Charles G. Macias

Clinical and demographic factors associated with urinary tract infection in young febrile infants

Objective. Previous research has identified clinical predictors for urinary tract infection (UTI) to guide urine screening in febrile children <24 months of age. These studies have been limited to single centers, and few have focused on young infants who may be most at risk for complications if a UTI is missed. The objective of this study was to identify clinical and demographic factors associated with UTI in febrile infants who are ≤60 days of age using a prospective multicenter cohort. Methods. We conducted a multicenter, prospective, cross-sectional study during consecutive bronchiolitis seasons. All febrile (≥38°C) infants who were ≤60 days of age and seen at any of 8 pediatric emergency departments from October through March 1999–2001 were eligible. Clinical appearance was evaluated using the Yale Observation Scale. UTI was defined as growth of a known bacterial pathogen from a catheterized specimen at a level of (1) ≥50000 cfu/mL or (2) ≥10000 cfu/mL in association with a positive dipstick test or urinalysis. We used bivariate tests and multiple logistic regression to identify demographic and clinical factors that were associated with the likelihood of UTI. Results. A total of 1025 (67%) of 1513 eligible patients were enrolled; 9.0% of enrolled infants received a diagnosis of UTI. Uncircumcised male infants had a higher rate of UTI (21.3%) compared with female (5.0%) and circumcised male (2.3%) infants. Infants with maximum recorded temperature of ≥39°C had a higher rate of UTI (16.3%) than other infants (7.2%). After multivariable adjustment, UTI was associated with being uncircumcised (odds ratio: 10.4; bias-corrected 95% confidence interval: 4.7–31.4) and maximum temperature (odds ratio: 2.4 per °C; 95% confidence interval: 1.5–3.6). Factors that were reported previously to be associated with risk for UTI in infants and toddlers, such as white race and ill appearance, were not significantly associated with risk for UTI in this cohort of young infants. Conclusions. Being uncircumcised and height of fever were associated with UTI in febrile infants who were ≤60 days of age. Uncircumcised male infants were at particularly high risk and may warrant a different approach to screening and management.

Effect of Antibiotic Pretreatment on Cerebrospinal Fluid Profiles of Children With Bacterial Meningitis

OBJECTIVE. The goal of this study was to evaluate the effect of antibiotic administration before lumbar puncture on cerebrospinal fluid profiles in children with bacterial meningitis. METHODS. We reviewed the medical records of all children (1 month to 18 years of age) with bacterial meningitis who presented to 20 pediatric emergency departments between 2001 and 2004. Bacterial meningitis was defined by positive cerebrospinal fluid culture results for a bacterial pathogen or cerebrospinal fluid pleocytosis with positive blood culture and/or cerebrospinal fluid latex agglutination results. Probable bacterial meningitis was defined as positive cerebrospinal fluid Gram stain results with negative results of bacterial cultures of blood and cerebrospinal fluid. Antibiotic pretreatment was defined as any antibiotic administered within 72 hours before the lumbar puncture. RESULTS. We identified 231 patients with bacterial meningitis and another 14 with probable bacterial meningitis. Of those 245 patients, 85 (35%) had received antibiotic pretreatment. After adjustment for patient age, duration and severity of illness at presentation, and bacterial pathogen, longer duration of antibiotic pretreatment was not significantly associated with cerebrospinal fluid white blood cell count, cerebrospinal fluid absolute neutrophil count. However, antibiotic pretreatment was significantly associated with higher cerebrospinal fluid glucose and lower cerebrospinal fluid protein levels. Although these effects became apparent earlier, patients with ≥12 hours of pretreatment, compared with patients who either were not pretreated or were pretreated for <12 hours, had significantly higher median cerebrospinal fluid glucose levels (48 mg/dL vs 29 mg/dL) and lower median cerebrospinal fluid protein levels (121 vs 178 mg/dL). CONCLUSIONS. In patients with bacterial meningitis, antibiotic pretreatment is associated with higher cerebrospinal fluid glucose levels and lower cerebrospinal fluid protein levels, although pretreatment does not modify cerebrospinal fluid white blood cell count or absolute neutrophil count results.

