Conservative and Surgical Modalities in the Management of Pediatric Parapneumonic Effusion and Empyema: A Living Systematic Review and Network Meta-Analysis

BACKGROUND

The optimal treatment for community-acquired childhood pneumonia complicated by empyema remains unclear.

RESEARCH QUESTION

In children with parapneumonic effusion or empyema, do hospital length of stay and other key clinical outcomes differ according to the treatment modality used?

STUDY DESIGN AND METHODS

A living systematic review of randomized controlled trials (RCTs) was conducted by searching the Cochrane Central Register of Controlled Trials, Embase, Latin American and Caribbean Health Sciences Literature, Ovid MEDLINE, and Web of Science Core Collection databases. Eligible RCTs included patients aged < 18 years and compared two of the following treatment modalities: antibiotics alone, chest tube insertion with or without fibrinolytics, video-assisted thoracoscopic surgery (VATS), and decortication via thoracotomy. A network meta-analysis was performed to evaluate treatment effects on hospital length of stay (LOS), the primary outcome.

RESULTS

Eleven trials including a total of 590 patients were selected for the network meta-analysis. Compared with a chest tube alone, a chest tube with fibrinolytics, thoracotomy, and VATS were all associated with shorter LOS, with a mean difference of 5.05 days (95% CI, 2.46-7.64), 6.33 days (95% CI, 3.17-9.50), and 5.86 days (95% CI, 3.38-8.35), respectively. No substantial differences in LOS were observed between the latter three interventions. None of the 11 RCTs compared antibiotics alone vs other types of treatment. Most trials reported peri-procedural complications and the need for reintervention, but the descriptions differed significantly between trials, preventing meta-analysis. In trials reporting health care-associated costs, fibrinolytics had cost advantages compared with VATS. Short- and long-term morbidity and mortality were very low, regardless of the treatment modality.

INTERPRETATION

The results of this network meta-analysis showed that a chest tube alone was associated with a longer LOS compared with other treatment modalities. The lower cost associated with a chest tube plus fibrinolytics warrants consideration when choosing between treatment options, given similar LOS and clinical outcomes compared with the other modalities.

Conversion From Intravenous Alteplase to Tenecteplase for Treatment of Acute Ischemic Stroke Across a Large Community Hospital Health System

BACKGROUND

Recent evidence suggests tenecteplase at an intravenous dose of 0.25 mg/kg is as safe and efficacious as intravenous alteplase standard dose and demonstrates a more favorable pharmacokinetic profile for treatment of acute ischemic stroke.

OBJECTIVE

The purpose was to compare the safety and efficacy of alteplase versus tenecteplase for the treatment of acute ischemic stroke at a large community hospital health system following conversion in the preferred formulary thrombolytic.

METHODS

Prior to converting, medication safety and operationalization analyses were conducted. A multicenter, retrospective medical record review was performed for patients who received alteplase 6 months prior to formulary thrombolytic conversion and for tenecteplase 6 months post-conversion for the treatment of acute ischemic stroke. Primary outcomes included the rate of symptomatic intracranial and extracranial hemorrhage complications. Secondary outcomes included door-to-needle time, reduction in National Institute Health Stroke Scale at 24 hours and at discharge, order-to-administration time, and thrombolytic errors. The rates of hemorrhage were compared using binomial regression.

RESULTS

Of the 287 patients reviewed, 115 received alteplase and 172 received tenecteplase. Symptomatic intracranial hemorrhagic complications occurred in 1 patient (1%) who received alteplase compared with 3 patients (2%) who received tenecteplase (P = 0.9). There was no statistical difference in rates of symptomatic intracranial or extracranial hemorrhagic complications.

CONCLUSION AND RELEVANCE

Conversion from alteplase to tenecteplase can be safely and effectively achieved at a large community hospital health system with differing levels of stroke certification. There were also additional cost savings and practical advantages including workflow benefits.

