Characteristics of Patients with Lymphangioleiomyomatosis and Pleural Effusion: A Systematic Review.

The characteristics of patients with lymphangioleiomyomatosis (LAM) are poorly defined, as they may present with or without pleural effusion (PE). We performed a systematic review across four electronic databases searching for studies reporting clinical findings, PE characteristics, and the most effective treatment of LAM. Case descriptions and retrospective studies were included, unrestricted by year of publication. The review consisted of 94 studies (199 patients) spanning a period of nearly 55 years. The median age was 38 years (range: 1 month to 69 years), and 79.7% were between 21 and 50 years old. All cases had dyspnea, 95% had a cough, and 87.5% had chest pain. PE was exudative chylothorax, usually unilateral (76%) and right-sided, predominantly lymphocytic, and with proportionately higher levels of proteins than lactate dehydrogenase. Sirolimus was effective in all cases, completely in 87%, and partially in 13%, although the number of patients receiving sirolimus was small. The present study confirmed that LAM and PE mainly occur in women of childbearing age (third to fifth decade of life). PE was usually unilateral and presented as a lymphocyte-predominant chylous exudate. The most effective treatment for PE seems to be sirolimus, although studies with larger series are needed to confirm this.

Characteristics of patients with yellow nail syndrome and pleural effusion.

Yellow nail syndrome (YNS) can be associated with a pleural effusion (PE) but the characteristics of these patients are not well defined. We performed a systematic review across four electronic databases for studies reporting clinical findings, PE characteristics, and most effective treatment of YNS. Case descriptions and retrospective studies were included, unrestricted by year of publication. We reviewed 112 studies (150 patients), spanning a period of nearly 50 years. The male/female ratio was 1.2/1. The median age was 60 years (range: 0-88). Seventy-eight percent were between 41-80 years old. All cases had lymphoedema and 85.6% had yellow nails. PEs were bilateral in 68.3%. The appearance of the fluid was serous in 75.3%, milky in 22.3% and purulent in 3.5%. The PE was an exudate in 94.7% with lymphocytic predominance in 96% with a low count of nucleated cells. In 61 of 66 (92.4%) of patients, pleural fluid protein values were >3 g/dL, and typically higher than pleural fluid LDH. Pleurodesis and decortication/pleurectomy were effective in 81.8% and 88.9% of cases, respectively, in the treatment of symptomatic PEs. The development of YNS and PE occurs between the fifth to eighth decade of life and is associated with lymphoedema. The PE is usually bilateral and behaves as a lymphocyte-predominant exudate. The most effective treatments appear to be pleurodesis and decortication/pleurectomy.

Clinical overview of the physiology and pathophysiology of pleural fluid movement: a narrative review.

In physiological conditions, the pleural space couples the lung with the chest wall and contains a small amount of fluid in continuous turnover. The volume of pleural fluid is the result from the balance between the entry of fluid through the pleural capillaries and drainage by the lymphatics in the most dependent areas of the parietal pleura. Fluid filtration is governed by Starling forces, determined by the hydrostatic and oncotic pressures of the capillaries and the pleural space. The reabsorption rate is 28 times greater than the rate of pleural fluid production. The mesothelial layer of the inner lining of the pleural space is metabolically active and also plays a role in the production and reabsorption of pleural fluid. Pleural effusion occurs when the balance between the amount of fluid that enters the pleural space and the amount that is reabsorbed is disrupted. Alterations in hydrostatic or oncotic pressure produce a transudate, but they do not cause any structural damage to the pleura. In contrast, disturbances in fluid flow (increased filtration or decreased reabsorption) produce an exudate via several mechanisms that cause damage to pleural layers. Thus, cellular processes and the inflammatory and immune reactions they induce determine the composition of pleural fluid. Understanding the underlying pathophysiological processes of pleural effusion, especially cellular processes, can be useful in establishing its aetiology.

[Diabetes and obstructive sleep apnoea: A case-control study]. / Diabetes y apnea obstructiva del sueño. Un estudio de casos y controles.

