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

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.

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).

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.

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.

An international survey on the use of intrapleural tissue plasminogen activator/DNase therapy for pleural infection

Introduction

Intrapleural tissue plasminogen activator (tPA) combined with human recombinant DNase (DNase) could be an effective alternative to surgery in managing pleural infection, as demonstrated in the Multi-centre Intrapleural Sepsis Trial (MIST)-2. However, the optimal delivery regimen is still unknown. The aim of this survey was to identify the current practice of tPA/DNase use by physicians with published interests in pleural infection, and their opinions on dose de-escalation of tPA/DNase therapy.

Methods

Potential participants were identified using four search strategies. Only practising physicians who were managing patients with pleural infections and either actively involved in pleural research and publications, or were members of relevant pleural disease guideline panels at the time of survey were included.

Results

An invitation email with the questionnaire was sent to 102 participants, of whom 49 (48%) responded. Most respondents (90%, n=44) have used tPA/DNase to manage pleural infection, but the dosing and delivery regimens employed varied. Many (86%, 38 out of 44) respondents have used 10 mg tPA, while 73% (n=32), 16% (n=7) and 9% (n=4) have used 5 mg, 2.5 mg and 1 mg doses, respectively. Most respondents instilled tPA/DNase concurrently (61%, n=27) and routinely administered six doses of tPA/DNase (52%, n=23) twice daily (82%, n=36). Respondents would consider using a lower starting dose of tPA (with the possibility of escalation if clinically needed) if a median 80% (interquartile range 50–80%) of patients could be successfully treated at that dose.

Conclusion

This survey observed a large variation in the current treatment protocol of intrapleural tPA/DNase therapy worldwide and the need for more data on this subject.

This international survey observed a large variation in the delivery of tPA/DNase therapy for pleural infection. Respondents were open to the concept of starting with a lower (<10 mg) dose of tPA (with the possibility of escalation) if evidence accumulates.https://bit.ly/2ZfPRrL

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.

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.

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).

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.

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.