Nebulized Recombinant Tissue Plasminogen Activator (rt-PA) for Acute COVID-19-Induced Respiratory Failure: An Exploratory Proof-of-Concept Trial

Acute lung injury in COVID-19 results in diffuse alveolar damage with disruption of the alveolar-capillary barrier, coagulation activation, alveolar fibrin deposition and pulmonary capillary thrombi. Nebulized recombinant tissue plasminogen activator (rt-PA) has the potential to facilitate localized thrombolysis in the alveolar compartment and improve oxygenation. In this proof-of-concept safety study, adults with COVID-19-induced respiratory failure and a <300 mmHg PaO2/FiO2 (P/F) ratio requiring invasive mechanical ventilation (IMV) or non-invasive respiratory support (NIRS) received nebulized rt-PA in two cohorts (C1 and C2), alongside standard of care, between 23 April-30 July 2020 and 21 January-19 February 2021, respectively. Matched historical controls (MHC; n = 18) were used in C1 to explore efficacy. Safety co-primary endpoints were treatment-related bleeds and <1.0-1.5 g/L fibrinogen reduction. A variable dosing strategy with clinical efficacy endpoint and minimal safety concerns was determined in C1 for use in C2; patients were stratified by ventilation type to receive 40-60 mg rt-PA daily for ≤14 days. Nine patients in C1 (IMV, 6/9; NIRS, 3/9) and 26 in C2 (IMV, 12/26; NIRS, 14/26) received nebulized rt-PA for a mean (SD) of 6.7 (4.6) and 9.1(4.6) days, respectively. Four bleeds (one severe, three mild) in three patients were considered treatment related. There were no significant fibrinogen reductions. Greater improvements in mean P/F ratio from baseline to study end were observed in C1 compared with MHC (C1; 154 to 299 vs. MHC; 154 to 212). In C2, there was no difference in the baseline P/F ratio of NIRS and IMV patients. However, a larger improvement in the P/F ratio occurred in NIRS patients (NIRS; 126 to 240 vs. IMV; 120 to 188) and fewer treatment days were required (NIRS; 7.86 vs. IMV; 10.5). Nebulized rt-PA appears to be well-tolerated, with a trend towards improved oxygenation, particularly in the NIRS group. Randomized clinical trials are required to demonstrate the clinical effect significance and magnitude.

Pulmonary Thromboembolism in Pregnancy: A Case Report and Literature Review

Data on the optimal diagnostic management of pregnant women with suspected pulmonary embolism are limited. Despite a lack of compelling evidence in some practices, clinical practice guidelines focus on the management of these patients. We present the case of a 24-year-old patient at 36 weeks of pregnancy in whom pulmonary thromboembolism (PTE) was diagnosed in a timely manner also with hemodynamic instability and echocardiographic images with clear involvement of the right cavities. She received thrombolytic therapy with alteplase 100 mg intravenously over 2 hours, which resulted in excellent outcomes for both the pregnant woman and fetus. Understanding the acute approach and management of these patients will improve our clinical practice; therefore, we reviewed a case report of a pregnant patient with high-risk PTE and compared it with current evidence. In conclusion, PE is a common disease with a high mortality rate during pregnancy. Therefore, having made a timely diagnosis using the relevant diagnostic aids and performing thrombolysis with rtPA increase the probability of survival in our patient, leading to successful results for both her and the fetus.

Advancements in the management of acute ischemic stroke: A narrative review

Primary literature detailing updated management principles of acute ischemic stroke outpaces current guidelines, resulting in heterogenous practices. Recent advancements in neuroimaging have shifted treatment from a time-based approach to an individualized, image-guided appraisal directed by the presence or absence of salvageable brain tissue. In addition, tenecteplase appears to be a safe and effective for the treatment of acute ischemic stroke and is becoming an attractive agent due to its practical administration. Several factors must be accounted for when implementing tenecteplase into the health-system including cost, education, and changes in clinician workflows. Larger studies with broad patient populations are needed to more definitively evaluate whether intravenous thrombolytics should be used in combination with endovascular thrombectomy in patients with anterior large-vessel occlusions. Although debate regarding the safety and efficacy of various endovascular therapies, delays encountered in the identification, triage, and care of acute ischemic stroke patients increase the likelihood of necrotic core lesion development and loss of salvageable penumbra.

