Case 322: Pyothorax-associated Lymphoma.

HISTORY: An 81-year-old man living in South Korea was referred to the pulmonology clinic because of abnormal findings at routine surveillance CT. His past medical history included right radical nephroureterectomy for ureteral cancer in 2016, transurethral resection of a bladder tumor in 2015, and tuberculous pleurisy in his third decade of life that was complicated by a chronic calcified empyema. He had been doing well clinically until 6 months prior, when he presented to an outside hospital with progressive right-sided chest pain and dyspnea and was found to have active tuberculosis. During that hospitalization, he underwent chest CT and CT-guided biopsy of an incidentally found thoracic lesion, which revealed chronic active inflammation. His symptoms improved after initiation of antituberculous medication, and he was discharged home to complete treatment. Because of interval growth of this lesion noted on a subsequent surveillance CT scan, he was referred to pulmonology for further evaluation. Laboratory tests obtained during his visit revealed mild leukocytosis (1258 cells × 109/L; normal range, 4000-10 000 cells × 109/L) with neutrophilic predominance (82% neutrophils; normal range, 50%-75% neutrophils), and a mildly elevated C-reactive protein level (3.17 mg/dL; normal range, 0-0.5 mg/dL). A sputum culture was negative for tuberculosis. The patient reported mild chest discomfort and dyspnea. Liver MRI was performed to further evaluate an abnormal lesion seen at CT. Given the patient's recent nonspecific biopsy results and tuberculosis treatment, no further work-up was pursued. Contrast-enhanced chest CT was performed 6 months later because the patient developed worsening chest pain and dyspnea. He remained afebrile, with persistent leukocytosis (1485 cells × 109/L) and an elevated C-reactive protein level (3.56 mg/dL). On the basis of the imaging findings, repeat CT-guided biopsy and PET/CT were performed, thereby enabling confirmation of the diagnosis, and appropriate treatment was initiated.

Thoracic empyema: aetiology, diagnosis, treatment, and prevention.

PURPOSE OF REVIEW: The aim of this study was to review current key points in the aetiology, diagnosis, treatment, and prevention of empyema thoracis. Early postpandemic trends have seen an increasing global incidence and evolution in the aetiology of empyema. Due to varied aetiology and typically lengthy treatment, empyema will be disproportionately affected by the rising tide of antimicrobial resistance (AMR), thus warranting attention and further research. RECENT FINDINGS: Multiple novel biomarkers (e.g. IL-36γ) are under investigation to aid diagnosis, while oral health assessment tools are now available for prognosticating and risk-stratifying patients with thoracic empyema. There exists an ongoing lack of evidence-based guidance surrounding antibiotic treatment duration, surgical intervention indication, and prognostic scoring utility. SUMMARY: Understanding aetiologies in different global regions and settings is pivotal for guiding empirical treatment. Antimicrobial resistance will make thoracic empyema increasingly challenging to treat and should prompt increased awareness of prescribing practices. Novel biomarkers are under investigation which may speed up differentiation of pleural effusion types, allowing faster cohorting of patients.Although newly identified predictors of morbidity and mortality have been suggested to be beneficial for incorporation into clinical practice, further work is required to prognosticate, risk-stratify, and standardize treatment.

Rapid detection of S. pyogenes and S. pneumoniae in pleural fluid for diagnosis of parapneumonic empyema.

The aim of this study was to assess the reliability of rapid antigen detection tests (RADT) for Streptococcus pyogenes (GAS) and Streptococcus pneumoniae on pleural fluid samples for diagnosis of parapneumonic effusion/empyema (PPE) and their potential for improving pathogen identification rates. Sixty-three pleural samples were included from 54 patients on which GAS and S. pneumoniae RADT (BinaxNOW), culture, 16S rRNA PCR, and S. pneumoniae-specific PCR were performed. GAS RADT showed a sensitivity of 95.2% and a specificity of 100%. Pneumococcal RADT showed a sensitivity of 100% and specificity of 88.6%. Both RADT increased the pathogen identification rate in PPE compared to culture.

Successful surgical management of a pyothorax in a Guinea baboon (Papio papio).

A 16-year-old male Guinea baboon (Papio papio) was evaluated for weakness and focal wet fur of 1-week duration. A pyothorax caused by Streptococcus anginosus was diagnosed. A surgical approach was chosen, combined with a systemic antibiotic therapy. Medical imaging and C-reactive protein follow-up revealed the resolution of the pyothorax.

