Increase in incidence of childhood empyema

Targeting plasminogen activator inhibitor-1 in tetracycline-induced pleural injury in rabbits

Elevated active plasminogen activator inhibitor-1 (PAI-1) has an adverse effect on the outcomes of intrapleural fibrinolytic therapy (IPFT) in tetracycline-induced pleural injury in rabbits. To enhance IPFT with prourokinase (scuPA), two mechanistically distinct approaches to targeting PAI-1 were tested: slowing its reaction with urokinase (uPA) and monoclonal antibody (mAb)-mediated PAI-1 inactivation. Removing positively charged residues at the "PAI-1 docking site" (¹⁷⁹RHRGGS¹⁸⁴→¹⁷⁹AAAAAA¹⁸⁴) of uPA results in a 60-fold decrease in the rate of inhibition by PAI-1. Mutant prourokinase (0.0625-0.5 mg/kg; n = 12) showed efficacy comparable to wild-type scuPA and did not change IPFT outcomes ( P > 0.05). Notably, the rate of PAI-1-independent intrapleural inactivation of mutant uPA was 2 times higher ( P < 0.05) than that of the wild-type enzyme. Trapping PAI-1 in a "molecular sandwich"-type complex with catalytically inactive two-chain urokinase with Ser¹⁹⁵Ala substitution (S195A-tcuPA; 0.1 and 0.5 mg/kg) did not improve the efficacy of IPFT with scuPA (0.0625-0.5 mg/kg; n = 11). IPFT failed in the presence of MA-56A7C10 (0.5 mg/kg; n = 2), which forms a stable intrapleural molecular sandwich complex, allowing active PAI-1 to accumulate by blocking its transition to a latent form. In contrast, inactivation of PAI-1 by accelerating the active-to-latent transition mediated by mAb MA-33B8 (0.5 mg/kg; n = 2) improved the efficacy of IPFT with scuPA (0.25 mg/kg). Thus, under conditions of slow (4-8 h) fibrinolysis in tetracycline-induced pleural injury in rabbits, only the inactivation of PAI-1, but not a decrease in the rate of its reaction with uPA, enhances IPFT. Therefore the rate of fibrinolysis, which varies in different pathologic states, could affect the selection of PAI-1 inhibitors to enhance fibrinolytic therapy.

Intrapleural Dornase and Tissue Plasminogen Activator in pediatric empyema (DTPA): a study protocol for a randomized controlled trial

BACKGROUND

A randomized controlled trial of adults with empyema recently demonstrated decreased length of stay in hospital in patients treated with intrapleurally administered dornase alfa and fibrinolytics compared to fibrinolytics alone. Whether this treatment strategy is safe and effective in children remains unknown.

METHODS/DESIGN

This study protocol is for a superiority, placebo-controlled, parallel-design, multicenter randomized controlled trial. The participants are previously well children admitted to a children's hospital with a diagnosis of empyema requiring chest tube insertion and fibrinolytics administered intrapleurally. Children will be randomized after the treating physician has decided that pleural drainage is required but prior to chest tube insertion. After chest tube insertion, participants in the treatment group will receive intrapleurally administered tissue plasminogen activator (tPA) 4 mg followed by dornase alfa 5 mg. Participants in the placebo group will receive tPA 4 mg followed by normal saline. Study treatments will be administered once daily for 3 days. All participants, parents or caregivers, clinicians, and research personnel will remain blinded. The primary outcome is length of stay from chest tube insertion to discharge from hospital. Secondary outcomes include time to meeting discharge criteria, chest tube duration, fever duration, need for additional procedures, adverse events, hospital readmission, cost of hospitalization, and mortality.

DISCUSSION

This multicenter randomized controlled trial will assess the safety, effectiveness, and cost-effectiveness of combined treatment with dornase alfa and fibrinolytics compared to fibrinolytics alone for the treatment of empyema in children.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01717742 . Registered on 8 October 2012.

Complicated community acquired pneumonia in childhood: Different types, clinical course, and outcome

The incidence of pediatric community acquired complicated pneumonia (PCACP) is increasing. Questions addressed: Are different types of PCACP one disease? How do different treatment protocols affect the outcome?

METHODS

Retrospective analysis of medical records of PCACP hospitalizations in the three major hospitals in Jerusalem in the years 2001-2010 for demographics, clinical presentation, management, and outcome.

