Intrapleural tissue plasminogen activator and deoxyribonuclease for pleural infection. An effective and safe alternative to surgery

Ultrasound in the Study of Thoracic Diseases: Innovative Aspects

Thoracic ultrasound (TU) has rapidly gained popularity over the past 10 years. This is in part because ultrasound equipment is available in many settings, more training programmes are educating trainees in this technique, and ultrasound can be done rapidly without exposure to radiation. The aim of this review is to present the most interesting and innovative aspects of the use of TU in the study of thoracic diseases. In pleural diseases, TU has been a real revolution. It helps to differentiate between different types of pleural effusions, guides the performance of pleural biopsies when necessary and is more cost-effective under these conditions, and assists in the decision to remove thoracic drainage after talc pleurodesis. With the advent of COVID19, the use of TU has increased for the study of lung involvement. Nowadays it helps in the diagnosis of pneumonias, tumours and interstitial diseases, and its use is becoming more and more widespread in the Pneumology ward. In recent years, TU guided biopsies have been shown to be highly cost-effective, with other advantages such as the absence of radiation and the possibility of being performed at bedside. The use of contrast in ultrasound to increase the cost-effectiveness of these biopsies is very promising. In the study of the mediastinum and peripheral pulmonary nodules, the introduction of echobronchoscopy has brought about a radical change. It is a fully established technique in the study of lung cancer patients. The introduction of elastography may help to further improve its cost-effectiveness. In critically-ill patients, diaphragmatic ultrasound helps in the assessment of withdrawal of mechanical ventilation, and is now an indispensable tool in the management of these patients. In neuromuscular patients, ultrasound is a good predictor of impaired lung function. Currently, in Neuromuscular Disease Units, TU is an indispensable tool. Ultrasound study of the intercostal musculature is also effective in the study of respiratory function, and is widely used in Respiratory Rehabilitation. In Intermediate Care Units, thoracic ultrasound is indispensable for patient management. In these units there are ultrasound protocols for the management of patients with acute dyspnoea that have proven to be very effective.

Early Video-assisted Thoracoscopic Surgery or Intrapleural Enzyme Therapy in Pleural Infection: A Feasibility Randomized Controlled Trial. The Third Multicenter Intrapleural Sepsis Trial-MIST-3

Rationale: Assessing the early use of video-assisted thoracoscopic surgery (VATS) or intrapleural enzyme therapy (IET) in pleural infection requires a phase III randomized controlled trial (RCT). Objectives: To establish the feasibility of randomization in a surgery-versus-nonsurgery trial as well as the key outcome measures that are important to identify relevant patient-centered outcomes in a subsequent RCT. Methods: The MIST-3 (third Multicenter Intrapleural Sepsis Trial) was a prospective multicenter RCT involving eight U.K. centers combining on-site and off-site surgical services. The study enrolled all patients with a confirmed diagnosis of pleural infection and randomized those with ongoing pleural sepsis after an initial period (as long as 24 h) of standard care to one of three treatment arms: continued standard care, early IET, or a surgical opinion with regard to early VATS. The primary outcome was feasibility based on >50% of eligible patients being successfully randomized, >95% of randomized participants retained to discharge, and >80% of randomized participants retained to 2 weeks of follow-up. The analysis was performed per intention to treat. Measurements and Main Results: Of 97 eligible patients, 60 (62%) were randomized, with 100% retained to discharge and 84% retained to 2 weeks. Baseline demographic, clinical, and microbiological characteristics of the patients were similar across groups. Median times to intervention were 1.0 and 3.5 days in the IET and surgery groups, respectively (P = 0.02). Despite the difference in time to intervention, length of stay (from randomization to discharge) was similar in both intervention arms (7 d) compared with standard care (10 d) (P = 0.70). There were no significant intergroup differences in 2-month readmission and further intervention, although the study was not adequately powered for this outcome. Compared with VATS, IET demonstrated a larger improvement in mean EuroQol five-dimension health utility index (five-level edition) from baseline (0.35) to 2 months (0.83) (P = 0.023). One serious adverse event was reported in the VATS arm. Conclusions: This is the first multicenter RCT of early IET versus early surgery in pleural infection. Despite the logistical challenges posed by the coronavirus disease (COVID-19) pandemic, the study met its predefined feasibility criteria, demonstrated potential shortening of length of stay with early surgery, and signals toward earlier resolution of pain and a shortened recovery with IET. The study findings suggest that a definitive phase III study is feasible but highlights important considerations and significant modifications to the design that would be required to adequately assess optimal initial management in pleural infection.The trial was registered on ISRCTN (number 18,192,121).

