Pleural Fluid Parameters Research Articles

Comparison of Pleural Fluid Adenosine Deaminase with the Lactate Dehydrogenase/Adenosine Deaminase Ratio in Differentiating Tubercular Pleural Effusion from Non-tubercular Effusion

Abstract Background: Pleural effusions are caused by various conditions, including tuberculosis and malignancies. Accurate differentiation between tuberculous pleural effusion (TPE) and non-tuberculous pleural effusion (NTPE) is crucial for effective treatment outcomes. While adenosine deaminase (ADA) levels are commonly used in diagnosing TPE, the pleural fluid LDH-to-ADA ratio is a potentially more accurate diagnostic marker. Objective: To evaluate the effectiveness of the LDH-to-ADA ratio in distinguishing between TPE and NTPE, especially in cases of increased ADA levels. Materials and Methods: This retrospective study included 80 patients who underwent their first thoracentesis with a pleural fluid ADA level of 40 IU/L or higher. Patients were categorized into TPE (n = 40) and NTPE (n = 40) groups based on clinical, radiological, and laboratory findings. Pleural fluid parameters, including LDH and ADA levels, were analyzed. Receiver operating characteristic (ROC) curve analysis was conducted to determine the diagnostic accuracy of the LDH-to-ADA ratio, with cut-off values assessed for the sensitivity and specificity. Odds ratios were calculated to evaluate the association between the LDH-to-ADA ratio and pleural effusion types. Results: ROC analysis demonstrated that the pleural fluid LDH-to-ADA ratio in comparison to the ADA levels was superior in identifying TPE, with an AUC of 0.86 (sensitivity: 75%; specificity: 90.1%), and for NTPE, with an AUC of 0.90 (sensitivity: 80%; specificity: 77.9%). The LDH-to-ADA ratio provided a strong correlation with TPE and NTPE, confirmed by both crude and adjusted odds ratios, respectively. Conclusion: The pleural fluid LDH-to-ADA ratio is a highly effective diagnostic tool for distinguishing between TPE and NTPE. It offers superior diagnostic performance compared to ADA levels alone, with well-defined cut off values enhancing its utility in clinical practice for accurate diagnosis and management of pleural effusions.

CANCER RATIO-BASED DIAGNOSTIC TOOL IN IDENTIFYING MALIGNANT PLEURAL EFFUSION: SENSITIVITY, SPECIFICITY AND CLINICAL INSIGHTS

Background: Malignant pleural effusion (MPE) is a common cause of exudative lymphocytic pleural effusion. Although pleural fluid evaluation is routinely performed, cytology or histopathology remains the gold standard for MPE diagnosis. The cancer ratio (CR), calculated by comparing serum LDH to pleural fluid ADA levels, has shown promise in diagnosing MPE. However, no studies have investigated its utility in the Thai population, which has a high tuberculosis prevalence.
 Objectives: This study aimed to evaluate the diagnostic accuracy of the CR in MPE diagnosis, compare clinical and pleural fluid parameters between MPE and nonMPE cases, determine the appropriate CR cut-off for the Thai population and develop a prediction score for prediagnosing MPE.
 Results: Between July 2021 and December 2022, patients presenting exudative lymphocytic pleural effusion were included in the study. Demographics, symptoms, radiographic findings and pleural fluid parameters were collected and cytology/histopathology served as the reference test. CR performance was assessed using receiver operating characteristic curves, and a prediction score was developed using multivariable logistic regression analysis. Among 122 patients, 46.7% received a diagnosis of MPE. The CR exhibited a sensitivity of 87.7% and specificity of 72.3% (AUC 0.83) with a cut-off level >10. Patients with MPE showed longer symptom duration, lower fever and massive pleural effusion, which were more common in MPE than nonMPE cases. A prediction score incorporating symptom duration, fever history, effusion amount and CR demonstrated superior diagnostic performance for MPE (AUC 0.94) compared with the CR alone.
 Conclusion: The CR can effectively differentiate MPE from nonMPE among patients with exudative lymphocytic pleural effusion. A cut-off level >10 is recommended for diagnosing MPE in the Thai population. Combining clinical, radiologic and CR data may aid in prediagnosing MPE; however, further research is needed for validation.

