Utility of the Ratio of Adenosine Deaminase and Serum C-reactive Protein in Differentiating Parapneumonic, Tuberculous, and Malignant Pleural Effusions.

Introduction Pleural effusion is a challenging diagnosis at times, especially due to the overlap of symptoms in effusions of various etiologies. In this study, we aimed to identify if pleural fluid adenosine deaminase (ADA) or serum C-reactive protein (CRP) can be used as an additional novel biomarker for ADA in diagnosing tubercular, parapneumonic, and malignant pleural effusions. Materials and methods A prospective, observational, cross-sectional study was conducted on 79 patients diagnosed with tubercular, parapneumonic, or malignant pleural effusion from August 2022 to April 2024 at the Department of Respiratory Medicine at Dr. D. Y. Patil Medical College, Hospital & Research Centre, Pimpri, Pune. The pleural fluid ADA/serum CRP ratio was identified in each group, and analysis was done to compare the ratio in each group. The correlation with pleural fluid ADA was also identified. Results A total of 79 patients were enrolled in this study. Out of these patients, 53 (67.1%) were identified as having tubercular pleural effusion, 10 (12.7%) patients had parapneumonic effusion, and 16 (20.3%) had malignant pleural effusion. For malignant effusions, the area under the curve (AUC) using the receiver operating characteristic (ROC) for the ADA/CRP ratio was observed to be 0.862. Sensitivity was 87.50% and specificity was 82.54% at a cut-off value of ≤0.5. The positive predictive value was found to be 56%, and the negative predictive value was found to be 96.3%. For parapneumonic effusions, the AUC using the ROC for the ADA/CRP ratio was observed to be 0.880. Sensitivity was 100% and specificity was 69.57% at a cut-off value of ≤0.67. The positive predictive value was found to be 32.3%, and the negative predictive value was found to be 100%. For tubercular effusions, the AUC using the ROC for the ADA/CRP ratio was observed to be 0.955. Sensitivity was 92.45% and specificity was 88.46% at a cut-off value of >0.54. The positive predictive value was found to be 94.2%, and the negative predictive value was found to be 85.2%. The Pearson correlation coefficient (r) of 0.633 indicates a moderately strong positive linear relationship between ADA and ADA/CRP levels. Conclusion The pleural fluid ADA-to-serum CRP ratio can be used as a useful diagnostic tool for differentiating between tubercular, parapneumonic, and malignant pleural effusions. ADA/CRP ratio has added diagnostic value over ADA. In clinically puzzling scenarios, the ADA/CRP ratio can be a cost-effective tool before opting for a more expensive and invasive procedure, which is also often difficult to obtain in resource-limited healthcare settings. More research with a larger sample size is indicated to incorporate the ADA/CRP ratio as an added diagnostic tool along with ADA.

ACR Appropriateness Criteria® Workup of Pleural Effusion or Pleural Disease.

Pleural effusions are categorized as transudative or exudative, with transudative effusions usually reflecting the sequala of a systemic etiology and exudative effusions usually resulting from a process localized to the pleura. Common causes of transudative pleural effusions include congestive heart failure, cirrhosis, and renal failure, whereas exudative effusions are typically due to infection, malignancy, or autoimmune disorders. This document summarizes appropriateness guidelines for imaging in four common clinical scenarios in patients with known or suspected pleural effusion or pleural disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Workup of pleural effusion or pleural disease

Pleural effusions are categorized as transudative or exudative, with transudative effusions usually reflecting the sequala of a systemic etiology and exudative effusions usually resulting from a process localized to the pleura. Common causes of transudative pleural effusions include congestive heart failure, cirrhosis, and renal failure, whereas exudative effusions are typically due to infection, malignancy, or autoimmune disorders. This document summarizes appropriateness guidelines for imaging in four common clinical scenarios in patients with known or suspected pleural effusion or pleural disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Disseminated Lodderomyces elongisporus and Pantoea dispersa: A Rare Dual Infection in an Immunocompromised Patient.

