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.

Children's exposure assessment: a review of factors influencing Children's exposure, and the data available to characterize and assess that exposure.

We review the factors influencing children's exposure to environmental contaminants and the data available to characterize and assess that exposure. Children's activity pattern data requirements are demonstrated in the context of the algorithms used to estimate exposure by inhalation, dermal contact, and ingestion. Currently, data on children's exposures and activities are insufficient to adequately assess multimedia exposures to environmental contaminants. As a result, regulators use a series of default assumptions and exposure factors when conducting exposure assessments. Data to reduce uncertainty in the assumptions and exposure estimates are needed to ensure chemicals are regulated appropriately to protect children's health. To improve the database, advancement in the following general areas of research is required: identification of appropriate age/developmental benchmarks for categorizing children in exposure assessment; development and improvement of methods for monitoring children's exposures and activities; collection of activity pattern data for children (especially young children) required to assess exposure by all routes; collection of data on concentrations of environmental contaminants, biomarkers, and transfer coefficients that can be used as inputs to aggregate exposure models.

The 1998 Baltimore Particulate Matter Epidemiology-Exposure Study: part 2. Personal exposure assessment associated with an elderly study population.

An integrated epidemiological-exposure panel study was conducted during the summer of 1998 which focused upon establishing relationships between potential human exposures to particulate matter (PM) and related co-pollutants with detectable health effects. The study design incorporated repeated individual 24-h integrated PM2.5 personal exposure monitoring. A total of 325 PM2.5 personal exposure samples were obtained during a 28-day study period using a subject pool of 21 elderly (65+ years of age) residents of an 18-story retirement facility near Baltimore, Maryland. Each sample represented a unique 24-h breathing zone measurement of PM2.5 mass concentration. PM2.5 and PM10 mass concentrations collected from the apartments of the subjects as well as residential and ambient sites were compared to individual and mean PM2.5 personal exposures. Daily PM2.5 personal exposure concentrations ranged from 2.4 to 47.8 microg/m3 with an overall individual study mean of 12.9 microg/m3. Mean PM2.5 personal exposures were determined to be highly correlated to those representing the central indoor (r=0.90) and ambient sites (r=0.89). Subjects reported spending an average of 92% of each day within the confines of the retirement center. Based upon measured and modeled exposures, a mean PM2.5 personal cloud of 3.1 microg/m3 was estimated. Data collected from these participants may be unique with respect to the general elderly population due to the communal lifestyle within the facility and reported low frequency of exposure to sources of PM.

The TEAM (Total Exposure Assessment Methodology) Study: personal exposures to toxic substances in air, drinking water, and breath of 400 residents of New Jersey, North Carolina, and North Dakota.

EPA's TEAM Study has measured exposures to 20 volatile organic compounds in personal air, outdoor air, drinking water, and breath of approximately 400 residents of New Jersey, North Carolina, and North Dakota. All residents were selected by a probability sampling scheme to represent 128,000 inhabitants of Elizabeth and Bayonne, New Jersey, 131,000 residents of Greensboro, North Carolina, and 7000 residents of Devils Lake, North Dakota. Participants carried a personal monitor to collect two 12-hr air samples and gave a breath sample at the end of the day. Two consecutive 12-hr outdoor air samples were also collected on identical Tenax cartridges in the backyards of some of the participants. About 5000 samples were collected, of which 1500 were quality control samples. Ten compounds were often present in personal air and breath samples at all locations. Personal exposures were consistently higher than outdoor concentrations for these chemicals and were sometimes 10 times the outdoor concentrations. Indoor sources appeared to be responsible for much of the difference. Breath concentrations also often exceeded outdoor concentrations and correlated more strongly with personal exposures than with outdoor concentrations. Some activities (smoking, visiting dry cleaners or service stations) and occupations (chemical, paint, and plastics plants) were associated with significantly elevated exposures and breath levels for certain toxic chemicals. Homes with smokers had significantly increased benzene and styrene levels in indoor air. Residence near major point sources did not affect exposure.

Utility of the routine left lateral view in gated blood pool studies.

One hundred twenty-four sequential gated blood pool studies were examined by four observers in order to determine the impact on overall interpretation created by the addition of a routine left lateral view to supplement the standard LAO and RAO projections. Of these 124 studies, 114 studies in 87 patients were considered technically adequate. Forty-one of the 114 studies revealed differences in the perception of apex motion in the LAO as compared with the left lateral view. In seven of these 41 cases, the overall diagnostic impression was altered by the left lateral view. A 15-minute increase in technician time at an incremental cost of $3.00 is attributed to the added view. Approximately 6% of overall diagnostic impressions were altered because of this additional routine view.