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.

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.

Clinical Risk Factors for Death in Patients With Empyema and Active Malignancy

Background Pleural infection is a common clinical problem resulting in prolonged hospitalization and increased mortality. In patients with active malignancy, management decisions are based on the need for further immunosuppressive therapies, the ability to tolerate surgery, and consideration of the limited life expectancy. Identifying patients at risk for death or poor outcomes is very important as it will guide care. Study design and methods This is a retrospective cohort study of all patients with active malignancy and empyema. The primary outcome was time to death from empyema at three months. The secondary outcome was surgery at 30 days. Standard Cox regression model and cause-specific hazard regression model were used to analyze the data. Results A total of 202 patients with active malignancy and empyema were included. The overall mortality rate at three months was 32.7%. On multivariable analysis, female gender and higher urea were associated with an increased risk of death from empyema at three months. The area under the curve (AUC) of the model was 0.70. The risk factors for surgery at 30 days included the presence of frank pus and postsurgical empyema. The AUC of the model was 0.76. Interpretation Patients with active malignancy and empyema have a high probability of death. In our model, the risk factors for death from empyema included female gender and higher urea.

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.

Management of complicated parapneumonic effusions

PURPOSE OF REVIEW

Approximately 36-57% of cases of pneumonia are associated with a parapneumonic effusion (PPE). It begins as sterile effusion, which can quickly evolve to a fibrinopurulent stage with evidence of infection called complicated parapneumonic effusions (CPPE). Marked fibrinous organization then follows. This study focuses on literature synthesis on management of CPPE.

RECENT FINDINGS

Ultrasound has become an indispensable tool in the identification and treatment of CPPE. Prompt antibiotic administration remains the universal standard of care. Decision to drain the fluid is based on fluid staging, characterization and assessment of risk of poor outcomes vs. risk of complications. There is growing evidence to support use of intrapleural fibrinolytic therapy (IPFT) in case of loculated effusions. Newer areas of research include antibodies against plasminogen activator inhibitors and stratification scores that can identify patients at an increased risk. Lastly, timing of surgical referral is an important area under study.

SUMMARY

Evolution of medical therapy over recent years has increased treatment success rates. Use of IPFT in conjunction to thoracostomy is now the standard of care for loculated effusions. Understanding available therapeutic options, both medical and interventional, can ensure evidence-based practice and improve patient-centred outcomes.

Bleeding Risk With Combination Intrapleural Fibrinolytic and Enzyme Therapy in Pleural Infection: An International, Multicenter, Retrospective Cohort Study

BACKGROUND

Combination intrapleural fibrinolytic and enzyme therapy (IET) has been established as a therapeutic option in pleural infection. Despite demonstrated efficacy, studies specifically designed and adequately powered to address complications are sparse. The safety profile, the effects of concurrent therapeutic anticoagulation, and the nature and extent of nonbleeding complications remain poorly defined.

RESEARCH QUESTION

What is the bleeding complication risk associated with IET use in pleural infection?

STUDY DESIGN AND METHODS

This was a multicenter, retrospective observational study conducted in 24 centers across the United States and the United Kingdom. Protocolized data collection for 1,851 patients treated with at least one dose of combination IET for pleural infection between January 2012 and May 2019 was undertaken. The primary outcome was the overall incidence of pleural bleeding defined using pre hoc criteria.

RESULTS

Overall, pleural bleeding occurred in 76 of 1,833 patients (4.1%; 95% CI, 3.0%-5.0%). Using a half-dose regimen (tissue plasminogen activator, 5 mg) did not change this risk significantly (6/172 [3.5%]; P = .68). Therapeutic anticoagulation alongside IET was associated with increased bleeding rates (19/197 [9.6%]) compared with temporarily withholding anticoagulation before administration of IET (3/118 [2.6%]; P = .017). As well as systemic anticoagulation, increasing RAPID score, elevated serum urea, and platelets of < 100 × 10⁹/L were associated with a significant increase in bleeding risk. However, only RAPID score and use of systemic anticoagulation were independently predictive. Apart from pain, non-bleeding complications were rare.

