Proadrenomedullin Predicts Severe Disease in Children With Suspected Community-acquired Pneumonia

BACKGROUND

Proadrenomedullin (proADM), a vasodilatory peptide with antimicrobial and anti-inflammatory properties, predicts severe outcomes in adults with community-acquired pneumonia (CAP) to a greater degree than C-reactive protein and procalcitonin. We evaluated the ability of proADM to predict disease severity across a range of clinical outcomes in children with suspected CAP.

METHODS

We performed a prospective cohort study of children 3 months to 18 years with CAP in the emergency department. Disease severity was defined as mild (discharged home), mild-moderate (hospitalized but not moderate-severe or severe), moderate-severe (eg, hospitalized with supplemental oxygen, broadening of antibiotics, complicated pneumonia), and severe (eg, vasoactive infusions, chest drainage, severe sepsis). Outcomes were examined using proportional odds logistic regression within the cohort with suspected CAP and in a subset with radiographic CAP.

RESULTS

Among 369 children, median proADM increased with disease severity (mild: median [IQR], 0.53 [0.43-0.73]; mild-moderate: 0.56 [0.45-0.71]; moderate-severe: 0.61 [0.47-0.77]; severe: 0.70 [0.55-1.04] nmol/L) (P = .002). ProADM was significantly associated with increased odds of developing severe outcomes (suspected CAP: OR, 1.68; 95% CI, 1.2-2.36; radiographic CAP: OR, 2.11; 95% CI, 1.36-3.38) adjusted for age, fever duration, antibiotic use, and pathogen. ProADM had an AUC of 0.64 (95% CI, .56-.72) in those with suspected CAP and an AUC of 0.77 (95% CI, .68-.87) in radiographic CAP.

CONCLUSIONS

ProADM was associated with severe disease and discriminated moderately well children who developed severe disease from those who did not, particularly in radiographic CAP.

Short- Versus Prolonged-Duration Antibiotics for Outpatient Pneumonia in Children

OBJECTIVE

To identify practice patterns in the duration of prescribed antibiotics for the treatment of ambulatory children with community-acquired pneumonia (CAP) and to compare the frequency of adverse clinical outcomes between children prescribed short-vs prolonged-duration antibiotics.

STUDY DESIGN

We performed a retrospective cohort study from 2010-2016 using the IBM Watson MarketScan Medicaid Database, a claims database of publicly insured patients from 11 states. We included children 1-18 years old with outpatient CAP who filled a prescription for oral antibiotics (n = 121 846 encounters). We used multivariable logistic regression to determine associations between the duration of prescribed antibiotics (5-9 days vs 10-14 days) and subsequent hospitalizations, new antibiotic prescriptions, and acute care visits. Outcomes were measured during the 14 days following the end of the dispensed antibiotic course.

RESULTS

The most commonly prescribed duration of antibiotics was 10 days (82.8% of prescriptions), and 10.5% of patients received short-duration therapy. During the follow-up period, 0.2% of patients were hospitalized, 6.2% filled a new antibiotic prescription, and 5.1% had an acute care visit. Compared with the prolonged-duration group, the aORs for hospitalization, new antibiotic prescriptions, and acute care visits in the short-duration group were 1.16 (95% CI 0.80-1.66), 0.93 (95% CI 0.85-1.01), and 1.06 (95% CI 0.98-1.15), respectively.

CONCLUSIONS

Most children treated for CAP as outpatients are prescribed at least 10 days of antibiotic therapy. Among pediatric outpatients with CAP, no significant differences were found in rates of adverse clinical outcomes between patients prescribed short-vs prolonged-duration antibiotics.

Predictive Value of Clinician "Gestalt" in Pediatric Community-Acquired Pneumonia

OBJECTIVES

Validated prognostic tools for pediatric community-acquired pneumonia (CAP) do not exist. Thus, clinicians rely on "gestalt" in management decisions for children with CAP. We sought to determine the ability of clinician gestalt to predict severe outcomes.

METHODS

We performed a prospective cohort study of children 3 months to 18 years old presenting to a pediatric emergency department (ED) with lower respiratory infection and receiving a chest radiograph for suspected CAP from 2013 to 2017. Clinicians reported the probability that the patient would develop severe complications of CAP (defined as respiratory failure, empyema or effusion, lung abscess or necrosis, metastatic infection, sepsis or septic shock, or death). The primary outcome was development of severe complications.

RESULTS

Of 634 children, 37 (5.8%) developed severe complications. Of children developing severe complications after the ED visit, 62.1% were predicted as having <10% risk by the ED clinician. Sensitivity was >90% at the <1% predicted risk threshold, whereas specificity was >90% at the 10% risk threshold. Gestalt performance was poor in the low-intermediate predicted risk category (1%-10%). Clinicians had only fair ability to discriminate children developing complications from those who did not (area under the receiver operator characteristic curve 0.747), with worse performance from less experienced clinicians (area under the receiver operator characteristic curve 0.693).

CONCLUSIONS

Clinicians have only fair ability to discriminate children with CAP who develop severe complications from those who do not. Clinician gestalt performs best at very low or higher predicted risk thresholds, yet many children fall in the low-moderate predicted risk range in which clinician gestalt is limited. Evidence-based prognostic tools likely can improve on clinician gestalt, particularly when risk is low-moderate.

