Management of Intrapleural Sepsis with Once Daily Use of Tissue Plasminogen Activator and Deoxyribonuclease

A Retrospective Review of Concurrent versus Sequential Administration of Intrapleural Tissue Plasminogen Activator and Dornase alfa for Empyemas

BACKGROUND

Intrapleural tissue plasminogen activator (tPA) and dornase alfa (DNase) administered sequentially, separated by a one to two hour interval, is a mainstay of pleural infection treatment. Recent literature supports similar efficacy and safety of concurrent therapy (administered immediately after one another). Insufficient evidence are available to utilize concurrent therapy routinely.

OBJECTIVE

The primary objective of this study was to assess the safety and effectiveness of concurrent versus sequential intrapleural tPA and DNase in pleural infections.

METHODS

This was a single-center, retrospective study of patients ≥ 18 years old admitted to the inpatient setting who received either concurrent or sequential intrapleural tPA or DNase between July 1, 2014, and January 1, 2023. The primary outcome was treatment failure, a composite of 30-day mortality and requirement for a video-assisted thoracoscopic surgery (VATS). Secondary outcomes included cumulative pleural fluid drainage, bleeding adverse events, and pain requiring analgesia dose escalation.

RESULTS

A total of 184 patients were included: 158 patients in the concurrent group and 26 patients in the sequential group. Treatment failure was similar between groups (18.4% vs 19.2%, P > 0.99). Increased pleural fluid drainage occurred in the concurrent versus sequential therapy group (1453 mL vs 836 mL, P = 0.05) with no differences in bleeding (23.4% vs 19.2%, P = 0.64) or analgesia dose escalation between groups (41.1% vs 23.1%, P = 0.09).

CONCLUSION

and Relevance Concurrent intrapleural fibrinolytics have similar effectiveness and safety compared to sequential administration however, further investigation into the compatibility and stability of the medications is warranted to optimize future pleural infection management.

Intrapleural fibrinolytic therapy for pleural infections: Outcomes from a cohort study

Introduction

Pleural infections are a significant cause of mortality. Intrapleural fibrinolytic therapy (IPFT) utilising alteplase and dornase is a treatment option for patients unsuitable for surgery. The optimal dose of alteplase is unknown, and factors affecting treatment success in an Asian population are unclear. We sought to determine the factors affecting treatment success in Tan Tock Seng Hospital, Singapore and evaluate the efficacy of lower doses of IPFT.

Method

A retrospective analysis of patients with pleural infections treated with IPFT between July 2016 and November 2023 was performed. Treatment success was defined as survival without surgery at 3 months. Data, including patient demographics; comorbidities; RAPID (renal, age, purulence, infection source and dietary factor) scores; and radiological characteristics, were extracted from medical records and analysed. Linear mixed effects model and logistic regression were performed to determine factors affecting treatment success.

Results

A total of 131 cases were analysed. Of these, 51 (38.9%) reported positive pleural fluid culture, and the most common organism was Streptoccocus anginosus. Mean age was 65 years (standard deviation [SD] 15.5). Mean time from chest tube insertion to first dose of IPFT was 10.2 days (SD 11.5). Median starting dose of alteplase was 5 mg. Treatment success was reported in 112 cases (85.5%). There were no significant differences between the alteplase dose and radiological clearance. Patient age (odds ratio [OR] 0.94, confidence interval [CI] 0.89-0.98) and interval between chest tube insertion to first dose (OR 0.95, CI 0.91-0.99) were statistically significant variables for the treatment success.

Conclusion

Lower starting doses of alteplase remain effective in the treatment of pleural infection. Early IPFT may result in better outcomes.

Beyond the double helix: the multifaceted landscape of extracellular DNA in Staphylococcus aureus biofilms

Staphylococcus aureus forms biofilms consisting of cells embedded in a matrix made of proteins, polysaccharides, lipids, and extracellular DNA (eDNA). Biofilm-associated infections are difficult to treat and can promote antibiotic resistance, resulting in negative healthcare outcomes. eDNA within the matrix contributes to the stability, growth, and immune-evasive properties of S. aureus biofilms. eDNA is released by autolysis, which is mediated by murein hydrolases that access the cell wall via membrane pores formed by holin-like proteins. The eDNA content of S. aureus biofilms varies among individual strains and is influenced by environmental conditions, including the presence of antibiotics. eDNA plays an important role in biofilm development and structure by acting as an electrostatic net that facilitates protein-cell and cell-cell interactions. Because of eDNA's structural importance in biofilms and its ubiquitous presence among S. aureus isolates, it is a potential target for therapeutics. Treatment of biofilms with DNase can eradicate or drastically reduce them in size. Additionally, antibodies that target DNABII proteins, which bind to and stabilize eDNA, can also disperse biofilms. This review discusses the recent literature on the release, structure, and function of eDNA in S. aureus biofilms, in addition to a discussion of potential avenues for targeting eDNA for biofilm eradication.

Infective Pleural Effusions-A Comprehensive Narrative Review Article

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

A Retrospective Cohort Study Evaluating the Safety and Efficacy of Sequential versus Concurrent Intrapleural Instillation of Tissue Plasminogen Activator and DNase for Pleural Infection

Methods

We conducted a retrospective review of patients with pleural infection requiring intrapleural therapy at two tertiary referral centres.

Results

We included 84 (62.2%) and 51 (37.8%) patients who received sequential and concurrent intrapleural therapy, respectively. Patient demographics and clinical characteristics, including age, RAPID score, and percentage of pleural opacity on radiographs before intrapleural therapy, were similar in both groups. Treatment failure rates (defined by either in-hospital mortality, surgical intervention, or 30-day readmission for pleural infection) were 9.5% and 5.9% with sequential and concurrent intrapleural therapy, respectively (p = 0.534). This translates to a treatment success rate of 90.5% and 94.1% for sequential and concurrent intrapleural therapy, respectively. There was no significant difference in the decrease in percentage of pleural effusion size on chest radiographs (15.1% [IQR 6-35.7] versus 26.6% [IQR 9.9-38.7], p = 0.143) between sequential and concurrent therapy, respectively. There were also no significant differences in the rate of pleural bleeding (4.8% versus 9.8%, p = 0.298) and chest pain (13.1% versus 9.8%, p = 0.566) between sequential and concurrent therapy, respectively.

Conclusion

Our study adds to the growing literature on the safety and efficacy of concurrent intrapleural therapy in pleural infection.

Diagnosis and management of pleural infection

Pleural infection remains a medical challenge. Although closed tube drainage revolutionised treatment in the 19th century, pleural infection still poses a significant health burden with increasing incidence. Diagnosis presents challenges due to non-specific clinical presenting features. Imaging techniques such as chest radiographs, thoracic ultrasound and computed tomography scans aid diagnosis. Pleural fluid analysis, the gold standard, involves assessing gross appearance, biochemical markers and microbiology. Novel biomarkers such as suPAR (soluble urokinase plasminogen activator receptor) and PAI-1 (plasminogen activator inhibitor-1) show promise in diagnosis and prognosis, and microbiology demonstrates complex microbial diversity and is associated with outcomes. The management of pleural infection involves antibiotic therapy, chest drain insertion, intrapleural fibrinolytic therapy and surgery. Antibiotic therapy relies on empirical broad-spectrum antibiotics based on local policies, infection setting and resistance patterns. Chest drain insertion is the mainstay of management, and use of intrapleural fibrinolytics facilitates effective drainage. Surgical interventions such as video-assisted thoracoscopic surgery and decortication are considered in cases not responding to medical therapy. Risk stratification tools such as the RAPID (renal, age, purulence, infection source and dietary factors) score may help guide tailored management. The roles of other modalities such as local anaesthetic medical thoracoscopy and intrapleural antibiotics are debated. Ongoing research aims to improve outcomes by matching interventions with risk profile and to better understand the development of disease.