INTERPRETATION

IET use in pleural infection confers a low overall bleeding risk. Increased rates of pleural bleeding are associated with concurrent use of anticoagulation but can be mitigated by withholding anticoagulation before IET. Concomitant administration of IET and therapeutic anticoagulation should be avoided. Parameters related to higher IET-related bleeding have been identified that may lead to altered risk thresholds for treatment.

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.

The cost of treatments for retained traumatic hemothorax: A decision analysis

INTRODUCTION

Early video-assisted thorascopic surgery (VATS) is the recommended intervention for retained hemothorax in trauma patients. Alternative options, such as lytic therapy, to avoid surgery remain controversial. The purpose of this decision analysis was to assess expected costs associated with treatment strategies.

METHODS

A decision tree analysis estimated the expected costs of three initial treatment strategies: 1) VATS, 2) intrapleural tissue plasminogen activator (TPA) lytic therapy, and 3) intrapleural non-TPA lytic therapy. Probability parameters were estimated from published literature. Costs were based on National Inpatient Sample data and published estimates. Our model compared overall expected costs of admission for each strategy. Sensitivity analyses were conducted to explore the impact of parameter uncertainty on the optimal strategy.

RESULTS

In the base case analysis, using TPA as the initial approach had the lowest total cost (U.S. $37,007) compared to VATS ($38,588). TPA remained the optimal initial approach regardless of the probability of complications after VATS. TPA was an optimal initial approach if TPA success rate was >83% regardless of the failure rate with VATS. VATS was the optimal initial strategy if its total cost of admission was <$33,900.

CONCLUSION

Lower treatment costs with lytic therapy does not imply significantly lower total cost of trauma admission. However, an initial approach with TPA lytic therapy may be preferred for retained traumatic hemothorax to lower the total cost of admission given its high probability of avoiding the operating room with its resultant increased costs. Future studies should identify differences in quality of life after recovery from competing interventions.

Hemothorax With White-Out Lung After Intrapleural Tissue Plasminogen Activator and Deoxyribonuclease Therapy in a Patient With Complicated Parapneumonic Effusion

Tissue plasminogen activator (tPA) and recombinant deoxyribonuclease (DNase ) are used in treating pleural infection due to their mucolytic activity by effectively reducing pleural fluid viscosity. The combination of tPA and DNase has attracted considerable interest as an alternative to surgical intervention for treating complicated parapneumonic effusion in high-risk patients who are not good candidates for surgery. However, intrapleural hemorrhage has been reported as a villainous outcome in a few cases which needs to be considered as a differential diagnosis with sudden clinical deterioration after the therapy. Here, we report the case of a patient who presented with pneumonia and later developed a large right complicated parapneumonic pleural effusion. A chest tube was placed with drainage of fluid while tPA and DNase were also considered as an additional treatment module. Following the first dose of DNase and tPA, the patient developed hypoxemia with hypotension and was found to have rapid development of white-out right hemothorax.

Modified regimen intrapleural alteplase with pulmozyme in pleural infection management: a tertiary teaching hospital experience

Background

Current management of poorly draining complex effusions favours less invasive image-guided placement of smaller tubes and adjunctive intrapleural fibrinolysis therapy (IPFT). In MIST-2 trial, intrapleural 10 mg alteplase (t-PA) with 5 mg of pulmozyme (DNase) twice daily for 72 h were used. We aimed to assess the effectiveness and safety of a modified regimen 16 mg t-PA with 5 mg of DNase administered over 24 h in the management of complex pleural infection.

Methods

This was a single centre, prospective study involving patients with poorly drained pleural infection. Primary outcome was the change of pleural opacity on chest radiograph at day 7 compared to baseline. Secondary outcomes include volume of fluid drained, inflammatory markers improvement, surgical referral, length of hospitalisation, and adverse events.

