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ObjectiveTo assess the co-occurrence and clustering of post-concussive symptoms in children, and to identify distinct patient phenotypes based on symptom type and severity.MethodsWe performed a secondary analysis of the prospective, multicentre Predicting and Preventing Post-concussive Problems in Pediatrics (5P) cohort study, evaluating children 5–17 years of age presenting within 48 hours of an acute concussion. Our primary outcome was the simultaneous occurrence of two or more persistent post-concussive symptoms on the Post-Concussion Symptom Inventory at 28 days post-injury. Analyses of symptom and patient clusters were performed using hierarchical cluster analyses of symptom severity ratings.Results3063 patients from the parent 5P study were included. Median age was 12.1 years (IQR: 9.2–14.6 years), and 1857 (60.6%) were male. Fatigue was the most common persistent symptom (21.7%), with headache the most commonly reported co-occurring symptom among patients with fatigue (55%; 363/662). Headache was common in children reporting any of the 12 other symptoms (range: 54%–72%). Physical symptoms occurred in two distinct clusters: vestibular-ocular and headache. Emotional and cognitive symptoms occurred together more frequently and with higher severity than physical symptoms. Fatigue was more strongly associated with cognitive and emotional symptoms than physical symptoms. We identified five patient groups (resolved/minimal, mild, moderate, severe and profound) based on symptom type and severity.ConclusionPost-concussive symptoms in children occur in distinct clusters, facilitating the identification of distinct patient phenotypes based on symptom type and severity. Care of children post-concussion must be comprehensive, with systems designed to identify and treat distinct post-concussion phenotypes.

Sophisticated network‐based approaches such as structural connectomics may help to detect a biomarker of mild traumatic brain injury (mTBI) in children. This study compared the structural connectome of children with mTBI or mild orthopedic injury (OI) to that of typically developing (TD) children. Children aged 8–16.99 years with mTBI (n = 83) or OI (n = 37) were recruited from the emergency department and completed 3T diffusion MRI 2–20 days postinjury. TD children (n = 39) were recruited from the community and completed diffusion MRI. Graph theory metrics were calculated for the binarized average fractional anisotropy among 90 regions. Multivariable linear regression and linear mixed effects models were used to compare groups, with covariates age, hemisphere, and sex, correcting for multiple comparisons. The two injury groups did not differ on graph theory metrics, but both differed from TD children in global metrics (local network efficiency: TD > OI, mTBI, d = 0.49; clustering coefficient: TD < OI, mTBI, d = 0.49) and regional metrics for the fusiform gyrus (lower degree centrality and nodal efficiency: TD > OI, mTBI, d = 0.80 to 0.96; characteristic path length: TD < OI, mTBI, d = −0.75 to −0.90) and in the superior and middle orbital frontal gyrus, paracentral lobule, insula, and thalamus (clustering coefficient: TD > OI, mTBI, d = 0.66 to 0.68). Both mTBI and OI demonstrated reduced global and regional network efficiency and segregation as compared to TD children. Findings suggest a general effect of childhood injury that could reflect pre‐ and postinjury factors that can alter brain structure. An OI group provides a more conservative comparison group than TD children for structural neuroimaging research in pediatric mTBI., Children with mTBI and OI demonstrated reduced global and regional network efficiency and segregation as compared to TD children. Findings suggest a general effect of childhood injury that could reflect pre‐ and postinjury factors that can alter brain structure. An OI group provides a more conservative comparison group than TD children for pediatric mTBI research.

Background We previously conducted the Probiotic Regimen for Outpatient Gastroenteritis Utility of Treatment (PROGUT) study, which identified no improvements in children with acute gastroenteritis (AGE) administered a probiotic. However, the aforementioned study did not evaluate immunomodulatory benefits. Objectives The object of this study was to determine if stool secretory immunoglobulin A (sIgA) concentrations in children with AGE increase more among participants administered a Lactobacillus rhamnosus/helveticus probiotic compared with those administered placebo. Methods This a priori planned multicenter, randomized, double-blinded, placebo-controlled ancillary study enrolled children presenting for emergency care who received a 5-d probiotic or placebo course. Participants submitted stool specimens on days 0, 5, and 28. The primary endpoint was the change in stool sIgA concentrations on day 5 compared with baseline. Results A total of 133 (n = 66 probiotic, 67 placebo) of 886 PROGUT participants (15.0%) provided all 3 specimens. Median stool sIgA concentrations did not differ between the probiotic and placebo groups at any of the study time points: day 0 median (IQR): 1999 (768, 4071) compared with 2198 (702, 5278) (P = 0.27, Cohen's d = 0.17); day 5: 2505 (1111, 5310) compared with 3207 (982, 7080) (P = 0.19, Cohen's d = 0.16); and day 28: 1377 (697, 2248) compared with 1779 (660, 3977) (P = 0.27, Cohen's d = 0.19), respectively. When comparing measured sIgA concentrations between days 0 and 5, we found no treatment allocation effects [β: −0.24 (−0.65, 0.18); P = 0.26] or interaction between treatment and specimen collection day [β: −0.003 (−0.09, 0.09); P = 0.95]. Although stool sIgA decreased between day 5 and day 28 within both groups (P

Background Norovirus is a leading cause of acute gastroenteritis. With vaccines in development, population-based estimates of norovirus burden are needed to identify target populations, quantify potential benefits, and understand disease dynamics. Methods We estimated the attributable fraction (AF) for norovirus infections in children, defined as the proportion of children testing positive for norovirus whose gastroenteritis was attributable to norovirus. We calculated the standardized incidence and emergency department (ED) visit rates attributable to norovirus using provincial gastroenteritis visit administrative data. Results From 3731 gastroenteritis case patients and 2135 controls we determined that the AFs were 67.0% (95% confidence interval [CI], 31.5%–100%) and 91.6% (88.8%–94.4%) for norovirus genogroups I (GI) and II (GII), respectively. Norovirus GII AF varied by season but not age. We attributed 116 episodes (95% CI, 103–129) and 59 (51–67) ED visits per 10 000 child-years to norovirus GII across all ages, accounting for 20% and 18% of all medically attended gastroenteritis episodes and ED visits, respectively. Conclusions In children, a large proportion of norovirus GII detections reflect causation, demonstrating significant potential for norovirus GII vaccines. Seasonal variation in the norovirus GII AF may have implications for understanding the role asymptomatic carriage plays in disease dynamics.

Study objective This study aimed to explore oral ondansetron usage and impact on outcomes in clinical practice. Methods This observational study was a planned secondary analysis of 2 trials conducted in 10 US and 6 Canadian institutions between 2014 and 2017. Children 3 to 48 months old with gastroenteritis and ≥3 episodes of vomiting in the 24 hours preceding emergency department (ED) presentation were included. Oral ondansetron was administered at the discretion of the provider. The principal outcomes were intravenous fluid administration and hospitalization at the index visit and during the subsequent 72 hours and diarrhea and vomiting frequency during the 24 hours following the ED visit. Results In total, 794 children were included. The median age was 16.0 months (interquartile range 10.0 to 26.0), and 50.1% (398/794) received oral ondansetron. In propensity-adjusted analysis (n=528), children administered oral ondansetron were less likely to receive intravenous fluids at the index visit (adjusted odds ratio [aOR] 0.50; 95% confidence interval [CI] 0.29 to 0.88). There were no differences in the frequencies of intravenous fluid administration within the first 72 hours (aOR 0.65; 95% CI 0.39 to 1.10) or hospitalization at the index visit (aOR 0.31; 95% CI 0.09 to 1.10) or the subsequent 72 hours (aOR 0.52; 95% CI 0.21 to 1.28). Episodes of vomiting (aRR 0.86; 95% CI 0.63 to 1.19) and diarrhea (aRR 1.11; 95% CI 0.93 to 1.32) during the 24 hours following ED discharge also did not differ. Conclusion Among preschool-aged children with gastroenteritis seeking ED care, oral ondansetron administration was associated with a reduction in index ED visit intravenous fluid administration; it was not associated with intravenous fluids administered within 72 hours, hospitalization, or vomiting and diarrhea in the 24 hours following discharge.

OBJECTIVES To identify independent predictors of and derive a risk score for invasive herpes simplex virus (HSV) infection. METHODS In this 23-center nested case-control study, we matched 149 infants with HSV to 1340 controls; all were ≤60 days old and had cerebrospinal fluid obtained within 24 hours of presentation or had HSV detected. The primary and secondary outcomes were invasive (disseminated or central nervous system) or any HSV infection, respectively. RESULTS Of all infants included, 90 (60.4%) had invasive and 59 (39.6%) had skin, eyes, and mouth disease. Predictors independently associated with invasive HSV included younger age (adjusted odds ratio [aOR]: 9.1 [95% confidence interval (CI): 3.4–24.5] 28 days), prematurity (aOR: 2.3, 95% CI: 1.1 to 5.1), seizure at home (aOR: 6.1, 95% CI: 2.3 to 16.4), ill appearance (aOR: 4.2, 95% CI: 2.0 to 8.4), abnormal triage temperature (aOR: 2.9, 95% CI: 1.6 to 5.3), vesicular rash (aOR: 54.8, (95% CI: 16.6 to 180.9), thrombocytopenia (aOR: 4.4, 95% CI: 1.6 to 12.4), and cerebrospinal fluid pleocytosis (aOR: 3.5, 95% CI: 1.2 to 10.0). These variables were transformed to derive the HSV risk score (point range 0–17). Infants with invasive HSV had a higher median score (6, interquartile range: 4–8) than those without invasive HSV (3, interquartile range: 1.5–4), with an area under the curve for invasive HSV disease of 0.85 (95% CI: 0.80–0.91). When using a cut-point of ≥3, the HSV risk score had a sensitivity of 95.6% (95% CI: 84.9% to 99.5%), specificity of 40.1% (95% CI: 36.8% to 43.6%), and positive likelihood ratio 1.60 (95% CI: 1.5 to 1.7) and negative likelihood ratio 0.11 (95% CI: 0.03 to 0.43). CONCLUSIONS A novel HSV risk score identified infants at extremely low risk for invasive HSV who may not require routine testing or empirical treatment.