Intrapleural tissue plasminogen activator and deoxyribonuclease administered concurrently and once daily for complex parapneumonic pleural effusion and empyema

BACKGROUND

Pleural infection is life-threatening and increasingly prevalent. In addition to usual care, twice-daily, separate administration of tissue plasminogen activator and deoxyribonuclease (tPA-DNase) reduces radiological pleural opacity with lower surgical referral rates.

AIMS

This retrospective cohort study examines the use of once-daily, concurrent administration of tPA-DNase for complex parapneumonic pleural effusion and empyema.

METHODS

Patients with pleural infection who received intrapleural tPA-DNase between October 2014 and July 2020 at Logan Hospital, where it is given concurrently and once-daily as salvage therapy, were retrospectively identified. Radiographic opacification, inflammatory markers, clinical response and complications were examined.

RESULTS

Thirty-one patients were identified. Mean age was 48.8 years (standard deviation [SD], 17.2). Median tPA-DNase administration was 3 (interquartile range [IQR], 2-3). Chest x-ray pleural opacity decreased significantly (P = 0.047) from a median of 39.6% (IQR, 28.8-65.7%) to 9.7% (IQR, 2.5-23.2%), a median relative reduction of 75.5% (IQR, 47.7-93.9%). White cell count and C-reactive protein improved significantly (P = 0.002 and P = 0.032, respectively) from a median of 16.3 × 109 /L (IQR, 11.8-20.6 × 109 /L) to 9.9 × 109 /L (IQR, 8.0-12.3 × 109 /L) and 311.0 mg/L (IQR, 218.8-374.0 mg/L) to 69.0 mg/L (IQR, 36.0-118.0 mg/L), respectively. No patients experienced significant bleeding or died. Five patients (16.1%) were referred for surgery.

CONCLUSION

This is pilot evidence that a practical regimen of concurrent, once-daily intrapleural tPA-DNase improved pleural opacification and inflammatory markers without bleeding or mortality. The surgical referral rate was higher than in studies assessing twice-daily administration, though the validity of this outcome as a measure of treatment success is limited, and further studies are needed to assess the optimal dose and frequency of intrapleural therapy and indications for surgical referral.

Effects of Concurrent Dosing on the Efficacy of Tissue Plasminogen Activator and Deoxyribonuclease in the Treatment of Pleural Infection

BACKGROUND

The goal of this study was to evaluate how the administration of concurrent tissue plasminogen activator (tPA) and deoxyribonuclease (DNase) therapy with variable dosing for complicated parapneumonic effusions and empyema affects patient outcomes in an inner-city community hospital.

METHODS

This retrospective analysis was performed at an inner-city hospital located in Raleigh, North Carolina. A list of all patients treated with tPA and DNase between July 1, 2015, and December 31, 2017, was generated and screened. Data were collected through a review of past medical records, including demographics, past medical history, and details about their hospital course.

RESULTS

A total of 38 patients were found to have been treated with concurrent tPA and DNase for complicated parapneumonic effusion or empyema. Twenty (52.6%) patients received the full six doses of combined concurrent tPA/DNase. Of the 18 (47.4%) patients who did not receive the full six doses, 11 did not require the full six doses for effusion resolution, and seven had to discontinue therapy due to tube blockage or pain. Only seven (18.4%) patients had complications related to tPA/DNase administration, most commonly pain. Nineteen (50%) patients had complete radiological clearance of effusion, with 13 (34.2%) having partial clearance, and six (15.8%) having no change or worsening of their effusion. Eight (21.1%) patients needed further surgical management of their effusion.

CONCLUSIONS

The current most common dosing pattern for combined tPA and DNase therapy of twice daily for three days may not be optimal for all patients. The dosing regimen should be individualized depending on clinical response. Concurrent dosing is safe.

Expert Review on Nonsurgical Management of Parapneumonic Effusion: Advances, Controversies, and New Directions

Parapneumonic effusion and empyema are rising in incidence worldwide, particularly in association with comorbidities in an aging population. Also driving this change is the widespread uptake of pneumococcal vaccines, leading to the emergence of nonvaccine-type pneumococci and other bacteria. Early treatment with systemic antibiotics is essential but should be guided by local microbial guidelines and antimicrobial resistance patterns due to significant geographical variation. Thoracic ultrasound has emerged as a leading imaging technique in parapneumonic effusion, enabling physicians to characterize effusions, assess the underlying parenchyma, and safely guide pleural procedures. Drainage decisions remain based on longstanding criteria including the size of the effusion and fluid gram stain and biochemistry results. Small-bore chest drains appear to be as effective as large bore and are adequate for the delivery of intrapleural enzyme therapy (IET), which is now supported by a large body of evidence. The IET dosing regimen used in the UK Multicenter Sepsis Trial -2 has the most evidence available but data surrounding alternative dosing, concurrent and once-daily instillations, and novel fibrinolytic agents are promising. Prognostic scores used in pneumonia (e.g., CURB-65) tend to underestimate mortality in parapneumonic effusion/empyema. Scores specifically based on pleural infection have been developed but require validation in prospective cohorts.

ERS/ESTS statement on the management of pleural infection in adults

Pleural infection is a common condition encountered by respiratory physicians and thoracic surgeons alike. The European Respiratory Society (ERS) and European Society of Thoracic Surgeons (ESTS) established a multidisciplinary collaboration of clinicians with expertise in managing pleural infection with the aim of producing a comprehensive review of the scientific literature. Six areas of interest were identified: 1) epidemiology of pleural infection, 2) optimal antibiotic strategy, 3) diagnostic parameters for chest tube drainage, 4) status of intrapleural therapies, 5) role of surgery and 6) current place of outcome prediction in management. The literature revealed that recently updated epidemiological data continue to show an overall upwards trend in incidence, but there is an urgent need for a more comprehensive characterisation of the burden of pleural infection in specific populations such as immunocompromised hosts. There is a sparsity of regular analyses and documentation of microbiological patterns at a local level to inform geographical variation, and ongoing research efforts are needed to improve antibiotic stewardship. The evidence remains in favour of a small-bore chest tube optimally placed under image guidance as an appropriate initial intervention for most cases of pleural infection. With a growing body of data suggesting delays to treatment are key contributors to poor outcomes, this suggests that earlier consideration of combination intrapleural enzyme therapy (IET) with concurrent surgical consultation should remain a priority. Since publication of the MIST-2 study, there has been considerable data supporting safety and efficacy of IET, but further studies are needed to optimise dosing using individualised biomarkers of treatment failure. Pending further prospective evaluation, the MIST-2 regimen remains the most evidence based. Several studies have externally validated the RAPID score, but it requires incorporating into prospective intervention studies prior to adopting into clinical practice.