Management of patient with Fusobacterim nucletum related pleural empyema: intrapleural antibiotic therapy can be considered for salvage therapy.

Pleural empyema can lead to significant morbidity and mortality despite chest drainage and antibiotic treatment, necessitating novel and minimally invasive interventions. Fusobacterium nucleatum is an obligate anaerobe found in the human oral and gut microbiota. Advances in sequencing and puncture techniques have made it common to detect anaerobic bacteria in empyema cases. In this report, we describe the case of a 65-year-old man with hypertension who presented with a left-sided encapsulated pleural effusion. Initial fluid analysis using metagenomic next-generation sequencing (mNGS) revealed the presence of Fusobacterium nucleatum and Aspergillus chevalieri. Unfortunately, the patient experienced worsening pleural effusion despite drainage and antimicrobial therapy. Ultimately, successful treatment was achieved through intrapleural metronidazole therapy in conjunction with systemic antibiotics. The present case showed that intrapleural antibiotic therapy is a promising measure for pleural empyema.

Empyema caused by Streptococcus constellatus in a patient infected with HIV: a case report and literature review.

BACKGROUND: Empyema caused by Streptococcus constellatus (S. constellatus) is rare in patients with HIV. To analyze the clinical data of a patient living with HIV (PLHIV), who got empyema caused by S. constellatus, investigating the diagnosis and treatment of this disease through literature review to improve the clinical understanding of this disease. CASE PRESENTATION: We have reported here a 58-year-old male PLHIV with cough, wheezing, and fever for 20 days. He has a history type 2 diabetes, alcohol abuse, and a teeth extracted. Chest computed tomography revealed multiple encapsulated pleural effusions, pneumatosis, and partial compressive atelectasis in the right lung. Submission of pleural efusions timely, and then cultures revealed S. constellatus. After comprehensive treatment, including antibiotics, closed pleural drainage, and intrapleural injection of urokinase, the pleural efusion was absorbed, and chest computed tomography also confirmed the improvement. CONCLUSIONS: S. constellatus should not be neglected as a pus pathogen in patients with HIV. comprehensive treatment is important for empyema of S. constellatus.

Lemierre syndrome complicated by bronchopleural fistula.

We present a 19-year-old woman, a case of Lemierre syndrome, who presented with fever, sore throat, and left shoulder pain. Imaging revealed a thrombus in the right internal jugular vein, multiple nodular shadows below both pleura with some cavitations, right lung necrotizing pneumonia, pyothorax, abscess in the infraspinatus muscle, and multiloculated fluid collections in the left hip joint. After inserting a chest tube and administering urokinase for the pyothorax, a bronchopleural fistula was suspected. The fistula was identified based on clinical symptoms and computed tomography scan findings. If a bronchopleural fistula is present, thoracic lavage should not be performed as it may cause complications such as contralateral pneumonia due to reflux.

The role of the early video-assisted thoracoscopic surgery in children with pleural empyema.

PURPOSE: Pleural empyema (PE) is a collection of purulent material in the pleural space. PE's management in children is a challenge and an inappropriate diagnostic-therapeutic work up can lead to serious short and long-term complications. The aim of this study is to define the correct timing to approach a pediatric PE by video-assisted thoracoscopic surgery (VATS). METHODS: A retrospective observational study was conducted including pediatric patients who underwent video-assisted thoracoscopy for pleural empyema between May 2005 and September 2022. RESULTS: 62 patients were subjected to VATS for PE (32 in Group Early VATS, 30 in Group Late VATS). It emerged that the elapsed period between the onset of symptoms and surgery correlates in a statistically significant way with the post-operative stay in intensive care (z score 4.3 and p value < 0.0001) and the analysis between early VATS, late VATS and postoperative hospitalization showed a statistically significant reduction of the post-operative hospitalization in the early VATS groups (p value < 0.02). CONCLUSIONS: VATS resulted to be safe and effective for the treatment of PE in children, and an early minimally invasive thoracoscopic intervention (early VATS) correlates with better outcomes, specifically in terms of intensive care hospitalization and overall hospitalization.

Intrathoracic Transposition of a Pedicled Latissimus Dorsi Muscle Flap for Complicated Chronic Empyema Thoracis: A Plea for its Popularity in our Subregion.

