Parapneumonic pleural effusions and empyema in adults: current practice

Benefit of intrapleural fibrinolytic therapy in the treatment of complicated parapneumonic effusion and empyema

Our study aimed to assess the benefit of intrapleural fibrinolysis before resorting to surgery to treat complicated parapneumonic effusion and empyema. We conducted a retrospective and descriptive study, including all patients hospitalized in the intensive care unit (ICU) of the Abderhaman Mami hospital, Tunisia for empyema treated with instillation of intrapleural fibrinolytic therapy between the 1st January 2000 and 31st December 2016. In all patients, empyema was diagnosed on clinical features, imaging findings (chest X-ray, thoracic echography and/or computed tomography (CT), and microbiological data. The fibrinolytic agent used was streptokinase. The efficiency of intrapleural fibrinolytic therapy was judged on clinical and paraclinical results. Among 103 cases of complicated parapneumonic effusion and empyema, 34 patients were included. The mean age was 34 years [15-81] with a male predominance (sex ratio at 2.77). Median APACH II score was 9. Fifty (50%) of the patients (n=17) had no past medical history; addictive behavior was described in 17 patients (50%). All patients were admitted for acute respiratory failure and one patient for septic shock. Pleural effusion was bilateral in 7 patients. Bacteria isolated were Streptococcus pneumonia (6 cases), Staphylococcus aureus (3 cases, including one which methicillin-resistant), Staphylococcus epidermidis (1 case), anaerobes (5 cases), and Klebsiella pneumoniae (1 case). First-line antimicrobial drug therapy was amoxicillin-clavulanate in 20 patients. A chest drain was placed in all cases in the first 38 hours of ICU admission. The median number of fibrinolysis sessions was 4 [2-9] and the median term of drainage was 7 days [3-16]. No side effects were observed. Video-assisted thoracoscopic surgery was proposed in 5 patients. The median length of hospitalization stay was 15 days [6-31]. One patient died due to multi-organ failure.

Differential Diagnosis of Pleural Effusion Using Machine Learning

Rationale: Differential diagnosis of pleural effusion is challenging in clinical practice. Objectives: We aimed to develop a machine learning model to classify the five common causes of pleural effusions. Methods: This retrospective study collected 49 features from clinical information, blood, and pleural fluid of adult patients who underwent diagnostic thoracentesis between October 2013 and December 2018. Pleural effusions were classified into the following five categories: transudative, malignant, parapneumonic, tuberculous, and other. The performance of five different classifiers, including multinomial logistic regression, support vector machine, random forest, extreme gradient boosting, and light gradient boosting machine (LGB), was evaluated in terms of accuracy and area under the receiver operating characteristic curve through fivefold cross-validation. Hybrid feature selection was applied to determine the most relevant features for classifying pleural effusion. Results: We analyzed 2,253 patients (training set, n = 1,459; validation set, n = 365; extra-validation set, n = 429) and found that the LGB model achieved the best performance in both validation and extra-validation sets. After feature selection, the accuracy of the LGB model with the selected 18 features was equivalent to that with all 49 features (mean ± standard deviation): 0.818 ± 0.012 and 0.777 ± 0.007 in the validation and extra-validation sets, respectively. The model's mean area under the receiver operating characteristic curve was as high as 0.930 ± 0.042 and 0.916 ± 0.044 in the validation and extra-validation sets, respectively. In our model, pleural lactate dehydrogenase, protein, and adenosine deaminase levels were the most important factors for classifying pleural effusions. Conclusions: Our LGB model showed satisfactory performance for differential diagnosis of the common causes of pleural effusions. This model could provide clinicians with valuable information regarding the major differential diagnoses of pleural diseases.

Application of Adenosine Deaminase and γ-Interferon Release Assay in Pleural Fluid for the Diagnosis of Tuberculous Pleural Effusion in Patients Over 40 Years Old

Background

In patients with tuberculous pleural effusion (TPE) of various ages, the diagnostic accuracy of pleural biomarkers varies, and there are insufficient studies specifically in different age groups. Therefore, we investigated the adenosine deaminase cut-off value and its combination with the gamma interferon release assay for the diagnosis of TPE among patients aged ≥40 years.

Methods

A retrospective analysis of 198 patients who underwent medical thoracoscopy and were admitted to the hospital between 2015 and 2020 with exudative pleural effusion and either fever, night sweats, fatigue, cough, or other clinical manifestations was performed. The medical thoracoscopy, ADA, and T-SPOT results were analysed in the pleural fluid. The patients were divided into groups based on age: 18-39, 40-59, and 60-87.

Results

The best cut-off values of ADA were 29.5, 31.5 and 19.5 U/L, respectively, for the aged 18-39, aged 40-87 and aged 60-87 groups. The accuracy of 31.5 U/L was higher than 40 U/L for aged ≥40 years (86 vs 83%). The ADA diagnostic accuracy was higher than that of people under 40 years (83 vs 77%) when cut-off value of ADA was 40 U/L, but the IGRA accuracy was lower than that of people under 40 (87 vs 91%). The sensitivity of ADA or IGRA detection in patients over 40 years was 99%, and the specificity was 78%. The ADA specificity combined with IGRA for TPE was the highest (100%) in the ≥40 age group, and the sensitivity was 69%.

Conclusion

Our study revealed the best cut-off values of ADA for TBE in different age groups. Combining ADA and IGRA in pleural fluid improves the detection rate of TPE in patients over 40 years of age with exudative pleural effusion. ADA combined with IGRA increases specificity, and ADA or IGRA increases sensitivity substantially.