Pleural Space Infections

Pleural space infections have been a well-recognized clinical syndrome for over 4000 years and continue to cause significant morbidity and mortality worldwide. However, our collective understanding of the causative pathophysiology has greatly expanded over the last few decades, as have our treatment options. The aim of this paper is to review recent updates in our understanding of this troublesome disease and to provide updates on established and emerging treatment modalities for patients suffering from pleural space infections. With that, we present a review and discussion synthesizing the recent pertinent literature surrounding the history, epidemiology, pathophysiology, diagnosis, and management of these challenging infections.

Comparing Initial Surgery versus Fibrinolytics for Pleural Space Infections: A Retrospective Multicenter Cohort Study

Rationale: When drainage of complicated pleural space infections alone fails, there exists two strategies in surgery and dual agent-intrapleural fibrinolytic therapy; however, studies comparing these two management strategies are limited. Objectives: To determine the outcomes of surgery versus fibrinolytic therapy as the primary management for complicated pleural space infections (CPSI). Methods: A retrospective review of adults with a CPSI managed with surgery or fibrinolytics between 1/2015 and 3/2018 within a multicenter, multistate hospital system was performed. Fibrinolytics was defined as any dose of dual-agent fibrinolytic therapy and standard fibrinolytics as 5-6 doses twice daily. Treatment failure was defined as persistent infection with a pleural collection requiring intervention. Crossover was defined by any fibrinolytics after surgery or surgery after fibrinolytics. Logistic regression with inverse probability of treatment weighting (IPTW) were employed to account for selection bias effect of management strategies in treatment failure and crossover. Results: We identified 566 patients. Surgery was the initial strategy in 55% (311/566). The surgery group had less additional treatments (surgery: 10% [32/311] versus fibrinolytics: 39% [100/255], P < 0.001), treatment failures (surgery: 7% [22/311] versus fibrinolytics: 29% [74/255], P < 0.001), and crossovers (surgery: 6% [20/311] versus fibrinolytics: 19% [49/255], P < 0.001). Logistic regression analysis with IPTW demonstrated a lower odds of treatment failure with surgery compared with any fibrinolytics (odds ratio [OR], 0.20; 95% confidence interval [CI], 0.10-0.30; P < 0.001); and compared with standard fibrinolytics (OR, 0.20; 95% CI, 0.11-0.35; P < 0.001). Conclusions: Although there is a lack of consensus as to the optimal management strategy for patients with a CPSI, in surgical candidates, operative management may offer more benefits and could be considered early in the management course. However, our study is retrospective and nonrandomized; thus, prospective trials are needed to explore this further.

From Bedside to the Bench—A Call for Novel Approaches to Prognostic Evaluation and Treatment of Empyema

Empyema, a severe complication of pneumonia, trauma, and surgery is characterized by fibrinopurulent effusions and loculations that can result in lung restriction and resistance to drainage. For decades, efforts have been focused on finding a universal treatment that could be applied to all patients with practice recommendations varying between intrapleural fibrinolytic therapy (IPFT) and surgical drainage. However, despite medical advances, the incidence of empyema has increased, suggesting a gap in our understanding of the pathophysiology of this disease and insufficient crosstalk between clinical practice and preclinical research, which slows the development of innovative, personalized therapies. The recent trend towards less invasive treatments in advanced stage empyema opens new opportunities for pharmacological interventions. Its remarkable efficacy in pediatric empyema makes IPFT the first line treatment. Unfortunately, treatment approaches used in pediatrics cannot be extrapolated to empyema in adults, where there is a high level of failure in IPFT when treating advanced stage disease. The risk of bleeding complications and lack of effective low dose IPFT for patients with contraindications to surgery (up to 30%) promote a debate regarding the choice of fibrinolysin, its dosage and schedule. These challenges, which together with a lack of point of care diagnostics to personalize treatment of empyema, contribute to high (up to 20%) mortality in empyema in adults and should be addressed preclinically using validated animal models. Modern preclinical studies are delivering innovative solutions for evaluation and treatment of empyema in clinical practice: low dose, targeted treatments, novel biomarkers to predict IPFT success or failure, novel delivery methods such as encapsulating fibrinolysin in echogenic liposomal carriers to increase the half-life of plasminogen activator. Translational research focused on understanding the pathophysiological mechanisms that control 1) the transition from acute to advanced-stage, chronic empyema, and 2) differences in outcomes of IPFT between pediatric and adult patients, will identify new molecular targets in empyema. We believe that seamless bidirectional communication between those working at the bedside and the bench would result in novel personalized approaches to improve pharmacological treatment outcomes, thus widening the window for use of IPFT in adult patients with advanced stage empyema.

Optimizing the management of complicated pleural effusion: From intrapleural agents to surgery

Pleural effusion is a frequent complication of acute pulmonary infection and can affect its morbidity and mortality. The possible evolution of a parapneumonic pleural effusion includes 3 stages: exudative (simple accumulation of pleural fluid), fibropurulent (bacterial invasion of the pleural cavity), and organized stage (scar tissue formation). Such a progression is favored by inadequate treatment or imbalance between microbial virulence and immune defenses. Biochemical features of a fibrinopurulent collection include a low pH (<7.20), low glucose level (<60 mg/dl), and high lactate dehydrogenase (LDH). A parapneumonic effusion in the fibropurulent stage is usually defined "complicated" since antibiotic therapy alone is not enough for its resolution and an invasive procedure (pleural drainage or surgery) is required. Chest ultrasound is one of the most useful imaging tests to assess the presence of a complicated pleural effusion. Simple parapneumonic effusions are usually anechoic, whereas complicated effusions often have a complex appearance (non-anechoic, loculated, or septated). When simple chest tube placement fails and/or patients are not suitable for more invasive techniques (i.e. surgery), intra-pleural instillation of fibrinolytic/enzymatic therapy (IPET) might represent a valuable treatment option to obtain the lysis of fibrin septa. IPET can be used as either initial or subsequent therapy. Further studies are ongoing or are required to help fill some gaps on the optimal management of parapneumonic pleural effusion. These include the duration of antibiotic therapy, the risk/benefit ratio of medical thoracoscopy and surgery, and new intrapleural treatments such as antibiotic-eluting chest tubes and pleural irrigation with antiseptic agents.

Comparing the outcomes of intrapleural fibrinolytic and DNase therapy versus intrapleural fibrinolytic or DNase therapy: A systematic review and meta-analysis

BACKGROUND

Multiple studies describing the benefits of intrapleural fibrinolytic over placebo and DNase therapy have been published, but few have been published on intrapleural fibrinolytic and DNase therapy.

OBJECTIVE

Our meta-analysis aims to compare the outcomes of surgical intervention, mortality, and hospital length of stay between intrapleural fibrinolytic and DNase therapy with either intrapleural fibrinolytic or DNase therapy alone in patients with pleural space infections.

