ROC) curve analysis. Ten metabolites significantly different between CPE and non-CPE were identified. A significantly lower level of glucose for glycolysis was found in CPE compared to non-CPE. Six metabolites involving bacterial biosynthesis and three metabolites involving bacterial fermentation were significantly higher in CPE compared to non-CPE. Glucose and 3-hydroxybutyric acid were the metabolites found to be useful in discriminating from receiving intervention procedures. Metabolic profiling of pleural fluid using ¹H-NMR spectroscopy provides direct observation of bacterial metabolism in the progress of pneumococcal pneumonia. An increase in the metabolism of butyric acid fermentation of glucose could potentially lead to the need of aggressive pleural drainage.

Serum amyloid alpha in parapneumonic effusions

STUDY OBJECTIVES

To assess serum amyloid alpha (SAA) pleural fluid levels in parapneumonic effusion (PPE) and to investigate SAA diagnostic performance in PPE diagnosis and outcome.

METHODS

We studied prospectively 57 consecutive patients with PPE (empyema (EMP), complicated (CPE), and uncomplicated parapneumonic effusion (UPE)). SAA, CRP, TNF-α, IL-1β, and IL-6 levels were evaluated in serum and pleural fluid at baseline. Patients were followed for 6-months to detect pleural thickening/loculations.

RESULTS

Pleural SAA levels (mg/dL) median(IQR) were significantly higher in CPE compared to UPE (P < 0.04); CRP levels were higher in EMP and CPE compared to UPE (P < 0.01). There was no significant difference between IL-1β, IL-6, TNF-α level in different PPE forms. No significant association between SAA levels and 6-month outcome was found. At 6-months, patients with no evidence of loculations/thickening had significantly higher pleural fluid pH, glucose levels (P = 0.03), lower LDH (P = 0.005), IL-1β levels (P = 0.001) compared to patients who presented pleural loculations/thickening.

CONCLUSIONS

SAA is increased in complicated PPE, and it might be useful as a biomarker for UPE and CPE diagnosis. SAA levels did not demonstrate considerable diagnostic performance in identifying patients who develop pleural thickening/loculations after a PPE.

Clinical practice: treatment of childhood empyema

INTRODUCTION

The incidence of empyema in children is increasing. Adequate knowledge of treatment modalities is therefore essential for every pediatrician. At the university hospital of Leuven, the incidence per 100,000 admissions increased from 40 in 1993 to 120 in 2005. The treatment of choice, however, is still a matter of debate. This is mainly due to the scarcity of prospective randomized trials in children but is further complicated by the absence of uniform terminology. This review starts with clarifying definitions of empyema and complicated versus noncomplicated parapneumonic effusion. The place of different imaging techniques--ultrasound, chest X-ray, computerized tomography and magnetic resonance imaging--is illustrated. All treatment steps are evaluated starting with antibiotic choices, duration of i.v. and oral antibiotics, pleural fluid analysis, indications for chest drain placement, and fibrinolysis. As to the surgical interventions, there is at present insufficient evidence that early surgery is superior to noninvasive medical treatment. Therefore, video-assisted thoracoscopy cannot be advised as general first-line therapy.

CONCLUSION

Since the pathogenicity of empyema is a dynamic process, therapeutic strategy must be decided based on empyema stage and clinical experience. Each referral center should agree on a diagnostic and therapeutic flowchart based on current evidence and local expertise. The flow chart outlined for our center is presented.

Proinflammatory cytokines, fibrinolytic system enzymes, and biochemical indices in children with infectious para-pneumonic effusions

BACKGROUND

In children, pleural empyema is a recognized complication of severe pneumonia and is characterized by loculated effusions with fibrin septations. The aim of this study was to evaluate the relationship between proinflammatory cytokines [tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6], intrapleural fibrinolytic system enzymes [tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor type 1 (PAI-1)], and common biochemical indices during pleural infection.

METHODS

Children with pneumonia complicated by para-pneumonic effusions were enrolled into our study and underwent real-time chest sonography. The patients were divided into 3 groups by ultrasound using a recognized staging system of pleural effusions. Staging of progressive pleural infection was used to correlate with the characteristics of pleural effusions. The correlation of various pleural variables with the formation of complicated para-pneumonic effusions (CPE) was performed and pleural variables for predicting subsequent intervention procedures were also analyzed.