Diagnostic value of pleural C-reactive protein levels in assessing severity of pediatric parapneumonic effusions

The immediate determination of complicated parapneumonic effusion is featured by instant remedial advantages. Consequently, we attempted to evaluate whether C-reactive protein (CRP) in pleural fluid can ameliorate the identification of cases with parapneumonic effusions that eventually require intervention. Patients and methods. A case-control study enrolled 43 patients with parapneumonic effusions from the inpatient ward and emergency room of Ain Shams Pediatric University Hospital, Egypt. Twenty of those patients had complicated effusions (complicated parapneumonic pleural effusion, CPPE), and 23 had uncomplicated parapneumonic pleural effusions (UCPPE). The differentiation characteristics of pleural fluid biochemical parameters as well as pleural CRP were estimated. Pleural fluid parameters were applied to classify cases of CPPE or UCPPE. ROC analysis established CRP setting to distinguish between both groups. Results. Pleural CRP was significantly higher in CPPE and empyema (48.97 mg/L) than in UCPPE (7.75 mg/L). The optimal cut-off point between CPPE and UCPPE in relation to pleural CRP was found to be 12.26 mg/L with a sensitivity of 95.00%, specificity of 95.65%, and AUC of 94.8%. Conclusion. Pleural fluid CRP can indeed be a beneficial spare test in pleural effusions and contribute to the differential diagnosis of CPPE and UCPPE. Key words: parapneumonic effusion, empyema, pleural CRP, pediatrics

CHARACTERIZATION OF ABNORMAL CELL DIFFERENTIAL IN THORACENTESIS FOR MALIGNANT PLEURAL EFFUSIONS

SESSION TITLE: Wednesday Abstract Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM PURPOSE: Malignancy is the second leading cause of pleural effusions in the US1 and account for approximately 125,000 hospital admissions per year2. Malignant pleural effusions are often diagnosed by cytology, but the turnaround time can be several days. Pleural fluid cell count differential is a routine part of pleural fluid analysis; results are obtained within a few hours, giving the clinician the opportunity to make patient care decisions before the definitive diagnosis is made. Pleural fluid cell differentials are typically obtained with automated cell counters, these counters cannot identify malignant cells. However, the presence of non-classifiable “other cells” may suggest a malignant diagnosis. METHODS: We performed a retrospective review of our institution’s internal database (Clinical Query 2) including all patients that underwent diagnostic and/or therapeutic thoracentesis from January 2016 to December 2018. Pleural fluid analysis and pleural fluid cytology were reviewed for all patients. Two groups were created based on the presence of “other cells” in the pleural fluid cell count differential. Atypical but non-diagnostic cytology was considered negative. A logarithmic regression analysis including the variables sex, active malignancy, heart failure, presence of other cells, exudate and glucose was performed. RESULTS: A total of 100 patients were included. The group of patients with “other cells” in pleural fluid had a total of 52 patients, within these patients, 28 had pleural fluid cytology positive for malignancy. The most common comorbidities were active malignancy, heart failure, chronic kidney disease and cirrhosis. The median time to obtain a cytology results was similar in both groups (3 vs 2.5 days). When pleural fluid parameters were compared between groups, it could be seen that the “other cells” group had a higher total number of cells (1243 vs 767.5, p=0.03), higher total protein (435 g/dL vs 355 g/dL, p<0.01), lower glucose levels (104 mg/dL vs 113.5 mg/dL, p=0.02), higher LDH (199 IU/L vs 150 IU/L, p=0.01), higher albumin (2.75 g/dL vs 2.1 g/dL, p<0.01) and higher cholesterol (81 mg/dL vs 53 mg/dL, p<0.01). Pleural fluid containing “other cells” was more likely to be exudative (43 vs 31, p=0.04); but more importantly a higher number of samples had malignant cytology (28 vs 4, p <0.01). When “other cells” are present in pleural fluid, the odds ratio for a malignant cytology result is 5.79 times higher than when these cells are absent (p= 0.01, CI=1.38-24.28). CONCLUSIONS: The presence of “other cells” in pleural fluid cell count differential increases the probability of a positive pleural fluid cytology for malignancy. CLINICAL IMPLICATIONS: This often-discarded value of the pleural fluid analysis holds potential as a screening tool for malignant pleural effusions. DISCLOSURES: Consultant relationship with Boston Scientific Please note: $1001 - $5000 Added 03/15/2019 by Alex Chee, source=Web Response, value=Consulting fee Consultant relationship with Boston Scientific Please note: $1001 - $5000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with olympus Please note: $5001 - $20000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with pinacle biologics Please note: $1001 - $5000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with cook medical Please note: $1001 - $5000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee No relevant relationships by Daniel Ospina-Delgado, source=Web Response No relevant relationships by Mihir Parikh, source=Web Response