METHODS

We searched Pubmed, EMBASE, Web of Science, and Cochrane library databases for observational studies and randomized controlled trials (RCTs) containing comparative data for hospitalized adults and children with pleural infections receiving intrapleural therapy of fibrinolytic and DNase versus those receiving intrapleural fibrinolytic or DNase alone. Meta-analysis was performed using the Review Manager software, and heterogeneity was tested using I² statistics.

RESULTS

A total of 2 cohorts and 2 RCTs involving 362 adult and children was included. There was significant reduction in surgical intervention requirement among patients who received intrapleural fibrinolytic and DNase (OR 0.30; 95% CI 0.11-0.83; I² = 31%; P = 0.02) than those receiving either intrapleural fibrinolytic or DNase alone. No difference was observed for mortality (OR 0.72; 95% CI 0.31-1.71; I² = 0%; P = 0.46) and complication rates (OR 3.09; 95% CI 0.75-12,74; I² = 54%; P = 0.12). The hospital length of stay (mean 13.70 vs. 16.67 days; P = 0.19) and duration of chest tube drainage (mean 6.47 vs. 6.30 days; P = 0.58) was similar between the two groups.

CONCLUSION

Combination of intrapleural fibrinolytic and DNase, compared to single-agent intrapleural therapy alone, is associated with a lesser need for surgical interventions. However, no difference was found in mortality, hospital length of stay, and chest tube drainage duration.

Management of complex pleural disease in the critically ill patient

Disorders of the pleural space are quite common in the critically ill patient. They are generally associated with the underlying illness. It is sometimes difficult to assess for pleural space disorders in the ICU given the instability of some patients. Although the portable chest X-ray remains the primary modality of diagnosis for pleural disorders in the ICU. It can be nonspecific and may miss subtle findings. Ultrasound has become a useful tool to the bedside clinician to aid in diagnosis and management of pleural disease. The majority of pleural space disorders resolve as the patient’s illness improves. There remain a few pleural processes that need specific therapies. While uncomplicated parapneumonic effusions do not have their own treatments. Those that progress to become a complex infected pleural space can have its individual complexity in therapy. Chest tube drainage remains the cornerstone in therapy. The use of intrapleural fibrinolytics has decreased the need for surgical referral. A large hemothorax or pneumothorax in patients admitted to the ICU represent medical emergencies and require emergent action. In this review we focus on the management of commonly encountered complex pleural space disorders in critically ill patients such as complicated pleural space infections, hemothoraces and pneumothoraces.

Evaluation and management of pleural sepsis

Pleural sepsis stems from an infection within the pleural space typically from an underlying bacterial pneumonia leading to development of a parapneumonic effusion. This effusion is traditionally divided into uncomplicated, complicated, and empyema. Poor clinical outcomes and increased mortality can be associated with the development of parapneumonic effusions, reinforcing the importance of early recognition and diagnosis. Management necessitates a multimodal therapeutic strategy consisting of antimicrobials, catheter/tube thoracostomy, and at times, video-assisted thoracoscopic surgery.

Intrapleural Fibrinolytic Therapy versus Early Medical Thoracoscopy for Treatment of Pleural Infection. Randomized Controlled Clinical Trial

Rationale: Pleural infection is frequently encountered in clinical practice and is associated with high morbidity and mortality. Limited evidence exists regarding the optimal treatment. Although both early medical thoracoscopy (MT) and tube thoracostomy with intrapleural instillation of tissue plasminogen activator and human recombinant deoxyribonuclease are acceptable treatments for patients with complicated pleural infection, there is a lack of comparative data for these modes of management.Objectives: The aim of this study was to compare the safety and efficacy of early MT versus intrapleural fibrinolytic therapy (IPFT) in selected patients with multiloculated pleural infection and empyema.Methods: This was a prospective multicenter, randomized controlled trial involving patients who underwent MT or IPFT for pleural infection. The primary outcome was the length of hospital stay after either intervention. Secondary outcomes included the total length of hospital stay, treatment failure, 30-day mortality, and adverse events.Results: Thirty-two patients with pleural infection were included in the study. The median length of stay after an intervention was 4 days in the IPFT arm and 2 days in the MT arm (P = 0.026). The total length of hospital stay was 6 days in the IPFT arm and 3.5 days in MT arm (P = 0.12). There was no difference in treatment failure, mortality, or adverse events between the treatment groups, and no serious complications related to either intervention were recorded.Conclusions: When used early in the course of a complicated parapneumonic effusion or empyema, MT is safe and might shorten hospital stays for selected patients as compared with IPFT therapy. A multicenter trial with a larger sample size is needed to confirm these findings.Clinical trial registered with ClinicalTrials.gov (NCT02973139).

Management of Pleural Infection

Pleural infection is a millennia-spanning condition that has proved challenging to treat over many years. Fourteen percent of cases of pneumonia are reported to present with a pleural effusion on chest X-ray (CXR), which rises to 44% on ultrasound but many will resolve with prompt antibiotic therapy. To guide treatment, parapneumonic effusions have been separated into distinct categories according to their biochemical, microbiological and radiological characteristics. There is wide variation in causative organisms according to geographical location and healthcare setting. Positive cultures are only obtained in 56% of cases; therefore, empirical antibiotics should provide Gram-positive, Gram-negative and anaerobic cover whilst providing adequate pleural penetrance. With the advent of next-generation sequencing techniques, yields are expected to improve. Complicated parapneumonic effusions and empyema necessitate prompt tube thoracostomy. It is reported that 16-27% treated in this way will fail on this therapy and require some form of escalation. The now seminal Multi-centre Intrapleural Sepsis Trials (MIST) demonstrated the use of combination fibrinolysin and DNase as more effective in the treatment of empyema compared to either agent alone or placebo, and success rates of 90% are reported with this technique. The focus is now on dose adjustments according to the patient's specific 'fibrinolytic potential', in order to deliver personalised therapy. Surgery has remained a cornerstone in the management of pleural infection and is certainly required in late-stage manifestations of the disease. However, its role in early-stage disease and optimal patient selection is being re-explored. A number of adjunct and exploratory therapies are also discussed in this review, including the use of local anaesthetic thoracoscopy, indwelling pleural catheters, intrapleural antibiotics, pleural irrigation and steroid therapy.

