Iterative thoracentesis as first-line treatment of complicated parapneumonic effusion

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.

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.

A feasibility randomised trial comparing therapeutic thoracentesis to chest tube insertion for the management of pleural infection: results from the ACTion trial

BACKGROUND

Pleural infection is a complex condition with a considerable healthcare burden. The average hospital stay for pleural infection is 14 days. Current standard of care defaults to chest tube insertion and intravenous antibiotics. There have been no randomised trials on the use of therapeutic thoracentesis (TT) for pleural fluid drainage in pleural infection.

AIMS AND OBJECTIVES

To assess the feasibility of a full-scale trial of chest tube vs TT for pleural infection in a single UK centre. The primary outcome was defined as the acceptability of randomisation to patients.

METHODS

Adult patients admitted with a pleural effusion felt to be related to infection and meeting criteria for drainage (based on international guidelines) were eligible for randomisation. Participants were randomised (1:1) to chest tube insertion or TT with daily review assessing need for further drainages or other therapies. Neither participant nor clinician were blinded to treatment allocation. Patients were followed up at 90 days post-randomisation.

RESULTS

From September 2019 to June 2021, 51 patients were diagnosed with pleural infection (complex parapneumonic effusion/empyema). Eleven patients met the inclusion criteria for trial and 10 patients were randomised (91%). The COVID-19 pandemic had a substantial impact on recruitment. Data completeness was high in both groups with no protocol deviations. Patients randomised to TT had a significantly shorter overall mean hospital stay (5.4 days, SD 5.1) compared to the chest tube control group (13 days, SD 6.0), p = 0.04. Total number of pleural procedures required per patient were similar, 1.2 in chest tube group and 1.4 in TT group. No patient required a surgical referral. Adverse events were similar between the groups with no readmissions related to pleural infection.

CONCLUSIONS

The ACTion trial met its pre-specified feasibility criteria for patient acceptability but other issues around feasibility of a full-scale trial remain. From the results available the hypothesis that TT can reduce length of stay in pleural infection should be explored further.

TRIAL REGISTRATION

ISRCTN: 84674413.

Nonmalignant Pleural Effusions

Although the potential causes of nonmalignant pleural effusions are many, the management of a few, including complicated pleural infections and refractory heart failure and hepatic hydrothoraces, can be challenging and requires the assistance of interventional pulmonologists. A pragmatic approach to complicated parapneumonic effusions or empyemas is the insertion of a small-bore chest tube (e.g., 14-16 Fr) through which fibrinolytics (e.g., urokinase and alteplase) and DNase are administered in combination. Therapeutic thoracenteses are usually reserved for small to moderate effusions that are expected to be completely aspirated at a single time, whereas video-assisted thoracic surgery should be considered after failure of intrapleural enzyme therapy. Refractory cardiac and liver-induced pleural effusions portend a poor prognosis. In cases of heart failure-related effusions, therapeutic thoracentesis is the first-line palliative therapy. However, if it is frequently needed, an indwelling pleural catheter (IPC) is recommended. In patients with hepatic hydrothorax, repeated therapeutic thoracenteses are commonly performed while a multidisciplinary decision on the most appropriate definitive management is taken. The percutaneous creation of a portosystemic shunt may be used as a bridge to liver transplantation or as a potential definitive therapy in nontransplant candidates. In general, an IPC should be avoided because of the high risk of complications, particularly infections, that may jeopardize candidacy for liver transplantation. Even so, in noncandidates for liver transplant or surgical correction of diaphragmatic defects, IPC is a therapeutic option as valid as serial thoracenteses.

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

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

Intrapleural use of urokinase and DNase in pleural infections managed with repeated thoracentesis: A comparative cohort study

Introduction

Evacuation of infected fluid in pleural infections is essential. To date, the use of an intrapleural fibrinolytic agent such as urokinase and DNase has not yet been assessed in infections managed by repeated therapeutic thoracentesis (RTT).

Methods

We performed a retrospective comparative study of two successive cohorts of consecutive patients with pleural infections from 2001 to 2018. Between 2001 and 2010, patients had RTT with intrapleural urokinase (RTT-U). After 2011, patients received intrapleural urokinase and DNase with RTT (RTT-UD). Data were collected through a standardized questionnaire.

Results

One hundred and thirty-three patients were included: 93 were men and the mean age was 59 years (standard deviation 17.2). Eighty-one patients were treated with a combination of intrapleural urokinase and DNase, and 52 were treated with intrapleural urokinase only. In the RTT-UD, RTT failure occurred in 14 patients (17%) compared to 10 (19%) in the RTT-U group (P = 0.82). There was no difference between the two groups in intensive care unit admission, surgical referrals or in-hospital mortality. RTT-UD was associated with faster time to apyrexia (aOR = 0.51, 95%CI [0.37–0.72]), a reduced length of hospital stay (aOR = 0.61, 95%CI [0.52–0.73]) and a higher volume of total pleural fluid retrieved (aOR = 1.38, 95%CI [1.02–1.88]). Complications were rare with only one hemothorax in the RTT-UD group and no pneumothorax requiring drainage in either group.