The Combined Use of Pleural Fluid Parameters Improves Diagnostic Accuracy in Complicated Pleural Infection/Empyema

Abstract Introduction Identifying infectious pleural effusions (IPE) that will progress to complicated infection or empyema is challenging. The purpose of this study was to determine whether a model based on multiple biochemical parameters in pleural fluid can predict which IPEs will produce empyema. Methods A prospective study was performed of all cases of IPEs treated in our unit. IPEs were classified as uncomplicated or complicated (empyema). Logistic regression was used to estimate the risk for complicated pleural infection (empyema). A predictive model was developed using biochemical parameters in pleural fluid. Discriminatory power (areas under the ROC curve), calibration, and diagnostic accuracy of the model were assessed. Results A total of 177 patients were included in the study (74 with uncomplicated infectious pleural effusion, and 103 with complicated pleural effusion/empyema). The area under the curve (AUC) for the model (pH, lactate dehydrogenase and interleukin 6) was 0.9783, which is significantly superior to the AUC of the individual biochemical parameters alone (0.921, 0.949, and 0.837, respectively; P Conclusion The multiple-marker model showed better diagnostic performance for predicting complicated infectious pleural effusion (empyema) compared to individual parameters alone.

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)).

Factors influencing pleural drainage in parapneumonic effusions

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)). 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. 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. 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.

Ultrasound guided pleural biopsy in undiagnosed exudative pleural effusion patients

Abstract Introduction Pleural biopsy for pathological confirmation is the standard diagnostic procedure for pleural diseases, transthoracic ultrasonography (TUS) has evolved as an important imaging tool for diagnosing pleural and pulmonary conditions. Aim of the study To assess the diagnostic yield of TUS guided pleural biopsy versus both CT guided and thoracoscopic pleural biopsy in the diagnosis of undiagnosed exudative pleural effusion. Patients and methods The study was conducted at chest department, Zagazig University Hospitals. The study included 60 patients with undiagnosed exudative pleural effusion. They were assigned randomly (by systematic randomization) after signing an informed consent into three groups according to the method by which pleural biopsy was obtained (Group A, TUS guided biopsy group, Group B, CT guided pleural biopsy, Group C, MT pleural biopsy) each included 20 patients. Results The mean age of the studied patients was 52 ± 10.3 years; they were 27 females and 33 males with no statistical significance. There was no statistical significance between the 3 studied groups regarding, co-morbidities, side of effusion, smoking pattern, and pleural fluid parameters except pleural fluid WBCs (was higher in group B). Malignancy was the most common etiology in 48/60 patients (80%). The diagnostic yield of TUS guided pleural biopsy was 80% versus 85% for CT guided pleural biopsy and 92.5% for thoracoscopic pleural biopsy. Reported complications were (for TUS guided pleural biopsy were; pain in 90% of patients, pneumothorax 5%, hemoptysis 35%, biopsy site bleeding 20% and shock in 15%), (for CT guided biopsy; pain in 100% of patients, pneumothorax 15%, hemoptysis 50%, biopsy site bleeding 60% and shock in 10%), and (for medical thoracoscopy; intra-operative bleeding 3.7%, broncho-pleural fistula 7.4%, failure of lung expansion 14.8%, surgical emphysema 18.5%, post-operative empyema 3.7%). MT was superior in the detection of pleural septations and visceral pleural nodules; the incidence of complication was correlated to the length of the procedure time in MT group. In conclusion Thoracic ultrasound (TUS) guided pleural biopsy had a diagnostic yield which was slightly lower but comparable to both CT guided pleural biopsy and medical thoracoscopic pleural biopsy (MT).