Precision targeting of the plasminogen activator inhibitor-1 mechanism increases efficacy of fibrinolytic therapy in empyema

Plasminogen activator inhibitor‐1 (PAI‐1) is an endogenous irreversible inhibitor of tissue‐type (tPA) and urokinase (uPA) plasminogen activators. PAI‐1‐targeted fibrinolytic therapy (PAI‐1‐TFT) is designed to decrease the therapeutic dose of tPA and uPA, attenuating the risk of bleeding and other complications. Docking site peptide (DSP) mimics the part of the PAI‐1 reactive center loop that interacts with plasminogen activators, thereby affecting the PAI‐1 mechanism. We used DSP for PAI‐1‐TFT in two rabbit models: chemically induced pleural injury and Streptococcus pneumoniae induced empyema. These models feature different levels of inflammation and PAI‐1 expression. PAI‐1‐TFT with DSP (2.0 mg/kg) converted ineffective doses of single chain (sc) tPA (72.5 µg/kg) and scuPA (62.5 µg/kg) into effective ones in chemically induced pleural injury. DSP (2.0 mg/kg) was ineffective in S. pneumoniae empyema, where the level of PAI‐1 is an order of magnitude higher. DSP dose escalation to 8.0 mg/kg resulted in effective PAI‐1‐TFT with 0.25 mg/kg sctPA (1/8th of the effective dose of sctPA alone) in empyema. There was no increase in the efficacy of scuPA. PAI‐1‐TFT with DSP increases the efficacy of fibrinolytic therapy up to 8‐fold in chemically induced (sctPA and scuPA) and infectious (sctPA) pleural injury in rabbits. PAI‐1 is a valid molecular target in our model of S. pneumoniae empyema in rabbits, which closely recapitulates key characteristics of empyema in humans. Low‐dose PAI‐1‐TFT is a novel interventional strategy that offers the potential to improve fibrinolytic therapy for empyema in clinical practice.

Advances in pleural infection and malignancy

Pleural infection and malignancy are among the most common causes of pleural disease and form the mainstay of pleural practice. There has been significant research and increase in scientific understanding in these areas in the past decade. With regard to pleural infection, the rising incidence remains worrying. An increased awareness allowing earlier diagnosis, earlier escalation of therapy and the use of validated risk stratification measures may improve outcomes. In pleural malignancy, research has enabled clinicians to streamline patient pathways with focus on reducing time to diagnosis, definitive management of malignant pleural effusion and achieving these with the minimum number of pleural interventions. Trials comparing treatment modalities of malignant pleural effusion continue to highlight the importance of patient choice in clinical decision-making. This article aims to summarise some of the most recent literature informing current practice in these two areas.

Intrapleural Fibrinolytics and Deoxyribonuclease for Treatment of Indwelling Pleural Catheter-Related Pleural Infection: A Multi-Center Observational Study

BACKGROUND

Indwelling pleural catheters (IPC) are increasingly used for management of recurrent (especially malignant) effusions. Pleural infection associated with IPC use remains a concern. Intrapleural therapy with tissue plasminogen activator (tPA) and deoxyribonuclease (DNase) significantly reduces surgical referrals in non-IPC pleural infection, but data on its use in IPC-related pleural infection are scarce.

OBJECTIVE

To assess the safety and efficacy of intrapleural tPA and DNase in IPC-related pleural infection.

METHODS

Patients with IPC-related pleural infection who received intrapleural tPA/DNase in five Australian and UK centers were identified from prospective databases. Outcomes on feasibility of intrapleural tPA/DNase delivery, its efficacy and safety were recorded.

RESULTS

Thirty-nine IPC-related pleural infections (predominantly Staphylococcus aureus and gram-negative organisms) were treated in 38 patients; 87% had malignant effusions. In total, 195 doses (median 6 [IQR = 3-6]/patient) of tPA (2.5 mg-10 mg) and DNase (5 mg) were instilled. Most (94%) doses were delivered via IPCs using local protocols for non-IPC pleural infections. The mean volume of pleural fluid drained during the first 72 h of treatment was 3,073 (SD = 1,685) mL. Most (82%) patients were successfully treated and survived to hospital discharge without surgery; 7 required additional chest tubes or therapeutic aspiration. Three patients required thoracoscopic surgery. Pleurodesis developed post-infection in 23/32 of successfully treated patients. No major morbidity/mortality was associated with tPA/DNase. Four patients received blood transfusions; none had systemic or significant pleural bleeding.

CONCLUSION

Treatment of IPC-related pleural infection with intrapleural tPA/DNase instillations via the IPC appears feasible and safe, usually without additional drainage procedures or surgery. Pleurodesis post-infection is common.

The Use of Intrapleural Thrombolytic or Fibrinolytic Therapy, or Both, via Indwelling Tunneled Pleural Catheters With or Without Concurrent Anticoagulation Use

BACKGROUND

Indwelling tunneled pleural catheters (IPCs) are used regularly for recurrent pleural effusion management. Catheter obstruction is not uncommon, often requiring intrapleural medications instillation (ie, alteplase) to restore flow. The safety profile of intrapleural medications has been reported previously; however, most studies exclude anticoagulated patients.

RESEARCH QUESTION

What is the safety profile of intrapleural alteplase, dornase alfa, or both when used in patients with IPCs, including in those who may be undergoing active anticoagulation?

STUDY DESIGN AND METHODS

Retrospective review of patients with previously placed IPCs from January 2009 through February 2020 undergoing intrapleural alteplase therapy. Basic demographics, laboratory studies, anticoagulation medication use, and complications were collected. Descriptive statistics were used to report demographics and outcomes. Univariate Firth's logistic regression analyses were used to identify factors associated with complications, followed by multivariate regression analyses.

RESULTS

A total of 94 patients underwent IPC placement and intrapleural instillation. The median age of patients was 66.1 years (interquartile range, 57.6-74.9 years). Intrapleural medications were administered 71 times in 30 anticoagulated patients and 172 times in 64 patients who were not anticoagulated. A total of 20 complications were identified in 18 patients, with one patient experiencing more than one complication. Five bleeding complications occurred with no significant increased risk with anticoagulation use (in 2 anticoagulated patients and 3 patients who were not anticoagulated; P = .092). Multivariate Firth's logistic regression demonstrated that alteplase dose (P = .04) and anticoagulation use (P = .05) were associated with any complication, but were not associated with bleeding complications.

INTERPRETATION

We report a relatively low incidence of complications and, in particular, bleeding complications in patients receiving intrapleural alteplase for nondraining IPCs. Bleeding episodes occurred in five of 94 patients (5.3%) with no apparent increased risk of bleeding complication, regardless of whether receiving anticoagulation. Additional study is warranted to identify risk factors for complications, in particular bleeding complications, in this patient population.

Use of fibrinolytics and deoxyribonuclease in adult patients with pleural empyema: a consensus statement

Although our understanding of the pathogenesis of empyema has grown tremendously over the past few decades, questions still remain on how to optimally manage this condition. It has been almost a decade since the publication of the MIST2 trial, but there is still an extensive debate on the appropriate use of intrapleural fibrinolytic and deoxyribonuclease therapy in patients with empyema. Given the scarcity of overall guidance on this subject, we convened an international group of 22 experts from 20 institutions across five countries with experience and expertise in managing adult patients with empyema. We did a literature and internet search for reports addressing 11 clinically relevant questions pertaining to the use of intrapleural fibrinolytic and deoxyribonuclease therapy in adult patients with bacterial empyema. This Position Paper, consisting of seven graded and four ungraded recommendations, was formulated by a systematic and rigorous process involving the evaluation of published evidence, augmented with provider experience when necessary. Panel members participated in the development of the final recommendations using the modified Delphi technique. Our Position Paper aims to address the existing gap in knowledge and to provide consensus-based recommendations to offer guidance in clinical decision making when considering the use of intrapleural therapy in adult patients with bacterial empyema.