INTRODUCTION: Empyema thoracis is a debilitating disease that still constitutes a significant burden among thoracic surgical diseases in our environment. It sometimes occurs secondary to ruptured lung abscess with varying degrees of lung destruction and bronchopleural fistula. CASE REPORT: A 65-year-old woman presented to our unit with a two-month history of cough which subsequently became productive of purulent sputum and posture-dependent, and fever, with progressive dyspnea on exertion. She was subsequently managed for chronic right empyema thoracis secondary to a ruptured lung abscess. We briefly describe the evaluation, indication, and technique for intrathoracic transposition of a pedicled latissimus dorsi muscle flap for operative management of this index disease, and the very good medium and long-term outcomes observed for this patient. CONCLUSION: Where indicated and with meticulous preoperative planning, transposition of a pedicled latissimus dorsi muscle flap for complicated chronic empyema thoracis can prevent a surgical albatross with a reduced hospital stay, cost of treatment and excellent patient satisfaction at the meagre expense of about 30 minutes or less extra intra-operative time.

INTRODUCTION: L'empyème thoracique est une maladie invalidante qui constitue toujours un fardeau significatif parmi les maladies chirurgicales thoraciques dans notre environnement. Il survient parfois secondairement à un abcès pulmonaire rompu avec des degrés variables de destruction pulmonaire et de fistule bronchopleurale. RAPPORT DE CAS: Une femme de 65 ans s'est présentée à notre unité avec une toux persistante depuis deux mois, qui est ensuite devenue productive de crachats purulents dépendant de la posture, ainsi que de la fièvre, avec une dyspnée progressive à l'effort. Elle a ensuite été traitée pour un empyème thoracique chronique droit secondaire à un abcès pulmonaire rompu. Nous décrivons brièvement l'évaluation, les indications et la technique de transposition intrathoracique d'un lambeau musculaire grand dorsal pédiéculé pour la prise en charge opératoire de cette maladie, ainsi que les très bons résultats à moyen et long terme observés pour cette patiente. CONCLUSION: Lorsque cela est indiqué et avec une planification préopératoire méticuleuse, la transposition d'un lambeau musculaire grand dorsal pédiéculé pour un empyème thoracique chronique compliqué peut éviter un fardeau chirurgical avec une réduction du séjour hospitalier, du coût du traitement et une excellente satisfaction du patient, avec un faible coût supplémentaire en temps opératoire de seulement environ 30 minutes ou moins. MOTS-CLÉS: Abcès pulmonaire, lambeau musculaire grand dorsal pédiéculé, empyème thoracique, résultats.

[Surgical Experience with Three Cases of Open-window Thoracostomy for Chronic Empyema Under Local Anesthesia].

We may encounter patients with chronic empyema for whom open-window thoracostomy is unavoidable. However, patients with chronic empyema are sometimes at high-risk for surgery under general anesthesia. We, herein, present our surgical experience with three chronic empyema cases who underwent open-window thoracostomy under local anesthesia. Indications for open-window thoracostomy under local anesthesia were raised PaCO2 in Case 1, old age and poor performance status in Case 2, and a history of esophageal reconstruction and vocal cordoplasty in Case 3. All patients were well during the surgery. Case 1 developed type 2 respiratory failure postoperatively and had to be put on a ventilator, but finally recuperated. The sedatives used could have exacerbated raised PaCO2 in this patient, and careful selection of anesthetic agents is mandatory. Considering pain and stress that patients suffer during open-window thoracostomy under local anesthesia, case selection is necessary. Nevertheless, we believe that open-window thoracostomy under local anesthesia is an effective option for high-risk patients.

Modern view on the problem of acute pleural empyema surgical treatment.

OBJECTIVE: Aim: data study on the results of treatment of acute non-specific purulent-destructive pleura diseases with the purpose of further improvement of its results on the basis of improvement of diagnostics, identification of factors of disease prognosis and by implementing differential tactics of surgical treatment with the use of minimally invasive interventions. PATIENTS AND METHODS: Materials and Methods: We have studied modern literary sources on the topic of current trends in the treatment of acute pleural empyema and its complications. The studied material is summarized and presented in the form of a literature review in this article. CONCLUSION: Conclusions: These issues cannot be considered to be completely solved and require further study. Everything mentioned above dictates the search of new effective methods of the treatment of the mentioned pathology and proves the relevance of the theme. The outlined information highlights the necessity of improvement of surgical tactics in patients with pleural empyema.