With the advancement of modern medicine and the prolonged survival of critically ill patients, unusual organisms are increasingly emerging. Initially found in the environment, these rare organisms started presenting as human pathogens, causing significant morbidity and mortality. Here, we present a rare case of disseminated Lodderomyces elongisporus fungemia and Pantoea dispersa bacteremia in a patient with parapneumonic effusion and ruptured liver abscess. This yeast was identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). Although this organism has no antifungal breakpoint, the isolate shows low minimum inhibitory concentration (MIC) to a wide range of antifungals. The importance of effective communication between microbiologists and clinicians and early referral to the infectious disease team was also highlighted in this case for prompt treatment.

Infective Pleural Effusions-A Comprehensive Narrative Review Article.

Infective pleural effusions are mainly represented by parapneumonic effusions and empyema. These conditions are a spectrum of pleural diseases that are commonly encountered and carry significant mortality and morbidity rates reaching upwards of 50%. The causative etiology is usually an underlying bacterial pneumonia with the subsequent seeding of the infectious culprit and inflammatory agents to the pleural space leading to an inflammatory response and fibrin deposition. Radiographical evaluation through a CT scan or ultrasound yields high specificity and sensitivity, with features such as septations or pleural thickening indicating worse outcomes. Although microbiological yields from pleural studies are around 56% only, fluid analysis assists in both diagnosis and prognosis by evaluating pH, glucose, and other biomarkers such as lactate dehydrogenase. Management centers around antibiotic therapy for 2-6 weeks and the drainage of the infected pleural space when the effusion is complicated through tube thoracostomies or surgical intervention. Intrapleural enzymatic therapy, used to increase drainage, significantly decreases treatment failure rates, length of hospital stay, and surgical referrals but carries a risk of pleural hemorrhage. This comprehensive review article aims to define and delineate the progression of parapneumonic effusions and empyema as well as discuss pathophysiology, diagnostic, and treatment modalities with aims of broadening the generalist's understanding of such complex disease by reviewing the most recent and relevant high-quality evidence.

Myeloid-derived suppressor cells in pleural effusion as a diagnostic marker for early discrimination of pulmonary tuberculosis from pneumonia.

Introduction: Tuberculous pleural effusion (TPE) stands as one of the primary forms of extrapulmonary tuberculosis (TB) and frequently manifests in regions with a high prevalence of TB, consequently being a notable cause of pleural effusion in such areas. However, the differentiation between TPE and parapneumonic pleural effusion (PPE) presents diagnostic complexities. This study aimed to evaluate the potential of myeloid-derived suppressor cells (MDSCs) in the pleural fluid as a potential diagnostic marker for distinguishing between TPE and PPE. Methods: Adult patients, aged 18 years or older, who presented to the emergency room of a tertiary referral hospital and received a first-time diagnosis of pleural effusion, were prospectively enrolled in the study. Various immune cell populations, including T cells, B cells, natural killer (NK) cells, and MDSCs, were analyzed in both pleural fluid and peripheral blood samples. Results: In pleural fluid, the frequency of lymphocytes, including T, B, and NK cells, was notably higher in TPE compared to PPE. Conversely, the frequency of polymorphonuclear (PMN)-MDSCs was significantly higher in PPE. Notably, compared to traditional markers such as the neutrophil-to-lymphocyte ratio and adenosine deaminase level, the frequency of PMN-MDSCs emerged as a more effective discriminator between PPE and TPE. PMN-MDSCs demonstrated superior positive and negative predictive values and exhibited a higher area under the curve in the receiver operating characteristic curve analysis. PMN-MDSCs in pleural effusion increased the levels of reactive oxygen species and suppressed the production of interferon-gamma from T cells following nonspecific stimulation. These findings suggest that MDSC-mediated immune suppression may contribute to the pathology of both TPE and PPE. Discussion: The frequency of PMN-MDSCs in pleural fluid is a clinically useful indicator for distinguishing between TPE and PPE.

Evaluation of the RAPID score as a predictor of postoperative morbidity and mortality in patients undergoing pulmonary decortication for stage III pleural empyema.