Immunopathogenesis of Respiratory Syncytial Virus Bronchiolitis

BACKGROUND The objective of this study was to elucidate the relation between respiratory syncytial virus (RSV) infection and cytokine/chemokine concentrations, as well as the impact that these factors have on the severity of bronchiolitis. METHODS Children <24 months old who presented to the emergency department with clinical symptoms of bronchiolitis were prospectively enrolled in the study. Nasal-wash samples were analyzed to identify viral pathogens and to quantify RSV and cytokine/chemokine concentrations. Severe cases of disease were defined as those requiring hospitalization, and severity was further determined on the basis of the duration of supplemental-oxygen and/or intravenous-fluid therapy. RESULTS A total of 101 children were enrolled, 63 of whom were infected with RSV and 13 of whom were infected with other respiratory viruses; in 22 children, no virus was detected. RSV bronchiolitis was associated with a greater inflammatory response than was non-RSV bronchiolitis, although RSV infection was not associated with more-severe disease. Levels of interleukin (IL)-6, IL-8, IL-10, interferon (IFN)-gamma, and macrophage inflammatory protein (MIP)-1beta were significantly inversely correlated with the duration of supplemental-oxygen therapy. CONCLUSION The robust inflammatory response associated with RSV infection does not contribute to the severity of RSV bronchiolitis any more than it contributes to the severity of non-RSV bronchiolitis. Elevated levels of proinflammatory mediators IL-6, IL-8, IFN-gamma, and MIP-1beta, as well as of the regulatory cytokine IL-10, may be protective against hypoxia in bronchiolitis.

Febrile Infants With Urinary Tract Infections at Very Low Risk for Adverse Events and Bacteremia

BACKGROUND: There is limited evidence from which to derive guidelines for the management of febrile infants aged 29 to 60 days with urinary tract infections (UTIs). Most such infants are hospitalized for ≥48 hours. Our objective was to derive clinical prediction models to identify febrile infants with UTIs at very low risk of adverse events and bacteremia in a large sample of patients. METHODS: This study was a 20-center retrospective review of infants aged 29 to 60 days with temperatures of ≥38°C and culture-proven UTIs. We defined UTI by growth of ≥50 000 colony-forming units (CFU)/mL of a single pathogen or ≥10 000 CFU/mL in association with positive urinalyses. We defined adverse events as death, shock, bacterial meningitis, ICU admission need for ventilator support, or other substantial complications. We performed binary recursive partitioning analyses to derive prediction models. RESULTS: We analyzed 1895 patients. Adverse events occurred in 51 of 1842 (2.8% [95% confidence interval (CI): 2.1%–3.6%)] and bacteremia in 123 of 1877 (6.5% [95% CI: 5.5%–7.7%]). Patients were at very low risk for adverse events if not clinically ill on emergency department (ED) examination and did not have a high-risk past medical history (prediction model sensitivity: 98.0% [95% CI: 88.2%–99.9%]). Patients were at lower risk for bacteremia if they were not clinically ill on ED examination, did not have a high-risk past medical history, had a peripheral band count of <1250 cells per μL, and had a peripheral absolute neutrophil count of ≥1500 cells per μL (sensitivity 77.2% [95% CI: 68.6%–84.1%]). CONCLUSION: Brief hospitalization or outpatient management with close follow-up may be considered for infants with UTIs at very low risk of adverse events.

Retrospective review of serious bacterial infections in infants who are 0 to 36 months of age and have influenza A infection.

Objective. Previous studies of febrile children who were 3 to 36 months of age and had clinically recognizable viral syndromes have shown low rates of concurrent bacteremia. We sought to determine the prevalence of serious bacterial infections (SBIs) among children with influenza A, a viral syndrome that can be established definitively by specific tests. Methods. We performed a retrospective cross-sectional study of patients who were 0 to 36 months of age and presented with fever to the emergency department (ED) over 4 consecutive influenza seasons. Chest radiographs and urine and cerebrospinal fluid cultures also were reviewed. Results. Of 705 included patients, 163 (23%) were influenza positive (IP) and 542 (77%) were influenza negative (IN). Only 1 IP patient was bacteremic (0.6%) versus 23 of the 542 IN control subjects (4.2%). Two (1.8%) of 110 IP cases had urinary tract infections versus 38 (9.9%) of the 382 IN control subjects. Thirteen (25.4%) of 51 IP patients had radiographic evidence of pneumonia versus 99 (41.9%) of 236 IN control subjects. There were no cases of meningitis in 41 cerebrospinal fluid samples obtained from IP patients versus 4 (2.2%) cases of culture-positive meningitis in 179 IN control subjects. A total of 16 (9.8%) SBIs were identified in the IP cases versus 153 (28.2%) in the IN control subjects. Conclusions. Febrile children with influenza A had a lower prevalence of bacteremia, urinary tract infections, consolidative pneumonia, or any SBI compared with those without influenza A infection in this study.