INTRODUCTION: Obstructive sleep apnoea (OSA) and diabetes mellitus (DM) are very prevalent diseases frequently associated. Their coexistence is independently associated with an increased prevalence of cardiovascular comorbidities. As this association is underdiagnosed, it is necessary to optimise clinical suspicion by studying independent predictors of DM or prediabetes (preDM) in patients with OSA. METHOD: A simple randomised case-control study, matched for sex, body mass index (BMI) and age, aimed to study the association of OSA with DM and preDM and to identify independent predictors for both diseases in people with OSA. RESULTS: We included 208 cases with OSA and 208 controls without OSA. In the former, 18.8% had DM compared to only 10.1% in the latter (P=.00). Prevalence of preDM was 41.8% vs. 10.6%, respectively (P=.00). One hundred and twenty-four cases (59.6%) reported excessive daytime sleepiness (EDS) (Epworth scale, 10.5±3.1) vs. 24.5% of the control group (Epworth scale, 6.6±2.9). Apnoea-hypopnoea index (AHI) and O2 desaturation indices (IDO, CT90 and CT80) were significantly higher in the case group. The risk of MD was related to age, nocturnal hypoxaemia and EDS. The risk of pre-MD was related to BMI and AHI. CONCLUSIONS: OSA is associated with DM and preDM. Age, nocturnal hypoxaemia and EDS are predictors of DM. BMI and AHI are predictors of pre-MD.

Use of mycophenolate mofetil for the treatment of fibrotic hypersensitivity pneumonitis.

INTRODUCTION: The optimal treatment of fibrosing hypersensitivity pneumonitis (fHP) is not well understood. The aim of the study was to obtain information about the usefulness of mycophenolate mofetil (MMF) in its treatment. MATERIAL AND METHODS: Quasi-experimental analysis of patients diagnosed with fHP and treated with MMF for one year, in a single centre. From the start of treatment, data collection was prospective. RESULTS: 73 were included and 58 completed the study. FVC% and DLCO% decreased until starting MMF (year -1 to year 0). After completion of treatment (year 1), FVC% stabilised (p=0.336) and DLCO% improved significantly (p=0.004) compared to year 0. Dyspnoea, number of patients without corticosteroids and mean corticosteroid dose also improved significantly (p<0.001 in all cases). Being male and having a history of tuberculosis were predictors of poor drug response [AUC = 0.89 (95% CI: 0.80-0.98)]. 45 adverse effects were observed in 34 patients (46.6%). In 4 cases (5.5%), the adverse effect was severe and required discontinuation of treatment. CONCLUSIONS: In patients with fHP, MMF improves lung function and dyspnoea and reduces both the number of patients requiring oral corticosteroids and their mean dose in those who completed 1 year of treatment. The model constructed predicts which patients will respond poorly to treatment, with good discriminative ability and only a small percentage of patients will not tolerate treatment. Further prospective, randomised clinical trials are needed to define the role of this treatment in fHP.

Analysis of the quality of e-Consultations in chronic obstructive pulmonary disease.

INTRODUCTION: The quality of e-Consultations in the COPD is unknown. The objectives of this study were (i) to evaluate the quality of referrals; (ii) to define the characteristics of patients referred from Primary Care (PC) to the Unit of Pulmonology; and (iii) to describe differences between accepted and rejected patients. METHODS: A retrospective, observational study of e-Consultations requested by PC for suspected COPD throughout 2022. To quantify the quality of the e-Consultations, an arbitrary scale of 12 variables (score 0-10) was created. RESULTS: In total, 384 e-Consultations were reviewed, of which 167 (43.5 %) resulted in a face-to-face visit, and 217 (56.5 %) were rejected. No differences were observed between the two types of patients, except for confirmations of diagnostic suspicion of COPD [significantly higher in accepted patients (p = 0.042)]; physical examination data of rejected patients (more data provided; p = 0.015); and lung function (significantly better in rejected patients). The mean quality of referrals was acceptable (5.6 ± 2.1 score): 121 (31.3 %) had insufficient quality; 118 (30.5 %) acceptable; 75 (19.4 %) good, and 30 (7.8 %) excellent. Quality was low in half of the variables analyzed (6/12); acceptable in 3, and good in another 3. The capacity of resolution of referrals was good (one e-Consultation) in 199 requests (66.1 %); deficient (two e-Consultations) in 72 (23.9 %), and poor (≥3 e-Consultations) in 30 (10 %). Overdiagnosis was 40.2 % (86/214 e-Consultations). The risk could be classified in 247 patients (64.3 %; 135 low-risk; 90 high-risk). CONCLUSIONS: When adequate information is provided, e-Consultations help identify different levels of severity. However, the quality and capacity of resolution of referrals were suboptimal, with a high percentage of overdiagnoses.