This cohort study assesses the association between intravenous magnesium therapy administered in the emergency department and subsequent hospitalization among pediatric patients with refractory acute asthma in Canada., Key Points Question Is receipt of intravenous (IV) magnesium sulfate therapy in the emergency department associated with subsequent hospitalization among children with refractory acute asthma after adjustment for patient-level characteristics? Findings In this secondary analysis of a randomized clinical trial of 816 children who experienced moderate to severe respiratory distress after stabilization therapy and inhaled magnesium therapy or placebo, 88.4% of those who received IV magnesium therapy were hospitalized compared with 29.0% of those who did not receive this therapy. After adjustment, children who received IV magnesium therapy had greater odds of hospitalization compared with those who did not receive this therapy. Meaning The findings suggest that, after adjustment of patient-level characteristics, receipt of IV magnesium in the emergency department is associated with subsequent hospitalization among children with asthma., Importance Despite guidelines recommending administration of intravenous (IV) magnesium sulfate for refractory pediatric asthma, the number of asthma-related hospitalizations has remained stable, and IV magnesium therapy is independently associated with hospitalization. Objective To examine the association between IV magnesium therapy administered in the emergency department (ED) and subsequent hospitalization among pediatric patients with refractory acute asthma after adjustment for patient-level variables. Design, Setting, and Participants This post hoc secondary analysis of a double-blind randomized clinical trial of children with acute asthma treated from September 26, 2011, to November 19, 2019, at 7 Canadian tertiary care pediatric EDs was conducted between September and November 2020. In the randomized clinical trial, 816 otherwise healthy children aged 2 to 17 years with Pediatric Respiratory Assessment Measure (PRAM) scores of 5 points or higher after initial therapy with systemic corticosteroids and inhaled albuterol with ipratropium bromide were randomly assigned to 3 nebulized treatments of albuterol plus either magnesium sulfate or 5.5% saline placebo. Exposures Intravenous magnesium sulfate therapy (40-75 mg/kg). Main Outcomes and Measures The association between IV magnesium therapy in the ED and subsequent hospitalization for asthma was assessed using multivariable logistic regression analysis. Analyses were adjusted for year epoch at enrollment, receipt of IV magnesium, PRAM score after initial therapy and at ED disposition, age, sex, duration of respiratory distress, previous intensive care unit admission for asthma, hospitalizations for asthma within the past year, atopy, and receipt of oral corticosteroids within 48 hours before arrival in the ED, nebulized magnesium, and additional albuterol after inhaled magnesium or placebo, with site as a random effect. Results Among the 816 participants, the median age was 5 years (interquartile range, 3-7 years), 517 (63.4%) were boys, and 364 (44.6%) were hospitalized. A total of 215 children (26.3%) received IV magnesium, and 190 (88.4%) of these children were hospitalized compared with 174 of 601 children (29.0%) who did not receive IV magnesium. Multivariable factors associated with hospitalization were IV magnesium receipt from 2011 to 2016 (odds ratio [OR], 22.67; 95% CI, 6.26-82.06; P

OBJECTIVES Describe the clinical presentation, prevalence, and outcomes of concurrent serious bacterial infection (SBI) among infants with mastitis. METHODS Within the Pediatric Emergency Medicine Collaborative Research Committee, 28 sites reviewed records of infants aged ≤90 days with mastitis who were seen in the emergency department between January 1, 2008, and December 31, 2017. Demographic, clinical, laboratory, treatment, and outcome data were summarized. RESULTS Among 657 infants (median age 21 days), 641 (98%) were well appearing, 138 (21%) had history of fever at home or in the emergency department, and 63 (10%) had reported fussiness or poor feeding. Blood, urine, and cerebrospinal fluid cultures were collected in 581 (88%), 274 (42%), and 216 (33%) infants, respectively. Pathogens grew in 0.3% (95% confidence interval [CI] 0.04–1.2) of blood, 1.1% (95% CI 0.2–3.2) of urine, and 0.4% (95% CI 0.01–2.5) of cerebrospinal fluid cultures. Cultures from the site of infection were obtained in 335 (51%) infants, with 77% (95% CI 72–81) growing a pathogen, most commonly methicillin-resistant Staphylococcus aureus (54%), followed by methicillin-susceptible S aureus (29%), and unspecified S aureus (8%). A total of 591 (90%) infants were admitted to the hospital, with 22 (3.7%) admitted to an ICU. Overall, 10 (1.5% [95% CI 0.7–2.8]) had sepsis or shock, and 2 (0.3% [95% CI 0.04–1.1]) had severe cellulitis or necrotizing soft tissue infection. None received vasopressors or endotracheal intubation. There were no deaths. CONCLUSIONS In this multicenter cohort, mild localized disease was typical of neonatal mastitis. SBI and adverse outcomes were rare. Evaluation for SBI is likely unnecessary in most afebrile, well-appearing infants with mastitis.

OBJECTIVE: Adult patients are increasingly receiving care in pediatric emergency departments (PEDs), but little is known about the epidemiology of these visits. The goal of this study was to examine the characteristics of adult patients (≥ 21 years) treated in PEDs, and to describe the variation in resource utilization across centers. METHODS: We conducted a cross-sectional study examining visits to 30 PEDs (2012–2016) using the Pediatric Health Information System. Visits were categorized using All Patient Refined Diagnosis Related Groups and compared between age cohorts. We used multivariable logistic models to examine variation in demographics, utilization, testing, treatment, and disposition. RESULTS: There were 12,958,626 visits to the 30 PEDs over 5 years; 70,636 (0.6%) were by adults. Compared with children, adult patients had more laboratory testing (49% vs. 34%), diagnostic imaging (32% vs. 29%) and procedures (48% vs. 31%), and were more often admitted (17% vs. 11%) or transferred (21% vs. 0.7%) (p

The identification of clinical phenotypes may help parse the substantial heterogeneity that characterizes children with concussion. This study used latent class analysis (LCA) to identify discernible phenotypes among children with acute concussion and examine the association between phenotypes and persistent post-concussive symptoms (PPCS) at 4 and 12 weeks post-injury. We conducted LCA of variables representing pre-injury history, clinical presentation, and parent symptom ratings, derived from a prospective cohort, observational study that recruited participants from August 2013 until June 2015 at nine pediatric emergency departments within the Pediatric Emergency Research Canada network. This substudy included 2323 children from the original cohort ages 8.00-17.99 years who had data for at least 80% of all variables included in each LCA. Concussion was defined according to Zurich consensus statement diagnostic criteria. The primary outcome was PPCS at 4 and 12 weeks after enrollment. Participants were 39.5% female and had a mean age of 12.8 years (standard deviation = 2.6). Follow-up was completed by 1980 (85%) at 4 weeks and 1744 (75%) at 12 weeks. LCA identified four groups with discrete pre-injury histories, four groups with discrete clinical presentations, and seven groups with discrete profiles of acute symptoms. Clinical phenotypes based on the profile of group membership across the three LCAs varied significantly in their predicted probability of PPCS at 4 and 12 weeks. The results indicate that children with concussion can be grouped into distinct clinical phenotypes, based on pre-injury history, clinical presentation, and acute symptoms, with markedly different risks of PPCS. With further validation, clinical phenotypes may provide a useful heuristic for clinical assessment and management.

Study objective We determine whether single-dose oral ondansetron administration to children with vomiting as a result of acute gastroenteritis without dehydration reduces administration of intravenous fluid rehydration. Methods In this 2-hospital, double-blind, placebo-controlled, emergency department–based, randomized trial conducted in Karachi Pakistan, we recruited children aged 0.5 to 5.0 years, without dehydration, who had diarrhea and greater than or equal to 1 episode of vomiting within 4 hours of arrival. Patients were randomly assigned (1:1), through an Internet-based randomization service using a stratified variable-block randomization scheme, to single-dose oral ondansetron or placebo. The primary endpoint was intravenous rehydration (administration of ≥20 mL/kg of an isotonic fluid during 4 hours) within 72 hours of randomization. Results Participant median age was 15 months (interquartile range 10 to 26) and 59.4% (372/626) were male patients. Intravenous rehydration use was 12.1% (38/314) and 11.9% (37/312) in the placebo and ondansetron groups, respectively (odds ratio 0.98; 95% confidence interval [CI] 0.60 to 1.61; difference 0.2%; 95% CI of the difference –4.9% to 5.4%). Bolus fluid administration occurred within 72 hours of randomization in 10.8% (34/314) and 10.3% (27/312) of children administered placebo and ondansetron, respectively (odds ratio 0.95; 95% CI 0.56 to 1.59). A multivariable regression model fitted with treatment group and adjusted for antiemetic administration, antibiotics, zinc prerandomization, and vomiting frequency prerandomization yielded similar results (odds ratio 0.91; 95% CI 0.55 to 1.53). There was no interaction between treatment group and age, greater than or equal to 3 stools in the preceding 24 hours, or greater than or equal to 3 vomiting episodes in the preceding 24 hours. Conclusion Oral administration of a single dose of ondansetron did not result in a reduction in intravenous rehydration use. In children without dehydration, ondansetron does not improve clinical outcomes.