RESULTS

Of the 144 children (51% aged 1-4 years), 91% of Jewish origin; 40% had para-pneumonic effusion (PPE), 40% empyema (EMP), and 20% necrotizing pneumonia (NP). Bacterial origin was identified in 42% (empyema 79%, P = 0.009), most common S. pneumoniae (32%), group A streptococcus (9%). Patients with EMP, compared to PPE and NP, were less likely to receive prior antibiotic treatment (35% vs. 57% and 59%, respectively, P = 0.04). Mean hospitalization was longer in patients with NP followed by EMP and PPE (16.4 ± 10.6, 15.2 ± 7.9, and 12.7 ± 4.7 days, respectively), use of fibrinolysis was not associated with the outcome. All children had recovered to discharge regardless of antibiotic therapy or fibrinolysis.

ANSWER

NP is a more severe disease with prolonged morbidity and hospitalization in spite of prior antibiotic treatment. All types had favorable outcome regardless of treatment-protocol. Complicated pneumonia has an ethnic predominance. Pediatr Pulmonol. 2017;52:247-254. © 2016 Wiley Periodicals, Inc.

Clinical outcome of parapneumonic empyema in children treated according to a standardized medical treatment

Treatment of parapneumonic empyema (PE) consists of intravenous antibiotics and, in case of large effusions and persisting fever, pleural chest drain (±intrapleural fibrinolytics) or video-assisted surgical intervention. We standardized the treatment for PE in our tertiary care center choosing a first-step nonsurgical approach. The aim was to evaluate the need for surgery and to collect data on disease course, outcome, and microbiology. For all children treated for PE between 2006 and 2013, data were prospectively collected concerning treatment, length of stay, duration of fever, complications, and causative agent. Of 132 children treated for PE, 20 % needed surgical intervention. Analyzed per year, the need for surgery decreased from almost 40 % in 2007 to 0 % in 2010 again increasing to 40 % although this did not reach statistical significance (p = 0.115). Median duration of "in-hospital fever" was 5 days (IQR, 3-8). The duration of fever correlated with pleural LDH (r = 0.324; p = 0.002) and pleural glucose (r = -0.248; p = 0.021) and was inversely correlated with pleural pH (r = -0.249; p = 0.046). Based on pleural PCR data, 85 % of PE were caused by Streptococcus pneumoniae (40 % serotype 1).

CONCLUSION

After introduction of a standardized primary medical approach (chest drain ± fibrinolysis) for PE in our institution, the need for surgical rescue interventions overall remained at 20 %, which is higher than in some other reports. Difference in microbiology or disease severity could not be proven.

Distribution of Streptococcus pneumoniae serotypes that cause parapneumonic empyema in Turkey

Streptococcus pneumoniae is the most common etiological cause of complicated pneumonia, including empyema. In this study, we investigated the serotypes of S. pneumoniae that cause empyema in children. One hundred fifty-six children who were diagnosed with pneumonia complicated with empyema in 13 hospitals in seven geographic regions of Turkey between 2010 and 2012 were included in this study. Pleural fluid samples were collected by thoracentesis and tested for 14 serotypes/serogroups using a Bio-Plex multiplex antigen detection assay. The serotypes of S. pneumoniae were specified in 33 of 156 samples. The mean age ± the standard deviation of the 33 patients was 6.17 ± 3.54 years (range, 0.6 to 15 years). All of the children were unvaccinated according to the vaccination reports. Eighteen of the children were male, and 15 were female. The serotypes of the non-7-valent pneumococcal conjugated vaccine (non-PCV-7), serotype 1, serotype 5, and serotype 3, were detected in eight (14.5%), seven (12.7%), and five (9.1%) of the samples, respectively. Serotypes 1 and 5 were codetected in two samples. The remaining non-PCV-7 serotypes were 8 (n = 3), 18 (n = 1), 19A (n = 1), and 7F/A (n = 1). PCV-7 serotypes 6B, 9V, 14, 19F, and 23F were detected in nine (16.3%) of the samples. The potential serotype coverages of PCV-7, PCV-10, and PCV-13 were 16.3%, 45.4%, and 60%, respectively. Pediatric parapneumonic empyema continues to be an important health problem despite the introduction of conjugated pneumococcal vaccines. Active surveillance studies are needed to monitor the change in S. pneumoniae serotypes that cause empyema in order to have a better selection of pneumococcal vaccines.

Pediatric parapneumonic empyema: risk factors, clinical characteristics, microbiology, and management

OBJECTIVE

Pediatric empyema is increasing in incidence and continues to be a source of morbidity in children. Our objective was to determine the risk factors, clinical characteristics, distribution of the pathogens, and outcome of pediatric empyema in 2 Israeli pediatric medical centers.

METHODS

This was a retrospective case-control study on children aged 2 months to 18 years hospitalized with community-acquired pneumonia (CAP) in the pre-Prevnar era (2000-2009). Demographic data, presenting symptoms, physical examination findings, imaging studies, laboratory results, hospital course, medical treatment, and surgical interventions were reviewed from medical records and computerized microbiology databases.