Extended Dwell Time Improves Results of Fibrinolytic Therapy for Complex Pleural Effusions

Introduction

Published trials of intrapleural therapy for complex pleural effusions rely on fibrinolytics and deoxyribonuclease (DNase) with dwell times of less than six hours and frequent dosing. We reviewed our experience with fibrinolytics alone but with a longer dwell time (12 hours).

Methods

Tissue plasminogen activator (tPA, 1-6 mg per dose) was given through pigtail catheters placed using image guidance. Planned treatment was for a dwell time of 12 hours with repeat dosing daily for three days or until drainage was less than 100 cc or grossly bloody. Chest x-ray and/or computed tomography (CT) were used to determine completeness of pleural drainage.

Results

Forty-six patients presenting with 47 complex pleural effusions were given 131 doses of tPA. Doses of 4, 5, and 6 mg were most common (n=17, 70, and 33, respectively). Dwell time ranged from five to 14 hours with 12 hours being most common (n=115). Additional chest tubes were placed in 18 effusions. Ten effusions (21%) required decortication: seven for trapped lung and three for incomplete drainage. Drainage was considered complete in 33/40 (82.5%) effusions without trapped lung. Median chest tube duration was seven days (range three to 28 days). tPA therapy was discontinued in two patients for bleeding, but neither experienced hemodynamic instability.

Conclusions

tPA with a 12-hour dwell time is effective and safe for management of complex pleural effusions, although chest tube duration was prolonged. tPA alone is less expensive and easier than when combined with DNase, and this strategy warrants a prospective evaluation.

Clinical efficacy and bleeding outcomes of tissue plasminogen activator and dornase alfa in pleural space infection with once daily concurrent administration: a retrospective cohort study

Objective

The use of intrapleural tissue plasminogen activator (tPA) and dornase alfa (DNase) is common in the management of pleural space infection. We review our experience with the efficacy and safety of this therapy. We performed a single center, retrospective study of consecutive patients with complicated parapneumonic effusion or empyema who received tPA/DNase therapy. Treatment success was defined as radiographic and clinical improvement in pleural space infection that precluded the need for surgical intervention, and the absence of mortality related to pleural infection.

Results

Fifty-six patients received concurrent once daily tPA/DNase therapy (median 3 days) from July 2014 to July 2019. Fifty-two patients (92.9%) had treatment success. Median duration of chest tube therapy was 10 days and length of stay was 15 days. Significant pleural bleeding requiring transfusion therapy occurred in five patients (8.9%). Of these, three patients (5.4%) required operative intervention. Concurrent once daily administration of tPA/DNase in patients with pleural infection yielded comparable rates of treatment success as compared to twice daily concurrent or sequential administration. However, adverse events highlight potential safety concerns with using once daily concurrent administration of tPA/DNAse.

Low dose intrapleural alteplase and pulmozyme (DNase) in two post-surgical patients with pleural sepsis

Alteplase and pulmozyme (DNase) administered intrapleurally have revolutionised the management of pleural infection in the last decade. However, the use of intrapleural fibrinolytic has not been well established in high risks patients. Here, we describe 2 patients with high risk of bleeding due to recent surgery who developed empyema; successfully treated with these medications. The first patient was a 36-year-old female post oesophagectomy for oesophageal carcinoma, complicated with anastomotic leak and empyema; and the second patient was a 56-year-old female post percutaneous nephrolithotomy for right obstructive uropathy who developed right-sided empyema. Both patients were treated successfully with 3 doses of intrapleural alteplase 2.5 mg and DNase 5 mg without any major adverse effects. This case report adds to the current literature on the safety of intrapleural fibrinolytics and highlights that lower doses of alteplase in combination with pulmozyme is efficacious and may be considered in high-risk patients.

Resolution of Empyema Thoracis after Patient Refusal of Surgical Intervention: A Case Series and Review of the Literature

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Parapneumonic effusions occur commonly in patients hospitalised with pneumonia. Both complicated parapneumonic effusions and empyema are often managed initially with tube thoracostomy and intrapleural t-PA and DNase. If complete expansion of the lung is not achieved, surgical intervention is considered. We present three cases of patients with complicated parapneumonic effusions who experienced complete recovery despite declining surgical intervention and discuss the pitfalls in management. While very few patients have complete radiological resolution at the time of discharge, medical therapy is successful in at least 90% of cases. At 3-6 months from presentation, the radiological findings may improve significantly with antibiotic therapy. Surgery should be considered for patients with non-resolving sepsis markers including elevated temperature, C-reactive protein, and white blood cell count, in addition to non-improving imaging. Incomplete resolution of the parapneumonic effusion should not be considered a treatment failure, and attempts to normalise CT imaging may result in prolonged hospitalisation and unnecessary surgical intervention.

The microbiology of pleural infection in adults: a systematic review

BACKGROUND AND OBJECTIVES

Pleural infection is a major cause of morbidity and mortality among adults. Identification of the offending organism is key to appropriate antimicrobial therapy. It is not known whether the microbiological pattern of pleural infection is variable temporally or geographically. This systematic review aimed to investigate available literature to understand the worldwide pattern of microbiology and the factors that might affect such pattern.

DATA SOURCES AND ELIGIBILITY CRITERIA

Ovid MEDLINE and Embase were searched between 2000 and 2018 for publications that reported on the microbiology of pleural infection in adults. Both observational and interventional studies were included. Studies were excluded if the main focus of the report was paediatric population, tuberculous empyema or post-operative empyema.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies of ≥20 patients with clear reporting of microbial isolates were included. The numbers of isolates of each specific organism/group were collated from the included studies. Besides the overall presentation of data, subgroup analyses by geographical distribution, infection setting (community versus hospital) and time of the report were performed.

RESULTS

From 20 980 reports returned by the initial search, 75 articles reporting on 10 241 patients were included in the data synthesis. The most common organism reported worldwide was Staphylococcus aureus. Geographically, pneumococci and viridans streptococci were the most commonly reported isolates from tropical and temperate regions, respectively. The microbiological pattern was considerably different between community- and hospital-acquired infections, where more Gram-negative and drug-resistant isolates were reported in the hospital-acquired infections. The main limitations of this systematic review were the heterogeneity in the method of reporting of certain bacteria and the predominance of reports from Europe and South East Asia.

CONCLUSIONS

In pleural infection, the geographical location and the setting of infection have considerable bearing on the expected causative organisms. This should be reflected in the choice of empirical antimicrobial treatment.

A systematic review of comorbidities and outcomes of adult patients with pleural infection

Background

Pleural infection remains an important cause of mortality. This study aimed to investigate worldwide patterns of pre-existing comorbidities and clinical outcomes of patients with pleural infection.

Methods

Studies reporting on adults with pleural infection between 2000 and 2017 were identified from a search of Embase and MEDLINE. Articles reporting exclusively on tuberculous, fungal or post-pneumonectomy infection were excluded. Two reviewers assessed 20 980 records for eligibility.