Clinical Impact of a Diagnostic Gastrointestinal Panel in Children

OBJECTIVES

Many hospitals have transitioned from conventional stool diagnostics to rapid multiplex polymerase chain reaction gastrointestinal panels (GIP). The clinical impact of this testing has not been evaluated in children. In this study, we compare use, results, and patient outcomes between conventional diagnostics and GIP testing.

METHODS

This is a multicenter cross-sectional study of children who underwent stool testing from 2013 to 2017. We used bivariate analyses to compare test use, results, and patient outcomes, including length of stay (LOS), ancillary testing, and hospital charges, between the GIP era (24 months after GIP introduction) and conventional diagnostic era (historic control, 24 months before).

RESULTS

There were 12 222 tests performed in 8720 encounters. In the GIP era, there was a 21% increase in the proportion of children who underwent stool testing, with a statistically higher percentage of positive results (40% vs 11%), decreased time to result (4 vs 31 hours), and decreased time to treatment (11 vs 35 hours). Although there was a decrease in LOS by 2 days among those who received treatment of a bacterial and/or parasitic pathogen (5.1 vs 3.1; P < .001), this represented only 3% of tested children. In the overall population, there was no statistical difference in LOS, ancillary testing, or charges.

CONCLUSIONS

The GIP led to increased pathogen detection and faster results. This translated into improved outcomes for only a small subset of patients, suggesting that unrestricted GIP use leads to low-value care. Similar to other novel rapid diagnostic panels, there is a critical need for diagnostic stewardship to optimize GIP testing.

Temporal airway microbiome changes related to ventilator-associated pneumonia in children

We sought to determine whether temporal changes in the lower airway microbiome are associated with ventilator-associated pneumonia (VAP) in children.Using a multicentre prospective study of children aged 31 days to 18 years requiring mechanical ventilation support for >72 h, daily tracheal aspirates were collected and analysed by sequencing of the 16S rRNA gene. VAP was assessed using 2008 Centers for Disease Control and Prevention paediatric criteria. The association between microbial factors and VAP was evaluated using joint longitudinal time-to-event modelling, matched case-control comparisons and unsupervised clustering.Out of 366 eligible subjects, 66 (15%) developed VAP at a median of 5 (interquartile range 3-5) days post intubation. At intubation, there was no difference in total bacterial load (TBL), but Shannon diversity and the relative abundance of Streptococcus, Lactobacillales and Prevotella were lower for VAP subjects versus non-VAP subjects. However, higher TBL on each sequential day was associated with a lower hazard (hazard ratio 0.39, 95% CI 0.23-0.64) for developing VAP, but sequential values of diversity were not associated with VAP. Similar findings were observed from the matched analysis and unsupervised clustering. The most common dominant VAP pathogens included Prevotella species (19%), Pseudomonas aeruginosa (14%) and Streptococcus mitis/pneumoniae (10%). Mycoplasma and Ureaplasma were also identified as dominant organisms in several subjects.In mechanically ventilated children, changes over time in microbial factors were marginally associated with VAP risk, although these changes were not suitable for predicting VAP in individual patients. These findings suggest that focusing exclusively on pathogen burden may not adequately inform VAP diagnosis.

Antibiotic Choice and Clinical Outcomes in Ambulatory Children with Community-Acquired Pneumonia

OBJECTIVES

To describe antibiotic prescribing patterns in ambulatory children with community-acquired pneumonia and to assess the relationship between antibiotic selection and clinical outcomes.

STUDY DESIGN

This was a retrospective cohort study of ambulatory Medicaid-enrolled children 0-18 years of age diagnosed with community-acquired pneumonia from 2010 to 2016. The exposure was antibiotic class: narrow-spectrum (aminopenicillins), broad-spectrum (amoxicillin/clavulanate and cephalosporins), macrolide monotherapy, macrolides with narrow-spectrum antibiotics, or macrolides with broad-spectrum antibiotics. The associations between antibiotic selection and the outcomes of subsequent hospitalization and development of severe pneumonia (chest drainage procedure, intensive care admission, mechanical ventilation) were assessed, controlling for measures of illness severity.

RESULTS

Among 252 177 outpatient pneumonia visits, macrolide monotherapy was used in 43.2%, narrow-spectrum antibiotics in 26.1%, and broad-spectrum antibiotics in 24.7%. A total of 1488 children (0.59%) were subsequently hospitalized and 117 (0.05%) developed severe pneumonia. Compared with children receiving narrow-spectrum antibiotics, the odds of subsequent hospitalization were higher in children receiving broad-spectrum antibiotics (aOR, 1.34; 95% CI, 1.17-1.52) and lower in children receiving macrolide monotherapy (aOR, 0.64; 95% CI, 0.55-0.73) and macrolides with narrow-spectrum antibiotics (aOR, 0.62; 95% CI, 0.39-0.97). Children receiving macrolide monotherapy had lower odds of developing severe pneumonia than children receiving narrow-spectrum antibiotics (aOR, 0.56; 95% CI, 0.33-0.93). However, the absolute risk difference was <0.5% for all analyses.

CONCLUSIONS

Macrolides are the most commonly prescribed antibiotic for ambulatory children with community-acquired pneumonia. Subsequent hospitalization and severe pneumonia are rare. Future efforts should focus on reducing broad-spectrum and macrolide antibiotic prescribing.