RESULTS

One hundred ninety-one children comprised of 47 (24.9%) with parapneumonic empyema and 144(75.4%) without empyema. The symptoms and course of the children with empyema were substantially worse compared with patients without empyema. The most prevalent pathogen was Streptococcus pneumonia. The most common pneumococcal serotype was serotype 5, and 86% of the recovered S. pneumoniae were susceptible to penicillin. Children with empyema most commonly presented with prolonged fever, dyspnea (51%), and chest pain (17%). Forty-five children with empyema (98%) required a chest tube, fibrinolysis, or decortication with video-assisted thoracoscopy (VATS). Hospitalization stay was similar for children with empyema who underwent VATS and those who were treated conventionally.

CONCLUSIONS

The most prevalent pathogen in children with CAP with and without empyema is S. pneumoniae. Children with empyema experience significantly more morbidity than did patients with CAP alone. In our experience, VATS apparently does not shorten the duration of hospitalization compared with conventional treatment. Immunization may affect the incidence of pediatric empyema and should be studied prospectively.

Increased paediatric hospitalizations for empyema in Australia after introduction of the 7-valent pneumococcal conjugate vaccine

OBJECTIVE

To examine rates of paediatric hospitalization for empyema and pneumonia in Australia before and after the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7).

METHODS

Rates of paediatric hospitalization for empyema and pneumonia (bacterial, viral and all types) were calculated following the codes of the International Classification of Diseases, tenth revision (ICD-10) as a principal diagnosis. The expected number of hospitalizations after the PCV7 was introduced was estimated on the basis of the observed number of hospitalizations before the introduction of the PCV7. Incidence rate differences (IRDs) and incidence rate ratios (IRRs) were calculated. Hospitalization incidence in each study period was expressed as the number of hospitalizations per million (10(6)) person-years. The population of children aged 0-19 years in Australia from 1998 to 2004 and from 2005 to 2010, as reported by the Australian Bureau of Statistics, was used to calculate the number of person-years in each period.

FINDINGS

In the 5 years following the introduction of the PCV7, hospitalizations for pneumonia were fewer than expected (15 304 fewer; 95% confidence interval, CI: 14 646-15 960; IRD: -552 per 10(6) person-years; 95% CI: -576 to -529 per 10(6) person-years; IRR: 0.78; 95% CI: 0.77-0.78). Hospitalizations for empyema, on the other hand, were more than expected (83 more; 95% CI: 37-128; IRD: 3 per 10(6) person-years; 95% CI: 1-5 per 10(6) person-years; IRR: 1.35; 95% CI: 1.14-1.59). Reductions in hospitalizations were observed for all ICD-10 pneumonia codes across all age groups. The increase in empyema hospitalizations was only significant among children aged 1 to 4 years.

CONCLUSION

The introduction of the PCV7 in Australia was associated with a substantial decrease in hospitalizations for childhood pneumonia and a small increase in hospitalizations for empyema.

What is different about serotype 1 pneumococci?

Serotype 1 Streptococcus pneumoniae is among the most commonly isolated serotype in invasive pneumococcal disease but is rarely found causing asymptomatic nasopharyngeal colonization. Compared to infection by other serotypes, infection caused by serotype 1 is more likely to be identified in young patients without comorbidities but is generally associated with a lower mortality. Empyema and extrapulmonary manifestations are common. Outbreaks of serotype 1 disease have been reported in closed communities and epidemics are particularly common in sub-Saharan Africa. The serotype 1 capsular polysaccharide is a zwitterionic structure that enables it to function as a T-cell dependent antigen under some circumstances, in contrast to other pneumococcal capsular polysaccharides that are T-cell independent antigens. There are also differences in the key virulence factor pneumolysin in some serotype 1 isolates. The clinical significance of these differences remains to be determined.

Bacterial causes of empyema in children, Australia, 2007-2009

An increase in the incidence of empyema worldwide could be related to invasive pneumococcal disease caused by emergent nonvaccine replacement serotypes. To determine bacterial pathogens and pneumococcal serotypes that cause empyema in children in Australia, we conducted a 2-year study of 174 children with empyema. Blood and pleural fluid samples were cultured, and pleural fluid was tested by PCR. Thirty-two (21.0%) of 152 blood and 53 (33.1%) of 160 pleural fluid cultures were positive for bacteria; Streptococcus pneumoniae was the most common organism identified. PCR identified S. pneumoniae in 74 (51.7%) and other bacteria in 19 (13.1%) of 145 pleural fluid specimens. Of 53 samples in which S. pneumoniae serotypes were identified, 2 (3.8%) had vaccine-related and 51 (96.2%) had nonvaccine serotypes; 19A (n = 20; 36.4%), 3 (n = 18; 32.7%), and 1 (n = 8; 14.5%) were the most common. High proportions of nonvaccine serotypes suggest the need to broaden vaccine coverage.