OBJECTIVE: This study aims to correlate the RAPID score with the 3-month survival and surgical results of patients undergoing lung decortication with stage III pleural empyema. METHODS: This was a retrospective study with the population of patients with pleural empyema who underwent pulmonary decortication between January 2019 and June 2022. Data were collected from the institution's database, and patients were classified as low, medium, and high risk according to the RAPID score. The primary outcome was 3-month mortality. Secondary outcomes were the length of hospital stay, readmission rate, and the need for pleural re-intervention. RESULTS: Of the 34 patients with pleural empyema, according to the RAPID score, patients were stratified into low risk (23.5 %), medium risk (47.1 %), and high risk (29.4 %). The high-risk group had a 3-month mortality of 40 %, while the moderate-risk group had a 6.25 % and the low-risk group had no deaths within 90 days, confirming a good correlation with the RAPID score (p < 0.05). Sensitivity and specificity for the primary outcome in the high-risk score were 80.0 % and 79.3 %, respectively. The secondary outcomes did not reach statistical significance. CONCLUSIONS: In this retrospective series, the RAPID score had a good correlation with 3-month mortality in patients undergoing lung decortication. The morbidity indicators did not reach statistical significance. The present data justifies further studies to explore the capacity of the RAPID score to be used as a selection tool for treatment modality in patients with stage III pleural empyema.

Empyema in children.

Empyema is the infection of the fluid in the pleural space due to different causes. The most common cause of empyema in children is parapneumonic effusion. Although its frequency has decreased significantly with the use of antibiotics, it is still a significant cause of morbidity and mortality worldwide. The main aim in the treatment of empyema is to drain the pleural cavity to provide reexpansion of the compressed lung, to treat the parenchymal infection with appropriate antibiotic therapy, and to prevent complications that may develop in the acute and chronic periods. Treatment options for this disease vary depending on the stage of the disease. Treatment success in childhood empyema detected at an early stage is high. The diagnosis and treatment of empyema in children differs from adults. Due to rapid tissue regeneration in childhood, healing can occur without the need for aggressive treatment options.

Case report of parapneumonic effusion and mesothelial subdiaphragmatic cyst: relationship or coincidence?

Parapneumonic pleural effusions are common in patients with pneumonia. When colonized by pathogenic bacteria or other microorganisms, these effusions can progress to empyema. Additionally, empyema formation may result in extension of the infection into the infradiaphragmatic region, further complicating the clinical scenario. Many subphrenic collections are found to be mesothelial cysts, which are congenital in origin. However, data regarding the potential association between mesothelial diaphragmatic cysts and parapneumonic effusions are limited. We herein describe a toddler with pneumonia complicated by parapneumonic effusion and a lung abscess with a subphrenic collection. After abscess drainage and a full course of antibiotics, imaging revealed clear lung parenchyma with an interval resolution of the effusion and a persistent unchanged subphrenic collection that was confirmed to be mesothelial diaphragmatic cyst. This case highlights the fact that not every subphrenic collection associated with parapneumonic effusion is a communicated collection formed by seeding. Such a collection can instead be an incidental cyst, which is congenital in origin and known as a mesothelial diaphragmatic cyst. A diaphragmatic mesothelial cyst is an uncommon benign congenital cyst that is unrelated to an adjacent parapneumonic effusion. It is usually incidental and can be monitored without invasive intervention.

A Rapidly Enlarging Asymptomatic Parapneumonic Effusion: A Case Report.

A pleural effusion is an accumulation of fluid in the pleural space due to an imbalance between formation and removal. They're commonly caused by heart failure or infections. We report a case of a 56-year-old male with community-acquired pneumonia and a trace pleural effusion on presentation. Despite clinical improvement with antibiotic therapy, the effusion significantly increased on day two. This case report is unique because the patient had an enlarging effusion, but remained asymptomatic and denied worsening shortness of breath, chest pain, or cough. The patient was treated successfully with chest tube placement and intrapleural fibrinolytic therapy. This report emphasizes the importance of repeat imaging for asymptomatic parapneumonic effusions (PPE) that can complicate community-acquired pneumonia. We aim to raise awareness of the atypical presentation and management of parapneumonic effusions through a case report.