COVID-19 coagulopathy - what should we treat?

NEW FINDINGS

What is the topic of this review? Overview of the coagulation abnormalities, including elevated D-dimers widely reported with COVID-19, often labelled as COVID coagulopathy. What advances does it highlight? The review highlights the changes in bronchoalveolar haemostasis due to apoptosis of alveolar cells, which contributes to acute lung injury and acute respiratory distress syndrome; the pathophysiological mechanisms, including endothelial dysfunction and damage responsible for thrombosis of pulmonary microcirculation and potential contribution to the hypoxaemia of COVID-19 acute lung injury; and changes in coagulation proteins responsible for the hypercoagulability and increased risk of thrombosis in other venous and arterial beds. The rationale for anticoagulation and fibrinolytic therapies is detailed, and potential confounders that might have led to less than expected improvement in the various randomised controlled trials are considered.

ABSTRACT

Coronavirus disease 19 (COVID-19) causes acute lung injury with diffuse alveolar damage, alveolar-capillary barrier disruption, thrombin generation and alveolar fibrin deposition. Clinically, hypoxaemia is associated with preserved lung compliance early in the disease, suggesting the lack of excessive fluid accumulation typical of other lung injuries. Notably, autopsy studies demonstrate infection of the endothelium with extensive capillary thrombosis distinct from the embolic thrombi in pulmonary arteries. The inflammatory thrombosis in pulmonary vasculature secondary to endothelial infection and dysfunction appears to contribute to hypoxaemia. This is associated with elevated D-dimers and acquired hypercoagulability with an increased risk of deep vein thrombosis. Hypercoagulability is secondary to elevated plasma tissue factor levels, von Willebrand factor, fibrinogen, reduced ADAMTS-13 with platelet activation and inhibition of fibrinolysis. Multi-platform randomised controlled studies of systemic therapeutic anticoagulation with unfractionated and low molecular mass heparins demonstrated a survival benefit over standard care with full-dose anticoagulation in patients with non-severe disease who require supplemental oxygen, but not in severe disease requiring ventilatory support. Late intervention and the heterogeneous nature of enrolled patients can potentially explain the apparent lack of benefit in severe disease. Improvement in oxygenation has been demonstrated with intravenous fibrinolytics in small studies. Inhaled anticoagulants, thrombolytic agents and non-specific proteolytic drugs in clinical trials for decreasing alveolar fibrin deposition might benefit early disease. Essentially, COVID-19 is a multi-system disorder with pulmonary vascular inflammatory thrombosis that requires an interdisciplinary approach to combination therapies addressing both inflammation and intravascular thrombosis or alveolar fibrin deposits to improve outcomes.

Pharmacological and interventional management of pulmonary embolism: where do we stand?

As the third most common cardiovascular disease, pulmonary embolism (PE) has an uptrending incidence and mortality, resulting in significant healthcare expenditure. Risk stratification of acute PE guides management. Although anticoagulation remains the cornerstone management, systemic fibrinolysis and targeted therapeutic approaches, catheter-directed thrombolysis and catheter-based embolectomy are available for high-risk patients. Life-threatening bleeding complications associated with systemic fibrinolysis have restricted its widespread implementation. Catheter-based techniques for intermediate high-risk categories were devised to reduce bleeding complications and improve outcomes. Catheter-directed thrombolysis helps minimize bleeding by way of direct drug delivery. Catheter-based embolectomy mechanically retrieves thrombi without using fibrinolytics. This focused review of medical and interventional management of acute PE provides a highlight of ongoing trials expected to add value to current practice.

Study of Aqueous Ecballium Elaterium as Fibrinolytic in The Rabbit Model of Intrapleural Empyema

Aims

We aimed to investigate of intrapleural use of ecballium elaterium (EE) in a rabbit model empyema.