A bedside assay to detect streptococcus pneumoniae in children with empyema

BACKGROUND

Empyema is a complication of pneumonia, commonly caused by Streptococcus pneumoniae.

AIMS

To validate the utility of an immunochromatographic test for the detection of S. pneumoniae antigen in the pleural fluid of children with empyema.

METHODS

Empyema patients had blood and pleural fluid cultured, and polymerase chain reaction (PCR) to detect the S. pneumoniae autolysin gene, lytA, in pleural fluid. Pleural fluid was tested using the Binax NOW S. pneumoniae antigen detection assay and compared with lytA PCR results and/or culture in blood or pleural fluid.

RESULTS

S. pneumoniae was detected by PCR in pleural fluid of 68 of 137 (49.6%) patients, by culture in 11 of 135 (8.1%) pleural specimens and 16 of 120 (13.3%) blood specimens. Pleural fluid Binax NOW testing from 130 patients demonstrated a sensitivity of 83.8% and specificity of 93.5% (positive predictive value of 93.4% and negative predictive value of 84.1%).

CONCLUSIONS

In pediatric empyema, high predictive values of pleural fluid Binax NOW S. pneumoniae antigen test suggest that this test may help rationalize antibiotic choice in these patients.

Empyema hospitalizations increased in US children despite pneumococcal conjugate vaccine

OBJECTIVE

To determine if the incidence of empyema among children in the United States has changed since the introduction of the pneumococcal conjugate vaccine in 2000.

METHODS

We used the nationally representative Kids' Inpatient Database to estimate the annual total number of hospitalizations of children < or = 18 years of age that were associated with empyema in 1997, 2000,2003, and 2006 [corrected]. Using US Census data, estimated counts were converted into annual incidence rates per 100000 children. Incidence rates were compared between 1997 and later years to determine the impact of pneumococcal conjugate vaccine on hospitalization rates.

RESULTS

During 2006, an estimated total of 2898 (95% confidence interval [CI]: 2532-3264) hospitalizations of children <or=18 years of age in the United States were associated with empyema. The empyema-associated hospitalization rate was estimated at 3.7 (95% CI: 3.3-4.2) per 100000 children, an increase of almost 70% from the 1997 empyema hospitalization rate of 2.2 (95% CI: 1.9-2.5) per 100000. The rate of complicated pneumonia (empyema, pleural effusion, or bacterial pneumonia requiring a chest tube or decortication) similarly increased 44%, to 5.5 (95% CI: 4.8-6.1) per 100000. The rate of bacterial pneumonia decreased 13%, to 244.3 (95% CI: 231.1-257.5) per 100000. The rate of invasive pneumococcal disease (pneumonia, sepsis, or meningitis caused by Streptococcus pneumoniae) decreased 50%, to 6.3 (95% CI: 5.7-6.9) per 100000.

CONCLUSIONS

Among children <or=18 years of age, the annual empyema-associated hospitalization rates increased almost 70% between 1997 and 2006, despite decreases in the bacterial pneumonia and invasive pneumococcal disease rates. Pneumococcal conjugate vaccine is not decreasing the incidence of empyema.

Assessment of the burden of paediatric empyema in Australia

AIMS

To investigate the change in incidence of childhood empyema and pneumonia in Australia, and ascertain the management trends in all hospitals caring for children with empyema.

METHODS

The incidences of empyema and pneumonia were calculated for each year between 1993/1994 and 2004/2005 using retrospective primary diagnostic coding from ICD-9 and 10 comprising the Australian National Hospital Morbidity Database for five age groups in patients less than 20 years of age. Hospitals with allocated paediatric beds were surveyed on referral pattern and treatment preferences.

RESULTS

In this study, 145 562 patients with pneumonia were admitted with a mean (range) incidence of 2306 (1846-2652) per million. The trend towards an overall increase was not statistically significant. Only the 1-4 years old age group demonstrated a significant increase (P < 0.01, r2 = 0.61). A total of 469 cases of empyema were identified with a mean incidence of 7.35 (4-10.2) per million. There was an overall increase in incidence (P < 0.05, r2 = 0.51) reflecting an increase in the 1- to 4-year-olds (P < 0.005, r2 = 0.60) and 15- to 19-year-olds (P < 0.05, r2 = 0.37). The overall percentage of empyema as a proportion of pneumonia increased from 0.27 to 0.70% (0.48% (0.27-0.70%), P < 0.05, r2 = 0.38). The survey response rate was 75%. Ninety-nine of 121 (82%) hospitals referred children with empyema to a more appropriate centre with wide variations in treatments provided.