Prospective cohort study of children with suspected SARS-CoV-2 infection presenting to paediatric emergency departments: a Paediatric Emergency Research Networks (PERN) Study Protocol

INTRODUCTION

Relatively limited data are available regarding paediatric COVID-19. Although most children appear to have mild or asymptomatic infections, infants and those with comorbidities are at increased risk of experiencing more severe illness and requiring hospitalisation due to COVID-19. The recent but uncommon association of SARS-CoV-2 infection with development of a multisystem inflammatory syndrome has heightened the importance of understanding paediatric SARS-CoV-2 infection.

METHODS AND ANALYSIS

The Paediatric Emergency Research Network-COVID-19 cohort study is a rapid, global, prospective cohort study enrolling 12 500 children who are tested for acute SARS-CoV-2 infection. 47 emergency departments across 12 countries on four continents will participate. At enrolment, regardless of SARS-CoV-2 test results, all children will have the same information collected, including clinical, epidemiological, laboratory, imaging and outcome data. Interventions and outcome data will be collected for hospitalised children. For all children, follow-up at 14 and 90 days will collect information on further medical care received, and long-term sequelae, respectively. Statistical models will be designed to identify risk factors for infection and severe outcomes.

ETHICS AND DISSEMINATION

Sites will seek ethical approval locally, and informed consent will be obtained. There is no direct risk or benefit of study participation. Weekly interim analysis will allow for real-time data sharing with regional, national, and international policy makers. Harmonisation and sharing of investigation materials with WHO, will contribute to synergising global efforts for the clinical characterisation of paediatric COVID-19. Our findings will enable the implementation of countermeasures to reduce viral transmission and severe COVID-19 outcomes in children.

TRIAL REGISTRATION NUMBER

NCT04330261.

408. Evaluation of the negative predictive value of the SARS-CoV-2 PCR respiratory assays in asymptomatic children undergoing surgery

Background

Universal pre-operative screening with SARS-CoV-2 PCR has been adopted by institutions to mitigate risk to healthcare workers (HCW) during aerosol-generating procedures such as intubation. However, there remains uncertainty regarding rates of false negative results and optimal sampling type. The objective was to determine the reliability of single, pre-operative SARS-CoV-2 testing from the nasopharynx in children undergoing general anesthesia.

Methods

Children < 18 years of age who underwent intubation for a procedure received pre-operative testing 24–48 hours prior with a nasopharyngeal (NP) swab or wash, in conjunction with intra-operative nasal wash (NW) and tracheal aspirate (TA) sampling. All paired samples underwent testing using the Simplexa DiaSorin platform or a modified Centers for Disease Control assay. Cohen’s Kappa was used for interrater reliability of each sample result. McNemar’s Test was used to compare result proportions by sample type. Positive and negative predictive values (PPV, NPV) were calculated based on the intraoperative NW as the reference standard. Analyses were conducted using SAS (v 9.4).

Results

We collected full sample sets from 364 children from April 14 to May 15; 66% of pre-operative samples were NP swabs. The median age was 6 years (IQR 2,13), 55% were male, 68% were white and 41% of children had a high-risk comorbidity. Most surgeries were conducted by general surgery (23%), followed by orthopedics (19%). Only 2.5% of children had respiratory symptoms, and 4.8% had a documented fever within a week of the procedure. SARS-CoV-2 positive samples occurred in 4/364 (1%) of pre-operative samples, 8/363 (2.2%) of intra-operative samples, and 8/348 (2.3%) of TA samples. The pre-operative test had 100% PPV and 99% NPV, and the TA had 100% PPV and 98.6% NPV (Table 1). There was very good agreement (Figure) between pre- and intraoperative upper respiratory sampling, with a Kappa of 0.66, (95% CI 0.35–0.97). There was no statistical difference in results by sample type.

Table 1. Comparison of intra-operative and pre-operative nasopharyngeal sample results, test characteristics and test concordance

Table 2. Comparison of intra-operative nasopharyngeal and tracheal aspirate sample results, test characteristics and test concordance

Figure 1 Percent agreement between pre-operative and intra-operative samples

Conclusion

There is a high PPV and NPV of pre-operative SARS-CoV-2 PCR testing among children undergoing anesthesia. These data can help inform guidelines regarding appropriate precautions for HCW performing high risk procedures in asymptomatic pediatric patients.

Disclosures

Suchitra Rao, MD, BioFire (Grant/Research Support) Samuel Dominguez, MD, PhD, BioFire (Consultant, Research Grant or Support)

Predicting severe pneumonia in the emergency department: a global study of the Pediatric Emergency Research Networks (PERN)-study protocol

INTRODUCTION

Pneumonia is a frequent and costly cause of emergency department (ED) visits and hospitalisations in children. There are no evidence-based, validated tools to assist physicians in management and disposition decisions for children presenting to the ED with community-acquired pneumonia (CAP). The objective of this study is to develop a clinical prediction model to accurately stratify children with CAP who are at risk for low, moderate and severe disease across a global network of EDs.