Results

Thirty patients were recruited. Majority, 27 (90%) patients were successfully treated. Improvement of pleural opacity on chest radiograph was observed from 36.9% [Interquartile range (IQR 21.8–54.9%)] to 18.1% (IQR 8.8–32.7%) of hemithorax (P < 0.05). T-PA/DNase increased fluid drainage from median of 45 mls (IQR 0–100) 24 h prior to intrapleural treatment to 1442 mls (IQR 905–2360) after 72 h; (P < 0.05) and reduction of C-reactive protein (P < 0.05). Pain requiring escalation of analgesia affected 20% patients and 9.9% experienced major adverse events. None required surgical intervention.

Conclusion

This study suggests that a modified regimen 16 mg t-PA with 5 mg DNase can be safe and effective for patients with poorly drained complex pleural infection.

Trial registration The study was registered retrospectively on 07/06/2021 with ClinicalTrials number NCT04915586 (https://clinicaltrials.gov/ct2/show/NCT04915586).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01995-z.

Alteplase Dose Assessment for Pleural infection Therapy (ADAPT) Study-2: Use of 2.5 mg alteplase as a starting intrapleural dose

BACKGROUND AND OBJECTIVE

Intrapleural tissue plasminogen activator/deoxyribonuclease (tPA/DNase) therapy is increasingly used in pleural infection. Bleeding risks and costs associated with tPA remain the clinical concerns. Our dose de-escalation series aims to establish the lowest effective dosing regimen for tPA/DNase. This study assesses the intrapleural use of 2.5 mg tPA/5 mg DNase for pleural infection.

METHODS

Consecutive patients with pleural infection treated with a starting regime of 2.5 mg tPA/5 mg DNase were included from two centres in Australia and UK. Escalation of tPA dose was permitted if clinical response was inadequate.

RESULTS

Sixty-nine patients (mean age 61.0 years) received intrapleural 2.5 mg tPA/5 mg DNase. Most (88.4%) were treated successfully and discharged from hospital without surgery by 90 days. Patients received a median of 5 [interquartile range [IQR] = 3-6] doses of tPA/DNase. Total amount of tPA used per patient was 12.5 mg [median, IQR = 7.5-15.0]. Seventeen patients required dose escalation of tPA; most (n = 12) for attempted drainage of distant non-communicating locule(s). Treatment success was corroborated by clearance of pleural opacities on radiographs (from median 27.0% [IQR = 17.1-44.5] to 11.0% [IQR = 6.4-23.3] of hemithorax, p < 0.0001), increased pleural fluid drainage (1.98 L [median, IQR = 1.38-2.68] over 72 h following commencement of tPA/DNase) and reduction of serum C-reactive protein level (by 45.0% [IQR = 39.3-77.0] from baseline at day 5, p < 0.0001). Two patients required surgery. Six patients with significant comorbidities (e.g., advanced cancer) had ongoing infection when palliated and died. Two patients experienced self-limiting pleural bleeding and received blood transfusion.

CONCLUSION

A starting intrapleural regime of 2.5 mg tPA/5 mg DNase, with up-titration if needed, can be effective and deserves further exploration.

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.

Parapneumonic Effusion and Empyema

The rising incidence and high morbidity of pleural infection remain a significant challenge to health care systems worldwide. With distinct microbiology and treatment paradigms from pneumonia, pleural infection is an area in which the evidence base has been rapidly evolving. Progress in recent years has revolved around characterizing the microbiome of pleural infection and the addition of new strategies such as intrapleural enzyme therapy to the established treatment pathway of drainage and antibiotics. The future of improving outcomes lies with personalizing treatment, establishing optimal timing of intrapleural agents and surgery, alongside wider use of risk stratification to guide treatment.

Parapneumonic Effusions Are Characterized by Elevated Levels of Neutrophil Extracellular Traps

BACKGROUND

Neutrophil extracellular traps (NETs) increasingly are implicated in acute and chronic conditions involving multiple organ systems.

RESEARCH QUESTION

Are NET concentrations higher in parapneumonic effusions compared with effusions of other origin and does this reflect the inflammatory nature of these effusions?

