A new approach to characterize cardiac sodium storage by combining fluorescence photometry and magnetic resonance imaging in small animal research.

Cardiac myocyte sodium (Na+) homoeostasis is pivotal in cardiac diseases and heart failure. Intracellular Na+ ([Na+]i) is an important regulator of excitation-contraction coupling and mitochondrial energetics. In addition, extracellular Na+ ([Na+]e) and its water-free storage trigger collagen cross-linking, myocardial stiffening and impaired cardiac function. Therefore, understanding the allocation of tissue Na+ to intra- and extracellular compartments is crucial in comprehending the pathophysiological processes in cardiac diseases. We extrapolated [Na+]e using a three-compartment model, with tissue Na+ concentration (TSC) measured by in vivo 23Na-MRI, extracellular volume (ECV) data calculated from T1 maps, and [Na+]i measured by in vitro fluorescence microscopy using Na+ binding benzofuran isophthalate (SBFI). To investigate dynamic changes in Na+ compartments, we induced pressure overload (TAC) or myocardial infarction (MI) via LAD ligation in mice. Compared to SHAM mice, TSC was similar after TAC but increased after MI. Both TAC and MI showed significantly higher [Na+]i compared to SHAM (around 130% compared to SHAM). Calculated [Na+]e increased after MI, but not after TAC. Increased TSC after TAC was primarily driven by increased [Na+]i, but the increase after MI by elevations in both [Na+]i and [Na+]e.

Nine Seasons of a Bronchiolitis Observation Unit and Home Oxygen Therapy Protocol.

BACKGROUND: We implemented an observation unit and home oxygen therapy (OU-HOT) protocol at our children's hospital during the 2010-2011 winter season to facilitate earlier discharge of children hospitalized with bronchiolitis. An earlier study demonstrated substantial reductions in inpatient length of stay and costs in the first year after implementation. OBJECTIVE: Evaluate long-term reductions in length of stay and cost. DESIGN, SETTING, AND PARTICIPANTS: Interrupted time-series analysis, adjusting for patient demographic factors and disease severity. Participants were children aged 3 to 24 months and hospitalized with bronchiolitis from 2007 to 2019. INTERVENTION: OU-HOT protocol implementation. MAIN OUTCOME AND MEASURES: Hospital length of stay. Process measures were the percentage of patients discharged from the OU; percentage of patients discharged with HOT. Balancing measures were 7-day hospital revisit rates; annual per-population bronchiolitis admission rates. Secondary outcomes were inflation-adjusted cost per episode of care and discharges within 24 hours. RESULTS: A total of 7,116 patients met inclusion criteria. The OU-HOT protocol was associated with immediate decreases in mean length of stay (-30.6 hours; 95% CI, -37.1 to -24.2 hours) and mean cost per episode of care (-$4,181; 95% CI, -$4,829 to -$3,533). These findings were sustained for 9 years after implementation. Hospital revisit rates did not increase immediately (-1.1% immediate change; 95% CI, -1.8% to -0.4%), but a small increase in revisits was observed over time (change in slope 0.4% per season, 95% CI, 0.1%-0.8%). CONCLUSION: The OU-HOT protocol was associated with sustained reductions in length of stay and cost, representing a promising strategy to reduce the inpatient burden of bronchiolitis.

Home-Monitoring Application for Children With Medical Complexity: A Feasibility Trial.

OBJECTIVES: Mobile apps are suggested for supporting home monitoring and reducing emergency department (ED) visits and hospitalizations for children with medical complexity (CMC). None have been implemented. We sought to assess the MyChildCMC app (1) feasibility for CMC home monitoring, (2) ability to detect early deteriorations before ED and hospital admissions, and (3) preliminary impact. METHODS: Parents of CMC (aged 1-21 years) admitted to a children's hospital were randomly assigned to MyChildCMC or usual care. MyChildCMC subjects recorded their child's vital signs and symptoms daily for 3 months postdischarge and received real-time feedback. Feasibility measures included parent's enrollment, retention, and engagement. The preliminary impact was determined by using quality of life, parent satisfaction with care, and subsequent ED and hospital admissions and hospital days. RESULTS: A total of 62 parents and CMC were invited to participate: 50 enrolled (80.6% enrollment rate) and were randomly assigned to MyChildCMC (n = 24) or usual care (n = 26). Retention at 1 and 3 months was 80% and 74%, and engagement was 68.3% and 62.6%. Run-chart shifts in vital signs were common findings preceding admissions. The satisfaction score was 26.9 in the MyChildCMC group and 24.1 in the control group (P = .035). No quality of life or subsequent admission differences occurred between groups. The 3-month hospital days (pre-post enrollment) decreased from 9.25 to 4.54 days (rate ratio = 0.49; 95% confidence interval = 0.39-0.62; P < .001) in the MyChildCMC group and increased from 1.08 to 2.46 days (rate ratio = 2.29; 95% confidence interval = 1.47-3.56; P < .001) in the control group. CONCLUSIONS: MyChildCMC was feasible and appears effective, with the potential to detect early deteriorations in health for timely interventions that might avoid ED and hospitalizations. A larger and definitive study of MyChildCMC's impact and sustainability is needed.