Bacterial Infection Elicits Heat Shock Protein 72 Release from Pleural Mesothelial Cells

Heat shock protein 70 (HSP70) has been implicated in infection-related processes and has been found in body fluids during infection. This study aimed to determine whether pleural mesothelial cells release HSP70 in response to bacterial infection in vitro and in mouse models of serosal infection. In addition, the in vitro cytokine effects of the HSP70 isoform, Hsp72, on mesothelial cells were examined. Further, Hsp72 was measured in human pleural effusions and levels compared between non-infectious and infectious patients to determine the diagnostic accuracy of pleural fluid Hsp72 compared to traditional pleural fluid parameters. We showed that mesothelial release of Hsp72 was significantly raised when cells were treated with live and heat-killed Streptococcus pneumoniae. In mice, intraperitoneal injection of S. pneumoniae stimulated a 2-fold increase in Hsp72 levels in peritoneal lavage (p<0.01). Extracellular Hsp72 did not induce or inhibit mediator release from cultured mesothelial cells. Hsp72 levels were significantly higher in effusions of infectious origin compared to non-infectious effusions (p<0.05). The data establish that pleural mesothelial cells can release Hsp72 in response to bacterial infection and levels are raised in infectious pleural effusions. The biological role of HSP70 in pleural infection warrants exploration.

Pleural Fluid Analysis and Radiographic, Sonographic, and Echocardiographic Characteristics of Hepatic Hydrothorax

There are limited published data defining complete pleural fluid analysis, echocardiographic characteristics, or the presence or absence of ascites on sonographic or CT imaging in patients with hepatic hydrothorax. We reviewed pleural fluid analysis and radiographic, sonographic, and echocardiographic findings in 41 consecutive patients with hepatic hydrothorax referred to the Pleural Procedure Service for thoracentesis. Ascites was detected on sonographic or CT imaging in 38 of 39 patients (97%). Diastolic dysfunction was found in 11 of 21 patients (52%). Contrast echocardiography with agitated saline demonstrated an intrapulmonary shunt in 18 of 23 cases (78%). Solitary hepatic hydrothorax had a median pleural fluid pH of 7.49 (fifth to 95th percentile, 7.40-7.57), total protein level of 1.5 g/dL (0.58-2.34), and lactate dehydrogenase (LDH) level of 65 IU/L (36-138). The median pleural fluid/serum protein ratio and pleural LDH/upper limit of normal serum LDH ratio were 0.25 (0.10-0.43) and 0.27 (0.14-0.57), respectively. The median absolute neutrophil count (ANC) was 26 cells/μL (1-230). Only a single patient had a protein discordant exudate despite 83% of patients receiving diuretics. When comparing solitary hepatic hydrothorax and spontaneous bacterial pleuritis, there was no statistically significant difference among pleural fluid total protein (P = .99), LDH (P = .33), and serum albumin (P = .47). ANC was higher in patients with spontaneous bacterial pleuritis (P < .0001). Hepatic hydrothorax virtually always presents with ascites that is detectable on sonographic or CT imaging. The development of an "exudate" from diuretic therapy is a rare phenomenon in hepatic hydrothorax. In contrast, diastolic dysfunction and intrapulmonary shunting are common in patients with hepatic hydrothorax. There was no statistically significant change in pleural fluid parameters with spontaneous bacterial pleuritis, except an increased ANC.

Update on uncommon pleural effusions

Although infections, malignancies and heart failure are responsible for the majority of pleural effusions, there are many other causes and several uncommon but distinctive types of pleural fluid. For this update we have chosen several uncommon forms of pleural effusions or disorders in which there have been recent advances in our understanding over the past several years. Chylothorax, pseudochylothorax and urinothorax are associated with characteristic clinical contexts and pleural fluid parameters but are likely underdiagnosed. Yellow nail syndrome is a rare disorder that can be associated with chylothorax and manifests multisystem features. Recognition of these entities is important because each of these disorders is associated with distinctive aetiology and management modalities. Correct diagnosis depends on the clinician's awareness of the clinical contexts and manifestations along with diagnostic pleural fluid findings in these disorders.