Methods

An empyema was induced in 21 rabbits after inoculation of Staphylococcus aureus. Glucose levels, pH, lactate dehydrogenase levels, and amounts of pleural drainage were evaluated in addition to pleural and empyema scores. The rabbits were divided into three groups, each 7, the isotonic solution, the streptokinase, and the ecballium group.

Results

At autopsy, there was no difference in pH, glucose, and LDH levels in three groups. The mean pleural drainage was greater in the ecballium group. A significant difference was detected between groups in terms of drainage amounts and pleural and empyema scores (P < 0.05). A significant difference in pleural and empyema scores was detected in the ecballium and streptokinase groups (P < 0.05). EE group had significant differences in drainage amounts and plural and empyema scores regard to the control group (P < 0.05). No significance was found between streptokinase and EE groups.

Conclusion

We conclude that intrapleural use of EE is at least as effective as streptokinase for the treatment of empyema.

Fibrinolytic Administration via EkoSonic™ Endovascular System (EKOS) Catheter Used in Acute Aortic Occlusion Secondary to COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or COVID-19 is the virus responsible for the 2019 global pandemic. Pulmonary complications of COVID-19 are well established in the literature. However, the virus causes numerous extrapulmonary manifestations, notably acute aortic occlusion (AAO). COVID-19 creates a hypercoagulable state via the upregulation of numerous procoagulant cytokines in endothelial cells of blood vessels. We present a case of a 63-year-old patient without a previous history of prothrombotic disorders who developed AAO in the distal abdominal aorta and bilateral common iliac arteries after contracting COVID-19. The patient was a poor surgical candidate and was treated with fibrinolytics that were administered via an EkoSonic™ Endovascular System (EKOS) catheter using a bilateral transfemoral approach. This case highlights a unique treatment option for non-surgical candidates with AAO.

The Potency of Seaweed Sulfated Polysaccharides for the Correction of Hemostasis Disorders in COVID-19

Hemostasis disorders play an important role in the pathogenesis, clinical manifestations, and outcome of COVID-19. First of all, the hemostasis system suffers due to a complicated and severe course of COVID-19. A significant number of COVID-19 patients develop signs of hypercoagulability, thrombocytopenia, and hyperfibrinolysis. Patients with severe COVID-19 have a tendency toward thrombotic complications in the venous and arterial systems, which is the leading cause of death in this disease. Despite the success achieved in the treatment of SARS-CoV-2, the search for new effective anticoagulants, thrombolytics, and fibrinolytics, as well as their optimal dose strategies, continues to be relevant. The wide therapeutic potential of seaweed sulfated polysaccharides (PSs), including anticoagulant, thrombolytic, and fibrinolytic activities, opens up new possibilities for their study in experimental and clinical trials. These natural compounds can be important complementary drugs for the recovery from hemostasis disorders due to their natural origin, safety, and low cost compared to synthetic drugs. In this review, the authors analyze possible pathophysiological mechanisms involved in the hemostasis disorders observed in the pathological progression of COVID-19, and also focus the attention of researchers on seaweed PSs as potential drugs aimed to correction these disorders in COVID-19 patients. Modern literature data on the anticoagulant, antithrombotic, and fibrinolytic activities of seaweed PSs are presented, depending on their structural features (content and position of sulfate groups on the main chain of PSs, molecular weight, monosaccharide composition and type of glycosidic bonds, the degree of PS chain branching, etc.). The mechanisms of PS action on the hemostasis system and the issues of oral bioavailability of PSs, important for their clinical use as oral anticoagulant and antithrombotic agents, are considered. The combination of the anticoagulant, thrombolytic, and fibrinolytic properties, along with low toxicity and relative cheapness of production, open up prospects for the clinical use of PSs as alternative sources of new anticoagulant and antithrombotic compounds. However, further investigation and clinical trials are needed to confirm their efficacy.