Information needs for designing a home monitoring system for children with medical complexity.

Background Children with medical complexity (CMC) are a growing population of medically fragile children with unique healthcare needs, who have recurrent emergency department (ED) and hospital admissions due to frequent acute escalations of their chronic conditions. Mobile health (mHealth) tools have been suggested to support CMC home monitoring and prevent admissions. No mHealth tool has ever been developed for CMC and challenges exist. Objective To: 1) assess information needs for operationalizing CMC home monitoring, and 2) determine technology design functionalities needed for building a mHealth application for CMC. Methods Qualitative descriptive study conducted at a tertiary care children's hospital with a purposive sample of English-speaking caregivers of CMC. We conducted 3 focus group sessions, using semi-structured, open-ended questions. We assessed caregiver's perceptions of early symptoms that commonly precede acute escalations of their child conditions, and explored caregiver's preferences on the design functionalities of a novel mHealth tool to support home monitoring of CMC. We used content analysis to assess caregivers' experience concerning CMC symptoms, their responses, effects on caregivers, and functionalities of a home monitoring tool. Results Overall, 13 caregivers of CMC (ages 18 months to 19 years, mean = 9 years) participated. Caregivers identified key symptoms in their children that commonly presented 1-3 days prior to an ED visit or hospitalization, including low oxygen saturations, fevers, rapid heart rates, seizures, agitation, feeding intolerance, pain, and a general feeling of uneasiness about their child's condition. They believed a home monitoring system for tracking these symptoms would be beneficial, providing a way to identify early changes in their child's health that could prompt a timely and appropriate intervention. Caregivers also reported their own symptoms and stress related to caregiving activities, but opposed monitoring them. They suggested an mHealth tool for CMC to include the following functionalities: 1) symptom tracking, targeting commonly reported drivers (symptoms) of ED/hospital admissions; 2) user friendly (ease of data entry), using voice, radio buttons, and drop down menus; 3) a free-text field for reporting child's other symptoms and interventions attempted at home; 4) ability to directly access a health care provider (HCP) via text/email messaging, and to allow real-time sharing of child data to facilitate care, and 5) option to upload and post a photo or video of the child to allow a visual recall by the HCP. Conclusions Caregivers deemed a mHealth tool beneficial and offered a set of key functionalities to meet information needs for monitoring CMC's symptoms. Our future efforts will consist of creating a prototype of the mHealth tool and testing it for usability among CMC caregivers.

Short-Term Elevation of Fine Particulate Matter Air Pollution and Acute Lower Respiratory Infection.

RATIONALE: Nearly 60% of U.S. children live in counties with particulate matter less than or equal to 2.5 µm in aerodynamic diameter (PM2.5) concentrations above air quality standards. Understanding the relationship between ambient air pollution exposure and health outcomes informs actions to reduce exposure and disease risk. OBJECTIVES: To evaluate the association between ambient PM2.5 levels and healthcare encounters for acute lower respiratory infection (ALRI). METHODS: Using an observational case-crossover design, subjects (n = 146,397) were studied if they had an ALRI diagnosis and resided on Utah's Wasatch Front. PM2.5 air pollution concentrations were measured using community-based air quality monitors between 1999 and 2016. Odds ratios for ALRI healthcare encounters were calculated after stratification by ages 0-2, 3-17, and 18 or more years. MEASUREMENTS AND MAIN RESULTS: Approximately 77% (n = 112,467) of subjects were 0-2 years of age. The odds of ALRI encounter for these young children increased within 1 week of elevated PM2.5 and peaked after 3 weeks with a cumulative 28-day odds ratio of 1.15 per +10 µg/m3 (95% confidence interval, 1.12-1.19). ALRI encounters with diagnosed and laboratory-confirmed respiratory syncytial virus and influenza increased following elevated ambient PM2.5 levels. Similar elevated odds for ALRI were also observed for older children, although the number of events and precision of estimates were much lower. CONCLUSIONS: In this large sample of urban/suburban patients, short-term exposure to elevated PM2.5 air pollution was associated with greater healthcare use for ALRI in young children, older children, and adults. Further exploration is needed of causal interactions between PM2.5 and ALRI.