STUDY DESIGN AND METHODS

Patients (N = 101) seeking hospital treatment for undifferentiated pleural effusion underwent pleural fluid classification based on cytologic analysis results, biochemical findings, microbiological characteristics, and clinical judgement. Concentrations of NET markers (extracellular DNA [eDNA], citrullinated histone H3 [citH3]), neutrophils (α-defensins), and inflammation (IL-1β)-related proteins were quantified by enzyme-linked immunosorbent assay. Differences between groups were analyzed using the Kruskal-Wallis one-way analysis of variance. Correlations used Spearman coefficient. Receiver operating characteristic (ROC) curves were calculated.

RESULTS

Effusions were classified into four groups: parapneumonic (n = 18), malignant (n = 35), transudative (n = 22), and unclassifiable (n = 26). Concentrations of NETs markers were significantly higher in the parapneumonic group compared with malignant, transudative, and unclassifiable groups (median eDNA, 12.8 ng/mL vs 0.77 ng/mL, 0.44 ng/mL, and 0.86 ng/mL [P < .001]; and median citH3, 127.1 ng/mL vs 0.44 ng/mL, 0.34 ng/mL, and 0.49 ng/mL [P < .001]). citH3 and eDNA were correlated highly with lactate dehydrogenase (LDH; Spearman r = 0.66 and r = 0.73, respectively; P < .001) and moderately negatively correlated with pH (r = -0.55 and r = -0.62, respectively; P < .001). α-Defensins and IL-1β were higher in the parapneumonic group than in other groups (median α-defensins, 124.4 ng/mL vs 4.7 ng/mL,7 ng/mL, and 6.9 ng/mL [P < .001]; and median IL-1β, 145 pg/mL vs 1.87 pg/mL, 1.39 pg/mL, and 2.6 pg/mL [P < .001]) and moderately correlated with LDH (r = 0.60 and r = 0.57; P < .001). ROC curves showed high sensitivity and specificity for NET markers for prediction of parapneumonic effusion.

INTERPRETATION

High levels of some NET-related mediators in parapneumonic effusions correlate with inflammation. Effusions of other causes do not show high levels of NETs. These results may have treatment implications because NETs may be an important contributor to the inflammation and viscosity of parapneumonic effusions and may help us to understand the therapeutic benefit of deoxyribonuclease in empyema.

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.

Ultrasound use in the ICU for interventional pulmonology procedures

Critical care ultrasound has shifted the paradigm of thoracic imaging by enabling the treating physician to acquire and interpret images essential for clinical decision-making, at the bedside, in real-time. Once considered impossible, lung ultrasound based on interpretation of artifacts along with true images, has gained momentum during the last decade, as an integral part of rapid evaluation algorithms for acute respiratory failure, shock and cardiac arrest. Procedural ultrasound image guidance is a standard of care for both common bedside procedures, and advanced procedures within interventional pulmonologist’s (IP’s) scope of practice. From IP’s perspective, the lung, pleural, and chest wall ultrasound expertise is a prerequisite for mastery in pleural drainage techniques and transthoracic biopsies. Another ultrasound application of interest to the IP in the intensive care unit (ICU) setting is during percutaneous dilatational tracheostomy (PDT). As ICU demographics shift towards older and sicker patients, the indications for closed pleural drainage procedures, bedside transthoracic biopsies, and percutaneous dilatational tracheostomies have dramatically increased. Although ultrasound expertise is considered an essential IP operator skill there is no validated curriculum developed to address this component. Further, there is a need for developing an educational tool that matches up with the curriculum and could be integrated real-time with ultrasound-guided procedures.

The use of fibrinolytic therapy for parapneumonic effusion in pregnancy: a case report and a review

The use of intrapleural fibrinolytics for complicated parapneumonic effusion has been shown to be an effective and safe alternative to surgery. However, there is limited evidence about its use during pregnancy. We present a case and a review of the literature of pregnant women who had successful treatment of their complicated parapneumonic effusion with intrapleural fibrinolytics. To our knowledge this is the first review of cases of pregnant women with parapneumonic effusion managed with intrapleural fibrinolytic.

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.