BACKGROUND: Between-country variation in health care resource use and its impact on outcomes in acute care settings have been challenging to disentangle from illness severity by using administrative data. METHODS: We conducted a preplanned analysis employing patient-level emergency department (ED) data from children enrolled in 2 previously conducted clinical trials. Participants aged 3 to RESULTS: In adjusted analysis, unscheduled revisits within 7 days did not differ (adjusted odds ratio [aOR]: 0.72; 95% confidence interval (CI): 0.50 to 1.02). At the index ED visit, although participants in Canada were assessed as being more dehydrated, intravenous fluids were administered more frequently in the United States (aOR: 4.6; 95% CI: 2.9 to 7.1). Intravenous fluid administration rates did not differ after enrollment (aOR: 1.4; 95% CI: 0.7 to 2.8; US cohort with Canadian as referent). Overall, intravenous rehydration was higher in the United States (aOR: 3.8; 95% CI: 2.5 to 5.7). Although hospitalization rates during the 7 days after enrollment (aOR: 1.1; 95% CI: 0.4 to 2.6) did not differ, hospitalization at the index visit was more common in the United States (3.9% vs 2.3%; aOR: 3.2; 95% CI: 1.6 to 6.8). CONCLUSIONS: Among children with gastroenteritis and similar disease severity, revisit rates were similar in our 2 study cohorts, despite lower rates of intravenous rehydration and hospitalization in Canadian-based EDs.

Objective To examine whether the presence of clinical guidelines and clinical decision support (CDS) for mild traumatic brain injury (mTBI) are associated with lower use of head computed tomography (CT). Study design We conducted a cross-sectional study of 45 pediatric emergency departments (EDs) in the Pediatric Hospital Information System from 2015 through 2019. We included children discharged with mTBI and surveyed ED clinical directors to ascertain the presence and implementation year of clinical guidelines and CDS. The association of clinical guidelines and CDS with CT use was assessed, adjusting for relevant confounders. As secondary outcomes, we evaluated ED length of stay and rates of 3-day ED revisits and admissions after revisits. Results There were 216 789 children discharged with mTBI, and CT was performed during 20.3% (44 114/216 789) of ED visits. Adjusted hospital-specific CT rates ranged from 11.8% to 34.7% (median 20.5%, IQR 17.3%, 24.3%). Of the 45 EDs, 17 (37.8%) had a clinical guideline, 9 (20.0%) had CDS, and 19 (42.2%) had neither. Compared with EDs with neither a clinical guideline nor CDS, visits to EDs with CDS (aOR 0.52 [0.47, 0.58]) or a clinical guideline (aOR 0.83 [0.78, 0.89]) had lower odds of including a CT for mTBI. ED length of stay and revisit rates did not differ based on the presence of a clinical guideline or CDS. Conclusions Clinical guidelines for mTBI, and particularly CDS, were associated with lower rates of head CT use without adverse clinical outcomes.

Importance While intravenous magnesium decreases hospitalizations in refractory pediatric acute asthma, it is variably used because of invasiveness and safety concerns. The benefit of nebulized magnesium to prevent hospitalization is unknown. Objective To evaluate the effectiveness of nebulized magnesium in children with acute asthma remaining in moderate or severe respiratory distress after initial therapy. Design, Setting, and Participants A randomized double-blind parallel-group clinical trial from September 26, 2011, to November 19, 2019, in 7 tertiary-care pediatric emergency departments in Canada. The participants were otherwise healthy children aged 2 to 17 years with moderate to severe asthma defined by a Pediatric Respiratory Assessment Measure (PRAM) score of 5 or greater (on a 12-point scale) after a 1-hour treatment with an oral corticosteroid and 3 inhaled albuterol and ipratropium treatments. Of 5846 screened patients, 4332 were excluded for criteria, 273 declined participation, 423 otherwise excluded, 818 randomized, and 816 analyzed. Interventions Participants were randomized to 3 nebulized albuterol treatments with either magnesium sulfate (n = 410) or 5.5% saline placebo (n = 408). Main Outcomes and Measures The primary outcome was hospitalization for asthma within 24 hours. Secondary outcomes included PRAM score; respiratory rate; oxygen saturation at 60, 120, 180, and 240 minutes; blood pressure at 20, 40, 60, 120, 180, and 240 minutes; and albuterol treatments within 240 minutes. Results Among 818 randomized patients (median age, 5 years; 63% males), 816 completed the trial (409 received magnesium; 407, placebo). A total of 178 of the 409 children who received magnesium (43.5%) were hospitalized vs 194 of the 407 who received placebo (47.7%) (difference, −4.2%; absolute risk difference 95% [exact] CI, −11% to 2.8%];P = .26). There were no significant between-group differences in changes from baseline to 240 minutes in PRAM score (difference of changes, 0.14 points [95% CI, −0.23 to 0.50];P = .46); respiratory rate (0.17 breaths/min [95% CI, −1.32 to 1.67];P = .82); oxygen saturation (−0.04% [95% CI, −0.53% to 0.46%];P = .88); systolic blood pressure (0.78 mm Hg [95% CI, −1.48 to 3.03];P = .50); or mean number of additional albuterol treatments (magnesium: 1.49, placebo: 1.59; risk ratio, 0.94 [95% CI, 0.79 to 1.11];P = .47). Nausea/vomiting or sore throat/nose occurred in 17 of the 409 children who received magnesium (4%) and 5 of the 407 who received placebo (1%). Conclusions and Relevance Among children with refractory acute asthma in the emergency department, nebulized magnesium with albuterol, compared with placebo with albuterol, did not significantly decrease the hospitalization rate for asthma within 24 hours. The findings do not support use of nebulized magnesium with albuterol among children with refractory acute asthma. Trial Registration ClinicalTrials.gov Identifier:NCT01429415

Objective: To assess the performance of a hemolytic uremic syndrome (HUS) severity score among children with Shiga toxin-producing Escherichia coli (STEC) infections and HUS by stratifying them according to their risk of adverse events. The score has not been previously evaluated in a North American acute care setting. Study design: We reviewed medical records of children 13 were designated as high-risk. We assessed score performance to predict severe adverse events (ie, dialysis, neurologic complication, respiratory failure, and death) using discrimination and net benefit (ie, threshold probability), with subgroup analyses by age and day-of-illness. Results: A total of 167 children had HUS, of whom 92.8% (155/167) had relevant data to calculate the score; 60.6% (94/155) experienced a severe adverse event. Discrimination was acceptable overall (area under the curve 0.71, 95% CI 0.63-0.79) and better among children 26%. Conclusions: The HUS severity score was able to discriminate between high- and low-risk children

Purpose of review The aim of this review is to provide an update of nonantibiotic therapies for acute gastroenteritis (AGE), focusing on antiemetics and probiotics. Recent findings The mainstay of therapy for nonsevere AGE remains oral rehydration therapy (ORT). Recent randomized controlled trials and metaanalyses have further strengthened the evidence-base supporting single-dose ondansetron administration in emergency departments to facilitate ORT based on evidence that it safely reduces intravenous fluid administration and hospitalization rates. Intravenous ondansetron administration and multiple-dose use should be avoided. A bimodal release ondansetron formulation was shown to improve outcomes in adolescents and adults with AGE in one study, but further evidence is required to support use. Recent large trials evaluating probiotic administration demonstrated a lack of benefit and guidelines that recommend their use should reevaluate their positions in light of this evidence. Furthermore, caution should be exercised when use is considered in high-risk populations and settings. Summary The benefits, dosing/route, and target populations most likely to benefit from ondansetron have been further clarified. Optimization of the real-life effectiveness of this therapy will require implementation strategies. Recent high-quality evidence showing a lack of efficacy and potential harm associated with probiotic use suggests that routine use for AGE should be discouraged.

BACKGROUND AND OBJECTIVES: International patterns of antibiotic use and laboratory testing in bronchiolitis in emergency departments are unknown. Our objective is to evaluate variation in the use of antibiotics and nonindicated tests in infants with bronchiolitis in 38 emergency departments in Pediatric Emergency Research Networks in Canada, the United States, Australia and New Zealand, the United Kingdom and Ireland, and Spain and Portugal. We hypothesized there would be significant variation, adjusted for patient characteristics. METHODS: We analyzed a retrospective cohort study of previously healthy infants aged 2 to 12 months with bronchiolitis. Variables examined included network, poor feeding, dehydration, nasal flaring, chest retractions, apnea, saturation, respiratory rate, fever, and suspected bacterial infection. Outcomes included systemic antibiotic administration and urine, blood, or viral testing or chest radiography (CXR). RESULTS: In total, 180 of 2359 (7.6%) infants received antibiotics, ranging from 3.5% in the United Kingdom and Ireland to 11.1% in the United States. CXR (adjusted odds ratio [aOR] 2.3; 95% confidence interval 1.6–3.2), apnea (aOR 2.2; 1.1–3.5), and fever (aOR 2.4; 1.7–3.4) were associated with antibiotic use, which did not vary across networks (P = .15). In total, 768 of 2359 infants (32.6%) had ≥1 nonindicated test, ranging from 12.7% in the United Kingdom and Ireland to 50% in Spain and Portugal. Compared to the United Kingdom and Ireland, the aOR (confidence interval) results for testing were Canada 5.75 (2.24–14.76), United States 4.14 (1.70–10.10), Australia and New Zealand 2.25 (0.86–5.74), and Spain and Portugal 3.96 (0.96–16.36). Testing varied across networks (P < .0001) and was associated with suspected bacterial infections (aOR 2.12; 1.30–2.39) and most respiratory distress parameters. Viral testing (591 of 768 [77%]) and CXR (507 of 768 [66%]) were obtained most frequently. CONCLUSIONS: The rate of antibiotic use in bronchiolitis was low across networks and was associated with CXR, fever, and apnea. Nonindicated testing was common outside of the United Kingdom and Ireland and varied across networks irrespective of patient characteristics.