Pleural Empyema Caused by Streptococcus intermedius and Fusobacterium nucleatum: A Distinct Entity of Pleural Infections.

BACKGROUND: Many community-acquired pleural infections are caused by facultative and anaerobic bacteria from the human oral microbiota. The epidemiology, clinical characteristics, pathogenesis, and etiology of such infections are little studied. The aim of the present prospective multicenter cohort study was to provide a thorough microbiological and clinical characterization of such oral-type pleural infections and to improve our understanding of the underlying etiology and associated risk factors. METHODS: Over a 2-year period, we included 77 patients with community-acquired pleural infection, whereof 63 (82%) represented oral-type pleural infections. Clinical and anamnestic data were systematically collected, and patients were offered a dental assessment by an oral surgeon. Microbial characterizations were done using next-generation sequencing. Obtained bacterial profiles were compared with microbiology data from previous investigations on odontogenic infections, bacteremia after extraction of infected teeth, and community-acquired brain abscesses. RESULTS: From the oral-type pleural infections, we made 267 bacterial identifications representing 89 different species. Streptococcus intermedius and/or Fusobacterium nucleatum were identified as a dominant component in all infections. We found a high prevalence of dental infections among patients with oral-type pleural infection and demonstrate substantial similarities between the microbiology of such pleural infections and that of odontogenic infections, odontogenic bacteremia, and community-acquired brain abscesses. CONCLUSIONS: Oral-type pleural infection is the most common type of community-acquired pleural infection. Current evidence supports hematogenous seeding of bacteria from a dental focus as the most important underlying etiology. Streptococcus intermedius and Fusobacterium nucleatum most likely represent key pathogens necessary for establishing the infection.

EBV-positive pyothorax-associated lymphoma expresses CXCL9 and CXCL10 chemokines that attract cytotoxic lymphocytes via CXCR3.

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma associated with chronic inflammation (DLBCL-CI) develops in the setting of long-standing inflammation. This type of lymphoma may have specific expression profiles of chemokines involved in the pathogenesis of DLBCL-CI. EBV-positive pyothorax-associated lymphoma (PAL) is a prototype of DLBCL-CI and represents a valuable model for the study of this disease category. Using a panel of PAL cell lines, we found that PAL cells expressed and secreted C-X-C motif chemokine ligands 9 and 10 (CXCL9 and CXCL10), the ligands of CXCR3, in contrast to EBV-negative DLBCL cell lines, which did not. Culture supernatants from PAL cell lines attracted CXCR3-expressing CD4+ T cells, CD8+ T cells, and CD56+ natural killer cells from human peripheral blood mononuclear cells. PAL cells injected into mice also attracted CXCR3-positive cytotoxic lymphocytes that expressed interferon-γ. The expression of CXCL9 and CXCL10 was detected in PAL tumor biopsy samples from patients, and CXCR3-positive lymphocytes were abundant in the tissue samples. Collectively, these findings suggest that CXCL9 and CXCL10 are produced by PAL cells and can elicit cytotoxic responses via CXCR3. This chemokine system is also likely to contribute to tissue necrosis, which is a signature histological feature of DLBCL-CI. Further studies are warranted to determine whether the CXCL9-CXCL10/CXCR3 axis exerts antitumor effects in DLBCL-CI.

The outcomes of thoracoscopic decortication between fungal empyema and bacterial empyema.

BACKGROUND: Fungal empyema is an uncommon disease and is associated with a high mortality rate. Surgical intervention is suggested in stage II and III empyema. However, there were no studies that reported the outcomes of surgery for fungal empyema. METHODS: This study is a retrospective analysis in a single institute. Patients with empyema thoracis who underwent thoracoscopic decortication between January 2012 and December 2021 were included in the study. We separated the patients into a fungal empyema group and a bacterial empyema group according to culture results. We used 1:3 propensity score matching to reduce selection bias. RESULTS: There were 1197 empyema patients who received surgery. Of these, 575 patients showed positive culture results and were enrolled. Twenty-eight patients were allocated to the fungal empyema group, and the other 547 patients were placed in the bacterial empyema group. Fungal empyema showed significantly longer intensive care unit stay (16 days vs. 3 days, p = 0.002), longer median ventilator usage duration (20.5 days vs. 3 days, p = 0.002), longer hospital stay duration (40 days vs. 17.5 days, p < 0.001) and a higher 30-day mortality rate (21.4% vs. 5.9%, p < 0.001). Fungal empyema revealed significantly poorer 1-year survival rate than bacterial empyema before matching (p < 0.001) but without significant difference after matching. CONCLUSIONS: The fungal empyema patients had much worse surgical outcomes than the bacterial empyema patients. Advanced age and high Charlson Comorbidity Index score are independent predictors for poor prognosis. Prompt surgical intervention combined with the use of antifungal agents was the treatment choice for fungal empyema.