RESULTS

A total of 57 patients were enrolled in the present study. Univariate analysis revealed that the amounts of biochemical indices (pH, glucose, lactate dehydrogenase), proinflammatory cytokines (TNF-alpha, IL-1beta, IL-6), and fibrinolytic system enzymes (tPA, PAI-1) were significantly different with the progressive stages of para-pneumonic effusions (Ptrend < 0.05). For all proinflammatory cytokines, a positive correlation was found with lactate dehydrogenase and PAI-1, whereas a negative correlation was found with pH, glucose, and tPA. Moreover, these cytokines were also significantly correlated with PAI-1 in both non-CPE and CPE. The pleural fluid findings of IL-1beta (> or =50 pg/mL), PAI-1 (> or =1252 ng/mL), and pH (< or =7.30) were the most significant predictive factors for subsequent intervention procedures (P < 0.001).

CONCLUSIONS

The increased release of proinflammatory cytokines in pleural fluid caused by bacteria may result in an imbalance of the fibrinolytic system, which can subsequently lead to fibrin deposition and intervention procedures.

Microbiological diagnostic procedures in respiratory infections: suppurative lung disease

Pursuing a microbiological diagnosis in suppurative lung disease can enable focused antibiotic therapy, identify pathogens of potential concern for infection control, and in some cases delineate a specific pathological process. Suppurative lung disease can be categorized as acute or chronic. Acute disease most commonly consists of lung abscess or parapneumonic empyema. The vast majority of chronic suppurative lung disease in childhood is due to cystic fibrosis. Samples from the respiratory tract offer the most useful information for diagnosis and management, but adjunctive information can also be obtained from serological methods, blood cultures and molecular techniques. The quality of respiratory tract samples is vital to aid accurate interpretation of results, and this varies according to the technique of collection. Antibiotic sensitivity testing is of particular importance in an era of evolving antibiotic resistance and can be problematical in cystic fibrosis.

Pleural Fluid PCR Method for Detection of Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae in Pediatric Parapneumonic Effusions

BACKGROUND

Parapneumonic effusions cause significant morbidity and mortality despite current developments in diagnostic and therapeutic approaches. Causative microorganisms may remain unidentified in a significant number of patients by cultures and Gram smears. Polymerase chain reaction (PCR) is a molecular technique for the detection of causative bacteria; however, its efficiency in pleural fluids is less known.

OBJECTIVES

The present study was performed to compare the efficiency of PCR in the detection of the three most common organisms (Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae) with conventional methods.

METHODS

Twenty-eight consecutive patients with parapneumonic pleural effusions were studied. On admission, pleural fluid samples were obtained for Gram staining, routine culture and PCR analysis for S. aureus, S. pneumoniae and H. influenzae.

RESULTS

PCR analysis allowed detection of 11 microorganisms in 10 patients (35.7%), whereas pleural fluid cultures detected the etiological agent in only 2 (7.1%). S. pneumoniae was the most frequent agent.

CONCLUSIONS

Pleural fluid cultures may have low diagnostic yields, partly due to prior antibiotic use. Pleural fluid PCR analysis may improve the etiologic diagnosis in parapneumonic pleural effusions, with technical advances leading to higher yields than obtained in this study.

Parapneumonic effusion and empyema in children: retrospective review of the duPont experience

Management of pediatric parapneumonic effusions and empyema remains controversial. Treatment includes antibiotics, chest tube, fibrinolytic therapy, video-assisted thoracoscopy and debridement, and open thoracotomy and decortication. A retrospective 10-year study was done to identify patient selection variables for specific therapies. Charts (n = 101) with diagnoses of empyema without comorbidity were reviewed, a database was developed, and variables between patients who did and did not receive thoracoscopic debridement were compared at admission and during hospitalization. The difference in positive culture reports with video-assisted thoracoscopy compared with medical management was significant (P < .018). Postsurgical patients used the intensive care unit and had 2 or more chest tubes with greater frequency than medically managed patients (P < .014, P < .002). Antibiotics, video-assisted thoracoscopy, and chest tube within 48 hours of admission shortened hospitalization by 4 days (P < .001) compared with delayed video-assisted thoracoscopy done after 48 hours of admission.

Pleural effusions

The ability to recognize, understand, and treat pleural effusions in the pediatric population is important for pediatric health care providers. The topic of pleural effusions has been extensively studied in the adult population. In recent years, these studies have extended into the pediatric population. This review describes pleural effusions in detail, including the different types and underlying pathophysiology. We then go on to provide a comprehensive review of the recent literature regarding the diagnosis and treatment of pleural effusions in the pediatric population.