OBJECTIVES: To determine if the clinical characteristics of children with gastroenteritis and influenza identified in their stool differ from those whose stool was influenza-negative. METHODS: Children

Objective There is a lack of definitive pediatric literature on effective pharmacotherapy for persistent post-concussion headache symptoms. This study assessed whether acute metoclopramide treatment in the Emergency Department (ED) was associated with a reduction in persistent headache in children at 1- and 4-weeks post-concussion. Methods Children aged 8–17 years with acute concussion presenting to 9-Canadian Pediatric EDs were enrolled in a prospective cohort study, from August 2013–June 2015. Primary and secondary outcomes were persistent headache at 1- and 4-week post-injury respectively. Headache persistence was based on the one and four-week headache scores minus recalled pre-injury score using the Post-Concussion Symptom Inventory. The association between metoclopramide and headache persistence at 1- and 4-weeks were examined using unadjusted and adjusted regression and 1:4 propensity score matching model. Results Baseline assessments were completed in 2095 participants; 65 (3.1%) received metoclopramide within 48-hours of injury. At 1- and 4-weeks, 54% (963/1808) and 26% (456/1780) of participants had persistent headache relative to baseline respectively. In unadjusted analysis, no association between metoclopramide and headache persistence at 1-week was found [treated vs. untreated: 1-week (53% vs. 53%; relative risk (RR) = 1.0 (95%CI: 0.8, 1.3); 4-weeks (27.3% vs. 25.6%; RR = 1.0 (95% CI: 0.9, 1.2)]. Metoclopramide was not associated with lower headache risk on propensity score matching [treated vs. untreated: 1-week, n = 220 (52% vs. 59.4%; RR = 0.8 (95%CI: 0.6, 1.2) and 4-weeks, n = 225 (27.1% vs. 32.8%; RR = 0.9 (95%CI: 0.8, 1.1)]. Conclusion Metoclopramide administration was not associated with a reduction in headache persistence in children seeking ED care due to a concussion. Further research is necessary to determine which pharmacotherapies may be effective for acute and persistent post-concussive headache.

Objective Serum bicarbonate reflects dehydration severity in children with gastroenteritis. Previous work in children receiving intravenous rehydration has correlated end-tidal carbon dioxide (EtCO2) with serum bicarbonate. We evaluated whether EtCO2 predicts weight change in children with vomiting and/or diarrhea. Methods A prospective cohort study was conducted. Eligible children were 3 months to 10 years old and presented for emergency department (ED) care because of vomiting and/or diarrhea. End-tidal carbon dioxide measurements were performed after triage. The diagnostic standard was weight change determined from serial measurements after symptom resolution. A receiver operating characteristic curve was constructed to identify a cut-point to predict 5% or more dehydration. Results In total, 195 children were enrolled. Among the 169 (87%) with EtCO2 measurements, the median (interquartile range [IQR]) was 30.4 (27.8 to 33.1). One hundred fifty-eight had repeat weights performed at home; the median (IQR) weight change from ED presentation to well weight was +0.06 (-0.14 to +0.30) or +0.72% (-1.2% to +2.1%). Sixteen percent (25/158) had 3% or more and 4% (6/158) had 5% or more weight gain (ie, percent dehydration). One hundred sixteen (60%) completed home follow-up and had acceptable EtCO2 recordings. Receiver operating curve analysis revealed an area under the curve of 0.34 (95% confidence interval, 0.06 to 0.62) for EtCO2 as a predictor of 5% or more dehydration. Conclusions The limited accuracy of EtCO2 measurement to predict 5% or more dehydration precludes its use as a tool to assess dehydration severity in children. End-tidal carbon dioxide monitoring does not have the ability to identify those children with 5% or more dehydration in a cohort of children with vomiting and/or diarrhea presenting for ED care.

ObjectiveOndansetron is increasingly administered to children suffering from concussion-associated nausea/vomiting. We examined the association between ondansetron administration and post-concussion symptoms in children at 1 week and 1 month following the concussion.MethodsThis was a secondary analysis of data collected prospectively in a cohort study conducted in nine pediatric emergency departments (EDs) (5P study). Participants were children ages between 5 and 17.99 years who sustained a concussion in the previous 48 hours. For the current study, only 5P participants who reported nausea and/or vomiting in the ED were eligible. The exposure of interest was ondansetron administration; the comparison group included all other participants. The primary outcome was an increase in at least three symptoms of the Post-Concussion Symptom Inventory score at 1 week and 1 month following trauma.ResultsAmong the 3,063 children included in the 5P study, 1805 (59%) reported nausea and provided data at 1 week and/or 1 month. Among them, 132 (7%) received ondansetron. Multivariable logistic regression adjusted for confounders did not show an association between ondansetron use and the risk of persistent post-concussion symptoms at 1 week (OR: 1.13 [95% CI: 0.86-1.49]), but it was associated with a higher risk at 1 month (OR: 1.33 [95% CI: 1.05-1.97]).ConclusionIn children presenting to the ED with an acute concussion, ondansetron use was associated with a higher risk of persistent post-concussion symptoms at 1 month. Although this may be related to the limitations of the design, it highlights the importance of evaluating this association using a randomized clinical trial.

Objectives Interventions to reduce frequent emergency department (ED) use in children are often limited by the inability to predict future risk. We sought to develop a population-based model for predicting Medicaid-insured children at risk for high frequency (HF) of low-resource-intensity (LRI) ED visits. Methods We conducted a retrospective cohort analysis of Medicaid-insured children (aged 1–18 years) included in the MarketScan Medicaid database with ≥1 ED visit in 2013. LRI visits were defined as ED encounters with no laboratory testing, imaging, procedures, or hospitalization; and HF as ≥3 LRI ED visits within 365 days of the initial encounter. A generalized linear regression model was derived and validated using a split-sample approach. Validity testing was conducted examining model performance using 3 alternative definitions of LRI. Results Among 743,016 children with ≥1 ED visit in 2013, 5% experienced high-frequency LRI ED use, accounting for 21% of all LRI visits. Prior LRI ED use (2 visits: adjusted odds ratio = 3.5; 95% confidence interval, 3.3, 3.7; and ≥3 visits: adjusted odds ratio = 7.7; 95% confidence interval, 7.3, 8.1) and presence of ≥3 chronic conditions (adjusted odds ratio = 1.7; 95% confidence interval, 1.6, 1.8) were strongly associated with future HF-LRI ED use. A model incorporating patient characteristics and prior ED use predicted future HF-LRI ED utilization with an area under the curve of 0.74. Conclusions Demographic characteristics and patterns of prior ED use can predict future risk of HF-LRI ED use in the following year. Interventions for reducing low-value ED use in these high-risk children should be considered.

Study objective We determine the optimal correction factor for cerebrospinal fluid WBC counts in infants with traumatic lumbar punctures. Methods We performed a secondary analysis of a retrospective cohort of infants aged 60 days or younger and with a traumatic lumbar puncture (cerebrospinal fluid RBC count ≥10,000 cells/mm3) at 20 participating centers. Cerebrospinal fluid pleocytosis was defined as a cerebrospinal fluid WBC count greater than or equal to 20 cells/mm3 for infants aged 28 days or younger and greater than or equal to 10 cells/mm3 for infants aged 29 to 60 days; bacterial meningitis was defined as growth of pathogenic bacteria from cerebrospinal fluid culture. Using linear regression, we derived a cerebrospinal fluid WBC correction factor and compared the uncorrected with the corrected cerebrospinal fluid WBC count for the detection of bacterial meningitis. Results Of the eligible 20,319 lumbar punctures, 2,880 (14%) were traumatic, and 33 of these patients (1.1%) had bacterial meningitis. The derived cerebrospinal fluid RBCs:WBCs ratio was 877:1 (95% confidence interval [CI] 805 to 961:1). Compared with the uncorrected cerebrospinal fluid WBC count, the corrected one had lower sensitivity for bacterial meningitis (88% uncorrected versus 67% corrected; difference 21%; 95% CI 10% to 37%) but resulted in fewer infants with cerebrospinal fluid pleocytosis (78% uncorrected versus 33% corrected; difference 45%; 95% CI 43% to 47%). Cerebrospinal fluid WBC count correction resulted in the misclassification of 7 additional infants with bacterial meningitis, who were misclassified as not having cerebrospinal fluid pleocytosis; only 1 of these infants was older than 28 days. Conclusion Correction of the cerebrospinal fluid WBC count substantially reduced the number of infants with cerebrospinal fluid pleocytosis while misclassifying only 1 infant with bacterial meningitis of those aged 29 to 60 days.