Clinical outcomes of patients with diabetes mellitus and acute ST-elevation myocardial infarction following fibrinolytic therapy: a nationwide inpatient sample (NIS) database analysis

The impact of diabetes mellitus (DM) on clinical outcomes of acute ST-segment elevation myocardial infarction (STEMI) following fibrinolytic therapy remains uncertain. We queried the National Inpatient Sample (NIS) for STEMI patients who received fibrinolytic therapy. Categorical and continuous variables were compared using the unadjusted odds ratio (uOR) and t-test analysis, respectively. A binary logistic regression model was used to control the outcomes for patient demographics, procedural characteristics, and baseline comorbidities. A total of 111,155 (no-DM 84,146, DM 27,009) were included. The unadjusted odds of in-hospital mortality (8.4% vs. 6.8%, uOR 1.25, 95% CI 1.19-1.31, P = <0.0001) and cardiogenic shock (7.7% vs. 6.2%, uOR 1.26, 95% CI 1.20-1.33, P = <0.0001) were significantly higher in patients with DM compared to those with no DM, respectively. The odds for major bleeding and cardiopulmonary arrest were significantly lower for in diabetes. The adjusted pooled estimates mirrored the unadjusted findings. Diabetic patients receiving fibrinolytic therapy for STEMI might have higher odds of all-cause mortality and cardiogenic shock compared to non-diabetic patients.

A Cost Variation Analysis of Drugs Available in the Indian Market for the Management of Thromboembolic Disorders

Introduction

Cardiovascular diseases (CVDs) have become one of the major causes of mortality among the Indian population. The costs of anticoagulant, antiplatelet, and fibrinolytic drugs that are used to treat various thromboembolic disorders and used as prophylactics for individuals at high risk of CVDs vary widely in the Indian pharmaceutical market. The aim of this study was to evaluate the cost variation of different brands of drug formulations and to compare the branded prices of the formulations with their corresponding generic and ceiling prices.

Materials and methods

This study followed an analytical method. Costs of various drugs were obtained from the October - December 2019 edition of the Current Index of Medical Specialities (CIMS) and December 2019 edition of the Monthly Index of Medical Specialities (MIMS) India. Cost ratio and percentage variation in cost per tablet/capsule/injection of different drugs available in the Indian market and manufactured by different pharmaceutical companies were calculated. Comparison of the branded prices with generic and ceiling prices was also performed for different drugs by using information available from official websites.

Results

Percentage variation in cost among the commonly prescribed drugs for the management of thromboembolic disorders was found to be highest for prasugrel 10 mg tablet (1,408.44%) while it was lowest for fondaparinux 2.5 mg / 0.5 ml injection (20%). Among the commonly prescribed drugs that are under Drugs Prices Control Order (DPCO) price control, streptokinase 1.5 MIU injection had the highest cost variation (132.02%) while enoxaparin 60 mg / 0.6 ml injection had the lowest (4.99%). Among some of the important formulations under the Jan Aushadhi scheme (JAS), acenocoumarol 2 mg tablet had the highest cost variation (680.09%) and cilostazol 50 mg tablet had the lowest (55.46%).

Conclusions

Wide differences exist in the costs of various anticoagulants, antiplatelets, and fibrinolytics available in the Indian market. The prescribing physician should be aware of theses variations and prescribe medicines accordingly, keeping in mind the financial status of the patients.

Biological effect of tissue plasminogen activator (t-PA) and DNase intrapleural delivery in pleural infection patients

Background

Pleural infection (PI) is a major global disease with an increasing incidence, and pleural fluid (PF) drainage is essential for the successful treatment. The MIST2 study demonstrated that intrapleural administration of tissue plasminogen activator (t-PA) and DNase, or t-PA alone increased the volume of drained PF. Mouse model studies have suggested that the volume increase is due to the interaction of the pleura with the t-PA via the monocyte chemoattractant protein 1 (MCP-1) pathway. We designed a study to determine the time frame of drained PF volume induction on intrapleural delivery of t-PA±DNase in humans, and to test the hypothesis that the induction is mediated by the MCP-1 pathway.