Results

211 studies met the inclusion criteria. 134 articles (227 898 patients, mean age 52.8 years) reported comorbidity and/or outcome data. The majority of studies were retrospective observational cohorts (n=104, 78%) and the most common region of reporting was East Asia (n=33, 24%) followed by North America (n=27, 20%). 85 articles (50 756 patients) reported comorbidity. The median (interquartile range (IQR)) percentage prevalence of any comorbidity was 72% (58–83%), with respiratory illness (20%, 16–32%) and cardiac illness (19%, 15–27%) most commonly reported. 125 papers (192 298 patients) reported outcome data. The median (IQR) length of stay was 19 days (13–27 days) and median in-hospital or 30-day mortality was 4% (IQR 1–11%). In regions with high-income economies (n=100, 74%) patients were older (mean 56.5 versus 42.5 years, p<0.0001), but there were no significant differences in prevalence of pre-existing comorbidity nor in length of hospital stay or mortality.

Conclusion

Patients with pleural infection have high levels of comorbidity and long hospital stays. Most reported data are from high-income economy settings. Data from lower-income regions is needed to better understand regional trends and enable optimal resource provision going forward.

In pleural infection, patients from higher-income countries tend to be older with more comorbidities and are more likely to be referred for fibrinolytic treatment in comparison to patients from lower-income countrieshttp://bit.ly/2K2M5HL

Comparison of intrapleural use of urokinase and tissue plasminogen activator/DNAse in pleural infection

Fibrinolysis can be used to improve fluid drainage in pleural infection. Treatment with either urokinase or tissue plasminogen activator (t-PA) in association with DNAse via a chest tube has been effective at reducing the need for surgery. This study is the first to compare the efficacy of these two treatments. We performed a single-centre, controlled, prospective cohort study. All individuals with pleural infection admitted to our hospital between January 2014 and December 2017 who were treated with antibiotics, a chest tube and fibrinolysis were included in this study. The rate of additional procedure requirements (additional chest tube or surgery) after initial fibrinolysis, complications, costs, and radiological and biological outcomes were analysed. Among the 93 patients included in this study, 34% required additional procedures after an initial fibrinolysis, including 21% who received an additional chest tube and 13% who underwent thoracoscopy. The need for additional procedures arose due to presence of multiple pleural collections (p=0.01) and was associated with the use of large-bore drain (p=0.01). The success rate of fibrinolysis was not significantly different between urokinase and t-PA/DNAse (p=0.35). The differences in drainage duration and in length of hospital stay were not significant either (p=0.05 and p=0.12, respectively). Treatment with t-PA/DNAse was cheaper (p=0.04) but was associated with a higher rate of haemothorax (p=0.002). In conclusion, treatment with urokinase is safer and equally effective when compared with treatment with t-PA/DNAse.

Cost-effectiveness of intrapleural use of tissue plasminogen activator and DNase in pleural infection: evidence from the MIST2 randomised controlled trial

The MIST2 (Second Multicentre Intrapleural Sepsis Trial) trial showed that combined intrapleural use of tissue plasminogen activator (t-PA) and recombinant human DNase was effective when compared with single agents or placebo. However, the treatment costs are significant and overall cost-effectiveness of combined therapy remains unclear.

An economic evaluation of the MIST2 trial was performed to assess the cost-effectiveness of combined therapy. Costs included were those related to study medications, initial hospital stay and subsequent hospitalisations. Outcomes were measured in terms of life-years gained. All costs were reported in euro and in 2016 prices.

Mean annual costs were lowest in the t-PA–DNase group (EUR 10 605 for t-PA, EUR 17 856 for DNase, EUR 13 483 for placebo and EUR 7248 for t-PA–DNase; p=0.209). Mean 1-year life expectancy was 0.988 for t-PA, 0.923 for DNase, and 0.969 for both placebo and t-PA–DNase (p=0.296). Both DNase and placebo were less effective, in terms of life-years gained, and more costly than t-PA. When placebo was compared with t-PA–DNase, the incremental cost per life-year gained of placebo was EUR 1.6 billion, with a probability of 0.85 of t-PA–DNase being cost-effective.

This study demonstrates that combined t-PA–DNase is likely to be highly cost-effective. In light of this evidence, a definitive trial designed to facilitate a thorough economic evaluation is warranted to provide further evidence on the cost-effectiveness of this promising combined intervention.

Emerging concepts in pleural infection

PURPOSE OF REVIEW

Pleural infection remains an important pulmonary disease, causing significant morbidity and mortality. There is a resurgence of disease burden despite introduction of antibiotics and pneumococcal vaccines. A revisit of the pathogenesis and update on intervention may improve the care of pleural infection.

RECENT FINDINGS

Recent studies have uncovered the prognostic implication of the presence of a pleural effusion in patients with pneumonia. Identifying where the bacteria lives may have diagnostic and therapeutic implications. Over-exaggerated pleural inflammation may underlie development of parapneumonic effusion as indirect evidence and a randomized study in children raised a role of corticosteroids in parapneumonic pleural effusions, but data are lacking for adults. Optimization of the delivery regimen of intrapleural fibrinolytic and deoxyribonuclease therapy is ongoing.

SUMMARY

The review aims to review the current practice and explore new directions of treatment on pleural infection.

Recent developments in the management of pleural infection: A comprehensive review

OBJECTIVES

Pleural infection is a condition commonly encountered by the respiratory physician. This review aims to provide the reader with an update on the most recent data regarding the epidemiology, microbiology, and the management of pleural infection.

DATA SOURCE

Medline was searched for articles related to pleural infection using the terms "pleural infection," "empyema," and "parapneumonic." The search was limited to the years 1997-2017. Only human studies and reports in English were included.

RESULTS

A rise in the incidence of pleural infection is seen worldwide. Despite the improvement in healthcare practices, the mortality from pleural infection remains high. The role of oral microflora in the etiology of pleural infection is firmly established. A concise review of the recent insights on the pathogenesis of pleural infections is presented. A particular focus is made on the role of tPA, DNAse and similar substances and their interaction with inflammatory cells and how this affects the pathogenesis and treatment of pleural infection.

CONCLUSION

Pleural infection is a common disease with significant morbidity and mortality, as well as a considerable economic burden. The role of medical management is expanding thanks to the widespread use of newer treatments.

Concurrent Versus Sequential Intrapleural Instillation of Tissue Plasminogen Activator and Deoxyribonuclease for Pleural Infection

BACKGROUND

Treatment of pleural infection with instillation of sequential intrapleural tissue plasminogen activator (tPA) and human recombinant deoxyribonuclease (DNase) twice daily for a total of 6 doses has been shown to decrease surgical referral and improve radiographic imaging. This labor-intensive regimen was empirically chosen. Thus, it remains unclear whether the 2 drugs can be administered immediately one after the other (concurrent administration) instead of instilling them separately with a 1-hour to 2-hour interval in between (sequential administration). The aim of this study was to compare the efficacy and safety of sequential versus concurrent tPA/DNase therapy in patients with pleural infection.

METHODS

This was a prospective observational study. Consecutive patients with pleural infection who received concurrent and sequential tPA/DNase were included. The initiation and number of doses of tPA/DNase therapy were based on the amount of pleural fluid drainage, clinical response and radiographic findings.