Fusobacterium/Peptostreptococcus - A Case Report of Community- Acquired Empyema Resulting in Surgical Decortication with Prolonged Antibiotic Therapy: A Case Series and Review of the Literature.

Background: Infections caused by anaerobic bacteria occur frequently and can be serious and life-threatening. Anaerobes are a rare cause of community-acquired pneumonia with Streptococcus pneumonia and respiratory viruses being the most frequently detected pathogens. We, herein, report a case of Fusobacterium/Peptostreptococcus parapneumonic effusion with empyema in a patient without risk factors for aspiration pneumonia. This case presents an opportunity to discuss an unusual case of community-acquired empyema secondary to anaerobic infection in a patient without the common risk factors for aspiration.

Case Presentation: A 59-year-old male patient without significant past medical history apart from a twenty-five-year history of smoking presented due to left flank pain and shortness of breath. Findings of a complicated parapneumonic effusion were found on imaging, resulting in surgical decortication and prolonged antibiotic therapy.

Discussion: Parapneumonic effusions and empyema are relatively common complications of pneumonia. It is important to note that the incidence of anaerobic empyema has been on the rise due to more modern culturing techniques.

Conclusion: This case highlights an unusual presentation of community-acquired empyema secondary to anaerobes without any risk factors for aspiration pneumonia. Therefore, clinicians should consider the possibility of anaerobic coverage in the treatment of community-acquired empyema in the appropriate setting.

Diagnostic Accuracy of Lactate Dehydrogenase/Adenosine Deaminase Ratio in Differentiating Tuberculous and Parapneumonic Effusions: A Systematic Review.

BACKGROUND: Tuberculous pleural effusion (TPE) and parapneumonic effusion (PPE) are often difficult to differentiate owing to the overlapping clinical features. Observational studies demonstrate that the ratio of lactate dehydrogenase to adenosine deaminase (LDH/ADA) is lower in TPE compared to PPE, but integrated analysis is warranted. METHODS: We conducted a systematic review to evaluate the diagnostic accuracy of the LDH/ADA ratio in differentiating TPE and PPE. We explored the PubMed and Scopus databases for studies evaluating the LDH/ADA ratio in differentiating TPE and PPE. RESULTS: From a yield of 110 studies, five were included for systematic review. The cutoff value for the LDH/ADA ratio in TPE ranged from <14.2 to <25. The studies demonstrated high heterogeneity, precluding meta-analysis. Quality Assessment of Diagnostic Accuracy Studies Tool 2 assessment revealed a high risk of bias in terms of patient selection and index test. CONCLUSION: LDH/ADA ratio is a potentially useful parameter to differentiate between TPE and PPE. Based on the limited data, we recommend an LDH/ADA ratio cutoff value of <15 in differentiating TPE and PPE. However, more rigorous studies are needed to further validate this recommendation.

Evaluation of the RAPID score as a predictor of postoperative morbidity and mortality in patients undergoing pulmonary decortication for stage III pleural empyema

Abstract Objective: This study aims to correlate the RAPID score with the 3-month survival and surgical results of patients undergoing lung decortication with stage III pleural empyema. Methods: This was a retrospective study with the population of patients with pleural empyema who underwent pulmonary decortication between January 2019 and June 2022. Data were collected from the institution's database, and patients were classified as low, medium, and high risk according to the RAPID score. The primary outcome was 3-month mortality. Secondary outcomes were the length of hospital stay, readmission rate, and the need for pleural re-intervention. Results: Of the 34 patients with pleural empyema, according to the RAPID score, patients were stratified into low risk (23.5 %), medium risk (47.1 %), and high risk (29.4 %). The high-risk group had a 3-month mortality of 40 %, while the moderate-risk group hada 6.25 % and the low-risk group had no deaths within 90days, confirmingagood correlation with the RAPID score (p < 0.05). Sensitivity and specificity for the primary outcome in the high-risk score were 80.0 % and 79.3%, respectively. The secondary outcomes did not reach statistical significance. Conclusions: In this retrospective series, the RAPID score had a good correlation with 3-month mortality in patients undergoing lung decortication. The morbidity indicators did not reach statistical significance. The present data justifies further studies to explore the capacity of the RAPID score to be used as a selection tool for treatment modality in patients with stage III pleural empyema.