BACKGROUND. Minimizing emergency department (ED) use is a common goal of emerging population health initiatives. Our objective was to assess the impact of chronic conditions on children’s ED use. METHODS. Retrospective analysis of 1,850,027 ED visits in 2010 by 3,250,383 children ages 1-21 years continuously enrolled in Medicaid from 10 states included in the Truven Marketscan Medicaid Database. The main outcome was the annual ED visit rate not resulting in hospitalization per 1,000 enrollees. We compared rates by enrollees’ characteristics, including type and number of chronic conditions, and medical technology (e.g., gastrostomy, tracheostomy), using Poisson regression. To assess chronic conditions, we used AHRQ’s Chronic Condition Indicator system, assigning chronic conditions with ED visit rates ≥75(th) percentile as having the “highest” visit rates. RESULTS. The overall annual ED visit rate was 569 per 1000 enrollees. As the number of the children’s chronic conditions increased from 0 to ≥3, visit rates increased by 180% (from 376 to 1053 per 1000 enrollees, p

BACKGROUND: Ondansetron is an effective antiemetic employed to prevent vomiting in children with gastroenteritis in high-income countries; data from low- and middle-income countries are sparse. METHODS: We conducted a randomized, double-blind, placebo-controlled superiority trial in 2 pediatric emergency departments in Pakistan. Dehydrated children aged 6 to 60 months with ≥1 diarrheal (ie, loose or liquid) stool and ≥1 vomiting episode within the preceding 4 hours were eligible to participate. Participants received a single weight-based dose of oral ondansetron (8–15 kg: 2 mg; >15 kg: 4 mg) or identical placebo. The primary outcome was intravenous administration of ≥20 mL/kg over 4 hours of an isotonic fluid within 72 hours of random assignment. RESULTS: All 918 (100%) randomly assigned children completed follow-up. Intravenous rehydration was administered to 14.7% (68 of 462) and 19.5% (89 of 456) of those administered ondansetron and placebo, respectively (difference: −4.8%; 95% confidence interval [CI], −9.7% to 0.0%). In multivariable logistic regression analysis adjusted for other antiemetic agents, antibiotics, zinc, and the number of vomiting episodes in the preceding 24 hours, children administered ondansetron had lower odds of the primary outcome (odds ratio: 0.70; 95% CI, 0.49 to 1.00). Fewer children in the ondansetron, relative to the placebo group vomited during the observation period (difference: −12.9%; 95% CI, −18.0% to −7.8%). The median number of vomiting episodes (P < .001) was lower in the ondansetron group. CONCLUSIONS: Among children with gastroenteritis-associated vomiting and dehydration, oral ondansetron administration reduced vomiting and intravenous rehydration use. Ondansetron use may be considered to promote oral rehydration therapy success among dehydrated children in low- and middle-income countries.

Although neonatal herpes simplex virus (HSV) causes significant morbidity, utilization of the cerebrospinal fluid (CSF) HSV polymerase chain reaction (PCR) test remains variable. Our objective was to examine the association of CSF HSV PCR testing with length of stay (LOS) in a 20-center retrospective cohort of hospitalized infants aged ≤60 days undergoing evaluation for meningitis after adjustment for patient-level factors and clustering by center. Of 20,496 eligible infants, 7,399 (36.1%) had a CSF HSV PCR test performed, and 46 (0.6% of those tested) had a positive test. Infants who had a CSF HSV PCR test performed had a 23% longer hospital LOS (incident rate ratio 1.23; 95% CI: 1.14-1.33). Targeted CSF HSV PCR testing may mitigate the impact on LOS for low-risk infants.

Little is known about the epidemiology and severity of gastroenteritis among children treated at home. We sought to compare illness severity and etiology between children brought for emergency department (ED) care to those managed at home (i.e., community). Prospective cohort study of children enrolled between December 2014 and December 2016 in two pediatric EDs in Alberta, Canada along with children treated at home after telephone triage (i.e., community). Primary outcomes were maximal frequency of vomiting and diarrhea in the 24-h pre-enrollment period; secondary outcomes included etiologic pathogens, dehydration severity, future healthcare visits, and treatments provided. A total of 1613 patients (1317 ED, 296 community) were enrolled. Median maximal frequency of vomiting was higher in the ED cohort (5 (3, 10) vs. 5 (2, 8); P < 0.001). Proportion of children with diarrhea and its 24-h median frequency were lower in the ED cohort (61.3 vs. 82.8% and 2 (0, 6) vs. 4 (1, 7); P < 0.001, respectively). In regression analysis, the ED cohort had a higher maximum number of vomiting episodes pre-enrollment (incident rate ratio (IRR) 1.25; 95% CI 1.12, 1.40) while the community cohort had higher maximal 24-h period diarrheal episodes (IRR 1.20; 95% CI 1.01, 1.43). Norovirus was identified more frequently in the community cohort (36.8% vs. 23.6%; P < 0.001). Children treated in the ED have a greater number of vomiting episodes; those treated at home have more diarrheal episodes. Norovirus is more common among children treated symptomatically at home and thus may represent a greater burden of disease than previously thought.

Data are lacking regarding the impact of visible pigment on rectal swab diagnostic accuracy. We describe the test characteristics of rectal swabs with and without pigment in children with gastroenteritis. Between December 2014 and September 2017, children (age

Given the lack of evidence regarding effective pharmacological and non-pharmacological interventions for pediatric mild traumatic brain injury (mTBI) and the resultant lack of treatment recommendations reflected in consensus guidelines, variation in the management of pediatric mTBI is to be expected. We therefore surveyed practitioners across 15 centers in the United States and Canada who care for children with pediatric mTBI to evaluate common-practice variation in the management of pediatric mTBI. The survey, developed by a panel of pediatric mTBI experts, consisted of a 10-item survey instrument regarding providers' perception of common pediatric mTBI symptoms and mTBI interventions. Surveys were distributed electronically to a convenience sample of local experts at each center. Frequencies and percentages (with confidence intervals [CI]) were determined for survey responses. One hundred and seven respondents (71% response rate) included specialists in pediatric Emergency Medicine, Sports Medicine, Neurology, Neurosurgery, Neuropsychology, Neuropsychiatry, Physical and Occupational Therapy, Physiatry/Rehabilitation, and General Pediatrics. Respondents rated headache as the most prevalently reported symptom after pediatric mTBI, followed by cognitive problems, dizziness, and irritability. Of the 65 (61%; [95% CI: 51,70]) respondents able to prescribe medications, non-steroidal anti-inflammatory medications (55%; [95% CI: 42,68]) and acetaminophen (59%; [95% CI: 46,71]) were most commonly recommended. One in five respondents reported prescribing amitriptyline for headache management after pediatric mTBI, whereas topiramate (8%; [95% CI: 3,17]) was less commonly reported. For cognitive problems, methylphenidate (11%; [95% CI: 4,21]) was used more commonly than amantadine (2%; [95% CI: 0,8]). The most common non-pharmacological interventions were rest ("always" or "often" recommended by 83% [95% CI: 63,92] of the 107 respondents), exercise (59%; [95%CI: 49,69]), vestibular therapy (42% [95%CI: 33,53]) and cervical spine exercises (29% [95%CI: 21,39]). Self-reported utilization for common pediatric mTBI interventions varied widely across our Canadian and United States consortium. Future effectiveness studies for pediatric mTBI are urgently needed to advance the evidence-based care.

Although enteric multianalyte syndromic panels are increasingly employed, direct comparisons with traditional methods and the inclusion of host phenotype correlations are limited. Luminex xTAG gastrointestinal pathogen panel (GPP) and culture results are highly concordant. However, phenotypic and microbiological confirmatory testing raises concerns regarding the accuracy of the GPP, especially for Salmonella spp. A total of 3,089 children with gastroenteritis submitted stool specimens, rectal swab specimens, and clinical data. The primary outcome was bacterial pathogen detection agreement for shared targets between culture and the Luminex xTAG GPP. Secondary analyses included phenotype assessment, additional testing of GPP-negative/culture-positive isolate suspensions with the GPP, and in-house and commercial confirmatory nucleic acid testing of GPP-positive/culture-negative extracts. The overall percent agreement between technologies was >99% for each pathogen. Salmonella spp. were detected in specimens from 64 participants: 12 (19%) by culture only, 9 (14%) by GPP only, and 43 (67%) by both techniques. Positive percent agreement for Salmonella spp. was 78.2% (95% confidence interval [CI], 64.6%, 87.8%). Isolate suspensions from the 12 participants with specimens GPP negative/culture positive for Salmonella tested positive by GPP. Specimens GPP positive/culture negative for Salmonella originated in younger children with less diarrhea and more vomiting. GPP-positive/culture-negative specimen extracts tested positive using additional assays for 0/2 Campylobacter-positive specimens, 0/4 Escherichia coli O157-positive specimens, 0/9 Salmonella-positive specimens, and 2/3 Shigella-positive specimens. For both rectal swab and stool samples, the median cycle threshold (CT) values, determined using quantitative PCR, were higher for GPP-negative/culture-positive samples than for GPP-positive/culture-positive samples (for rectal swabs, 36.9 [interquartile range {IQR}, 33.7, 37.1] versus 30.0 [IQR, 26.2, 33.2], respectively [P = 0.002]; for stool samples, 36.9 [IQR, 33.7, 37.1] versus 29.0 [IQR, 24.8, 30.8], respectively [P = 0.001]). GPP and culture have excellent overall agreement; however, for specific pathogens, GPP is less sensitive than culture and, notably, identifies samples false positive for Salmonella spp.