CONCLUSIONS

The rise in incidence of empyema reflects that seen in other countries. Furthermore, there are diverse management practices suggesting a clear need for national guidelines.

Clinical practice: treatment of childhood empyema

INTRODUCTION

The incidence of empyema in children is increasing. Adequate knowledge of treatment modalities is therefore essential for every pediatrician. At the university hospital of Leuven, the incidence per 100,000 admissions increased from 40 in 1993 to 120 in 2005. The treatment of choice, however, is still a matter of debate. This is mainly due to the scarcity of prospective randomized trials in children but is further complicated by the absence of uniform terminology. This review starts with clarifying definitions of empyema and complicated versus noncomplicated parapneumonic effusion. The place of different imaging techniques--ultrasound, chest X-ray, computerized tomography and magnetic resonance imaging--is illustrated. All treatment steps are evaluated starting with antibiotic choices, duration of i.v. and oral antibiotics, pleural fluid analysis, indications for chest drain placement, and fibrinolysis. As to the surgical interventions, there is at present insufficient evidence that early surgery is superior to noninvasive medical treatment. Therefore, video-assisted thoracoscopy cannot be advised as general first-line therapy.

CONCLUSION

Since the pathogenicity of empyema is a dynamic process, therapeutic strategy must be decided based on empyema stage and clinical experience. Each referral center should agree on a diagnostic and therapeutic flowchart based on current evidence and local expertise. The flow chart outlined for our center is presented.

Efficacy of video-assisted thoracoscopic surgery in managing childhood empyema: a large single-centre study

BACKGROUND/PURPOSE

A randomised controlled trial evaluating the role of video-assisted thoracoscopic surgery (VATS) in childhood empyema reported a failure rate of 16.6%. Our aim is to determine the outcome of VATS in a large series of children managed by 3 paediatric surgeons experienced in endoscopic surgery.

METHOD

A retrospective study of all children with empyema admitted under the care of the 3 surgeons between February 2004 and February 2008 was undertaken. Recorded details included demographic data, mode of presentation, preoperative investigations, operative details, antibiotic usage, microbiological data, postoperative course, follow-up data and complications.

RESULTS

114 children (69 boys, 45 girls) had VATS for empyema. Their median age was 5 (0.2-15) years. The pleural cavity was drained for a median of 4 (2-13) days. Median postoperative hospital stay was 7 (4-36) days. Median follow-up was 8 (1-24) months. There were 8 (7%) treatment failures: 5 conversions to thoracotomy and 3 recurrent empyemas. There were 7 complications (6%): air leak (n = 6) and lung injury (n = 1). 104 (91%) children had full resolution of symptoms. There were no deaths.

CONCLUSION

Video-assisted thoracoscopic surgery has a better outcome in childhood empyema than reported in a recent randomised trial and it has an important role in the management of this condition.

Complicated parapneumonic effusion in Belgian children: increased occurrence before routine pneumococcal vaccine implementation

An increased occurrence of complicated parapneumonic effusions in children has been reported from the UK and USA. Data from mainland Europe are scarce. We investigated the incidence of complicated parapneumonic effusion and empyaema in children admitted to the University Hospital of Leuven between 1993 and 2005, an era when pneumococcal conjugated vaccination had not yet been implemented. Sixty-eight cases were identified. The incidence increased from 20-55/100,000 hospital admissions to 120-130/100,000 hospital admissions in 2005, with 50% of the cases occurring from 2003 onwards (late cohort). This increase occurred later than that reported in the UK and US, but is of similar magnitude. The median patient age was 3.6 years (range 0.5-17 years). The median duration of symptoms before admission was 4 days (quartile values 3-7 days). The median white blood cell (WBC) count was 15,450 WBC/mm3 (quartile values 11,300-21,200 WBC/mm3) and the median C-reactive protein (CRP) level was 242 mg/L (quartile values 143-344 mg/L). Patients in the late cohort seemed to have worse disease compared to early cohort patients; significantly higher pleural lactate dehydrogenase (LDH) level (P = 0,02), higher pleural WBC, lower pleural glucose level and significantly longer duration of hospitalisation in the later cohort (P < 0,05), possibly reflecting more severe disease. In both cohorts, Streptococcus pneumoniae was the most frequently isolated pathogen, with serogroup 1 prevailing. The occurrence of complicated parapneumonic effusion increased in Belgian children before pneumococcal vaccination was added to routine childhood immunisations. This increase is pronounced from 2003 onwards (late cohort) and, thus, occurred later than that reported in the UK and USA; several parameters point towards the occurrence of more serious disease in the late cohort patients.