A multicenter study on the epidemiology of complicated parapneumonic effusion in the era of currently available pneumococcal conjugate vaccines.

BACKGROUND: Parapneumonic effusion (PPE) is a common complication of pneumonia. Streptococcus pneumoniae is the most common cause of bacterial pneumonia. A reduction in pneumonia hospitalizations has been observed since the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7). Despite this apparent benefit, an increase in the incidence of PPE was recorded in some countries following PCV7 implementation. As the 13-valent pneumococcal conjugate vaccine (PCV13) was expected to provide a wider protection against PPE, the aim of the present study was to evaluate the impact of PCV13 introduction on the epidemiology of complicated parapneumonic effusion (c-PPE) among children in the Athens greater area. METHODS: All cases of community-acquired pneumonia (CAP) with PPE requiring chest tube insertion (complicated PPE, c-PPE) hospitalized in the 3 public Children's hospitals in Athens between 01/01/2004 and 31/12/2019 were included in the study. RESULTS: A total of 426 cases of c-PPE associated with pneumonia were recorded of which 198 were admitted during 2004-2010 (period A, prePCV13/PCV -7 introduction period) and 228 during 2011-2018 (period B, post - PCV13 period). A definite bacterial etiology was established in 44.4 % of all cases and of those 25.4 % were caused by S. pneumoniae. An increasing trend in c-PPE incidence was observed during period A; although, a significant decrease on c-PPE annual rates was observed during the period B (p = 0.011), a remarkable increase in serotype 3 cases was recorded. CONCLUSION: A decreasing time trend in c-PPE cases among children was shown after the introduction of PCV13 in our area. However, serotype 3 is nowadays a common cause of PPE. Hence, continuous surveillance is imperative in order to follow c-PPE epidemiology over time.

Percutaneous management of complicated empyema thoracis using pigtail, report of a case from University Hospital of Nepal: a case report.

Empyema thoracis is a condition characterized by the accumulation of pus in the pleural cavity of the lungs. Empyema thoracis is a cause of high mortality in man and its occurrence is increasing in both children and adults. Traditionally, chest tube drainage has been a preferred method of treatment, but recent studies have shown that pigtail catheter drainage is a more effective and less invasive alternative. Image-guided drainage is also preferred over blind drainage, and alternative drainage sites are being explored. These management changes have improved patient outcomes and reduced the risk of complications. Case presentation and clinical discussion: A 66-year-old female presented with complaints of cough, fever, and chest pain. A clinical examination was done and relevant investigations were sent. She was then treated in the line of left-sided empyema thoracis. A pigtail catheter was inserted into the loculated empyema via the left 9th intercostal space through a posterolateral approach with ultrasonography guidance. Conclusion: The main aim of this article is to provide an overview of a rare management approach for empyema, a condition characterized by the accumulation of pus in the pleural cavity of the lungs. In this case report, the authors have focused on pigtail catheter drainage over traditionally performed chest tube drainage, and image-guided drainage has been performed over blind drainage ensuring accurate placement and reducing the risk of damage to surrounding tissues. Another notable change in empyema management is the shift in drainage sites from the safety triangle to other sites based on the site of loculations under ultrasonography guidance.

Choice of intrapleural fibrinolytic agents in the treatment of adult complicated parapneumonic effusion and empyema: Network meta-analysis.