Conclusion

Compared to urokinase only, intrapleural use of urokinase and DNase in RTT was associated with quicker defervescence, shorter hospital stay and increased volumes of pleural fluid drained. Randomized controlled trials evaluating urokinase and DNase with RTT technique would be required to confirm these results.

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.

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.

Advances in pleural infection and malignancy

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

Pleural infection: a closer look at the etiopathogenesis, microbiology and role of antibiotics

INTRODUCTION

Pleural infection is a condition that continues to pose a significant challenge to respiratory physicians. We hypothesize that the main barriers to progress include limited understanding of the etiopathogenesis, microbiology,and role of antibiotics in the pleural space. Areas covered: PubMed was searched for articles related to adult pleural infection using the terms 'pleural infection', 'empyema' and 'parapneumonic'. The search focused on relevant literature within the last 10 years, with any older citations used only to display context or lack of progress. Tuberculous pleural infection was excluded. We chose to give specific attention to the etiopathogenesis of pleural infection, including recent advances in diagnostics and biomarkers. We discuss our understanding of the pleural microbiome and rationalize the current use of antibiotics in treating this condition. Expert commentary: Understanding of key events in the development of this condition remains limited. The microbiology is unique compared to the lung, and highly variable. Higher culture yields from pleural biopsy may add new insights into the etiopathogenesis. There is little evidence into achievable effective antibiotic concentration within the pleura. Research into issues including the relevance of biofilm formation and significance of pleural thickening is necessary for treatment progress.

Repeated therapeutic thoracentesis to manage complicated parapneumonic effusions

PURPOSE OF REVIEW

In complicated parapneumonic effusion (CPPE), antibiotics and evacuation of the infected pleural fluid are mandatory. The first-line evacuation treatment is still controversial. The aim of this article is to highlight the usefulness of repeated therapeutic thoracentesis (RTT) as a first-line treatment.

RECENT FINDINGS

In the most recent study on RTT in CPPE, disposable pleural needles were used and the median number of thoracentesis was 3. The success rate was 81%, and only 4% of the patients were referred for thoracic surgery. The 1-year survival rate was 88%. On multivariate analysis, the observation of microorganisms in the pleural fluid after Gram staining and first thoracentesis volume at least 450 ml was associated with a higher risk of RTT failure. RTT is less invasive and can target different loculated pleural collections. Patients are less confined to beds between each procedure, and could even be ambulatory managed. The use of intrapleural fibrinolytics in association with DNase could most likely enhance the efficacy of RTT.

SUMMARY

RTT is efficient and well tolerated in the management of CPPE, including pleural empyema, and could be proposed as a first-line therapy for CPPE. This technique could be used in association with intrapleural fibrinolytics and DNase.

[The management of complicated parapneumonic effusions in France]

INTRODUCTION

There are no French guidelines for the management of complicated parapneumonic effusions. A national observational study was carried out to assess the main features of current clinical practice for this condition.

MATERIAL AND METHODS

A questionnaire was sent by email to the 1500 members of the Société de Pneumologie de Langue Française (SPLF) between 15th November and 15th December 2012.

RESULTS

There were 92 responders, i.e. a response rate of 6%. Of these, 87 physicians mentioned that they were involved in the management of patients with complicated parapneumonic effusions with a median number of cases of 10 per year (IQR: 5-20). Chest tube drainage was the main approach used for pleural fluid aspiration (n=51/87), followed by repeated thoracentesis (n=29/87) and early surgery (1/87). Five physicians answered both chest tube drainage or repeated thoracentesis and one physician either chest tube drainage or early surgery. Pleural fibrinolytics were never used by 20% of physicians, only in case of loculations by 70% and by 10% of respondents in all cases. Only 3 physicians combined fibrinolytics with DNAse. A double antibiotic dose was used by one third of physicians. All the physicians used respiratory physiotherapy during hospitalization and to aid recovery. Follow-up practices were heterogeneous.

CONCLUSIONS

The management of complicated parapneumonic effusions varies significantly in France. National guidelines may be helpful to define best practice and aid in its implementation.

[Parapneumonic pleural effusions: Epidemiology, diagnosis, classification and management]

Parapneumonic pleural effusions represent the main cause of pleural infections. Their incidence is constantly increasing. Although by definition they are considered to be a "parapneumonic" phenomenon, the microbial epidemiology of these effusions differs from pneumonia with a higher prevalence of anaerobic bacteria. The first thoracentesis is the most important diagnostic stage because it allows for a distinction between complicated and non-complicated parapneumonic effusions. Only complicated parapneumonic effusions need to be drained. Therapeutic evacuation modalities include repeated therapeutic thoracentesis, chest tube drainage or thoracic surgery. The choice of the first-line evacuation treatment is still controversial and there are few prospective controlled studies. The effectiveness of fibrinolytic agents is not established except when they are combined with DNase. Antibiotics are mandatory; they should be initiated as quickly as possible and should be active against anaerobic bacteria except for in the context of pneumococcal infections. There are few data on the use of chest physiotherapy, which remains widely used. Mortality is still high and is influenced by underlying comorbidities.