Empyema associated with community-acquired pneumonia: a Pediatric Investigator's Collaborative Network on Infections in Canada (PICNIC) study

BACKGROUND

Although the incidence of serious morbidity with childhood pneumonia has decreased over time, empyema as a complication of community-acquired pneumonia continues to be an important clinical problem. We reviewed the epidemiology and clinical management of empyema at 8 pediatric hospitals in a period before the widespread implementation of universal infant heptavalent pneumococcal vaccine programs in Canada.

METHODS

Health records for children<18 years admitted from 1/1/00-31/12/03 were searched for ICD-9 code 510 or ICD-10 code J869 (Empyema). Empyema was defined as at least one of: thoracentesis with microbial growth from pleural fluid, or no pleural fluid growth but compatible chemistry or cell count, or radiologist diagnosis, or diagnosis at surgery. Patients with empyemas secondary to chest trauma, thoracic surgery or esophageal rupture were excluded. Data was retrieved using a standard form with a data dictionary.

RESULTS

251 children met inclusion criteria; 51.4% were male. Most children were previously healthy and those<or=5 years of age comprised 57% of the cases. The median length of hospitalization was 9 days. Admissions occurred in all months but peaked in winter. Oxygen supplementation was required in 77% of children, 75% had chest tube placement and 33% were admitted to an intensive care unit. While similarity in use of pain medication, antipyretics and antimicrobial use was observed, a wide variation in number of chest radiographs and invasive procedures (thoracentesis, placement of chest tubes) was observed between centers. The most common organism found in normally sterile samples (blood, pleural fluid, lung biopsy) was Streptococcus pneumoniae.

CONCLUSION

Empyema occurs most commonly in children under five years and is associated with considerable morbidity. Variation in management by center was observed. Enhanced surveillance using molecular methods could improve diagnosis and public health planning, particularly with regard to the relationship between immunization programs and the epidemiology of empyema associated with community-acquired pneumonia in children.

[Why are pediatric empyemas on the increase in Spain?]

There is a widespread perception among Spanish pediatricians that the incidence of empyema has significantly increased in the last few years, even though the objective information available is limited, and there is no specific active epidemiological surveillance system for this condition. In the present article, we review the situation of empyema in Spain, and discuss the main hypotheses put forward in the international literature to explain this increase, as well as the limitations of the sources available. Despite the scarcity of information, we draw the following conclusions: 1) the incidence of pediatric empyema is increasing in Spain, both generally and when caused by pneumococcus in particular; 2) the reason for this increase remains unknown, and to date no firm link has been established between this phenomenon and the heptavalent conjugate pneumococcal vaccine; and 3) this situation justifies the establishment of prospective systems for the surveillance and control of empyema and, once again, highlights the importance of developing active surveillance systems for pneumococcal disease.

Pleural effusions

The ability to recognize, understand, and treat pleural effusions in the pediatric population is important for pediatric health care providers. The topic of pleural effusions has been extensively studied in the adult population. In recent years, these studies have extended into the pediatric population. This review describes pleural effusions in detail, including the different types and underlying pathophysiology. We then go on to provide a comprehensive review of the recent literature regarding the diagnosis and treatment of pleural effusions in the pediatric population.

Current treatment of pediatric empyema

Pneumonia with complicated parapneumonic effusion and empyema is increasing in incidence and continues to be a source of morbidity in children seen in our institution. Current diagnostic modalities include chest radiographs and CT scanning with ultrasound being helpful in some situations. Exact management of empyema remains controversial. Although open thoracotomy drainage is well accepted in children, video-assisted thoracoscopic surgery (VATS) drainage has become more prevalent in the current era. Over the last 4 years, we have treated 58 children with intrapleural placement of pigtail catheters and administration fibrinolytics consisting of tissue plasminogen activator (tPA). Successful drainage and resolution of 54 of the 58 effusions was achieved with percutaneous methods alone. There was no mortality or 30-day recurrence. Mean hospital stay was 9.1 days (range 5 to 21) and mean chest catheter removal was 6 days post placement (range 1.5 to 20). Of the four patients that failed percutaneous tube therapy, 3 underwent video assisted thoracic surgery (VATS), and one had open thoracotomy with decortication. Based on our experience, tPA administered through a small bore chest tube for drainage of complicated parapneumonic effusions has become our standard practice. We reserve VATS for treatment failures and open thoracotomy and decortication for patients with VATS failure.

Ready for the Frontline: Is Early Thoracoscopic Decortication the New Standard of Care for Advanced Pneumonia with Empyema?