Performance of Ultrasound in the Diagnosis of Appendicitis in Children in a Multicenter Cohort

OBJECTIVES The objectives were to assess the test characteristics of ultrasound (US) in diagnosing appendicitis in children and to evaluate site-related variations based on the frequency of its use. Additionally, the authors assessed the test characteristics of US when the appendix was clearly visualized. METHODS This was a secondary analysis of a prospective, 10-center observational study. Children aged 3 to 18 years with acute abdominal pain concerning for appendicitis were enrolled. US was performed at the discretion of the treating physician. RESULTS Of 2,625 patients enrolled, 965 (36.8%) underwent abdominal US. US had an overall sensitivity of 72.5% (95% confidence interval [CI] = 58.8% to 86.3%) and specificity 97.0% (95% CI = 96.2% to 97.9%) in diagnosing appendicitis. US sensitivity was 77.7% at the three sites (combined) that used it in 90% of cases, 51.6% at a site that used it in 50% of cases, and 35% at the four remaining sites (combined) that used it in 9% of cases. US retained a high specificity of 96% to 99% at all sites. Of the 469 (48.6%) cases across sites where the appendix was clearly visualized on US, its sensitivity was 97.9% (95% CI = 95.2% to 99.9%), with a specificity of 91.7% (95% CI = 86.7% to 96.7%). CONCLUSIONS Ultrasound sensitivity and the rate of visualization of the appendix on US varied across sites and appeared to improve with more frequent use. US had universally high sensitivity and specificity when the appendix was clearly identified. Other diagnostic modalities should be considered when the appendix is not definitively visualized by US.

Delivering Tailored Asthma Family Education in a Pediatric Emergency Department Setting: A Pilot Study

OBJECTIVE. Many children are brought to the pediatric emergency department (ED) with acute asthma symptoms. Emergency asthma care is costly, and many ED visits may be preventable. Families often do not have written asthma action plans and lack asthma self-managment skills. This study tests a tailored self-managment intervention delivered in the ED for families of children with asthma. The primary hypotheses were that the intervention group would have greater confidence to manage asthma 14 days postintervention and more well-asthma visits and fewer urgent care/ED visits at 9 and 12 months. METHODS. This randomized intervention/usual-care study was part of a larger ED asthma surveillance project in 4 urban pediatric ED sites. Asthma educators used a computer-based resource to tailor the intervention messages and provide a customized asthma action plan and educational summary. Children with acute asthma were enrolled during an ED visit, and follow-up telephone interviews were conducted during the next 9 months. The ED clinician classified the child’s acute and chronic severity. RESULTS. To date, 464 subjects aged 1 to 18 years have been enrolled. The ED clinicians reported that 46% had intermittent and 54% had persistent chronic severity with 51% having mild acute severity episodes. The confidence level to prevent asthma episodes and keep them from getting worse was significantly higher in the intervention group at 14 days postintervention. More subjects in the intervention group reported well-asthma visits by 9 months. Return ED visits were significantly lower in the intervention group in those with intermittent asthma. Twelve-month follow-up is in process. CONCLUSIONS. The tailored ED self-management intervention demonstrates significant effects on caregiver self-confidence and well-visit follow-up. Additional evaluation is needed to determine what impact this intervention has long-term.

A Comparison of Supination/Flexion to Hyperpronation in the Reduction of Radial Head Subluxations