BACKGROUND: The appropriate use of intrapleural fibrinolytic agents in patients with complicated parapneumonic effusion and empyema remains unclear, especially regarding the choice of fibrinolytic agents. We conducted a network meta-analysis comparing outcomes of intrapleural fibrinolytic agents in patients with complicated parapneumonic effusion and empyema. METHODS: MEDLINE and EMBASE were searched through April 2022 to identify randomized controlled trials (RCTs) that investigated outcomes in patients with complicated parapneumonic effusion or empyema who were treated with intrapleural fibrinolytic agents. The outcomes of interest were surgical requirements, bleeding, length of hospital stay, and all-cause mortality. RESULTS: Our analysis included 10 RCTs that enrolled 1085 patients treated with intrapleural tissue plasminogen activator (TPA) (n = 138), TPA + deoxyribonuclease (DNase) (n = 52), streptokinase (n = 311), urokinase (n = 75), DNase (n = 51), or placebo (n = 458). The rates of surgical requirement were significantly lower with TPA and TPA + DNase than with placebo (risk ratio [RR]; 95% confidence interval [CI] = 0.36 [0.14-0.97], p = 0.038, RR [95% CI] = 0.25 [0.08-0.78], p = 0.017, respectively). The risk of bleeding was higher with TPA + DNase than with placebo (RR [95% CI] = 10.91 [1.53-77.99], p = 0.017), as well as TPA and TPA + DNase than with urokinase (RR [95% CI] = 17.90 [1.07-299.44], p = 0.044, RR [95% CI] = 89.3 [2.88-2772.49], p = 0.010, respectively). All-cause mortality was similar among the groups. CONCLUSION: TPA and TPA + DNase reduced the rates of surgical requirement compared with placebo. However, TPA + DNase increased the risk of bleeding compared with placebo. Intrapleural agents for complicated parapneumonic effusion and empyema should be selected with an individual risk assessment.

Differentiating between tuberculous and non-tuberculous pleural effusions using the pleural fluid ratio of 10× adenosine deaminase/lactate dehydrogenase.

Background: Adenosine deaminase (ADA) is a sensitive marker of tuberculous pleural effusion (TBPE). However, in pleural effusion (PE), the detection of ADA alone cannot be used to determine whether the increase in the ADA level is caused by the rising proportion of macrophages and lymphocytes in the cell components or by the increase in the total cell number. The diagnostic precision of ADA is probably restricted due to the false positive and negative results. Thus, we explored the clinical value of the ratio of PE ADA to lactate dehydrogenase (LDH) in differentiating between TBPE and non-TBPE. Methods: Patients hospitalized with PEs between January 2018 and December 2021 were retrospectively recruited for this study. We analyzed the values of ADA, LDH, and 10× ADA/LDH in the patients with TBPE and non-TBPE. We also determined the sensitivity, specificity, Youden index, and area under the curve for 10× ADA/LDH at different ADA levels and evaluated its diagnostic accuracy. Results: In total, 382 patients with PEs were included in the study. Among whom, 144 were diagnosed with TBPE, this supposes a "pre-test probability" >40%. It is quite high, 134 with malignant PEs, 19 with parapneumonic PEs, 43 with empyema, 24 with transudate PEs, and 18 with other types of PE of a known etiology. The ADA levels were positively correlated with the LDH levels in TBPE. LDH levels usually increase in response to cell damage or cell death. The 10× ADA/LDH level was significantly increased in the TBPE patients. In addition, the 10× ADA/LDH level increased as the ADA level increased in TBPE. To differentiate between TBPE and non-TBPE, the optimal cut-off value of 10× ADA/LDH at different ADA levels was assessed using receiver operating curves. At an ADA level >20 U/L, 10× ADA/LDH showed the best diagnostic performance, and had a specificity and sensitivity of 0.94 (95% CI: 0.84-0.98) and 0.95 (95% CI: 0.88-0.98), respectively. Conclusions: The 10× ADA/LDH dependent diagnostic index can be used to distinguish TBPE from non-TBPE and could be used to guide future clinical decisions.

Streptococcus anginosus Lung Abscess With Complicated Parapneumonic Empyema.