Recent Insights into the Management of Pleural Infection

Pleural infection in adults has considerable morbidity and continues to be a life-threatening condition. The term “pleural infection” encompasses complicated parapneumonic effusions and primary pleural infections, and includes but is not limited to empyema, which refers to collection of pus in the pleural cavity. The incidence of pleural infection in adults has been continuously increasing over the past two decades, particularly in older adults, and most of such patients have comorbidities. Management of pleural infection requires prolonged duration of hospitalization (average 14 days). There are recognized differences in microbial etiology of pleural infection depending on whether the infection was acquired in the community or in a health-care setting. Anaerobic bacteria are acknowledged as a major cause of pleural infection, and thus anaerobic coverage in antibiotic regimens for pleural infection is mandatory. The key components of managing pleural infection are appropriate antimicrobial therapy and chest-tube drainage. In patients who fail medical therapy by manifesting persistent sepsis despite standard measures, surgical intervention to clear the infected space or intrapleural fibrinolytic therapy (in poor surgical candidates) are recommended. Recent studies have explored the role of early intrapleural fibrinolytics or first-line surgery, but due to considerable costs of such interventions and the lack of convincing evidence of improved outcomes with early use, early intervention cannot be recommended, and further evidence is awaited from ongoing studies. Other areas of research include the role of routine molecular testing of infected pleural fluid in improving the rate of identification of causative organisms. Other research topics include the benefit of such interventions as medical thoracoscopy, high-volume pleural irrigation with saline/antiseptic solution, and repeated thoracentesis (as opposed to chest-tube drainage) in reducing morbidity and improving outcomes of pleural infection. This review summarizes current knowledge and practice in managing pleural infection and future research directions.

Bilateral empyema secondary to Hemophilus influenzae epiglottitis

An empyema is a collection of pus in the pleural space, often due to aerobic bacteria, that requires drainage typically done with a small bore chest tube and fibrinolytics. The large majority of empyemas are unilateral. Bilateral empyemas are rare, usually non-infectious and typically require surgical management. We report a case of Hemophilus influenzae epiglottitis complicated by bilateral culture proven empyema successfully managed without surgery. The aim of this report is to present a rare complication of epiglottitis and discuss the theoretical issues with management of multiple infected pleural spaces requiring fibrinolytics.

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.

A combined intrapleural administration of dornase alfa and tissue plasminogen activator is safe in children with empyema - A pilot study

OBJECTIVE

There is still no consensus regarding the treatment of empyema in children. Intrapleural combination of tissue plasminogen activator and dornase alfa is a promising treatment for empyema in adults. The aim of this pilot study was to determine whether this combination is safe and successful in pediatric empyema.

METHODS

Previous well children diagnosed with empyema as classified by the British Thoracic Society. After chest tube insertion, intrapleurally dornase alfa 2.5 mg for 2 days and tissue plasminogen activator 0.15 mg/kg for 3 days was given after which the chest tube was clamped for 4 h. Primary outcome was safety.

RESULTS

Ten consecutive children were included (4 boys, aged 3.2 (1.3-15.0) years old). No serious adverse events were seen. One child developed urticaria but additional intervention or cessation of the trial was not needed. There was no bleeding or mortality and no additional procedures were performed. The median hospital stay after intervention was 7.5 days.

CONCLUSIONS

The intrapleural treatment of dornase alfa and tissue plasminogen activator as treatment of empyema was safe in ten children with empyema. If confirmed in further studies, this combination of intrapleural therapy may improve the management of pediatric empyema.

Ambulatory Intrapleural Fibrinolytic Therapy in Highly Viscous Recurrent Malignant Pleural Effusion

Malignant pleural effusion (MPE) is common in lung cancer. We report a case of highly viscous recurrent MPE associated with lung cancer. The viscosity prohibited gravity-dependent drainage initially with a 6-Fr aspiration catheter and subsequently with a 12-Fr intercostal drain. The effusion was eventually evacuated after a single dose of intrapleural fibrinolytic therapy. This process was repeated a total of 13 times over a 12-month period in an ambulatory setting. No bleeding complications were observed. This case highlights the feasibility and safety of repeated intrapleural fibrinolysis in the management of highly viscous recurrent MPE in an ambulatory setting.

