Faculty Bibliography

OBJECTIVES/OBJECTIVE:The 2009 outbreak of novel influenza A H1N1 reached a pandemic status on June 11, 2009. Early detection is a key factor for management and infection-control practices. Recent studies have suggested a difference in performance of rapid influenza kits for influenza A H1N1. Our goal was to evaluate the performance of the QuickVue influenza A+B test (Quidel Corp., San Diego, CA) in an emergency department setting and determine the most current epidemiologic trends in our community. METHODS:Results from 1137 samples for influenza A collected between April 8, 2009 and June 30, 2009 were retrospectively reviewed. Results of QuickVue influenza A+B test were compared with R-Mix viral culture and DFA results. Age distribution and hospitalization rates by age group were analyzed to further delineate the epidemiology of influenza A in a suburban hospital. RESULTS:The sensitivity of the rapid test was 77%, the specificity was 85%, the positive predictive value was 74%, and the negative predictive value was 87%. We found a similar age distribution for positive influenza tests and admissions when compared with the national Centers for Disease Control and Prevention data. CONCLUSIONS:The QuickVue influenza A+B test is a sensitive assay for the novel H1N1 strain of influenza. In our hospital, the group with highest risk of hospital admission was patients aged < 25 years.

OBJECTIVE:Associations between pleural and pericardial effusions have been described in malignancy and autoimmune disorders. Bacterial pneumonia is the most frequent cause of parapneumonic effusion; however, knowledge of the relationship between parapneumonic effusion and the presence of pericardial fluid in children is limited. We examined this relationship. METHODS:We performed a retrospective chart review of pediatric patients who were admitted to our institution during a 6-year period with a diagnosis of either parapneumonic effusion or empyema and who had undergone an echocardiogram, a computed tomography scan of the thorax, or both. All demographic, clinical, radiographic, and laboratory data of these patients were collected, and statistical analysis was done with Student's t tests and chi2 analyses. RESULTS:We reviewed the charts of 59 children with parapneumonic effusions. Forty-eight underwent 2-dimensional echocardiography, chest computed tomography scan, or both. Of these 48 patients, 54.2% (n=26) were found to have a concomitant pericardial effusion. The majority of patients with pericardial effusions had left-sided pleural disease. Patients with pericardial effusions had more symptomatic days before hospitalization, lower pleural fluid albumin levels, elevated serum white blood cell counts, elevated pleural fluid white blood cell and absolute neutrophil counts, and an increased incidence of surgical intervention. One patient had evidence of hemodynamic compromise that required pericardiocentesis. CONCLUSIONS:We found a high incidence of pericardial effusions in pediatric patients with parapneumonic effusions. Leukocytosis, higher pleural fluid leukocyte and neutrophil counts, and a propensity for surgical intervention suggest a prognostic relationship between pericardial effusions and more severe parapneumonic disease. The majority of these pericardial collections resolve with treatment of the underlying pleural disease.

Polysomnographic recordings of 43 children and adults with Prader-Willi syndrome (PWS) were inspected and classified into 5 age groups. The effect of age and body mass index (BMI) on measures of breathing, oxygen saturation, and sleep efficiency were analyzed. Body mass index (BMI) increased significantly between early childhood and preadolescent groups. Subjecting the data to analysis of variance showed an overall significant effect of BMI but no age effect on breathing parameters and oxygen saturation. Increased BMI was associated with decreased oxygen saturation and with higher apnea/hypopnea index. Sleep efficiency index was significantly lower in adults than in young children, preadolescent, and adolescent groups. These findings emphasize the role of obesity in the development of sleep-related breathing abnormalities and nocturnal oxygen desaturation in patients with PWS

Patients with Prader Willi syndrome (PWS) often complain of daytime hypersomnolence. Because of reported daytime sleepiness and high prevalence of morbid obesity, these patients have been considered at risk for sleep related disordered breathing, but polysomnographic studies have been limited. We evaluated sleep and breathing polysomnographically in 24 PWS patients including 15 adults and 9 children. All adult patients completed MSLT testing on the day following the nocturnal sleep study. Both adult and children groups showed little or no sleep apnea, but REM related oxygen desaturation was quite common, its severity significantly correlated with increased obesity. Sleep patterns in both groups showed abnormal REM sleep cycles with variable REM latency (at times significantly shortened) and fragmented REM sleep with multiple brief REM periods. REM sleep abnormalities were still present in some patients without REM related desaturation. As a group, patients with PWS demonstrated pathological somnolence as measured by MSLT, which correlated with nocturnal sleep efficiency but not with nocturnal REM latency. It is hypothesized that the abnormal sleep findings in PWS reflect an underlying hypothalamic dysfunction characteristic of this syndrome