Combining clinical and analytical parameters improves prediction of malignant pleural effusion.

PURPOSE: The usefulness of a panel of tumour markers and clinical-radiological criteria for diagnosing malignant pleural effusion (MPE) is not clearly stated. Our purpose was to assess the performance of those parameters in the diagnosis of MPE. METHODS: Consecutive patients with exudative PE were enrolled and divided into two groups: MPE and non-MPE. Logistic regression analysis was used to estimate the probability of MPE. Four prognostic models were considered: (1) clinical-radiological variables; (2) analytical variables; (3) combination of clinical and analytical variables; and (4) simpler model removing some analytical variables. Calibration and discrimination (receiver operating characteristics curves and AUC) were performed. RESULTS: A total of 491 pleural exudates were included: tuberculous (n = 72), malignant (n = 211), parapneumonic (n = 115), empyemas (n = 32), or miscellaneous (n = 61). The AUC obtained with Model 1 (absence of chest pain and fever and radiological images compatible with malignancy), Model 2 (CEA, NSE, CYFRA 21-1, and TPS), Model 3 (sum of the variables of models 1 and 2), and Model 4 (the variables of model 1 plus CEA) were 0.918, 0.832, 0.952 (all with a P < 0.05), and 0.939 (P < 0.01 compared to models 1 and 2), respectively. The correct classification rate for Models 1, 2, 3, and 4, was 87.2, 79.5, 88.4, and 87.6 %, respectively. CONCLUSIONS: All models analysed had a good diagnostic yield for MPE, being greater in those that combined radiological and analytical criteria. Although Model 3 obtained a higher yield, the simplest model (Model 4) is very attractive due to its simplicity of use in daily practice.

Development of prognostic models to estimate the probability of lung injury one year after COVID-19-related hospitalization-a prospective study.

Background: Long-term effects of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection still under study. The objectives of this study were to identify persistent pulmonary lesions 1 year after coronavirus disease 2019 (COVID-19) hospitalization and assess whether it is possible to estimate the probability that a patient develops these complications in the future. Methods: A prospective study of ≥18 years old patients hospitalized for SARS-COV-2 infection who develop persistent respiratory symptoms, lung function abnormalities or have radiological findings 6-8 weeks after hospital discharge. Logistic regression models were used to identify prognostic factors associated with a higher risk of developing respiratory problems. Models performance was assessed in terms of calibration and discrimination. Results: A total of 233 patients [median age 66 years [interquartile range (IQR): 56, 74]; 138 (59.2%) male] were categorized into two groups based on whether they stayed in the critical care unit (79 cases) or not (154). At the end of follow-up, 179 patients (76.8%) developed persistent respiratory symptoms, and 22 patients (9.4%) showed radiological fibrotic lesions with pulmonary function abnormalities (post-COVID-19 fibrotic pulmonary lesions). Our prognostic models created to predict persistent respiratory symptoms [post-COVID-19 functional status at initial visit (the higher the score, the higher the risk), and history of bronchial asthma] and post-COVID-19 fibrotic pulmonary lesions [female; FVC% (the higher the FVC%, the lower the probability); and critical care unit stay] one year after infection showed good (AUC 0.857; 95% CI: 0.799-0.915) and excellent performance (AUC 0.901; 95% CI: 0.837-0.964), respectively. Conclusions: Constructed models show good performance in identifying patients at risk of developing lung injury one year after COVID-19-related hospitalization.

Response to inhaled ceftazidime in patients with non-cystic fibrosis bronchiectasis and chronic bronchial infection unrelated to Pseudomonas aeruginosa.

INTRODUCTION: Inhaled antibiotics reduce the frequency of exacerbations. The objective was to assess the efficacy of inhaled ceftazidime in patients with non-cystic fibrosis bronchiectasis (NCFB) and concomitant chronic bronchial infection (CBI) caused by potentially pathogenic microorganisms (PPM) other than Pseudomonas aeruginosa (PA). MATERIAL AND METHOD: Quasi-experimental study in 21 patients with exacerbations who developed CBI by a PPM other than PA. RESULTS: Bacterial infection was resolved in 85.7% patients. Rehospitalizations, length of hospital stay, moderate exacerbations and blood levels of CRP decreased significantly. In addition, SGRQ questionnaire also decreased more than 4 points in 57.1% of the patients. CONCLUSION: The results suggest that inhaled ceftazidime in NCFB unrelated to PA is a plausible alternative to the standard therapies used in clinical practice.