METHODS AND ANALYSIS

This study is a prospective cohort study enrolling up to 4700 children with CAP at EDs at ~80 member sites of the Pediatric Emergency Research Networks (PERN; https://pern-global.com/). We will include children aged 3 months to <14 years with a clinical diagnosis of CAP. We will exclude children with hospital admissions within 7 days prior to the study visit, hospital-acquired pneumonias or chronic complex conditions. Clinical, laboratory and imaging data from the ED visit and hospitalisations within 7 days will be collected. A follow-up telephone or text survey will be completed 7-14 days after the visit. The primary outcome is a three-tier composite of disease severity. Ordinal logistic regression, assuming a partial proportional odds specification, and recursive partitioning will be used to develop the risk stratification models.

ETHICS AND DISSEMINATION

This study will result in a clinical prediction model to accurately identify risk of severe disease on presentation to the ED. Ethics approval was obtained for all sites included in the study. Cincinnati Children's Hospital Institutional Review Board (IRB) serves as the central IRB for most US sites. Informed consent will be obtained from all participants. Results will be disseminated through international conferences and peer-reviewed publications. This study overcomes limitations of prior pneumonia severity scores by allowing for broad generalisability of findings, which can be actively implemented after model development and validation.

Development and Internal Validation of a Prediction Model to Risk Stratify Children with Suspected Community-Acquired Pneumonia

BACKGROUND

Although community-acquired pneumonia (CAP) is one of the most common infections in children, no tools exist to risk stratify children with suspected CAP. We developed and validated a prediction model to risk stratify and inform hospitalization decisions in children with suspected CAP.

METHODS

We performed a prospective cohort study of children age 3 months to 18 years with suspected CAP in a pediatric emergency department (ED). Primary outcome was disease severity, defined as mild (discharge home or hospitalization for <24 hours with no oxygen or intravenous (IV) fluids), moderate (hospitalization <24 hours with oxygen or IV fluids, or hospitalization >24 hours), or severe (intensive care unit (ICU) stay for >24 hours, septic shock, vasoactive agents, positive-pressure ventilation, chest drainage, extracorporeal membrane oxygenation, or death). Ordinal logistic regression and bootstrapped backwards selection were used to derive and internally validate our model.

RESULTS

Of 1128 children, 371 (32.9%) developed moderate disease and 48 (4.3%) severe disease. Severity models demonstrated excellent discrimination (optimism-corrected c-indices of 0.81) and outstanding calibration. Severity predictors in the final model included respiratory rate, systolic blood pressure, oxygenation, retractions, capillary refill, atelectasis or pneumonia on chest radiograph, and pleural effusion.

CONCLUSIONS

We derived and internally validated a score that accurately predicts disease severity in children with suspected CAP. Once externally validated, this score has potential to facilitate management decisions by providing individualized risk estimates that can be used in conjunction with clinical judgment to improve the care of children with suspected CAP.

Corticosteroid choice and clinical outcomes for asthma exacerbations in the primary care setting

OBJECTIVE

To evaluate clinical outcomes in young children with acute asthma exacerbations treated with prednisone/prednisolone versus dexamethasone in the primary care setting.

METHODS

Retrospective cohort study of children ages 3-9 years with a primary care clinic visit for asthma and an associated oral corticosteroid (OCS) prescription fill in the Colorado All Payers Claim Database between 2/2013-3/2019. This was a secondary analysis of a dataset extracted to analyze risk of future development of asthma in younger children. The primary outcome was subsequent ED visit or hospital admission for asthma within 2-14 days after the index clinic visit. Demographics and asthma health services characteristics were assessed. Multivariable logistic regression was used to estimate the association between type of OCS prescription filled within 1 day of the index clinic visit and the primary outcome.

RESULTS

There were 3236 index clinic visits for asthma for 1918 children during the study period. Sixty-two percent were male and 66% were 3-4 years old. Prednisone/prednisolone accounted for 84% of OCS prescriptions fills within 1 day of the index clinic visit. One percent visited the ED and 1% required hospital admission within 2-14 days. In multivariate analysis, there was no statistical association between type of OCS prescribed and the primary outcome (OR 0.82; 95% CI: 0.37-1.8).

CONCLUSIONS

There are no differences in clinical outcomes by type of OCS prescribed for acute asthma exacerbations in the primary care setting. Due to better adherence and side effect profile, primary care providers may consider to use dexamethasone as the preferred OCS.

Improved Diagnostics Help to Identify Clinical Features and Biomarkers That Predict Mycoplasma pneumoniae Community-acquired Pneumonia in Children

BACKGROUND

There are no reliable signs or symptoms that differentiate Mycoplasma pneumoniae (Mp) infection in community-acquired pneumonia (CAP) from other etiologies. Additionally, current diagnostic tests do not reliably distinguish between Mp infection and carriage. We previously determined that the measurement of Mp-specific immunoglobulin M antibody-secreting cells (ASCs) by enzyme-linked immunospot assay allowed for differentiation between infection and carriage. Using this new diagnostic test, we aimed to identify clinical and laboratory features associated with Mp infection.

METHODS

This is a prospective cohort study of children, 3-18 years of age, with CAP from 2016 to 2017. Clinical features and biomarkers were compared between Mp-positive and -negative groups by Mann-Whitney U test or Fisher exact test, as appropriate. Area under the receiver operating characteristic curve (AUC) differences and optimal thresholds were determined by using the DeLong test and Youden J statistic, respectively.