Comparative proteomic studies of plasma from children with pneumococcal pneumonia

Streptococcus pneumoniae is the primary pathogen causing community acquired pneumonia in children. Despite medical progress, the prevalence of complicated pneumococcal pneumonia became increased without apparent explanations. Two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were used to compare the plasma protein profiles from children with different severities of pneumococcal pneumonia. Plasma samples from 14 cases, 7 with complicated and the other 7 with uncomplicated pneumonia, were analyzed. Complicated pneumonia was defined by the presence of pleural fluid parameters consistent with empyema, and/or a computed tomography compatible with necrotizing pneumonitis. The normal control group included 7 age-matched volunteers. By comparing the plasma proteins of patients with different severities, 4 proteins with significant differences were identified. The up-regulated proteins were haptoglobin and immunoglobulin kappa chain. The down-regulated were apolipoprotein A-I (Apo-AI) and transthyretin. All these proteins are known to take part in the inflammation reaction, which implicates the active innate immune responses in severe infections of S. pneumoniae. In addition, the up-regulated haptoglobin, which protects lung tissues against oxidative damage by the clearance of hemoglobin, can also act as an inflammatory inhibitor. Thus, our data seem to indicate that inflammation balance may take place in the occurrence of complicated pneumococcal pneumonia.

Diagnosis and Management of Parapneumonic Effusions

Parapneumonic effusions affect many patients and are associated with considerable morbidity and mortality. It is necessary to differentiate complicated effusions requiring intervention from uncomplicated effusions. Differentiation is achieved using clinical, pleural fluid, and imaging parameters. Intervention takes the form of blind catheter placement and drainage, image-guided catheter placement and drainage, and surgical decortication [video-assisted thoracoscopic surgery (VATS) or open thoracotomy]. Image-guided drainage and management of complicated effusions in adults and pediatric patients are safe and highly effective in select patients. The use of intrapleural fibrinolytic agents to facilitate resolution of complicated effusions is widespread and considered effective by many despite a lack of conclusive data supporting this method. We propose an algorithmic approach to patients with parapneumonic effusions and advocate image-guided drainage and management in patients likely to benefit from this treatment.

Intrapleural heparin or heparin combined with human recombinant DNase is not effective in the treatment of empyema in a rabbit model

The aim of this study was to investigate the effectiveness of intrapleural heparin or heparin combined with human recombinant DNase in the treatment of empyema. Empyema was induced in rabbits with an intrapleural injection of 10(9)Pasteurella multicoda organisms in infusion agar via a surgically placed chest tube. Once empyema was verified, a blinded investigator administered drugs via the chest tube. There were three treatment groups each with six rabbits. One group was given 1000 IU heparin, a second group was given 1000 IU heparin plus 1 mg of human recombinant DNase via chest tube and the control group received saline. The rabbits received treatment every 12 h for a total of six treatments and the volume of each treatment was 3 mL. The animals were sacrificed at day 10 and the amount of empyema and pleural thickening was scored macroscopically on a scale of 0-6. The total volume of pleural effusion aspirated was significantly higher in the heparin group (25.8+/-10.7 mL) compared with either saline (8+/-8.9) or heparin plus human recombinant DNase (6.8+/-6.1) groups (P=0.003). The mean empyema and pleural thickening scores did not differ significantly between the groups (P=0.8, P=0.5 respectively). A weak correlation was found between total volume of aspirated pleural fluid and pleural parameters of white blood cell counts and LDH levels (r=0.546 and P=0.02, r=0.631 and P=0.02 respectively). The intrapleural administration of 1000 IU heparin alone or in combination with 1 mg of human recombinant DNase is no more effective than saline in the treatment of empyema in rabbits. Intrapleural heparin significantly increased the drainage of pleural fluid compared with the combination and saline group.