To characterize the pain experienced by children with acute gastroenteritis (AGE) in the 24 hours before emergency department (ED) presentation. Secondary objectives included characterizing ED pain, discharge recommendations, overall analgesic use, and factors that influenced analgesic use and pain severity.A prospective cohort was recruited from 2 pediatric EDs (December 2014 to September 2017). Eligibility criteria included18 years of age, AGE (≥3 episodes of diarrhea or vomiting in the previous 24 hours), and symptom duration7 days at presentation.We recruited 2136 patients, median age 20.8 months (IQR 10.4, 47.4) and 45.8% (979/2136) female. In the 24 hours before enrollment, most caregivers reported moderate (28.6% [610/2136, 95% CI 26.7-30.5]) or severe (46.2% [986/2136, CI 44.0-48.3]) pain for their child. In the ED, they reported moderate (31.1% [664/2136, 95% CI 29.1-33.1]) or severe ([26.7% [571/2136, 95% CI 24.9-28.7]) pain; analgesia was provided to 21.2% (452/2131). The most common analgesics used in the ED were acetaminophen and ibuprofen. At discharge, these were also most commonly recommended. Factors associated with greater analgesia use in the ED were high pain scores during the index visit, having a primary care physician, earlier presentation to emergency care, fewer diarrheal episodes, presence of fever, and hospitalization at index visit.Most caregivers of children presenting to the ED with AGE reported moderate or severe pain, both before and during their visit. Future research should focus on the development of effective, safe, and timely pain management plans.

Key Points Question Does the use of diagnostic imaging for children receiving care in US pediatric emergency departments (EDs) differ by race and ethnicity? Findings This multicenter cross-sectional study of more than 13 million pediatric ED visits to 44 children’s hospitals demonstrated that non-Hispanic Black and Hispanic patients were less likely to undergo diagnostic imaging compared with non-Hispanic White patients. Meaning In these findings, race and ethnicity appear to be independently associated with imaging decisions in the pediatric ED, highlighting the need to better understand and mitigate these disparities., This cross-sectional study assesses the racial and ethnic differences in the performance of common emergency department imaging studies and examines patterns across diagnoses among US children’s hospitals., Importance Diagnostic imaging is frequently performed as part of the emergency department (ED) evaluation of children. Whether imaging patterns differ by race and ethnicity is unknown. Objective To evaluate racial and ethnic differences in the performance of common ED imaging studies and to examine patterns across diagnoses. Design, Setting, and Participants This cross-sectional study evaluated visits by patients younger than 18 years to 44 US children’s hospital EDs from January 1, 2016, through December 31, 2019. Exposures Non-Hispanic Black and Hispanic compared with non-Hispanic White race/ethnicity. Main Outcomes and Measures The primary outcome was the proportion of visits for each race/ethnicity group with at least 1 diagnostic imaging study, defined as plain radiography, computed tomography, ultrasonography, and magnetic resonance imaging. The major diagnostic categories classification system was used to examine race/ethnicity differences in imaging rates by diagnoses. Results A total of 13 087 522 visits by 6 230 911 children and adolescents (mean [SD] age, 5.8 [5.2] years; 52.7% male) occurred during the study period. Diagnostic imaging was performed during 3 689 163 visits (28.2%). Imaging was performed in 33.5% of visits by non-Hispanic White patients compared with 24.1% of visits by non-Hispanic Black patients (odds ratio [OR], 0.60; 95% CI, 0.60-0.60) and 26.1% of visits by Hispanic patients (OR, 0.66; 95% CI, 0.66-0.67). Adjusting for confounders, visits by non-Hispanic Black (adjusted OR, 0.82; 95% CI, 0.82-0.83) and Hispanic (adjusted OR, 0.87; 95% CI, 0.87-0.87) patients were less likely to include any imaging study compared with visits by non-Hispanic White patients. Limiting the analysis to only visits by nonhospitalized patients, the adjusted OR for imaging was 0.79 (95% CI, 0.79-0.80) for visits by non-Hispanic Black patients and 0.84 (95% CI, 0.84-0.85) for visits by Hispanic patients. Results were consistent in analyses stratified by public and private insurance groups and did not materially differ by diagnostic category. Conclusions and Relevance In this study, non-Hispanic Black and Hispanic children were less likely to receive diagnostic imaging during ED visits compared with non-Hispanic White children. Further investigation is needed to understand and mitigate these potential disparities in health care delivery and to evaluate the effect of these differential imaging patterns on patient outcomes.

To characterize symptom burden, school function, and physical activity in youth 1 year following acute concussion and those with subsequent repeat concussion.Secondary analysis of Predicting Persistent Postconcussive Problems in Pediatrics prospective, multicenter cohort study conducted in 9 Canadian emergency departments. Participants were children between ages 5 and 18 years who presented consecutively ≤48 hours of concussion and agreed to participate in a post hoc electronic survey 1 year after injury. Outcomes were assessed using a standardized 25-question symptom scale derived from the Post-Concussion Symptom Inventory-Parent; school function and physical activity outcomes were queried. The primary outcome was total symptom score 1 year following concussion, defined as the number of symptoms experienced more than before injury.Of 3052 youth enrolled in the Predicting Persistent Postconcussive Problems in Pediatrics study, 432 (median [IQR] age, 11.5 [9,14] years; 266 [62%] male) completed the 1-year survey; 34 respondents reported a repeat concussion. Following acute concussion, youth were more likely to be symptom-free than following repeat concussion (75% vs 50%; difference = 25% [95% CI 8-41]; P = .002) and to have recovered fully (90% vs 74%; difference = 17% [95% CI 5-34]; P = .002) after 1 year. Although physical symptoms were less 1 year after initial emergency department presentation for both groups (P .001), youth with a repeat concussion reported greater headache persistence (26% vs 13%; difference = 13% [95% CI 1,31]; P = .024). Both groups returned to their normal school routine (100% vs 95%; difference = 5% [95% CI -5 to 8; P = .618). Youth without repeat concussion more frequently returned to normal physical activities (98% vs 85%; difference = 13% [95% CI 4-28]; P .0001) and sport (95% vs 82%; difference = 13% [95% CI 3-29]; P = .009).Most youth are symptom-free and fully recovered 1 year following concussion. Some children with repeat concussion have worse outcomes and have delays in returning to normal school routines and sport.

To determine age-stratified prevalence of concomitant bacterial meningitis in infants ≤60 days with a urinary tract infection, we performed a 23-center, retrospective study of 1737 infants with urinary tract infection. Concomitant bacterial meningitis was rare, but more common in infants 0-28 days of age [0.9%; 95% confidence interval (CI): 0.4%-1.9%) compared with infants 29-60 days of age (0.2%; 95% CI: 0%-0.8%).

There is increased awareness of radiation risks from computed tomography (CT) in pediatric patients. In emergency departments (EDs), evidence-based guidelines, improvements in imaging technology, and availability of nonradiating modalities have potentially reduced CT use.To evaluate changes over time and hospital variation in advanced imaging use.This cross-sectional study assessed 26 082 062 ED visits by children younger than 18 years from the Pediatric Health Information System administrative database from January 1, 2009, through December 31, 2018.Imaging.The primary outcome was the change in CT, ultrasonography, and magnetic resonance imaging (MRI) rates from January 1, 2009, to December 31, 2018. Imaging for specific diagnoses was examined using all patient-refined diagnosis related groups. Secondary outcomes were hospital admission and 3-day ED revisit rates and ED length of stay.There were a total of 26 082 062 visits by 9 868 406 children (mean [SD] age, 5.59 [5.15] years; 13 842 567 [53.1%] male; 9 273 181 [35.6%] non-Hispanic white) to 32 US pediatric EDs during the 10-year study period, with 1 or more advanced imaging studies used in 1 919 283 encounters (7.4%). The proportion of ED encounters with any advanced imaging increased from 6.4% (95% CI, 6.2%-6.2%) in 2009 to 8.7% (95% CI, 8.7%-8.8%) in 2018. The proportion of ED encounters with CT decreased from 3.9% (95% CI, 3.9%-3.9%) to 2.9% (95% CI, 2.9%-3.0%) (P .001 for trend), with ultrasonography increased from 2.5% (95% CI, 2.5%-2.6%) to 5.8% (95% CI, 5.8%-5.9%) (P .001 for trend), and with MRI increased from 0.3% (95% CI, 0.3%-0.4%) to 0.6% (95% CI, 0.6%-0.6%) (P .001 for trend). The largest decreases in CT rates were for concussion (-23.0%), appendectomy (-14.9%), ventricular shunt procedures (-13.3%), and headaches (-12.4%). Factors associated with increased use of nonradiating imaging modalities included ultrasonography for abdominal pain (20.3%) and appendectomy (42.5%) and MRI for ventricular shunt procedures (17.9%) (P .001 for trend). Across the study period, EDs varied widely in the use of ultrasonography for appendectomy (median, 57.5%; interquartile range [IQR], 40.4%-69.8%) and MRI (median, 15.8%; IQR, 8.3%-35.1%) and CT (median, 69.5%; IQR, 54.5%-76.4%) for ventricular shunt procedures. Overall, ED length of stay did not change, and hospitalization and 3-day ED revisit rates decreased during the study period.This study found that use of advanced imaging increased from 2009 to 2018. Although CT use decreased, this decrease was accompanied by a greater increase in the use of ultrasonography and MRI. There appears to be substantial variation in practice and a need to standardize imaging practices.