RESULTS

Of 63 CAP patients, 29 were Mp-positive (46%). Mp positivity was statistically associated with older age (median, 8.6 vs 4.7 years), no underlying disease, family with respiratory symptoms, prior antibiotic treatment, prolonged prodromal respiratory symptoms and fever, and extrapulmonary (skin) manifestations. Lower levels of C-reactive protein, white blood cell count, absolute neutrophil count, and procalcitonin (PCT), specifically PCT <0.25 μg/L, were statistically associated with Mp infection. A combination of age >5 years (AUC = 0.77), prodromal fever and respiratory symptoms >6 days (AUC = 0.79), and PCT <0.25 μg/L (AUC = 0.81) improved diagnostic performance (AUC = 0.90) (P = .05).

CONCLUSIONS

A combination of clinical features and biomarkers may aid physicians in identifying patients at high risk for Mp CAP.

Antibiotics for Aspiration Pneumonia in Neurologically Impaired Children

OBJECTIVE

To compare hospital outcomes associated with commonly used antibiotic therapies for aspiration pneumonia in children with neurologic impairment (NI).

DESIGN/METHODS

A retrospective study of children with NI hospitalized with aspiration pneumonia at 39 children's hospitals in the Pediatric Health Information System database. Exposure was empiric antibiotic therapy classified by antimicrobial activity. Outcomes included acute respiratory failure, intensive care unit (ICU) transfer, and hospital length of stay (LOS). Multivariable regression evaluated associations between exposure and outcomes and adjusted for confounders, including medical complexity and acute illness severity.

RESULTS

In the adjusted analysis, children receiving Gram-negative coverage alone had two-fold greater odds of respiratory failure (odds ratio [OR] 2.15; 95% CI: 1.41-3.27), greater odds of ICU transfer (OR 1.80; 95% CI: 1.03-3.14), and longer LOS [adjusted rate ratio (RR) 1.28; 95% CI: 1.16-1.41] than those receiving anaerobic coverage alone. Children receiving anaerobic and Gram-negative coverage had higher odds of respiratory failure (OR 1.65; 95% CI: 1.19-2.28) than those receiving anaerobic coverage alone, but ICU transfer (OR 1.15; 95% CI: 0.73-1.80) and length of stay (RR 1.07; 95% CI: 0.98-1.16) did not statistically differ. For children receiving anaerobic, Gram-negative, and P. aeruginosa coverage, LOS was shorter (RR 0.83; 95% CI: 0.76-0.90) than those receiving anaerobic coverage alone; odds of respiratory failure and ICU transfer rates did not significantly differ.

CONCLUSIONS

Anaerobic therapy appears to be important in the treatment of aspiration pneumonia in children with NI. While Gram-negative coverage alone was associated with worse outcomes, its addition to anaerobic therapy may not yield improved outcomes.

Biomarkers and Disease Severity in Children With Community-Acquired Pneumonia

BACKGROUND

Host biomarkers predict disease severity in adults with community-acquired pneumonia (CAP). We evaluated the association of the white blood cell (WBC) count, absolute neutrophil count (ANC), C-reactive protein (CRP), and procalcitonin with the development of severe outcomes in children with CAP.

METHODS

We performed a prospective cohort study of children 3 months to 18 years of age with CAP in the emergency department. The primary outcome was disease severity: mild (discharged from the hospital), mild-moderate (hospitalized but not moderate-severe or severe), moderate-severe (eg, hospitalized with receipt of intravenous fluids, supplemental oxygen, complicated pneumonia), and severe (eg, intensive care, vasoactive infusions, chest drainage, severe sepsis). Outcomes were examined within the cohort with suspected CAP and in a subset with radiographic CAP.

RESULTS

Of 477 children, there were no statistical differences in the median WBC count, ANC, CRP, or procalcitonin across severity categories. No biomarker had adequate discriminatory ability between severe and nonsevere disease (area under the curve [AUC]: 0.53-0.6 for suspected CAP and 0.59-0.64 for radiographic CAP). In analyses adjusted for age, antibiotic use, fever duration, and viral pathogen detection, CRP was associated with moderate-severe disease (odds ratio 1.12; 95% confidence interval, 1.0-1.25). CRP and procalcitonin revealed good discrimination of children with empyema requiring chest drainage (AUC: 0.83) and sepsis with vasoactive infusions (CRP AUC: 0.74; procalcitonin AUC: 0.78), although prevalence of these outcomes was low.

CONCLUSIONS

WBC count, ANC, CRP, and procalcitonin are generally not useful to discriminate nonsevere from severe disease in children with CAP, although CRP and procalcitonin may have some utility in predicting the most severe outcomes.

Antibiotic Use and Outcomes in Children in the Emergency Department With Suspected Pneumonia

BACKGROUND AND OBJECTIVES

Antibiotic therapy is often prescribed for suspected community-acquired pneumonia (CAP) in children despite a lack of knowledge of causative pathogen. Our objective in this study was to investigate the association between antibiotic prescription and treatment failure in children with suspected CAP who are discharged from the hospital emergency department (ED).

METHODS

We performed a prospective cohort study of children (ages 3 months-18 years) who were discharged from the ED with suspected CAP. The primary exposure was antibiotic receipt or prescription. The primary outcome was treatment failure (ie, hospitalization after being discharged from the ED, return visit with antibiotic initiation or change, or antibiotic change within 7-15 days from the ED visit). The secondary outcomes included parent-reported quality-of-life measures. Propensity score matching was used to limit potential bias attributable to treatment selection between children who did and did not receive an antibiotic prescription.