Video-assisted thoracoscopic decortication (VATD) has been established as an effective and potentially less morbid alternative to open thoracotomy for the management of empyema. However, the timing and role of VATD for advanced pneumonia with empyema is still controversial. In assessing surgical outcome, the authors reviewed their VATD experience in children with empyema or empyema with necrotizing pneumonia. The charts of 42 children who underwent VATD at our institution between July 2001 and July 2005 were retrospectively reviewed for surgical outcome. For purposes of analysis, patients were cohorted into four classes with increasing severity of pneumonia: 1 (-) intraoperative pleural fluid cultures, (-) necrotizing pneumonia, 18 (43%); 2 (+) pleural fluid cultures, (-) necrotizing pneumonia, 10 (24%); 3 (-) pleural fluid cultures, (+) necrotizing pneumonia, 6 (14%); 4 (+) pleural fluid cultures, (+) necrotizing pneumonia, 8 (19%). A P value of <0.05 via Student's t test or Fischer's exact analysis was considered an indicator of significant difference in the comparison of group outcomes. VATD was successfully completed in all 42 patients with no mortality and without significant morbidity (82% had less than 20 cc blood loss). There was found to be no significant difference (p = NS) in time to surgical discharge (removal of chest tube) among all groups. Hospital length of stay postsurgery was found to be significantly increased between 1 and 4 (6 days vs 9 days; P = 0.038). 14/14 (100%) of children with necrotizing pneumonia were found to have evidence of lung parenchymal preservation with improved aeration on follow-up CT scan and/or chest x-rays. The authors conclude that early VATD in children with advanced pneumonia with empyema is indicated to avoid unnecessarily lengthy hospitalization and prolonged intravenous antibiotic therapy. Furthermore, early VATD can be safely performed in various stages of advanced pneumonia with empyema, promoting lung salvage, and accelerating clinical recovery.

Conservative use of chest-tube insertion in children with pleural effusion

The aim of this work was to evaluate the effect of a more conservative use of chest-tube insertion on the short-term and long-term outcome of pleural infection. Sixty-five patients with pleural infection, aged 1 month to 16 years were each treated according to one of the two protocols: classical management with chest-tube insertion (classical group, n = 33), or conservative use of chest-tube insertion (conservative group, n = 32), with drainage indicated only in the case of voluminous pleural effusion defined by a mediastinal shift and respiratory distress and/or an uncontrolled septic situation. The two groups were comparable with regard to age, baseline C-reactive protein (CRP) value and white blood cell counts, pleural thickness, identified bacteria, and antibiotic treatment. Chest-tube insertion was performed in 17 patients (52%) of the classical group compared to eight patients (25%) of the conservative group (P = 0.03). Duration of temperature above 39 degrees C was shorter in the conservative group (10 +/- 1 vs. 14 +/- 1 days, P = 0.01), as was the normalization of CRP (13 +/- 1 vs. 17 +/- 1 days, P = 0.03). Duration of hospitalization and intravenous (IV) antibiotherapy as well as the delay of chest-radiograph normalization was not significantly different between the two groups. A more conservative use of chest-tube insertion did not change short- and long-term outcome of the pleural infection in children. Drainage could be restricted to the most severely affected patients with pleural empyema causing a mediastinal shift and respiratory distress and/or presenting with an uncontrolled septic situation.

Management of empyema in children

The incidence of empyema complicating community-acquired pneumonia is increasing and causes significant childhood morbidity. Pneumococcal infection remains the most common isolated cause in developed countries, with Staphylococcus aureus the predominant pathogen in the developing world. Newer molecular techniques utilizing the polymerase chain reaction have led to an increase in identification of causative bacteria, previously not isolated by conventional culture techniques. This remains an important epidemiological tool, and may help in guiding correct antibiotic use in the future. There are many treatment options, however, and the care a child currently receives is dependent on local practice, which is largely determined by availability of medical personnel and their preferences. Although there are many reported case series comparing treatment options, only two randomized controlled studies exist to guide treatment in children. There is an urgent need for this to be addressed, particularly with the introduction of relatively new surgical techniques such as video-assisted thorascopic surgery.

