Outcome of parapneumonic empyema managed surgically or by fibrinolysis: a multicenter study

Pleural infection: controversies on the therapeutic strategies

PURPOSE OF REVIEW

Management of pleural infection remains heterogeneous worldwide. This review highlights current controversies in therapeutic strategies for pleural infection, focusing particularly on recent studies and their implications.

RECENT FINDINGS

The introduction of intrapleural therapy combining alteplase [a tissue plasminogen activator (tPA)] and deoxyribonuclease (DNase) has revolutionized treatment practices, though the optimal delivery and dosing regimen is an area of active investigation. Variations to simplify administration protocols and/or to lower the required drug doses have been published. Most were exploratory studies, but the variations showed maintained therapeutic efficacy.Whether intrapleural alteplase/DNase or video-assisted thoracoscopic surgery (VATS) is superior is a topic of debate. Retrospective comparative analyses between the two revealed no clear benefits on all-cause mortality from either approach. Pilot randomized trials have been published and further full-scale, head-to-head trials are underway.

SUMMARY

Effective management of pleural infection involves adequate pleural drainage and appropriate antibiotic use. This review outlines the current evidence (and its limitations) and highlights knowledge gaps in optimizing the therapeutic strategies.

Perspective and update: intrapleural fibrinolytic therapy for pleural infections and other forms of pleural organization

Intrapleural fibrinolytic therapy (IPFT), also known as intrapleural enzymatic therapy (IET), has been utilized for decades to treat pleural infections by expediting drainage in patients with pleural organization. The successful MIST2 trial demonstrated that IPFT improves pleural opacification, reduces hospital stays, and decreases short-term surgical referrals. Despite significant progress, gaps remain in identification of the optimal fibrinolytic agents, dosing, and safety improvements. IPFT is generally recommended for patients with loculation and failed pleural drainage, with a consensus panel advocating for combined tissue plasminogen activator (tPA) and DNase therapy. How each agent may affect the activity or function of the other in the combination remains unclear. While IPFT can reduce the need for surgical intervention, there are relatively few comparative clinical trials to guide initial therapy. Emerging low-dose IPFT treatment approaches may benefit patients who are poor surgical candidates. Personalized IPFT candidate approaches, such as the Fibrinolytic Potential Assay (FPA), could refine dosing and improve outcomes. Additionally, biomarkers like pleural fluid PAI-1 and suPAR concentrations may predict clinical outcomes and guide treatment. New therapeutic agents, including PAI-1 inhibiting peptides and mesothelial profibrogenic targets, are under investigation to enhance IPFT efficacy. These advances hold promise for improving the management of pleural infections and other forms of pleural organization.

Surgery versus intrapleural fibrinolysis for management of complicated pleural infections: a systematic review and meta-analysis

BACKGROUND

Complicated pleural infection comprises of complex effusions and empyema. When tube thoracostomy is ineffective, treatment options include surgical drainage, deloculation and decortication or intrapleural fibrinolysis. We performed a systematic review and meta-analysis to examine which technique is superior in treating complicated pleural infections.

METHODS

PubMed, MEDLINE and EMBASE databases were searched for studies published between January 2000 to July 2023 comparing surgery and intrapleural fibrinolysis for treatment of complicated pleural infection. The primary outcome was treatment success. Secondary outcomes included hospital length of stay, chest drain duration and in-hospital mortality.

RESULTS

Surgical management of complicated pleural infections was more likely to be successful than intrapleural fibrinolysis (RR 1.18; 95% CI 1.02, 1.38). Surgical intervention group benefited from statistically significant shorter hospital length of stay (MD: 3.85; 95% CI 1.09, 6.62) and chest drain duration (MD: 3.42; 95% CI 1.36, 5.48). There was no observed difference between in-hospital mortality (RR: 1.00; 95% CI 0.99, 1.02).

CONCLUSION

Surgical management of complicated pleural infections results in increased likelihood of treatment success, shorter chest drain duration and hospital length of stay in the adult population compared with intrapleural fibrinolysis. In-hospital mortality did not differ. Large cohort and randomized research need to be conducted to confirm these findings.

Efficacy, Safety, and Complications of Pigtail Thoracostomy for the Treatment of Pediatric Pleuropneumonia

OBJECTIVE

Pigtail thoracostomy (PT) has become the mainstay technique for the drainage of pediatric pleuropneumonic effusions (PLPe). However, its efficacy and complication profile has been questioned when compared with video-assisted thoracoscopic surgery and larger bore traditional tube thoracostomy. The aim of this study was to assess the efficacy, safety, and complications associated with PT.