RESULTS

Of 337 eligible children, 294 were matched on the basis of propensity score. There was no statistical difference in treatment failure between children who received antibiotics and those who did not (odds ratio 1.0; 95% confidence interval 0.45-2.2). There was no difference in the proportion of children with return visits with hospitalization (3.4% with antibiotics versus 3.4% without), initiation and/or change of antibiotics (4.8% vs 6.1%), or parent-reported quality-of-life measures.

CONCLUSIONS

Among children with suspected CAP, the outcomes were not statistically different between those who did and did not receive an antibiotic prescription.

Impact of Multiplex Testing on the Identification of Pediatric Clostridiodes Difficile

OBJECTIVES

To evaluate whether the implementation of a multiplex gastrointestinal pathogen panel (GIP) was associated with changes in Clostridioides difficile (C difficile) testing and detection rates.

STUDY DESIGN

We conducted an observational study using interrupted time series analysis and included pediatric patients with testing capable of detecting C difficile. From 2013 to 2015 ("conventional diagnostic era"), stool testing included C difficile-selective polymerase chain reaction and other pathogen-specific tests. From 2015 to 2017 ("GIP era"), C difficile polymerase chain reaction was available along with the GIP, which detected 22 pathogens including C difficile, and replaced the need for additional tests. Outcomes included C difficile testing and detection rates in ambulatory, emergency department, and inpatient settings.

RESULTS

There were 6841 tests performed and 1214 C difficile positive results. Across the 3 settings, GIP era had significantly higher C difficile testing (1.7-2.3 times higher) and C difficile detection rates (1.9-3.4 times higher) compared with conventional diagnostic era. After adjusting for the number of tests performed, detection rates were no longer significantly different. Of C difficile positive GIPs, 31% were coinfected with another organism. With GIP testing, patients 1 year of age had a significantly higher C difficile percent positivity than 2-year-old (P = .02) and 3- to 18-year-old children (P < .01). Younger children with C difficile were more likely to be coinfected (P < .01).

CONCLUSIONS

Introducing a multiplex panel led to increased C difficile testing, which resulted in increased C difficile detection rates and potential identification and treatment of colonized patients. This highlights an important target for diagnostic stewardship and the challenges associated with multiplex testing.

Risk Factors for the Development of Hospital-Associated Venous Thromboembolism in Adult Patients Admitted to a Children's Hospital

BACKGROUND AND OBJECTIVES

Hospital-associated venous thromboembolism (HA-VTE) is a leading cause of preventable in-hospital mortality in adults. Our objective was to describe HA-VTE and evaluate risk factors for its development in adults admitted to a children's hospital, which has not been previously studied. We also evaluated the performance of commonly used risk assessment tools for HA-VTE.

METHODS

A case-control study was performed at a freestanding children's hospital. Cases of HA-VTE in patients ≥18 years old (2013-2017) and age-matched controls were identified. We extracted patient and HA-VTE characteristics and HA-VTE risk factors on the basis of previous literature. Thrombosis risk assessment was performed retrospectively by using established prospective adult tools (Caprini and Padua scores).

RESULTS

Thirty-nine cases and 78 controls were identified. Upper extremities were the most common site of thrombosis (62%). Comorbid conditions were common (91.5%), and malignancy was more common among case patients than controls (P = .04). The presence of a central venous catheter (P < .01), longer length of stay (P < .01), ICU admission (P = .005), and previous admission within 30 days (P = .01) were more common among case patients when compared with controls. Median Caprini score was higher for case patients (P < .01), whereas median Padua score was similar between groups (P = .08).

CONCLUSIONS

HA-VTE in adults admitted to children's hospitals is an important consideration in a growing high-risk patient population. HA-VTE characteristics in our study were more similar to published data in pediatrics.

Dynamic Changes in Natural Killer Cell Subset Frequencies in the Absence of Cytomegalovirus Infection

Individuals lacking functional natural killer (NK) cells suffer severe, recurrent infections with cytomegalovirus (CMV), highlighting the critical role of NK cells in antiviral defense. Therefore, ongoing attempts to develop an efficacious vaccine to prevent CMV infection should potentially aim to elicit NK-cell antiviral responses as an accessory to conventional T- and B-cell based approaches. In this regard, CMV infection provokes marked phenotypic and functional differentiation of the NK-cell compartment, including development of adaptive NK cells that exhibit enhanced antiviral activity. We examined longitudinal blood samples collected from 40 CMV-seronegative adolescents to ascertain whether a CMV glycoprotein B (gB) vaccine in the absence of CMV infection can stimulate differentiation or expansion of CMV-associated subsets of NK cells. Study participants uniformly lacked the CMV-dependent NKG2C⁺ subset of NK cells, suggesting that an adjuvanted CMV gB vaccine alone is an inadequate stimulus for sustained expansion of these cells. In contrast, we observed unexpected dynamic fluctuations in the frequency of NK cells lacking FcRγ, EAT-2, and SYK, which were independent of vaccination or CMV infection. Whereas, FcRγ^neg NK cells in CMV infection are reported to express increased levels of the maturation marker CD57, the FcRγ^neg NK cells observed in our CMV-negative vaccine cohort express less CD57 than their FcRγ⁺ counterparts. The FcRγ^neg NK cells in CMV-negative individuals were also functionally distinct from this subset in CMV infection, exhibiting comparable IFN-γ production and degranulation as FcRγ⁺ NK cells in response to cytokine or antibody-dependent stimuli. These results suggest that frequencies of some NK cell subsets may increase in response to unknown environmental or inflammatory cues distinct from that which occurs after CMV infection. Greater understanding of the nature of the signals driving CMV-independent accumulation of these subsets should permit development of mechanisms to facilitate vaccine-driven expansion of CMV-reactive NK cells.