The aim of this study was to improve follow-up laboratory testing for children infected by Shiga toxin-producing Escherichia coli (STEC) through the provision of an information sheet to healthcare providers in the province of Alberta, Canada. An information sheet recommending the performance of laboratory tests, every 24–48h until 3 days after diarrhoea resolves or the platelet count stabilises or begins to rise, was sent to all physicians who ordered a STEC-positive stool test as of 1 November 2016. The information sheet was only distributed to physicians in one of the province’s five healthcare delivery zones (i.e. intervention zone). Medical records for children aged

Background The ability to identify bacterial pathogens that necessitate specific clinical management or public health action in children with acute gastroenteritis is crucial to patient care and public health. However, existing stool-testing guidelines offer inconsistent recommendations, and their performance characteristics are unknown. We evaluated 6 leading gastroenteritis guidelines (eg, those of the Centers for Disease Control and Prevention and Infectious Disease Society of America) that recommend when to test children’s stool for bacterial enteropathogens. Methods Via 2 emergency departments in Alberta, Canada, we enrolled 2447 children Results Outcome data were available for 2391 (97.7%) participants, and 6% (144/2391) of participants tested positive for a bacterial enteropathogen. Guideline sensitivity ranged from 25.8% (95% confidence interval [CI] 18.7–33.0%) to 66.9% (95% CI 59.3–74.6%), and varied for individual pathogens. Guideline specificity for all bacterial enteropathogens ranged from 63.6% (95% CI 61.6–65.6%) to 96.5% (95% CI 95.7–97.2%). Conclusions No guideline provided optimally balanced performance. The most sensitive guidelines missed one-third of cases and would drastically increase testing volumes. The most specific guidelines missed almost 75% of cases.

BackgroundAcute gastroenteritis develops in millions of children in the United States every year, and treatment with probiotics is common. However, data to support the use of probiotics in this population are limited.MethodsWe conducted a prospective, randomized, double-blind trial involving children 3 months to 4 years of age with acute gastroenteritis who presented to one of 10 U.S. pediatric emergency departments. Participants received a 5-day course of Lactobacillus rhamnosus GG at a dose of 1×1010 colony-forming units twice daily or matching placebo. Follow-up surveys were conducted daily for 5 days and again 14 days after enrollment and 1 month after enrollment. The primary outcome was moderate-to-severe gastroenteritis, which was defined as an illness episode with a total score on the modified Vesikari scale of 9 or higher (scores range from 0 to 20, with higher scores indicating more severe disease), within 14 days after enrollment. Secondary outcomes included the duration and frequency of diarrhea and vomiting, the duration of day-care absenteeism, and the rate of household transmission (defined as the development of symptoms of gastroenteritis in previously asymptomatic household contacts).ResultsAmong the 971 participants, 943 (97.1%) completed the trial. The median age was 1.4 years (interquartile range, 0.9 to 2.3), and 513 participants (52.9%) were male. The modified Vesikari scale score for the 14-day period after enrollment was 9 or higher in 55 of 468 participants (11.8%) in the L. rhamnosus GG group and in 60 of 475 participants (12.6%) in the placebo group (relative risk, 0.96; 95% confidence interval, 0.68 to 1.35; P=0.83). There were no significant differences between the L. rhamnosus GG group and the placebo group in the duration of diarrhea (median, 49.7 hours in the L. rhamnosus GG group and 50.9 hours in the placebo group; P=0.26), duration of vomiting (median, 0 hours in both groups; P=0.17), or day-care absenteeism (median, 2 days in both groups; P=0.67) or in the rate of household transmission (10.6% and 14.1% in the two groups, respectively; P=0.16).ConclusionsAmong preschool children with acute gastroenteritis, those who received a 5-day course of L. rhamnosus GG did not have better outcomes than those who received placebo. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT01773967 .).

In 4292 infants aged ≤60 days with cerebrospinal fluid (CSF) pleocytosis, the bacterial meningitis score had excellent sensitivity (121 of 121 [100.0%] [95% confidence interval, 96.5%–100.0%]) but low specificity (66 of 4171 [1.6%] [95% confidence interval, 1.3%–2.0%]) and therefore should not be applied clinically to infants in this age group.

BACKGROUND AND OBJECTIVES: Early risk stratification of infants with bronchiolitis receiving airway support is critical for focusing appropriate therapies, yet the tools to risk categorize this subpopulation do not exist. Our objective was to identify predictors of “escalated care” in bronchiolitis. We hypothesized there would be a significant association between escalated care and predictors in the emergency department. We subsequently developed a risk score for escalated care. METHODS: We conducted a retrospective cohort study of previously healthy infants aged RESULTS: Of 2722 patients, 261 (9.6%) received escalated care. Multivariable predictors of escalated care were oxygen saturation CONCLUSIONS: We identified variables measured in the emergency department predictive of escalated care in bronchiolitis and derived a risk score to stratify risk of this outcome. This score may be used to aid management and disposition decisions.

BACKGROUND: Although neonatal herpes simplex virus (HSV) is a potentially devastating infection requiring prompt evaluation and treatment, large-scale assessments of the frequency in potentially infected infants have not been performed. METHODS: We performed a retrospective cross-sectional study of infants ≤60 days old who had cerebrospinal fluid culture testing performed in 1 of 23 participating North American emergency departments. HSV infection was defined by a positive HSV polymerase chain reaction or viral culture. The primary outcome was the proportion of encounters in which HSV infection was identified. Secondary outcomes included frequency of central nervous system (CNS) and disseminated HSV, and HSV testing and treatment patterns. RESULTS: Of 26 533 eligible encounters, 112 infants had HSV identified (0.42%, 95% confidence interval [CI]: 0.35%–0.51%). Of these, 90 (80.4%) occurred in weeks 1 to 4, 10 (8.9%) in weeks 5 to 6, and 12 (10.7%) in weeks 7 to 9. The median age of HSV-infected infants was 14 days (interquartile range: 9–24 days). HSV infection was more common in 0 to 28-day-old infants compared with 29- to 60-day-old infants (odds ratio 3.9; 95% CI: 2.4–6.2). Sixty-eight (0.26%, 95% CI: 0.21%–0.33%) had CNS or disseminated HSV. The proportion of infants tested for HSV (35%; range 14%–72%) and to whom acyclovir was administered (23%; range 4%–53%) varied widely across sites. CONCLUSIONS: An HSV infection was uncommon in young infants evaluated for CNS infection, particularly in the second month of life. Evidence-based approaches to the evaluation for HSV in young infants are needed.

To assess the hypothesis that ondansetron administration to children with type 1 diabetes mellitus (T1DM) presenting for emergency department (ED) care with intercurrent illness and vomiting improves clinical outcomes by reducing hospitalization rates (primary), length of ED stay, intravenous fluid (IVF) administration, and revisits (secondary outcomes).We conducted a single-center, 10-year retrospective cohort study of 345 ED encounters of children aged 6 months-8 years with T1DM and vomiting. We compared outcomes among children receiving and not receiving ondansetron. To avoid selection bias related to ondansetron administration, we also investigated outcomes by conducting comparisons by ondansetron usage periods (ie, low [2002-2004] vs high [2009-2011]).Ondansetron usage increased from 0% to 67% of ED encounters between 2002 and 2011. Admission rates were similar among those administered [54% (58/107)] and not administered ondansetron [55% (131/238)]. Length of stay was longer in children receiving ondansetron (409 vs 315 minutes; P = .03). IVF administration (77% vs 77%) and revisits (5.6% vs 5.9%) were similar. Ondansetron administration was not associated with reduced admission in logistic regression modeling. Admission rate (62%; 56/91 vs 49%; 57/111) (-13%, 95% CI -23%, 3%), length of stay (395 vs 327 minutes [IQR 164 501]; P.001), and IVF administration decreased (84% [77/91] to 70% [78/111]; P = .02] when comparing low and high ondansetron usage periods.Ondansetron administration was not independently associated with lower admission rates. Over time, along with increasing ondansetron use, there have been reductions in admissions, length of stay, and IVF administration in children with T1DM.

The accurate identification of children with a concussion by emergency physicians is important to initiate appropriate anticipatory guidance and management.We compared the frequency of persistent concussion symptoms in children who were provided the diagnosis of concussion by an emergency physician versus those who met Berlin/Zurich international criteria for this diagnosis. We also determined the clinical variables independently associated with a physician-diagnosed concussion.This was a planned secondary analysis of a prospective, multicenter cohort study. Participants were 5-17 years of age and met the Zurich/Berlin International Consensus Statement criteria for concussion.There were 2946 enrolled children. In those with physician-diagnosed concussion vs. no concussion, the frequency of persistent symptoms was 62.5% vs. 38.8% (p 0.0001) at 1 week, 46.3% vs. 25.8% (p 0.0001) at 2 weeks, and 33.0% vs. 23.0% (p 0.0001) at 4 weeks. Of those meeting international criteria, 2340 (79.4%) were diagnosed with a concussion by an emergency physician and 12 variables were associated with this diagnosis. Five had an odds ratio (OR) 1.5: older age (13-17 vs. 5-7 years, OR 2.9), longer time to presentation (≥16 vs.16 h, OR 2.1), nausea (OR 1.7), sport mechanism (OR 1.7), and amnesia (OR 1.6).Relative to international criteria, the more selective assignment of concussion by emergency physicians was associated with a greater frequency of persistent concussion symptoms. In addition, while most children meeting international criteria for concussion were also provided this diagnosis for concussion by an emergency physician, the presence of 5 specific variables made this diagnosis more likely.