Impact of sleep apnoea-hypopnoea syndrome on diabetic neuropathy. A systematic review. / Impacto del síndrome de apnea-hipopnea del sueño en la neuropatía diabética. Revisión sistemática.

INTRODUCTION: Diabetes mellitus and sleep apnoea-hypopnoea syndrome appear to be related, but it is not well defined whether there is an increased risk of peripheral neuropathy in patients with both diseases. For this reason, we conducted a systematic review. METHODS: Bibliographic search in 3 electronic databases using a predefined strategy and the PRISMA methodology. Only original studies (any type of design) published from 2000 onwards in English, French, Portuguese or Spanish were included. A study quality scale was established. RESULTS: Twelve articles were selected, of which six studied type 2 diabetic patients. The overall prevalence of sleep apnoea-hypopnoea syndrome was 43.7% (1,559/3,564 patients). Diabetic neuropathy was more frequent in patients with sleep apnoea-hypopnoea syndrome in nine studies, although significantly only in four (60% vs 27%, P<.001; 64.5% vs 36%, P=.03; 37% vs 23.4%, P<.02; 66.6% vs 0%, P=.007). In one study, diabetic neuropathy was more frequent in patients without sleep apnoea-hypopnoea syndrome (although not statistically significant) and in 2 no comparison was made between patients with/without sleep apnoea/hypopnoea syndrome. CONCLUSIONS: The observed results suggest a relationship between diabetes mellitus and sleep apnoea-hypopnoea syndrome in the occurrence of diabetic neuropathy.

Advances in pleural effusion diagnostics.

Introduction: Pleural effusion is a common clinical problem. Yet, in a significant proportion of patients (~20%), the cause of pleural effusion remains unknown. Understanding the diagnostic value of pleural fluid tests is crucial for the development of accurate diagnostic models.Areas covered: This paper provides an overview of latest advances in the diagnosis of pleural effusion based on the best evidence available.Expert opinion: For pleural fluid tests to have a good diagnostic value, it is necessary that data obtained from clinical history, physical examination, and radiological studies are correctly interpreted. Thoracentesis and pleural biopsy should always be performed under image guidance to improve its diagnostic sensitivity and prevent complications. Nucleic acid amplification tests, pleural tissue cultures, and collection of pleural fluid in blood culture bottles improve the diagnostic yield of pleural fluid cultures. Although undiagnosed pleural effusions generally have a favorable prognosis, follow-up is recommended to prevent the development of a malignant pleural effusion.

Malignant Pleural Effusion: Diagnosis and Management.

Symptomatic malignant pleural effusion is a common clinical problem. This condition is associated with very high mortality, with life expectancy ranging from 3 to 12 months. Studies are contributing evidence on an increasing number of therapeutic options (therapeutic thoracentesis, thoracoscopic pleurodesis or thoracic drainage, indwelling pleural catheter, surgery, or a combination of these therapies). Despite the availability of therapies, the management of malignant pleural effusion is challenging and is mainly focused on the relief of symptoms. The therapy to be administered needs to be designed on a case-by-case basis considering patient's preferences, life expectancy, tumour type, presence of a trapped lung, resources available, and experience of the treating team. At present, the management of malignant pleural effusion has evolved towards less invasive approaches based on ambulatory care. This approach spares the patient the discomfort caused by more invasive interventions and reduces the economic burden of the disease. A review was performed of the diagnosis and the different approaches to the management of malignant pleural effusion, with special emphasis on their indications, usefulness, cost-effectiveness, and complications. Further research is needed to shed light on the current matters of controversy and help establish a standardized, more effective management of this clinical problem.

Identification of Pleural Response Patterns: A Cluster Analysis.