RESULTS

A total of 38 patients with pleural infection received tPA/DNase treatment: 18 in the sequential group and 20 in the concurrent group. Treatment was successful in 77.7% in the sequential group and 75% in concurrent group (P=0.57). There was no statistically significant difference between the 2 treatment groups (sequential and concurrent) in median pleural fluid drainage (P=0.45), median volume of pleural effusion estimated on chest computed tomography scan (P=0.4) or median hemithorax occupied by effusion on chest radiography (P=0.83) following intrapleural therapy. One patient required a blood transfusion for gradual pleural blood loss in each treatment group. Pain needing escalation of analgesia affected 3 patients in each arm but none required cessation of therapy.

CONCLUSION

A simpler regimen of concurrent administration of intrapleural tPA/DNase as compared with sequential intrapleural therapy is safe, effective, and represents a viable option for the management of pleural infection.

Rethinking the Doses of Tissue Plasminogen Activator and Deoxyribonuclease Administrated Concurrently for Intrapleural Therapy for Complicated Pleural Effusion and Empyema

Background

Complicated parapneumonic effusions empyema (CPEE) is fairly common and associated with increased morbidity and mortality. The Multicenter Intrapleural Sepsis Trial 2 (MIST 2) established the combination of intrapleural deoxyribonuclease (DNase) and tissue plasminogen activator (tPA) as an effective treatment for CPEE, thereby avoiding surgery and decreasing the length of hospitalization. MIST 2, however, used a labor-intensive protocol with some risk of bleeding. We hypothesize the simpler regimen of concurrent administration of intrapleural tPA and DNase (lower dose of tPA and a higher DNAse dose) to be equally effective with a decreased risk of bleeding.

Methods

Retrospective analysis of the concurrent administration of intrapleural tPA and DNase for CPEE during November 2014 to February 2016 was done at a tertiary care center. The inclusion criteria included 1) pleural fluid with any of the following: (a) exudative and loculated effusion in a patient with pneumonia, (b) gram stain/culture positive, (c) macroscopically purulent 2) chest tube placement during current hospitalization 3) concurrent administration of intrapleural tPA and DNase (4mg and 10mg per instillation respectively). The exclusion criteria was 1) chest tube placement prior to current hospitalization and 2) age < eighteen.

Results

Seventeen patients received concurrent tPA and DNase therapy for CPEE in the study period. Two had chest tubes placed prior to current hospitalization and were excluded. Twelve patients (80%) were successfully discharged with clinical resolution of CPEE with medical therapy. One (7%) patient required surgery. No mortality due to pleural sepsis was noted. The median number of concurrent tPA and DNase treatment was two. Median cumulative tPA dose was 8 mg (mean: 14.1±17 mg) and median cumulative DNase dose was 20mg (mean: 19.7 ± 12.2 mg). The median dwell time for the chest tubes was 8.5 days. Our regimen had similar success when compared to MIST 2 and allowed for lesser treatments and cumulative doses. No complication of intrapleural therapy with hemorrhagic conversion of CPEE, or worsening pain leading to discontinuation of therapy was noted.

Conclusion

The concurrent administration of intrapleural therapy at lower doses than the current standard MIST 2 protocol is practical, efficient and effective. We suggest a higher DNase dose with a lower tPA dose which may further decrease hemorrhagic complications. Further randomized trials are required to establish the optimal dose of intrapleural therapy for CPEE.

Fibrin turnover and pleural organization: bench to bedside

Recent studies have shed new light on the role of the fibrinolytic system in the pathogenesis of pleural organization, including the mechanisms by which the system regulates mesenchymal transition of mesothelial cells and how that process affects outcomes of pleural injury. The key contribution of plasminogen activator inhibitor-1 to the outcomes of pleural injury is now better understood as is its role in the regulation of intrapleural fibrinolytic therapy. In addition, the mechanisms by which fibrinolysins are processed after intrapleural administration have now been elucidated, informing new candidate diagnostics and therapeutics for pleural loculation and failed drainage. The emergence of new potential interventional targets offers the potential for the development of new and more effective therapeutic candidates.

Infectious pleural effusion status and treatment progress

Pleural cavity infection continuously seriously threatens human health with continuous medical progress. From the perspective of pathophysiology, it can be divided into three stages: exudative stage, fibrin exudation and pus formation stage, and organization stage. Due to the pathogenic bacteria difference of pleural cavity infection and pulmonary infection, it is very important for disease treatment to analyze the bacteria and biochemical characteristics of the infectious pleural effusion. Most prognoses of patients have been relatively good, while for some patients, the complicated parapneumonic effusion or empyema could be evolved. Antibiotic treatment and sufficient drainage are the foundation for this treatment. No evidence can support the routine use of a fibrin agent. However, it has been reported that the plasminogen activator and deoxyribonuclease can be recommended to be applied in the pleural cavity. In case of failure on conservative medical treatment, operative treatment can be applied such as thoracoscopy and pleural decortication. According to the clinical characteristics of these patients, it is a key to research prognosis, as well as early evaluation and stratification, in the future.

Use of intrapleural tissue plasminogen activator and deoxyribonuclease in pleural space infections: an update on alternative regimens

PURPOSE OF REVIEW

Pleural infection remains a common problem with significant associated morbidity and mortality. The current treatment paradigm for pleural infection appears to be shifting as more recent data have suggested that the use of intrapleural fibrinolytic therapy (IPFT) may be adequate for treatment, potentially avoiding the need for surgical intervention in a significant number of patients.

RECENT FINDINGS

The previous Multicenter Intrapleural Sepsis Trial demonstrated improved outcomes when utilizing combined IPFT, however, more recently alterations in this dosing regimen have been explored. Successful retrospective studies have examined the role of extended dosing (more than six sequential doses), concurrent dosing (instilling both medications together as opposed to separate medication dwell times), and daily dosing of intrapleural medications.

SUMMARY

Although the use of IPFT is likely shifting the management of pleural infection to less surgical intervention, the optimal dosing strategy of intrapleural therapy remains undefined. Within the last few years more data on variations of IPFT have emerged. This data remains of lower quality because of its retrospective nature and future prospective evaluation is required to further define the optimal dosing regimen for IPFT in complicated pleural space infections.

Pleural diseases

PURPOSE OF REVIEW

Due to the increasing burden of pleural diseases worldwide, a personalized cost-effective management of these conditions is essential to optimize the healthcare sources. The current review is focused on latest evidence in diagnostic work-up and management of pleural diseases.

RECENT FINDINGS

Recent research highlights the increasing role of thoracic ultrasound in both diagnostic and therapeutic interventions and the potential suitability of cytological sampling from pleural effusions for molecular analysis, essential requirement for a satisfactory test in the era of personalized anticancer therapy. The thoracoscopic approach, by means of rigid or semirigid instruments, remains the gold standard, and attractive tools to increase diagnostic yield in semirigid pleuroscopy include insulated-tip diathermic knife and cryprobe. Talc pleurodesis and indwelling pleural catheters are the most effective interventions, and their combination, likely to result in additional benefits, is currently under investigation.

SUMMARY

Because of the huge variety of possible clinical settings, a proper management of pleural diseases should be tailored on a case-by-case basis and requires a multidisciplinary approach. Recent advances in technologies has conferred to interventional pulmonology an increasing relevant role in this context, leading to the development of a dedicated subspecialty, and training programs are urgently needed to standardize skills and care pathways.