Objective. To compare supination at the wrist followed by flexion at the elbow (the traditional reduction technique) to hyperpronation at the wrist in the reduction of radial head subluxations (nursemaids elbow). Materials and Methods. This prospective, randomized study involved a consecutive sampling of children younger than 6 years of age who presented to one of two urban pediatric emergency departments and two suburban pediatric ambulatory care centers with a clinical diagnosis of radial head subluxation. Patients were randomized to undergo reduction by one of the two methods and were followed every 5 minutes for return of elbow function. The initial procedure was repeated if baseline functioning did not return 15 minutes after the initial reduction attempt. Failure of that technique 30 minutes after the initial reduction attempt resulted in a cross-over to the alternate method of reduction. The alternate procedure was repeated if baseline functioning did not return 15 minutes after the alternate procedure was attempted. If the patient failed both techniques, radio-graphy of the elbow was performed. Results. A total of 90 patients were enrolled in the study. Five patients were removed from further analysis secondary to a final diagnosis of fracture, 84 were reduced successfully, and 1 failed both techniques. Demographic characteristics of each group were similar. Thirty-nine of 41 patients (95%) randomized to hyper-pronation were reduced successfully on the first attempt versus 34 of 44 patients (77%) randomized to supination. Two patients in the hyperpronation group required two attempts versus 10 patients in the supination group. Hyperpronation was more successful; 40 of 41 patients (97.5%) in the hyperpronation group were reduced successfully versus 38 of 44 patients (86%) in the supination group. Of the 6 patients who crossed over from supination to hyperpronation, 5 were reduced on the first attempt and 1 was reduced on the second attempt. Conclusions. In the reduction of radial head subluxations, the hyperpronation technique required fewer attempts at reduction compared with supination, was successful more often than supination, and was often successful when supination failed.

Prospective Evaluation of the Risk of Serious Bacterial Infection in Children Who Present to the Emergency Department With Hyperpyrexia (Temperature of 106°F or Higher)

BACKGROUND. Previous studies of children with temperatures ≥106°F (hyperpyrexia) disagree as to whether hyperpyrexia confers a high risk of serious bacterial infection. OBJECTIVES. The purpose of this study was to determine (1) the risk of serious bacterial infection in children with hyperpyrexia and (2) whether clinical presentation can identify hyperpyrexic patients at risk for serious bacterial infection. METHODS. Data were collected prospectively on all children <18 years of age presenting to a pediatric emergency department during a 2-year period with rectal temperatures of ≥106°F. History, physical examination, complete blood cell counts, blood cultures, and nasopharyngeal viral cultures were obtained on all of the patients. RESULTS. Of 130828 visits, 103 children had hyperpyrexia (1 per 1270 patient visits). Of the 103 subjects, 20 had serious bacterial infection, and 22 had laboratory-proven viral illness (including 1 subject with bacterial/viral coinfection). The presence of a chronic underlying illness was associated with an increased risk of serious bacterial infection. The presence of rhinorrhea or any viral symptom was associated with a decreased risk of serious bacterial infection, although diarrhea itself was associated with an increased risk of serious bacterial infection. Age, maximum temperature, and total white blood cell count were not predictive of either bacterial or viral illness. CONCLUSIONS. Children with hyperpyrexia are at equally high risk for serious bacterial infection and for viral illness. Bacterial and viral coinfection also occurs. No aspect of the clinical presentation reliably distinguishes between bacterial and viral illness. We recommend consideration of antibiotic treatment for all children presenting to the emergency department with hyperpyrexia without confirmed viral illness.

Predictors of severe H1N1 infection in children presenting within Pediatric Emergency Research Networks (PERN): retrospective case-control study.

Objective To identify historical and clinical findings at emergency department presentation associated with severe H1N1 outcome in children presenting with influenza-like illness. Design Multicentre retrospective case-control study. Setting 79 emergency departments of hospitals associated with the Pediatric Emergency Research Networks in 12 countries. Participants 265 children (<16 years), presenting between 16 April and 31 December 2009, who fulfilled Centers for Disease Control and Prevention criteria for influenza-like illness and developed severe outcomes from laboratory confirmed H1N1 infection. For each case, two controls presenting with influenza-like illness but without severe outcomes were included: one random control and one age matched control. Main outcome measures Severe outcomes included death or admission to intensive care for assisted ventilation, inotropic support, or both. Multivariable conditional logistic regression was used to compare cases and controls, with effect sizes measured as adjusted odds ratios. Results 151 (57%) of the 265 cases were male, the median age was 6 (interquartile range 2.3-10.0) years, and 27 (10%) died. Six factors were associated with severe outcomes in children presenting with influenza-like illness: history of chronic lung disease (odds ratio 10.3, 95% confidence interval 1.5 to 69.8), history of cerebral palsy/developmental delay (10.2, 2.0 to 51.4), signs of chest retractions (9.6, 3.2 to 29.0), signs of dehydration (8.8, 1.6 to 49.3), requirement for oxygen (5.8, 2.0 to 16.2), and tachycardia relative to age). Conclusion These independent risk factors may alert clinicians to children at risk of severe outcomes when presenting with influenza-like illness during future pandemics.