A case of hemothorax secondary to intrapleural fibrinolytic therapy: Considerations for use of fibrinolytics in high-risk patients

Indwelling Pleural Catheters (IPC) are increasingly being used for management of recurrent pleural effusions (RPEs). Use of IPC for management of both malignant and non-malignant recurrent pleural effusions has been associated with complications such as dysfunctional or nonfunctioning IPCs. Alteplase, a tissue plasminogen activator (tPA) is often used to restore flow of non-draining IPC in symptomatic patients. We present a case of a sixty-eight-year old patient with life-threatening pleural hemorrhage following intrapleural catheter instillation of tPA that was managed successfully by thoracotomy. Our case describe the importance of individualizing the fibrinolytic dose, frequency and the indwelling time in high risk patients. We have reviewed the current literature and recommendations for use of fibrinolytic therapy for IPC in high risk patients on anticoagulation.

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.

Successful drainage of complex haemoserous malignant pleural effusion with a single modified low-dose intrapleural alteplase and dornase alfa

Patients with symptomatic complex malignant pleural effusion (MPE) are frequently unfit for decortication and have a poorer prognosis. Septations can develop in MPE, which may lead to failure of complete drainage and pleural infection. Intrapleural fibrinolytic therapy (IPFT) is an alternative treatment. The use of IPFT in patients with anaemia and high risk for intrapleural bleeding is not well established. We report a successful drainage of complex haemoserous MPE with a single modified low-dose of intrapleural 5 mg of alteplase and 5 mg of dornase alfa in a patient with pre-existing anaemia with no significant risk of intrapleural bleeding.

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.

Prospective validation of the RAPID clinical risk prediction score in adult patients with pleural infection: the PILOT study

BACKGROUND

Over 30% of adult patients with pleural infection either die and/or require surgery. There is no robust means of predicting at baseline presentation which patients will suffer a poor clinical outcome. A validated risk prediction score would allow early identification of high-risk patients, potentially directing more aggressive treatment thereafter.

OBJECTIVES

To prospectively assess a previously described risk score (the RAPID (Renal (urea), Age, fluid Purulence, Infection source, Dietary (albumin)) score) in adults with pleural infection.

METHODS

Prospective observational cohort study that recruited patients undergoing treatment for pleural infection. RAPID score and risk category were calculated at baseline presentation. The primary outcome was mortality at 3 months; secondary outcomes were mortality at 12 months, length of hospital stay, need for thoracic surgery, failure of medical treatment and lung function at 3 months.

RESULTS

Mortality data were available in 542 out of 546 patients recruited (99.3%). Overall mortality was 10% at 3 months (54 out of 542) and 19% at 12 months (102 out of 542). The RAPID risk category predicted mortality at 3 months. Low-risk mortality (RAPID score 0-2): five out of 222 (2.3%, 95% CI 0.9 to 5.7%); medium-risk mortality (RAPID score 3-4): 21 out of 228 (9.2%, 95% CI 6.0 to 13.7%); and high-risk mortality (RAPID score 5-7): 27 out of 92 (29.3%, 95% CI 21.0 to 39.2%). C-statistics for the scores at 3 months and 12 months were 0.78 (95% CI 0.71-0.83) and 0.77 (95% CI 0.72-0.82), respectively.

CONCLUSIONS

The RAPID score stratifies adults with pleural infection according to increasing risk of mortality and should inform future research directed at improving outcomes in this patient population.

Short-course intrapleural alteplase and DNase in complex effusion with bleeding risk

Pleural infection is an important clinical problem with significant morbidity. In poorly draining complex pleural effusions, the current management favours a less invasive image-guided placement of smaller bore catheters and adjunctive intrapleural fibrinolysis therapy (IPFT). We describe our experience of using IPFT in three patients with different bleeding risks with complex pleural effusions. The first was a 30-year-old with transfusion-dependent β-thalassemia with haemoglobin of 7.8 g/dL; second was an 87-year-old on dabigatran with haemoglobin of 10 g/dL; and the third was an 80-year-old with diffuse large B-cell lymphoma with haemoglobin of 8.6 g/dL. All three patients received three doses of alteplase and deoxyribonuclease (DNase) without any adverse effects of bleeding and had resolution of the effusion. This case series is an addition to the current literature on the safety of IPFT and we highlight the use of IPFT in patients with low baseline haemoglobin and on anticoagulation therapy.