METHODS

A cross-sectional study at a freestanding tertiary children's hospital. We extracted the medical records of all children aged younger than 18 years treated with PT for PLPe from June 2016 to June 2020. The primary efficacy outcome was treatment failure defined as the need for a repeat drainage procedure, thoracostomy, or video-assisted thoracoscopic surgery. Secondary efficacy outcomes were length of hospital stay (LOS) and duration of in situ PT. The primary safety outcomes were adverse events during or after insertion. We also recorded any associated complications.

RESULTS

During the study period, 55 children required PT. The median age was 25 months (interquartile range, 14-52) and 58.2% were boys. Eight (14.4%) were bacteremic or in septic shock. There were no adverse events related to insertion. Forty-two (76.3%) children were treated with fibrinolysis. There were 2 (3.6%) treatment failures. The median LOS and PT durations were 13 and 4 days (interquartile ranges, 10-14.8, 3-6.7), respectively. Eight (14.4%) children experienced complications that were nonoperatively managed.

CONCLUSIONS

Our findings suggest that PT drainage offers a safe and highly effective option for managing PLPe and carries a very low failure rate.

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.

Targeting the PAI-1 Mechanism with a Small Peptide Increases the Efficacy of Alteplase in a Rabbit Model of Chronic Empyema

The incidence of empyema is increasing and associated with a mortality rate of 20% in patients older than 65 years. Since 30% of patients with advanced empyema have contraindications to surgical treatment, novel, low-dose, pharmacological treatments are needed. A Streptococcus pneumoniae-induced rabbit model of chronic empyema recapitulates the progression, loculation, fibrotic repair, and pleural thickening of human disease. Treatment with single chain (sc) urokinase (scuPA) or tissue type (sctPA) plasminogen activators in doses 1.0-4.0 mg/kg were only partially effective in this model. Docking Site Peptide (DSP; 8.0 mg/kg), which decreased the dose of sctPA for successful fibrinolytic therapy in acute empyema model did not improve efficacy in combination with 2.0 mg/kg scuPA or sctPA. However, a two-fold increase in either sctPA or DSP (4.0 and 8.0 mg/kg or 2.0 and 16.0 mg/kg sctPA and DSP, respectively) resulted in 100% effective outcome. Thus, DSP-based Plasminogen Activator Inhibitor 1-Targeted Fibrinolytic Therapy (PAI-1-TFT) of chronic infectious pleural injury in rabbits increases the efficacy of alteplase rendering ineffective doses of sctPA effective. PAI-1-TFT represents a novel, well-tolerated treatment of empyema that is amenable to clinical introduction. The chronic empyema model recapitulates increased resistance of advanced human empyema to fibrinolytic therapy, thus allowing for studies of muti-injection treatments.

Parapneumonic effusions related to Streptococcus pneumoniae: serotype and disease severity trends from 2006 to 2018 in Bristol, UK

RATIONALE

Streptococcus pneumoniae epidemiology is changing in response to vaccination and some data suggest that empyema incidence is increasing. However, differences exist between the UK and US studies. We describe trends in the clinical phenotype of adult pneumococcal pleural infection, including simple parapneumonic effusions (SPE) in the pneumococcal conjugate vaccination (PCV) era.

OBJECTIVES

To determine whether there were differences in pneumococcal disease presentation and severity associated with pleural infection.

METHODS

A retrospective cohort study, all adults ≥16 years admitted to three large UK hospitals, 2006-2018 with pneumococcal disease. 2477 invasive pneumococcal cases were identified: 459 SPE and 100 pleural infection cases. Medical records were reviewed for each clinical episode. Serotype data were obtained from the UK Health Security Agency national reference laboratory.

RESULTS

Incidence increased over time, including non-PCV-serotype disease. PCV7-serotype disease declined following paediatric PCV7 introduction, but the effect of PCV13 was less apparent as disease caused by the additional six serotypes plateaued with serotypes 1 and 3 causing such parapneumonic effusions from 2011 onwards.Patients with pleural infection had a median survival 468 days (95% CI 340 to 590) vs 286 days (95% CI 274 to 335) in those with SPE. Pleural infection associated with frank pus had lower 90-day mortality than pleural infection without pus (0% vs 29%, p<0.0001). 90-day mortality could be predicted by baseline increased RAPID (Renal, Age, Purulence, Infection source, and Dietary factors) score (HR 15.01, 95% CI 1.24 to 40.06, p=0.049).

CONCLUSIONS

Pneumococcal infection continues to cause severe disease despite the introduction of PCVs. The predominance of serotype 1 and 3 in this adult UK cohort is in keeping with previous studies in paediatric and non-UK studies. Rising non-PCV serotype disease and limited impact of PCV13 on cases caused by serotypes 1 and 3 offset the reductions in adult pneumococcal parapneumonic effusion disease burden observed following the introduction of the childhood PCV7 programme.