Introduction Acute gastroenteritis (AGE) is a common and burdensome condition that affects millions of children worldwide each year. Currently available strategies are limited to symptomatic management, treatment and prevention of dehydration and infection control; no disease-modifying interventions exist. Probiotics, defined as live microorganisms beneficial to the host, have shown promise in improving AGE outcomes, but existing studies have sufficient limitations such that the use of probiotics cannot currently be recommended with confidence. Here we present the methods of a large, rigorous, randomised, double-blind placebo-controlled study to assess the effectiveness and side effect profile of Lactobacillus rhamnosus GG (LGG) (ATCC 53103) in children with AGE. Methods and analysis The study is being conducted in 10 US paediatric emergency departments (EDs) within the federally funded Pediatric Emergency Care Applied Research Network, in accordance with current SPIRIT and CONSORT statement recommendations. We will randomise 970 children presenting to participating EDs with AGE to either 5 days of treatment with LGG (1010colony-forming unit twice a day) or placebo between July 2014 to December 2017. The main outcome is the occurrence of moderate-to-severe disease over time, as defined by the Modified Vesikari Scale. We also record adverse events and side effects related to the intervention. We will conduct intention-to-treat analyses and use an enrichment design to restore the statistical power in case the presence of a subpopulation with a substantially low treatment effect is identified. Ethics and dissemination Institutional review board approval has been obtained at all sites, and data and material use agreements have been established between the participating sites. The results of the trial will be published in peer-reviewed journals. A deidentified public data set will be made available after the completion of all study procedures. Trial registration number NCT01773967.

BACKGROUND AND OBJECTIVES: Studies characterizing hospitalizations in bronchiolitis did not identify patients receiving evidence-based supportive therapies (EBSTs). We aimed to evaluate intersite and internetwork variation in receipt of ≥1 EBSTs during the hospital management of infants diagnosed with bronchiolitis in 38 emergency departments of pediatric emergency research networks in Canada, the United States, Australia, New Zealand, the United Kingdom, Ireland, Spain, and Portugal. We hypothesized that there would be significant variation, adjusted for patient characteristics. METHODS: Retrospective cohort study of previously healthy infants aged RESULTS: Out of 3725 participants, 1466 (39%) were hospitalized, and 1023 out of 1466 participants (69.8%) received EBST. The use of EBST varied by site (P < .001; range 6%–99%, median 23%), but not by network (P = .2). Significant multivariable predictors and their odds ratios (ORs) were as follows: age (0.9), oxygen saturation (1.3), apnea (3.4), dehydration (3.2), nasal flaring and/or grunting (2.4), poor feeding (2.1), chest retractions (1.9), and respiratory rate (1.2). The use of pharmacotherapy and radiography varied by network and site (P < .001), with respective intersite ranges 2% to 79% and 1.6% to 81%. Compared with Australia and New Zealand, the multivariable OR for the use of pharmacotherapy in Spain and Portugal was 22.7 (95% confidence interval [CI]: 4.5–111), use in Canada was 11.5 (95% CI: 3.7–36), use in the United States was 6.8 (95% CI: 2.3–19.8), and use in the United Kingdom was 1.4 (95% CI: 0.4–4.2). Compared with United Kingdom, OR for radiography use in the United States was 4.9 (95% CI 2.0–12.2), use in Canada was 4.9 (95% CI 1.9–12.6), use in Spain and Portugal was 2.4 (95% CI 0.6–9.8), and use in Australia and New Zealand was 1.8 (95% CI 0.7–4.7). CONCLUSIONS: More than 30% of infants hospitalized with bronchiolitis received no EBST. The hospital site was a source of variation in all study outcomes, and the network also predicted the use of pharmacotherapy and radiography.

BACKGROUND AND OBJECTIVES: Some children repeatedly use the emergency department (ED) at high levels. Among Medicaid-insured children with high-frequency ED use in 1 year, we sought to describe the characteristics of children who sustain high-frequency ED use over the following 2 years. METHODS: Retrospective longitudinal cohort study of 470 449 Medicaid-insured children appearing in the MarketScan Medicaid database, aged 1–16 years, with ≥1 ED discharges in 2012. Children with high ED use in 2012 (≥4 ED discharges) were followed through 2014 to identify characteristics associated with sustained high ED use (≥8 ED discharges in 2013–2014 combined). A generalized linear model was used to identify patient characteristics associated with sustained high ED use. RESULTS: A total of 39 945 children (8.5%) experienced high ED use in 2012, accounting for 25% of total ED visits in 2012. Sixteen percent of these children experienced sustained high ED use in the following 2 years. Adolescents (adjusted odds ratio [aOR]: 1.4 [95% confidence interval: 1.3–1.5]), disabled children (aOR: 1.3 [95% confidence interval: 1.1–1.5]), and children with 3 or more chronic conditions (aOR: 2.1, [95% confidence interval: 1.9–2.3]) experienced the highest likelihood for sustaining high ED use. CONCLUSIONS: One in 6 Medicaid-insured children with high ED use in a single year experienced sustained high levels of ED use over the next 2 years. Adolescents and individuals with multiple chronic conditions were most likely to have sustained high rates of ED use. Targeted interventions may be indicated to help reduce ED use among children at high risk.

Introduction Paediatric mild traumatic brain injury (mTBI) is a public health burden. Clinicians urgently need evidence-based guidance to manage mTBI, but gold standards for diagnosing and predicting the outcomes of mTBI are lacking. The objective of the Advancing Concussion Assessment in Pediatrics (A-CAP) study is to assess a broad pool of neurobiological and psychosocial markers to examine associations with postinjury outcomes in a large sample of children with either mTBI or orthopaedic injury (OI), with the goal of improving the diagnosis and prognostication of outcomes of paediatric mTBI. Methods and analysis A-CAP is a prospective, longitudinal cohort study of children aged 8.00–16.99 years with either mTBI or OI, recruited during acute emergency department (ED) visits at five sites from the Pediatric Emergency Research Canada network. Injury information is collected in the ED; follow-up assessments at 10 days and 3 and 6 months postinjury measure a variety of neurobiological and psychosocial markers, covariates/confounders and outcomes. Weekly postconcussive symptom ratings are obtained electronically. Recruitment began in September 2016 and will occur for approximately 24 months. Analyses will test the major hypotheses that neurobiological and psychosocial markers can: (1) differentiate mTBI from OI and (2) predict outcomes of mTBI. Models initially will focus within domains (eg, genes, imaging biomarkers, psychosocial markers), followed by multivariable modelling across domains. The planned sample size (700 mTBI, 300 OI) provides adequate statistical power and allows for internal cross-validation of some analyses. Ethics and dissemination The ethics boards at all participating institutions have approved the study and all participants and their parents will provide informed consent or assent. Dissemination will follow an integrated knowledge translation plan, with study findings presented at scientific conferences and in multiple manuscripts in peer-reviewed journals.

ObjectiveTo determine parental experiences and preferences regarding the conduct of pediatric research in an emergency department (ED) setting.MethodsWe conducted a cross-sectional study of parents of children ages 0 – 14 years who visited the ED of a tertiary care children’s hospital. Parents completed a Web-based survey designed to assess perceptions regarding: 1) background/training of research personnel, 2) location and timing of research discussions, and 3) factors influencing their consent/refusal decision.ResultsParents totalling 339 were approached, and 227 (67%) surveys were completed. Overall, 87% (197/227; 95% confidence interval [CI] 83, 92) reported they would be comfortable being approached by a university student to discuss research. This proportion did not change when stratified by the child’s gender, illness severity, or season of visit. Whereas only 37% (84/227; 95% CI 31, 43) of respondents would be comfortable being approached in the waiting room, 68% (154/227; 95% CI 62, 75) would be comfortable if approached in a separate area of the main waiting room. The majority reported comfort with follow-up via email (83%; 188/227; 95% CI 78, 88) or telephone (80%; 182/227; 95% CI 75, 85); only 51% (116/227; 95% CI 44, 57) would be comfortable with a scheduled follow-up visit in the hospital. Participants identified potential complications or side effects as the most common reason for declining consent (69%; 157/227; 95% CI 63, 75).ConclusionsThe majority of parents are comfortable being approached by trained university students, preferably in a separate area of an ED waiting room, and email and telephone follow-ups are preferred over a scheduled re-visit.

In our multi-center cohort of infants ≤ 60 days of age, we identified 2,646 infants with a traumatic lumbar puncture of which 31 (1.2%) had bacterial meningitis. For every 1,000 cerebrospinal fluid (CSF) red blood cells per mm3, cerebrospinal (CSF) protein increased 1.1 mg/dL [95% confidence interval (CI) 1.0–1.2 mg/dL].

Research has highlighted the potential role that hydration status may play in predicting outcomes in Shiga toxin-producing Escherichia coli (STEC)-infected children. Because little is known about the management of STEC-infected children in the pre-haemolytic uremic syndrome phase, we compared paediatric emergency medicine and nephrologist-stated management approaches to STEC-infected children.Members of the Pediatric Emergency Research Canada (PERC; n = 228), the Pediatric Emergency Medicine Collaborative Research Committee (PEM CRC; n = 221) and the Canadian Association of Pediatric Nephrologists (CAPN; n = 66) were surveyed. Five individualised e-mail requests containing a link to a 42-question web-based survey were sent to eligible participants.Of 496 potentially eligible participants, 276 (56%) submitted complete survey responses. In children with classic features of STEC infection, baseline haemoglobin/haematocrit is obtained by 54% of PERC, 41% of PEM CRC and 83% of CAPN members (P 0.001), and baseline renal function is obtained by 51% of PERC, 38% of PEM CRC and 83% of CAPN members (P 0.001). Intravenous fluids are more often recommended by nephrologists (28%) compared with PEM physicians (7%), P 0.001. In children with known E. coli O157:H7 infection, nephrologists more commonly recommend clinical follow-up (P = 0.003), complete blood counts (P 0.001) and renal function/electrolyte testing (P 0.001). Intravenous fluid administration and admission are more commonly recommended by nephrologists (P = 0.03 and P 0.001, respectively).Compared with paediatric nephrologists, paediatric emergency medicine physicians are less likely to perform baseline and follow-up blood tests and to administer intravascular volume expansion in children at risk of, and with confirmed, E. coli O157:H7 infection.