Pleural empyema secondary to nephropleural fistula in complicated pyonephrosis

Pleural empyema of extra pulmonary origin is uncommon and empyema secondary to a fistula between the urinary tract and thorax is extremely rare. We report a case of nephropleural fistula causing massive pleural empyema in a 64-year-old woman with a long history of urological problems, including nephrolitiasis and urinary tract infection. She was admitted with sepsis, fever, chills, tachypnea, productive cough and pyuria. At clinical examination, breath sounds were reduced over the left hemithorax. CT revealed a fistulous connection from the upper left calyceal group and the pleural space. Drainage of thoracic and perinephric collection was carried out, but nephrectomy and pleural decortication were required due to haemopurulent urine and decreased hemoglobin levels during the hospitalization. This case demonstrates the unusual and prolonged evolution of an obstructive hydroureteronephrosis complicated by pyonephrosis, culminating in retroperitoneal abscess that fistulized into the pleural space, leading to empyema.

A review of the management of complex para-pneumonic effusion in adults

A complex para-pneumonic effusion is a descriptive term for exudative effusions, which complicate or are likely to complicate the anatomy of the pleural space after pneumonia. We performed an online search was performed using the resources PubMed and Google Scholar to provide an update on the management of such effusions based on review of published literature. Search terms including pleural effusion (PE), parapneumonic effusion, and empyema were used. Relevant studies were identified and original articles were studied, compared and summarized. References in these articles were examined for relevance and included where appropriate. Studies involving pediatric patients were excluded. Management of para-pneumonic PE has changed tremendously over the last decade. As we accumulate more evidence in this area, approach to pleural fluid drainage is becoming more specific and guideline based. An example of a practice changing study in this aspect is the Multi-center Intrapleural Streptokinase Trial (MIST) 2 trial which demonstrated that a combination of intra-pleural tPA and DNAse improved outcomes in pleural infections compared to DNase or t-PA alone. More randomized control trials are needed to describe the role of surgical techniques like VATS (video-assisted thoracoscopic surgery) when MIST 2 protocol fails; this combination has revolutionized the management of empyema in recently.

Factors influencing pleural drainage in parapneumonic effusions

OBJECTIVE

The identification of parapneumonic effusions (PPE) requiring pleural drainage is challenging. We aimed to determine the diagnostic accuracy of radiological and pleural fluid findings in discriminating between PPE that need drainage (complicated PPE (CPPE)) and those that could be resolved with antibiotics only (uncomplicated PPE (UPPE)).

SUBJECTS AND METHODS

A retrospective review of 641 consecutive PPE, of which 393 were categorized as CPPE and 248 as UPPE. Demographics, radiological (size and laterality on a chest radiograph) and pleural fluid parameters (pus, bacterial cultures, biochemistries) were compared among groups. Logistic regression was performed to determine variables useful for predicting chest drainage, and receiver-operating characteristic curves assisted in the selection of the best cutoff values.

RESULTS

According to the likelihood ratios (LR), findings increasing the probability of chest tube usage the most were: effusions occupying ≥1/2 of the hemithorax (LR 13.5), pleural fluid pH ≤7.15 (LR 6.2), pleural fluid glucose ≤40mg/dL (LR 5.6), pus (LR 4.8), positive pleural fluid cultures (LR 3.6), and pleural fluid lactate dehydrogenase >2000U/L (LR 3.4). In the logistic regression analysis only the first two were selected as significant predictors of CPPE. In non-purulent effusions, the effusion's size and pleural fluid pH retained their discriminatory properties, in addition to a pleural fluid C-reactive protein (CRP) level >100mg/L.

CONCLUSION

Large radiological effusions and a pleural fluid pH ≤7.15 were the best predictors for chest drainage in patients with PPE. In the subgroup of patients with non-purulent effusions, pleural fluid CRP also contributed to CPPE identification.

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.

Emergencies in pleural diseases

A parapneumonic effusion should be drained if it is large (≥ 1/2 of the hemithorax), loculated, frank pus is obtained, if the fluid is non-purulent fluid but has a low pH (< 7.20) or if the culture is positive. Instillation of fibrinolytics and DNase thorough the chest catheter in locutated effusions and empyemas is currently recommended. Management of spontaneous pneumothorax is fundamentally influenced by the patient's symptoms. Insertion of a chest catheter is mandatory if there is significant dyspnea, hemodynamic instability or large pneumothoraces (≥ 2 cm). Pleural ultrasonography confirms the presence of air or fluid in the pleural space and serves to guide any pleural procedure (e.g., thoracentesis, chest tubes). The use of small-bore 12F catheters inserted via the percutaneous Seldinger technique under ultrasonography guidance is a safe and effective procedure in complicated parapneumonic effusions/empyema and most pneumothoraces.

[Aetiology and diagnosis of community acquired pneumonia and its complicated forms]

Community Acquired Pneumonia (CAP) is a common childhood disease, involving several paediatric subspecialties in its diagnosis and treatment. This has prompted the Spanish Society of Paediatric Pulmonology (SENP) and the Spanish Society of Paediatric Infectious Diseases (SEIP) to prepare a consensus document on the diagnosis of CAP, assessing the practical aspects by means of evidence-based medicine. It discusses the aetiology and epidemiology, with the current changes and the validity of certain laboratory tests, such as acute phase reactants, microbiological and imaging techniques, guiding the paediatricians in the real value of these tests.