Routine use of pleural fluid cultures. Are they indicated?: Limited yield, minimal impact on treatment decisions

In pleural infection, it has been recommended that Gram stain and cultures should be obtained on a routine basis. However, this recommendation has not been tested prospectively. We evaluated the yield of microbiological studies in 259 patients with parapneumonic pleural effusion. Microbiological studies were positive on the pleural fluid of 50 patients (19.3%). In 48 of the 50 patients with positive microbiological results (96%), the need for pleural drainage was correctly predicted by pleural fluid parameters. There were no differences in hospital stay (9.5+/-2.5 days versus 9.9+/-3.2 days, P=0.68) or in mortality (2 deaths in each group, P=0.58) between the group of patients in which antibiotic treatment was changed according to microbiological results and the group of patients in which it is not. In conclusion, this study demonstrates that, at least in our institution, routine microbial investigation of pleural fluid adds very little to the standard management of parapneumonic effusions.

Revaluación del método estándar (criterios de Light) para identificar exudados pleurales

Light's criteria remain the best method for separating pleural exudates from transudates. We assessed their operating characteristics, as well as those resulting from omitting the pleural fluid to serum lactate dehydrogenase (LDH) ratio from the original criteria (abbreviated Light criteria), in a large series of patients. We also searched for the best combination of pleural fluid parameters, including protein, LDH and cholesterol that identify exudates. We conducted a retrospective study of 1,490 consecutive patients with pleural effusion who underwent a diagnostic thoracentesis. There were 1,192 exudates and 298 transudates. Sensitivity, specificity, area under ROC curve, and odds ratio for both individual and combined pleural fluid parameters were calculated. Light's criteria yielded 97.5% sensitivity and 80% specificity. Both abbreviated Light criteria (sensitivity: 95.4%; specificity: 83.3%) and the combined use in an "or" rule of pleural fluid protein and LDH (sensitivity: 95.4%; specificity: 80,2%) had similar discriminative properties than standard criteria. Diagnostic separation of pleural effusions into exudates or transudates can be done effectively thorough the abbreviated Light criteria when the serum LDH value is not available. On the other hand, if venipuncture wants to be avoided (an unusual circumstance) the combination of pleural fluid protein and LDH represents an alternative to Light's criteria.

Usefulness of the British Thoracic Society and the American College of Chest Physicians guidelines in predicting pleural drainage of non-purulent parapneumonic effusions

To assess the value of the British Thoracic Society (BTS) and the American College of Chest Physicians (ACCP) guidelines to predict which patients with non-purulent parapneumonic effusions (PPE) warrant chest tube drainage. A retrospective chart review was performed on all patients who underwent thoracentesis because of a PPE over a 10-year period at a Spanish medical center. Classification of PPE as complicated (CPPE) or uncomplicated (UPPE) was based on the clinician's decision to insert a chest tube to resolve the effusion. Empyema was defined as pus in the pleural space. Data collected included patient demographics, size of the effusion, and microbiological and pleural fluid chemistries that might influence the physician's decision to place a chest tube. Of the 240 patients with PPE who entered the study, 85 had UPPE, 67 had CPPE, and 88 had empyema. Individual pleural fluid parameters, namely a pH<7.20, a glucose<40 mg/dL or <60 mg/dL, a LDH>1000 U/L or a positive culture had a relatively high specificity (from 78% for LDH to 94% for glucose<40 mg/dL), but low to moderate sensitivity (from 25% for culture to 73% for LDH) in predicting the need for chest tube placement in non-purulent PPE. While pleural fluid cultures performed poorly in discriminating UPPE from CPPE (likelihood ratio positive 1.7), effusion's size performed the best (likelihood ratio positive 5.7). BTS and ACCP guidelines yielded measures of sensitivity (98% and 97%, respectively), and negative likelihood ratio (0.03 and 0.05, respectively) for identifying a CPPE. Both guidelines have similar accuracy and perform satisfactorily in distinguishing CPPE from UPPE, albeit at an admissible cost of needlessly increasing chest tube drainage.