A 55-year-old female with hypertension presented to our facility with complicated pneumonia. She complained of progressively worsening shortness of breath and pleuritic chest pain. She was in her usual state of health except for an upper respiratory infection treated with oral antibiotics a month prior. At the presentation, she was febrile, tachycardic, and hypoxic on room air. A chest computed tomography (CT) showed near-complete opacification of the right lung, a cavitation with the fluid level in the right middle lobe, and moderate-to-large effusion. Broad-spectrum antibiotics were started. Sputum culture was later positive for methicillin-resistant Staphylococcus aureus, which prompted antibiotic de-escalation to vancomycin. A chest tube was placed into the right pleural space draining 700 mL of exudative fluid, which cultures grew Streptococcus anginosus group (SAG) bacteria. Due to persistent respiratory distress and residual effusion, right thoracotomy and decortication were performed. A right upper lobe abscess ruptured into the pleural space was noted during the procedure. Pathology revealed necrotic tissue, and the microbiological workup was negative. The patient clinically improved postoperatively and was discharged home with oral Linezolid.

A retrospective study on parapneumonic effusion in 130 dogs with a clinical diagnosis of pneumonia.

Objective: To screen the occurrence of parapneumonic effusion in dogs. Methods: Medical records were searched for dogs with a presumptive diagnosis of bacterial pneumonia from 2017 to 2021 at the Liege university teaching hospital. Bacterial pneumonia was presumptively diagnosed based on compatible clinical signs and findings; thoracic radiographs compatible with bacterial bronchopneumonia; and either increased serum C-reactive protein (CRP) levels, a positive bronchoalveolar lavage culture or a positive clinical evolution in response to antibiotic therapy. Patients diagnosed with parasitic or other non-bacterial inflammatory pneumonia or with pulmonary neoplasia were excluded. Signalment, clinical findings, and outcome were recorded. Results: One hundred and thirty dogs were included in the study, of which 44 dogs (33.8%) developed a parapneumonic effusion. Four of these dogs (4/44; 9%) had thoracocentesis performed, displaying a modified transudate (2) or septic exudate (2). Conclusions: Although parapneumonic effusion in dogs with a presumptive diagnosis of bacterial pneumonia appears to be rather common (33.8%), thoracocentesis or chest tube placement was rarely performed. Furthermore, the outcome of dogs with and without parapneumonic effusion appears to be similar.

Measurement of lactate in pleural fluid rapidly identify infection and guide therapy.

BACKGROUND: Measurements of pleural fluid biomarkers for rapid identification of complicated parapneumonic effusion (CPPE) are crucial for optimal management. Previous studies for biomarker evaluation were however based on pleura culture, not modern DNA technique. Lactate has not been thoroughly studied earlier as a potential biomarker in this regard. OBJECTIVES: To evaluate whether the routine biomarkers pH, glucose, lactate dehydrogenase (LDH) measured in pleural fluid in a microbiological well characterised cohort could differentiate simple parapneumonic effusion (SPPE) from CPPE and if pleural fluid lactate could be of additional use in this discrimination. METHODS: Pleural fluid prospectively collected from adult patients (n = 112) with PPE admitted to the Departments of Infectious Diseases (DIDs) at four Stockholm County hospitals were characterised microbiologically with bacterial culture and 16S rDNA sequencing, and biochemically with pH, glucose, LDH and lactate. RESULTS: Forty and seventy two patients were categorised as SPPE/CPPE. The median values between SPPE/CPPE differed significantly for all biomarkers with varying overlap. Receiver operating characteristics (ROC) curves showed the area under the curve (AUC) for pH 0.905 (CI 0.847-0.963), glucose 0.861 (CI 0.79-0.932), LDH 0.917 (CI 0.860-0.974) and lactate 0.927 (CI 0.877-0.977), corresponding to best cut-off levels and sensitivity/specificity for pH of 7.255, 0.819/0.9, glucose 5.35 mmol/L, 0.847/0.775, LDH 9.8 µcat/L, 0.905/0.825 and lactate 4.9 mmol/L, 0.875/0.85. CONCLUSIONS: To distinguish between SPPE/CPPE, pH and LDH performed well, but optimal cut-off values differed from earlier established recommendations. Pleura lactate had the largest AUC of the investigated biomarkers and may be used in the analyses of PPE-staging.