Methods

Data and samples from the MIST2 study were used (210 PI patients randomised to receive for 3 days either: t-PA and DNase, t-PA and placebo, DNase and placebo or double placebo). PF MCP-1 levels were measured by ELISA. One-way and two-way analysis of variance (ANOVA) with Tukey's post hoc tests were used to estimate statistical significance. Pearson's correlation coefficient was used to assess linear correlation.

Results

Intrapleural administration of t-PA±DNase stimulated a statistically significant rise in the volume of drained PF during the treatment period (days 1-3). No significant difference was detected between any groups during the post-treatment period (days 5-7). Intrapleural administration of t-PA increased MCP-1 PF levels during treatment; however, no statistically significant difference was detected between patients who received t-PA and those who did not. PF MCP-1 expression was not correlated to the drug given nor the volume of drained PF.

Conclusions

We conclude that the PF volume drainage increment seen with the administration of t-PA does not appear to act solely via activation of the MCP-1 pathway.

Pediatric empyema thoracis: What has changed over a decade?

OBJECTIVES

The purposes of this paper are to study clinicobacteriological profile, treatment modalities and outcome of pediatric empyema thoracis and to identify changes over a decade.

DESIGN

This is a retrospective study.

SETTING

Department of Pediatrics of a tertiary care hospital in North India.

PATIENTS

We enrolled 205 patients (1 month-12 years) of empyema thoracis admitted over 5 years (2007-11) and compared the profile with that of a previous study from our institute (1989-98).

RESULTS

Pleural fluid cultures were positive in 40% (n = 82) cases from whom 87 isolates were obtained. Staphylococcus aureus was the most common isolate (66.7%). Methicillin-sensitive S. aureus accounted for 56%, Methicillin-resistant S. aureus (MRSA) 10% and gram-negative organisms 18.3% of isolates. Intercostal drainage tube (ICDT) was inserted in 97.5%, intrapleural streptokinase was administered in 33.6%, and decortication performed in 27.8% cases. Duration of hospital stay was 17.2 (±6.3) days, duration of antibiotic (intravenous and oral) administration was 23.8 (±7.2) days and mortality rate was 4%. In the index study (compared with a previous study), higher proportion of cases received parenteral antibiotics (51.7% vs. 23.4%) and ICDT insertion (20.5% vs. 7%) before referral and had disseminated disease (20.5% vs. 14%) and septic shock (11.2% vs. 1.6%), less culture positivity (40% vs. 48%), more MRSA (10.3% vs. 2.5%) and gram-negative organisms (18.4% vs. 11.6%), increased use of intrapleural streptokinase and surgical interventions (27.8% vs. 19.7%), shorter hospital stay (17 vs. 25 days) and higher mortality (3.9% vs. 1.6%).

CONCLUSIONS

Over a decade, an increase in the incidence of empyema caused by MRSA has been noticed, with increased use of intrapleural streptokinase and higher number of surgical interventions.

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

Background

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

Methods

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

Results

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

Conclusion

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

Staphylokinase Enzyme: An Overview of Structure, Function and Engineered Forms

BACKGROUND

One of the most important causes of death in the modern lifestyle is acute ischemic stroke, which is related to thrombosis in the blood vessels. Staphylokinase (SAK), a fibrinolytic agent, which is produced mainly by Staphylococcus aureus, is an indirect activator of plasminogen and belongs to the third generation of fibrinolytic enzymes.

METHODS

Considering the very low level of production and immunogenicity concerns of natural SAK produced by Staphylococcus aureus, attempts have been made to produce recombinant SAKs with high production levels, more fibrinolytic activities and low immunogenicity.

RESULTS AND CONCLUSION

In this review, we summarized a number of expression systems based on recombinant DNA technology and protein-engineering approaches, which have been developed for the production of engineered recombinant SAK molecules with higher fibrinolytic activities and lower antigenicity.