BACKGROUND: Pleural effusion occurs as a response of the pleura to aggressions. The pleura reacts differently according to the type of injury. However, pleural reactions have not yet been characterized. The objective of this study was to identify homogeneous clusters of patients based on the analytical characteristics of their pleural fluid and identify pleural response patterns. METHODS: A prospective study was conducted of consecutive patients seen in our unit for pleural effusion. Principal component and cluster analyses were carried out to identify pleural response patterns based on a combination of pleural fluid biomarkers. RESULTS: A total of 1613 patients were grouped into six clusters, namely: cluster 1 (10.5% of the cohort, primarily composed of patients with malignant pleural effusions); cluster 2 (17.4%, pleural effusions with inflammatory biomarkers); cluster 3 (16.1%, primarily composed of patients with infectious pleural effusions); cluster 4 (2.5%, a subcluster of cluster 3, superinfectious effusions); cluster 5 (23.4%, paucicellular pleural effusions); and cluster 6 (30.1%, miscellaneous). Significant differences were observed across clusters in terms of the analytical characteristics of PF (p<0.001 for all), age (p<0.001), and gender (p=0.016). A direct relationship was found between the type of cluster and the etiology of pleural effusion. CONCLUSION: Pleural response is heterogeneous. The pleura may respond differently to the same etiology or similarly to different etiologies, which hinders diagnosis of pleural effusion.

Development and validation of a clinical score to estimate progression to severe or critical state in COVID-19 pneumonia hospitalized patients.

The prognosis of a patient with COVID-19 pneumonia is uncertain. Our objective was to establish a predictive model of disease progression to facilitate early decision-making. A retrospective study was performed of patients admitted with COVID-19 pneumonia, classified as severe (admission to the intensive care unit, mechanic invasive ventilation, or death) or non-severe. A predictive model based on clinical, laboratory, and radiological parameters was built. The probability of progression to severe disease was estimated by logistic regression analysis. Calibration and discrimination (receiver operating characteristics curves and AUC) were assessed to determine model performance. During the study period 1152 patients presented with SARS-CoV-2 infection, of whom 229 (19.9%) were admitted for pneumonia. During hospitalization, 51 (22.3%) progressed to severe disease, of whom 26 required ICU care (11.4); 17 (7.4%) underwent invasive mechanical ventilation, and 32 (14%) died of any cause. Five predictors determined within 24 h of admission were identified: Diabetes, Age, Lymphocyte count, SaO2, and pH (DALSH score). The prediction model showed a good clinical performance, including discrimination (AUC 0.87 CI 0.81, 0.92) and calibration (Brier score = 0.11). In total, 0%, 12%, and 50% of patients with severity risk scores ≤ 5%, 6-25%, and > 25% exhibited disease progression, respectively. A risk score based on five factors predicts disease progression and facilitates early decision-making according to prognosis.

Influenza A H1N1 Community-Acquired Pneumonia: Characteristics and Risk Factors-A Case-Control Study.

Introduction: Influenza A H1N1 community-acquired pneumonia (CAP) is a quite frequent respiratory disease. Despite being considered more serious than other CAPs, there are very few studies comparing its characteristics with noninfluenza CAP. We aim to establish the differences between pneumonia due to H1N1 virus and pneumonia not caused by H1N1 influenza virus and to determine the probability that a pneumonia is due to an H1N1 virus infection based on the most relevant variables. Methods: We used a case-control study where cases were H1N1 CAP patients with confirmed microbiological diagnosis and controls were patients with CAP admitted to hospital. H1N1 and other influenza types were discarded among controls. We calculated the probability of being a case or control using multivariate logistic regression. Results: We included 99 cases and 270 controls. Cases were younger than controls (53 vs 71 years, respectively). Mortality was much higher for H1N1 patients (13% vs 0.3%), and admission to intensive care unit was more frequent for H1N1 cases. The variables most associated with presenting H1N1 CAP were bilateral affectation on chest X-rays (OR: 5.70; 95% CI 2.69-10.40), followed by presence of arthromyalgias, with cases presenting close to three times more arthromyalgias compared to controls. Low leukocytes count and high AST values were also significantly associated with H1N1 CAP. H1N1 CAPs are characterized by bilateral affectation, low leukocyte count, presence of arthromyalgias, and high AST. Conclusions: A few and easy to obtain clinical parameters might be extremely useful to distinguish H1N1 CAP from CAPs of other origin.

The Combined Use of Pleural Fluid Parameters Improves Diagnostic Accuracy in Complicated Pleural Infection/Empyema. / La combinación de la determinación de parámetros bioquímicos del líquido pleural mejora la predicción diagnóstica de la infección pleural complicada/empiema.

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<.001 using all parameters). The rate of correct classification of infectious pleural effusions was 96% [170/177: 72/74 (97.3%) for uncomplicated and 98/103 (95.1%) for complicated effusion (empyema)]. CONCLUSION: The multiple-marker model showed better diagnostic performance for predicting complicated infectious pleural effusion (empyema) compared to individual parameters alone.