Culture-Negative Fusobacterium nucleatum Brain Abscess and Pleural Empyema Cases Revealed by 16S rRNA Sequencing.

BACKGROUND: We reported two Fusobacterium nucleatum cases each of brain abscesses and pleural empyema, using 16S rRNA sequencing technology. METHODS: We reviewed clinical records and microbiological findings in four patients with F. nucleatum infection. RESULTS: All conventional culture results from peripheral blood, cerebrospinal fluid, and pleural fluid samples were found to be negative for this pathogen. Three patients were treated with antimicrobial agents for more than a week before specimen sampling. All patients recovered from their fusobacterial infections and were discharged. CONCLUSIONS: Molecular identification methods such as 16S rRNA sequencing should accompany conventional culture to detect obligate anaerobic bacteria in deep-seated sites and organs.

Aspiration Pneumonia Caused by Prevotella Causing Prothorax after Pulmonary Puncture: a Case Report.

BACKGROUND: Aspiration pneumonia in patients in immunocompetent populations is rare, and secondary pyothorax due to puncture operations during treatment has been reported rarely. METHODS: We report a confirmed case of aspiration pneumonia caused by Prevotella. The pathogen was detected and confirmed using percutaneous lung puncture and high-throughput next-generation sequencing (NGS). RESULTS: The patient developed secondary pyothorax, severe rash, and exacerbation of symptoms following the lung puncture. Finally, after adjusting the antibiotic regimen and performing chest drainage and washout, the patient's lesions were absorbed, symptoms improved, and the rash disappeared. CONCLUSIONS: Prevotella aspiration pneumonia can occur in immunocompetent individuals, and invasive bronchoscopic alveolar lavage may be considered as an option to reduce the risk of infectious organism translocation.

Effectiveness of Immediate Video-Assisted Thoracoscopic Surgery for Empyema: A Multicentre, Retrospective Cohort Study.

BACKGROUND: Because of limitations in previous randomised controlled trials and observational studies, the effectiveness of immediate video-assisted thoracoscopic surgery (VATS) for patients with empyema in real-world settings remains unclear. OBJECTIVE: This study aimed to evaluate whether immediate VATS improves clinical outcomes in patients with empyema. METHODS: This multicentre retrospective cohort study included 744 patients with physician-diagnosed empyema from six hospitals between 2006 and 2021. The exposure was VATS performed within 3 days of empyema diagnosis, the primary outcome was 30-day mortality, and secondary outcomes were 90-day mortality, length of hospital stay, and time from diagnosis to discharge. We used propensity score weighting to account for potential confounders. For outcome analyses, we used logistic regression for mortality outcomes and gamma regression for the number of days. RESULTS: Among the 744 patients, 53 (7.1%) underwent VATS within 3 days, and 691 (92.9%) initially received conservative treatment. After propensity score weighting, the differences in 30- and 90-day mortalities between the immediate VATS and initial conservative treatment groups were 1.18% (95% confidence interval [CI], -10.7 to 13.0%) and -0.08% (95% CI, -10.3 to 10.2%), respectively. The differences in length of hospital stay and time from diagnosis to discharge were -3.22 (95% CI, -6.19 to -0.25 days) and -5.04 days (95% CI, -8.19 to -1.90 days), respectively. CONCLUSIONS: Our real-world study showed that immediate VATS reduced the length of hospital stay and the time from diagnosis to discharge. Considering the small sample and differences in protocols between countries, further large-scale studies are warranted.