[Fibrinolytics in lung thromboembolism. New alternatives for a controversial prescription]

The use of fibrinolytics in lung thromboembolism (PTE) is a subject under debate since its first description in the 1960s. This therapy, which can rapidly resolve the mechanical obstruction in the pulmonary artery, has the limiting of a high hemorrhagic risk. Precisely because of the prohibitive incidence of major and cerebral bleeding and the lack of benefit in survival, the use of systemic thrombolytics is only indicated in the small number of patients with severe PE and hemodynamic instability. In moderate-risk PE, even with right ventricular (RV) dysfunction, they are not indicated. In recent years, an alternative has arisen, by combining low doses of fibrinolytics released locally into the pulmonary artery through a catheter that may, or may not, be attached to ultrasound at the site of thrombosis. This way of administering thrombolytics can correct acute pulmonary hypertension and eliminate the thrombus without major or CNS bleeds. Although the published studies are very encouraging, the evidence is still poor, a laboratory of hemodynamics is required at all times and this procedure is not free of risks, with a considerable cost. At the moment, only a small number of patients with moderate PE and poor prognosis seem to have an indication for this new alternative.

Management of Complicated Pneumonia in Childhood: A Review of Recent Literature

BACKGROUND

Despite declining rates of community acquired pneumonia (CAP) in children, complicated pneumonia has been on the rise in the last two decades. The management of complicated pneumonia is challenging and continues to be an area of investigation. Despite recently published guidelines, many gaps exist and recent studies attempt to answer challenging questions.

OBJECTIVE

The aim was to review recently published literature to inform the clinician about the most up to date management of complicated pneumonia in children.

METHODS

Using Medline, a search of the medical literature was conducted in order to find relevant clinical trials and review articles published in the last 5 years.

RESULTS

Narrow spectrum antibiotics including ampicillin and azithromycin remain important first line agents, but directed therapy towards causative pathogens is the ideal standard practice. Novel DNA isolation technologies hold promise for raising the diagnostic yield of pleural fluid. Surgical interventions are often required and new literature further supports the use of fibrinolytics and minimally invasive chest tube thoracostomy. Not to be overlooked is the importance of supportive measures including oxygen therapy and adequate fluid, electrolyte and nutrition support. The use of other adjunctive therapies such as steroids in pediatric complicated pneumonia remains controversial.

CONCLUSION

Recent studies have shown promise in establishing best practices for evaluation and management of complicated pneumonia in children. Despite these robust efforts however, many areas are in need of future inquiry and prospective studies could help to better understand the optimal therapeutic and diagnostic options for children with this common and persistent childhood illness.

Intrapleural tissue plasminogen activator and deoxyribonuclease therapy for pleural infection

Pleural infection remains a global health burden associated with significant morbidity. Drainage of the infected pleural fluid is important but can often be hindered by septations and loculations. Intrapleural fibrinolytic therapy alone, to break pleural adhesions, has shown no convincing advantages over placebo in improving clinical outcome. Deoxyribonucleoprotein from degradation of leukocytes contributes significantly to high viscosity of infected pleural fluid. Recombinant deoxyribonuclease (DNase) is effective in reducing pleural fluid viscosity in pre-clinical studies. The combination of tissue plasminogen activator (tPA) and DNase was effective in animal model experiments of empyema. The benefits were established in a randomized clinical trial: those (n=48) treated with tPA/DNase had significantly improved radiological outcomes and reduced need of surgery and duration of hospital stay. A longitudinal observational series of 107 patients further confirmed the effectiveness and safety of tPA/DNase therapy, including its use as 'rescue therapy' when patients failed to respond to antibiotics and chest tube drainage. Overall, a short course of intrapleural tPA (10 mg) and DNase (5 mg) therapy provides a cure in over 90% of patients without requiring surgery. The treatment stimulates pleural fluid formation, enhances radiographic clearance and resolution of systemic inflammation. Serious complications are uncommon; pleural bleeding requiring transfusion occurred in ~2% of cases. Pain can occur, especially with the first dose. Treatment is contraindicated in those with significant bleeding diathesis or a bronchopleural fistula. Future research is required to optimize dosing regimens and in refining patient selection.