Bronchopleural communication following intrapleural doses of tPA/DNase for empyema

Intrapleural tissue plasminogen activator (tPA) and deoxyribonuclease (DNase) therapy is a new treatment for pleural infection. Clinical experiences of tPA/DNase therapy, and its complications, are cumulating. We present a patient with multiloculated empyema but no initial evidence of a bronchopleural fistula. She was treated with antibiotics and chest tube drainage of the basal collection through which four doses of tPA/DNase were delivered with success. The lateral collection worsened necessitating separate tube drainage and tPA/DNase treatment. She reported chest "fullness" when instilled the second dose. The third instillation of tPA triggered immediate vigorous coughing and expectoration of salty-tasting fluid, likely the tPA/saline solution. The symptoms spontaneously settled after 15 min, with no evidence of air leak. The loculated fluid was successfully evacuated. The patient made a full recovery after an antibiotic course with no long-term consequences. Pulmonary migration of drugs via a bronchopleural communication, although rare, can occur with intrapleural tPA/DNase therapy.

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.

Cell-free DNA in human ex vivo lung perfusate as a potential biomarker to predict the risk of primary graft dysfunction in lung transplantation

BACKGROUND

Cell-free DNA (cfDNA), such as mitochondrial DNA (mtDNA) and nuclear DNA (nuDNA), are known to be released from injured cells and as such have been explored as biomarkers for tissue injury in different clinical settings. Ex vivo lung perfusion (EVLP) has been developed as an effective technique for marginal donor lung functional assessment. We hypothesized that the level of cfDNA in EVLP perfusate may reflect tissue injury and thus can be developed as a biomarker to quantify the degree of donor lung injury or predict the development of primary graft dysfunction (PGD) after lung transplantation (LTx).

METHODS

The perfusate from 62 donor lungs transplanted at our institution between May 2010 and December 2015 was sampled for cfDNA at 1 and 4 hours of perfusion. Sequences of genes encoding nicotinamide adenine dinucleotide dehydrogenase 1 (NADH-1) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were used to represent mtDNA and nuDNA, respectively. Levels were quantified by real-time polymerase chain reaction and correlated with clinical outcome after LTx.

RESULTS

In our entire cohort, 14 patients developed PGD grade 3 (PGD3) within 72 hours after LTx. The non-PGD group included 48 patients (PGD0-1). Concentrations of mtDNA in the perfusate of the PGD3 group were significantly higher than those in non-PGD group at 1 hour of EVLP (1874 ± 844 vs 1259 ± 885 copies/μL; P = .011). The perfusate of the PGD3 group had significantly higher levels of nuDNA compared with the non-PGD group at both 1 hour (1498 ± 1895 vs 675 ± 391 copies/μL; P = .008) and 4 hours (4521 ± 5810 vs 1764 ± 1494 copies/μL; P = .001). In donation after cardiac death (DCD) cases, mtDNA levels were significantly higher in the PGD3 group compared with the non-PGD group at 1 hour of EVLP (2060 ± 997 vs 1184 ± 782 copies/μL; P = .040), and the levels of nuDNA were significantly higher in the PGD3 group compared with the non-PGD group at both 1 hour (1021 ± 495 vs 606 ± 305 copies/μL; P = .041) and 4 hours (2358 ± 1028 vs 1185 ± 967 copies/μL; P = .006). In donation after brain death (DBD) cases, cfDNA scores did not show a significant difference.

CONCLUSIONS

We found that the amount of cfDNA, especially nuDNA, in EVLP perfusate was higher in the severe PGD group (PGD3) compared with the non-PGD group. This proof-of-concept study supports the concept that the analysis of cfDNA levels in EVLP perfusate can help estimate the damage to donor lungs before implantation. Larger studies are needed to validate this concept.

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.

Canine and Feline Exudative Pleural Diseases

Exudative pleural diseases are a common cause of respiratory distress and systemic illness in dogs and cats. This article covers the pathophysiology, development, and classification of exudative pleural effusions. The most current diagnostic strategies, causes, imaging findings, and medical or surgical treatment options for select diseases are reviewed in detail.

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.