Medical management of parapneumonic pleural disease

Considerable heterogeneity exists in the management of parapneumonic pleural disease. A randomized controlled trial (RCT) demonstrated the effectiveness of small-catheter drainage with fibrinolysis, but surgical devotees suggest this may only be applicable to "early" cases. We examined evidence-based medical management in "all-comers." We performed a retrospective database analysis of the management of all children with complex pleural effusion admitted to the John Radcliffe Hospital over the 7-year period 1996-2003. One hundred and ten children were admitted. Ten were excluded as they were part of a multicenter RCT and had received intrapleural saline instead of urokinase. Of the remaining 100, 51 were female and 49 male. Median age on admission was 5.8 years (range, 0.3-16.5). Symptoms preadmission averaged 11 days, with December the most common month for presentation. Ninety-six underwent chest ultrasound, confirming an effusion in all, described as loculated/septated (68) or echogenic (11). In 17 cases, no specific comment was made regarding the nature of the fluid seen on ultrasound. Ninety-five had subsequent chest tube drainage and then received intrapleural fibrinolysis with urokinase. An etiological organism was identified in 21 cases (21%) (Streptococcus pneumoniae in 10, group A Streptococcus in 5, Staphylococcus aureus in 4, Haemophilus influenzae in 1, and coliform in 1). In a further 9 cases (9%), Gram-positive organisms were seen on pleural fluid microscopy, but did not grow on culture. Two (2%) required surgery due to the persistence of symptoms and an inadequate response to medical management. Median duration of admission was 7 days (range, 2-21 days); median duration of stay from intervention was 5 days (range, 2-19 days). At median follow-up of 8 weeks (range, 3-20 weeks), all children were symptom-free, with minimal pleural thickening on chest X-ray. In conclusion, antibiotic therapy with chest drain insertion and intrapleural urokinase is effective in treating complex parapneumonic effusion and is associated with a good long-term outcome.

The changing face of pleural empyemas in children: epidemiology and management

OBJECTIVE

Empyema remains a significant cause of morbidity in children. This study evaluates the changes that have affected the outcome in children with pleural empyema, including the emergence of resistant organisms, the introduction of the pneumococcal conjugate vaccine, and earlier treatment with video-assisted thoracoscopy (VATS).

METHODS

A retrospective chart review was performed on all patients who were discharged with a diagnosis of empyema and community-acquired pneumonia over a 10-year period (1993-2002) at Texas Children's Hospital in Houston, Texas. Data collected included demographic information, clinical presentation, radiographic studies, laboratory data including culture results, and hospital course.

RESULTS

A total of 230 charts were available for review. The mean age of the patients was 4.0 +/- 3.6 years. Of the pleural fluid cultures performed, 32% (69 of 219) were positive. An additional 27 patients had a cause identified by blood culture. The first penicillin-nonsusceptible Streptococcus pneumoniae was identified in 1995, and the first methicillin-resistant Staphylococcus aureus was identified in 1998. After the universal use of the pneumococcal conjugate vaccine, 3 major changes have occurred (1999-2000 vs 2001-2002): 1) the number of patients admitted with empyema (per 10 000 admissions) has decreased from 23 to 12.6; 2) the prevalence of S pneumoniae has decreased from 66% (29 of 44) to 27% (4 of 15); and 3) S aureus has become the most common pathogen isolated (18% vs 60%), with 78% of those being methicillin resistant. The use of early VATS (<48 hours after admission) versus late VATS (>48 hours after admission) significantly decreased the length of hospitalization (11.49 +/- 6.56 days vs 15.18 +/- 8.62 days).

CONCLUSIONS

The microbiologic cause of empyema has changed with an increasing incidence of S aureus, particularly methicillin-resistant S aureus. The use of VATS for initial therapy of empyema results in decreased duration of fever and length of hospitalization.

Current issues in the diagnosis and management of pediatric empyema

Empyema is a rare but recognized complication of bacterial pneumonia in children. The incidence of empyema may be rising as vaccination practices and antibiotic prescribing practices promote the emergence of more virulent and resistant organisms. Diagnostic methods vary widely, from thoracentesis to plain radiographs to detailed computed tomography scans. Treatment practices also vary, with some practitioners preferring medical treatment, others employing chest tube drainage or fibrinolytic therapy, and still others aggressively pursuing surgical options. Further study is needed to define the ideal management of empyema. The authors review the current literature and propose an updated management algorithm that incorporates accepted practices as well as emerging trends in diagnosis and management of empyema.

[Value of thoracoscopy in purulent pleuresies in children younger than four years]

Video-assisted thoracoscopic surgery is widely performed in adults but there are few publications concerning the paediatric population. The objective is to effect optimal adhesiolysis of post-pneumonic loculated empyema with lower morbidity.

PATIENTS AND METHODS

Over a 4-year period we used thoracoscopic debridement in five children younger than 4 years of age with loculated thoracic empyema. All patients failed initial treatment, including antibiotics and chest tube drainage. Early sonographic evaluation of the empyema organization guided the most appropriate moment for the intervention. The average duration of tube drainage after thoracoscopy was 4 days (range: 1 to 7 days).

RESULTS

All patients made an uneventful postoperative recovery. At a follow-up visit 1 month after discharge, the children were clinically asymptomatic; however, some degree of pleural thickening was still visible on chest X-rays.

CONCLUSION

In skilled hands, thoracoscopy is a safe procedure for post-pneumonic empyema in young children, providing a rapid clinical and radiological recovery with a good cosmetic result.