Pulmonary vasculitis.

Systemic vasculitides frequently affect the pulmonary vasculature. As the signs and symptoms of pulmonary vasculitis are variable and nonspecific, diagnosis and treatment represent a real challenge. Vasculitides should be given consideration, as these diseases present severe manifestations of rapidly progressing pulmonary disease. Examining other organs usually affected by vasculitides (e.g., the skin and kidneys) and determining autoantibody levels are essential to a better management of the disease. A radiological study would also contribute to establishing a diagnosis. The lungs are commonly involved in small-vessel vasculitis, anti-glomerular basement membrane disease, and vasculitides associated with antineutrophil cytoplasmic antibodies. Associated life-threatening diffuse alveolar haemorrhages and irreversible damage to other organs-usually the kidneys-are severe complications that require early diagnosis. Vasculitides are rare diseases that affect multiple organs. An increasing number of treatments-including biological agent-based therapies-requiring cooperation between specialists and centers have become available in the recent years. In the same way, clinicians should be familiar with the complications associated with immunosuppressive therapies.

Factors Influencing Hospital Stay for Pulmonary Embolism. A Cohort Study. / Factores que influyen en la estancia hospitalaria por embolia pulmonar. Un estudio de cohortes.

INTRODUCTION: The aim of this study was to identify factors influencing hospital stay due to pulmonary embolism. METHODS: We performed a retrospective cohort study of patients hospitalized between 2010 and 2015. Patients were identified using information recorded in hospital discharge reports (ICD-9-CM codes 415.11 and 415.19). RESULTS: We included 965 patients with a median stay of 8 days (IQR 6-13 days). Higher scores on the simplified Pulmonary Embolism Severity Index (sPESI) were associated with increased probability of longer hospital stay. The probability of a hospital stay longer than the median was 8.65 (95% CI 5.42-13.79) for patients referred to the Internal Medicine Department and 1.54 (95% CI 1.07-2.24) for patients hospitalized in other departments, compared to those referred to the Pneumology Department. Patients with grade 3 on the modified Medical Research Council dyspnea scale had an odds ratio of 1.63 (95% CI: 1.07-2.49). The likelihood of a longer than median hospital stay was 1.72 (95% CI: 0.85-3.48) when oral anticoagulation (OAC) was initiated 2-3 days after admission, and 2.43 (95% CI: 1.16-5.07) when initiated at 4-5 days, compared to OAC initiation at 0-1 days. CONCLUSIONS: sPESI grade, the department of referral from the Emergency Department, the grade of dyspnea and the time of initiating OAC were associated with a longer hospital stay.

Urinothorax: a systematic review.

BACKGROUND: The characteristics of patients with urinothorax (UT) are poorly defined. METHODS: A systematic review was performed searching for studies reporting clinical findings, pleural fluid (PF) characteristics, and the most effective treatment of UT. Case descriptions and retrospective studies were included. RESULTS: The review included 78 studies with a total of 88 patients. Median age was 45 years, male/female ratio was 1.6:1 and in 76% of cases the etiology was trauma. Pleural effusion (PE) was predominantly unilateral (87%) and occupied over 2/3 of the hemithorax in most cases (64.4%). PF was straw-colored (72.7%) or hematic (27.3%) with urine-like odor in all cases. PF was transudate in 56.2% of cases (18/32) and among 14 exudates (43.8%), 3 were concordant exudates, 1 protein-discordant and 10 LDH-discordant, with lymphocyte (44.4%) and neutrophil (38.5%) predominance. The PF/serum (PF/S) creatinine ratio was >1 in all cases except one (97.9%). The diagnosis was established on the basis of PF/S creatinine ratio >1 (56.6%), urinary tract contrast extravasation (12%), abnormal computed tomography (8.4%), laparotomy findings (6%), and association of obstructive uropathy with PE (6%). The outcome was favorable (74/77; 96.1%) when treatment was direct towards the uropathy (alone or associated with thoracentesis/thoracic drainage). Outcome was unfavorable in the 15 patients who were only treated with thoracentesis/thoracic drainage. CONCLUSIONS: UT is usually traumatic, unilateral, and PF does not have a specific pattern or cellularity predominance, with a PF/S creatinine ratio almost always >1. Treatment should include the uropathy, with or without PF evacuation.