Efficacy of Small versus Large-Bore Chest Drain in Pleural Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: Pleural infection represents a significant clinical challenge worldwide. Although prompt drainage of pleural fluid is thought to play a key role in pleural infection management, the optimal size of intrapleural catheter has yet to be defined. OBJECTIVES: The aim of this systematic review and meta-analysis was to summarize data on efficacy and complications of small-bore drain (SBD), defined as ≤14F, in comparison to large-bore drain (LBD) in patients with pleural infection. METHOD: We searched MEDLINE and Embase for all studies reporting outcomes of interest published up to October 2021. Two authors reviewed selected full text to identify studies according to predefined eligibility criteria. Summary estimates were derived using the random-effects model. RESULTS: Twelve original studies were included for qualitative analysis and 7 of these for quantitative analysis. The surgical referral rate of SBD and LBD were, respectively, 0.16 (95% confidence interval [CI], 0.12-0.21) and 0.20 (95% CI, 0.10-0.32), the pooled mortality were 0.12 (95% CI, 0.05-0.21) and 0.20 (95% CI, 0.10-0.32), and the length of hospital stay was 24 days in both groups. Data on complications suggest similar proportions of tube dislodgement. Intensity of pain was evaluated in one study only, reporting higher scores for LBD. CONCLUSIONS: This systematic review and meta-analysis provide the first synthesis of data on performance of SBD and LBD in management of pleural infection, and, overall, clinical outcomes and complications did not substantially differ, although the limited number of studies and the absence of dedicated randomized trials does limit the reliability of results.

Medical Thoracoscopy and Intrapleural Fibrinolytic Therapy for the Management of Pleural Empyema: A Cohort Study.

BACKGROUND: Pleural empyema is associated with relevant morbidity and mortality, and it may be classified, according to evolution and ultrasound, into three stages: stage I (free-flowing effusion), stage II (viscous effusion with the tendency to loculate), and stage III (organizing phase). According to guidelines, antibiotic therapy and pleural drainage are recommended, with surgery being performed when patients fail and/or in case of organized empyema. OBJECTIVES: The aim of the study was to report the efficacy and safety of medical thoracoscopy in patients with pleural empyema stratified by chest ultrasound. METHOD: Observational retrospective cohort study analyzing patients with pleural empyema treated with medical thoracoscopy. Procedure success and mortality were evaluated at 30 days and 90 days after the procedure; complications were also reported. RESULTS: 131 patients were included. Intrapleural fibrinolytic therapy was performed thereafter in the majority of cases. Medical thoracoscopy was considered successful without subsequent intervention in 99 patients (76%); 19 patients (15%) underwent a second procedure (drainage, thoracoscopy, video-assisted thoracic surgery, or thoracotomy); and 6 patients (5%) died of the evolution of empyema. Patients treated in stages I and II showed significantly better post-procedure results compared with patients treated in stage III (100%, 83.3%, and 58.1%, respectively). Thoracoscopy complications were observed in 18 patients and were reversible in all cases. CONCLUSIONS: Patients with pleural empyema treated in earlier stages (free-flowing or multiloculated effusion) with medical thoracoscopy show significantly better results than patients treated in later stages (organized empyema). This approach is safe, minimally invasive, and efficient in these patients with disease having relevant mortality; however, patient selection remains essential.

Association between intrapleural urokinase monotherapy and treatment failure in patients with pleural infection: a retrospective cohort study.

BACKGROUND: Pleural infection, an infection of the pleural space, is frequently treated with antibiotics and thoracic tube drainage. In case of insufficient drainage, an intrapleural fibrinolytic agent is considered before surgical intervention. However, the effectiveness of fibrinolytic monotherapy is still controversial. Therefore, we aimed to examine the association between urokinase monotherapy and treatment failure in patients with pleural infection. METHODS: In this retrospective observational study, patients with pleural infection underwent chest tube insertion were divided into two groups including patients treated with or without intrapleural instillation of urokinase. The propensity score overlap weighting was used to balance the baseline characteristics between the groups. Treatment failure was defined by the composite primary outcome of in-hospital death and referral for surgery. RESULTS: Among the 94 patients, 67 and 27 patients were in the urokinase and non-urokinase groups, respectively. Urokinase monotherapy improved the composite outcome between the groups (19.4% vs. 48.1%, p = 0.01). After adjusting using propensity score overlap weighting, urokinase monotherapy improved the composite outcome compared to the non-urokinase group (19.0% vs. 59.5%, p = 0.003). CONCLUSIONS: Urokinase monotherapy can be an important nonsurgical treatment option for patients with pleural infection. TRIAL REGISTRATION: The participants were retrospectively registered.