Clinical Risk Factors for Revisits for Children With Community-Acquired Pneumonia

BACKGROUND

Children discharged from the emergency department (ED) with community-acquired pneumonia (CAP) revisit for several reasons, including disease progression or treatment failure. Understanding factors associated with revisits may assist clinicians in preventing subsequent visits.

METHODS

Children aged 3 months to 18 years with an International Classification of Diseases, Ninth Revision diagnosis of CAP between December 1, 2009 and April 31, 2013 were eligible. The primary outcome was a CAP-related ED visit or hospitalization within 30 days of the index visit. The secondary outcome was a CAP-related ED visit within 48 hours of discharge from the index visit. The association between clinical variables and an ED revisit for children with CAP was assessed by using multivariable logistic regression models.

RESULTS

Of the 3304 index ED visits by patients with CAP, 148 (4.5%) revisited the ED. Children with complex chronic conditions (CCCs) were 2.23 times as likely to revisit the ED as those without a CCC (95% confidence interval: 1.29-3.86). Children admitted and those who received aminopenicillins at the index visit were less likely (63% and 49%, respectively) to revisit the ED (95% confidence interval: 0.24-0.56 and 0.30-0.85, respectively).

CONCLUSIONS

Although children with CAP have a relatively low revisit rate to the ED, patients who received aminopenicillins at their index visit were statistically less likely to revisit when adjusting for markers of severity (eg, age, CCCs, and disposition at index visit). Clinical factors alone, however, may not be the only indicators of revisits, and additional factors may need to be considered in future studies.

Validation of the Pediatric Infectious Diseases Society-Infectious Diseases Society of America Severity Criteria in Children With Community-Acquired Pneumonia

Background

The Pediatric Infectious Diseases Society (PIDS)-Infectious Diseases Society of America (IDSA) guideline for community-acquired pneumonia (CAP) recommends intensive care unit (ICU) admission or continuous monitoring for children meeting severity criteria. Our objective was to validate these criteria.

Methods

This was a retrospective cohort study of children aged 3 months-18 years diagnosed with CAP in a pediatric emergency department (ED) from September 2014 through August 2015. Children with chronic conditions and recent ED visits were excluded. The primary predictor was the PIDS-IDSA severity criteria. Outcomes included disposition, and interventions and diagnoses that necessitated hospitalization (ie, need for hospitalization [NFH]).

Results

Of 518 children, 56.6% were discharged; 54.3% of discharged patients and 80.8% of those hospitalized for less than 24 hours were classified as severe. Of those admitted, 10.7% did not meet severity criteria; 69.5% met PIDS-IDSA severity criteria. Of those children, 73.1% did not demonstrate NFH. The areas under the receiver operator characteristic curves (AUC) for PIDS-IDSA major criteria were 0.63 and 0.51 for predicting disposition and NFH, respectively. For PIDS-IDSA minor criteria, the AUC was 0.81 and 0.56 for predicting disposition and NFH, respectively. The sensitivity, specificity, and likelihood ratios (LR)+ and LR- of the PIDS-IDSA criteria were 89%, 46%, 1.65, and 0.23 for disposition and 95%, 16%, 1.13, and 0.31 for NFH.

Conclusions

More than half of children classified as severe by PIDS-IDSA criteria were not hospitalized. The PIDS-IDSA CAP severity criteria have only fair ability to predict the need for hospitalization. New predictive tools specifically for children are required to improve clinical decision making.

2210. Nasopharyngeal Detection of Streptococcus pneumoniae and Clinical Disease Severity in Children with Community-Acquired Pneumonia (CAP)

Background

Streptococcus pneumoniae is the most common pyogenic bacteria associated with CAP in children, but the proportion of cases might be underestimated because of the low sensitivity of current standard diagnostic methods. Nasopharyngeal (NP) carriage of pneumococcus commonly precedes the development of pneumococcal pneumonia, and facilitates pneumococcus interactions with other respiratory pathogens and the host immune response. This study investigated the relationship between pneumococcal carriage and the severity of CAP in children.

Methods

We conducted a prospective, multicenter, observational study for CAP among previously healthy children aged 2 months through 18 years in six children’s hospitals in Ohio. Blood, pleural fluid, and NP swabs were collected for pathogen detection by culture and/or polymerase chain reaction (PCR). S. pneumoniae was quantified in NP swabs by real-time PCR. Patient management followed the standard of care in each study site.

Results

Among 441 children with radiologically confirmed CAP, 156 (35.4%) had no bacterial or viral pathogens identified as etiologic agents. NP pneumococcal carriage rate in this group was 34.6%. Children with CAP and pneumococcal carriage (53/156) were younger (5.9 vs. 9.6 years, P < 0.001) than those with no carriage (103/156). Median neutrophil counts and median procalcitonin concentrations were significantly higher in the pneumococcal carriage group (12,030 vs. 8,370 cells/mm³ and 1.0 vs. 0.5 mg/dl, respectively; P < 0.05 for both) than in the non-carriage group. Children with documented pneumococcal carriage received respiratory support more frequently (50.0% vs. 28.2%, p = 0.012) and had a longer duration of hospitalization (3.5 ± 3.8 vs. 2.1 ± 2.0 days, P = 0.026) than those without pneumococcal carriage. Age was not associated with any of the variables used to assess clinical disease severity.