Closed pleural needle biopsy: predicting diagnostic yield by examining pleural fluid parameters

Pleural fluid parameters that predict a diagnostic closed pleural needle biopsy were investigated. A retrospective analysis. The Institute of Pulmonology, Hadassah University Hospital. Forty-four patients who underwent closed pleural needle biopsies were included in this study. Pleural fluid values of protein, glucose, lactate dehydrogenase (LDH), pH, and white blood cell count with differential cell counts, from patients with diagnostic and non-diagnostic pleural biopsies were compared. Thirteen patients (29%) had diagnostic biopsies. Malignancy was identified in 10 patients (23%), of whom 70% had adenocarcinoma. Three other patients had non-malignant specific diagnosis. LDH levels in pleural fluid from patients with diagnostic pleural biopsy were higher than in patients with non-diagnostic pleural biopsies (1436 +/- 333 U l(-1) vs. 775 +/- 109 U l(-1); P < 0.05). LDH levels less than 510 U l(-1) were highly predictive of a negative biopsy (negative predictive value of 86.6%). Follow up revealed malignancy including mesothelioma and lymphoma, in 10 of 30 (33%) patients with non-diagnostic biopsies, and one patient died of unrelated cause, while the pleural effusion either resolved, remained stable or an alternative benign process was identified in 19 patients (63%). Low levels of LDH (< 510 U l(-1)) were highly predictive of a negative pleural needle biopsy. Thus, LDH may serve as a useful guide in deciding whether to perform closed pleural biopsy or to proceed to thoracoscopically guided biopsy.

Derrame pleural y empiema complicado en niños: Evolución y factores pronósticos

Complicated pleural empyema has a torpid and longer clinical evolution, requiring in some patients surgical management. The predictive factors for surgical treatment are not well known. To search for clinical, laboratory or radiological predictors for the requirement of surgical treatment in pediatric patients with empyema. A retrospective review of the charts of 108 patients hospitalized for pneumonia plus pleural effusion at the Pediatric Service of the Catholic University Hospital between January 1985 and July 2000. Eighty one patients had complete radiological evaluation and pleural fluid biochemical analysis. Forty nine (60%) fulfilled the criteria for empyema and 32 (40%) for an exudate. Thirteen patients with empyema required surgery and 36 were treated medically. The mean age was 3 years (range 9 months-6 years) for the surgically treated and 4 years (range 12 months-14 years) for the non-surgical group. The male/female ratio was 5:1 in the surgical group and 1:1 for the non-surgical group. Pleural fluid cultures were positive in 21 of 79 patients. Streptococcus pneumonia was the most frequently isolated agent. No significant differences were found between groups for the average days of fever prior to the diagnosis or total days of fever, days of hospital stay, pleural fluid pH (6.8 and 7.0 respectively) and glucose (21 and 31 mg/dl respectively). No differences were either observed for pleural fluid risk factors (pH < 7 and glucose < 20 mgdl), the presence of extensive pleural effusions, pleural loculations or bands on pleural ultrasonography and positive Gram stain or cultures in the pleural fluid. Surgical patients required oxygen for more days than medical patients (7.7 and 5.1 days; p = 0.037). This study failed to find predictive clinical, radiological or pleural fluid parameters, for the requirement of surgical treatment of empyema.

Tuberculous Pleural Effusion and Tuberculous Empyema

Tuberculous pleuritis has increased worldwide, especially in developing countries, as a consequence of human immunodeficiency virus co-infection. Tuberculous pleuritis is a delayed hypersensitivity reaction against mycobacterial antigens in the pleural space. Mycobacteria are detected in less than 50% of pleural samples, but the characteristic pleural involvement, granulomas with or without caseous necrosis, is evident in 56 to 80% of cases from samples obtained by percutaneous pleural biopsy. Of several pleural fluid parameters studied, adenosine deaminase and interferon gamma (IFN-gamma) have the best diagnostic yield, while polymerase chain reaction remains a promising test. Treatment of patients with tuberculous pleuritis is discussed. Tuberculous empyema is a rare form of tuberculous pleuritis. It consists of a purulent infection of the pleural cavity with detectable bacilli in pleural fluid. Diagnosis is easily established clinically and bacteriologically. Treatment is to adequately drain the pleural space and achieve lung reexpansion, in conjunction with antituberculous chemotherapy. The efficacy of different surgical techniques is discussed.