Urokinase versus VATS for treatment of empyema: a randomized multicenter clinical trial

BACKGROUND AND OBJECTIVE

Parapneumonic empyema (PPE) is a frequent complication of acute bacterial pneumonia in children. There is limited evidence regarding the optimal treatment of this condition. The aim of this study was to compare the efficacy of drainage plus urokinase versus video-assisted thoracoscopic surgery in the treatment of PPE in childhood.

METHODS

This prospective, randomized, multicenter clinical trial enrolled patients aged <15 years and hospitalized with septated PPE. Study patients were randomized to receive urokinase or thoracoscopy. The main outcome variable was the length of hospital stay after treatment. The secondary outcomes were total length of hospital stay, number of days with the chest drain, number of days with fever, and treatment failures. The trial was approved by the ethics committees of all the participating hospitals.

RESULTS

A total of 103 patients were randomized to treatment and analyzed; 53 were treated with thoracoscopy and 50 with urokinase. There were no differences in demographic characteristics or in the main baseline characteristics between the 2 groups. No statistically significant differences were found between thoracoscopy and urokinase in the median postoperative stay (10 vs 9 days), median hospital stay (14 vs 13 days), or days febrile after treatment (4 vs 6 days). A second intervention was required in 15% of children in the thoracoscopy group versus 10% in the urokinase group (P = .47).

CONCLUSIONS

Drainage plus urokinase instillation is as effective as video-assisted thoracoscopic surgery as first-line treatment of septated PPE in children.

Two sequential tPA/DNase courses for noncommunicating loculated collections in pleural infection

Intrapleural tissue plasminogen activator (tPA) and deoxyribonuclease (DNase) therapy is being increasingly employed as an alternative to surgical intervention for the treatment of complicated parapneumonic effusions and empyema. Published cases are limited to one randomized control trial and few case reports. No data exist on employing sequential or repeated courses of intrapleural tPA/DNase to aid evacuation of separate collections in patients' with a multiloculated pleural infection. This is the first report of successful use of sequential delivery of separate courses of intrapleural tPA/DNase to two noncommunicating infected pleural fluid collections within the same hemithorax of a patient. Our case confirms that prior treatment with tPA/DNase therapy does not preclude subsequent effective and safe use of this intrapleural treatment.

Emergent management of empyema

Empyema is a frankly purulent infection of the pleural space most often occurring secondary to parapneumonic effusion. Imaging, specifically contrast-enhanced computed tomography, plays a critical role in diagnosis with a "split pleura" sign being highly suggestive in the appropriate clinical setting. Diagnostic thoracentesis with culture and Gram stain further guides appropriate antibiotic therapy. Therapeutic drainage with small-bore tube thoracostomy has been shown to be a safe and effective treatment of early stage empyema. Augmentation of tube placement with intrapleural fibrinolytics and mucolytics facilitates catheter drainage by degrading loculations and decreasing fluid viscosity, respectively.

Percutaneous management of thrombosed dialysis access grafts

This article reviews current concepts in the percutaneous management of thrombosed polytetrafluoroethylene (PTFE) dialysis access grafts. The maintenance of dialysis access grafts remains a challenging task. Graft surveillance is critical in the prevention of graft thrombosis to prolong graft survival. Once a graft is thrombosed, surgical and percutaneous options are available for restoration of flow. There has been an evolution in the percutaneous treatment of thrombosed dialysis access grafts during the last 20 years, with refinement of pharmacomechanical techniques, allowing for safe and efficacious restoration of flow in thrombosed grafts. There has been emergence of alternative thrombolytic agents to urokinase, which was withdrawn from the United States in late 1998 and recently reintroduced. These alternative thrombolytic agents have similar outcomes compared with urokinase, with the additional advantage of being less expensive. In addition, several mechanical devices, which were popular briefly when urokinase was unavailable, are available currently for use within grafts, with similar success, although their prices have limited widespread use.