Conclusion

Pneumococcal carriage was associated with higher inflammatory markers and greater clinical disease severity in children with CAP in whom no pathogens were identified by standard diagnostics. This suggests that NP carriage of pneumococcus in children with CAP may modulate the host immune response and possibly influence clinical disease severity.

Disclosures

Octavio Ramilo, MD, Bill & Melinda Gates Foundation: Research Grant; Janssen: Research Grant; Merck: Advisory Board; NIH: Research Grant; Ohio Children’s Hospital Association (OCHA): Research Grant; Pfizer: Advisory Board, Consultant, Lectures; Sanofi/Medimmune: Advisory Board.

2619. Clinical Characteristics and Etiology of Community-Acquired Pneumonia in Children: A Contemporary, Prospective, Multicenter Study in Ohio, 2015–2018

Background

Worldwide, pneumonia is the leading cause of death in children <5 years of age and the second most common reason for hospitalization in children in the United States and Europe. This study was designed to describe the clinical characteristics and etiology of community-acquired pneumonia (CAP) in children.

Methods

We conducted a prospective, multicenter, observational study of CAP among previously healthy children aged 2 months through 18 years in six children’s hospitals in Ohio. Blood, pleural fluid, and nasopharyngeal swabs were collected for pathogen detection by culture and/or molecular diagnostics. Patient clinical management including antibiotic therapy and respiratory support, followed the standard of care at each study site. Follow-up information regarding clinical outcomes was collected via a survey 6–8 weeks after enrollment.

Results

We enrolled 441 children (n = 380, 86% hospitalized) with CAP from 2015 to 2018. Median age was 5 years (IQR: 2.1–8.9y). Intensive care and respiratory support were required for 15% and 49% of children, respectively. Consolidation and pleural effusion were identified in 26% and 21%, respectively. Among hospitalized children, 99% received antibiotics during hospitalization, and 91% continued antibiotic treatment at discharge. There were no children with any kind of sequelae or deaths from CAP, but 4.4% were readmitted within 30 days after discharge. Pathogens were identified in 64% patients; including pyogenic bacteria in 4%, atypical bacteria in 9%, and viruses in 56%. A total of 18 (4%) children had both bacterial (9 pyogenic and 9 mycoplasma) and viral pathogens. Among children with a virus detected (n = 245), 17% had more than one virus. The most commonly detected bacteria were M. pneumoniae (n = 39) and S. pneumoniae (n = 10). Rhinovirus was the most common virus detected (RV; n = 81, 28%), followed by respiratory syncytial virus (RSV; n = 75, 26%).

Conclusion

In this multicenter cohort, the most commonly detected viruses in children with CAP were RV and RSV, and M. pneumoniae and S. pneumoniae among bacteria. Clinical outcomes in children with CAP were overall good, but there was a high burden of hospitalization and antibiotic use.

Disclosures

Octavio Ramilo, MD, Bill & Melinda Gates Foundation: Research Grant; Janssen: Research Grant; Merck: Advisory Board; NIH: Research Grant; Ohio Children’s Hospital Association (OCHA): Research Grant; Pfizer: Advisory Board, Consultant, Lectures; Sanofi/Medimmune: Advisory Board.

Predictors of Bacteremia in Children Hospitalized With Community-Acquired Pneumonia

BACKGROUND AND OBJECTIVES

The yield of blood cultures in children hospitalized with community-acquired pneumonia (CAP) is low. Characteristics of children at increased risk of bacteremia remain largely unknown.

METHODS

We conducted a secondary analysis of a retrospective cohort study of children aged 3 months to 18 years hospitalized with CAP in 6 children's hospitals from 2007 to 2011. We excluded children with complex chronic conditions and children without blood cultures performed at admission. Clinical, laboratory, microbiologic, and radiologic data were assessed to identify predictors of bacteremia.

RESULTS

Among 7509 children hospitalized with CAP, 2568 (34.2%) had blood cultures performed on the first day of hospitalization. The median age was 3 years. Sixty-five children with blood cultures performed had bacteremia (2.5%), and 11 children (0.4%) had bacteremia with a penicillin-nonsusceptible pathogen. The prevalence of bacteremia was increased in children with a white blood cell count >20 × 10³ cells per µL (5.4%; 95% confidence interval 3.5%-8.1%) and in children with definite radiographic pneumonia (3.3%; 95% confidence interval 2.4%-4.4%); however, the prevalence of penicillin-nonsusceptible bacteremia was below 1% even in the presence of individual predictors. Among children hospitalized outside of the ICU, the prevalence of contaminated blood cultures exceeded the prevalence of penicillin-nonsusceptible bacteremia.

CONCLUSIONS

Although the prevalence of bacteremia is marginally higher among children with leukocytosis or radiographic pneumonia, the rates remain low, and penicillin-nonsusceptible bacteremia is rare even in the presence of these predictors. Blood cultures should not be obtained in children hospitalized with CAP in a non-ICU setting.