Background: Feedback reports summarizing clinician performance are effective tools to improve antibiotic stewardship in the ambulatory setting, but few studies have evaluated their effectiveness for pediatric inpatients. We developed and implemented feedback reports reflecting electronically-derived measures of appropriate antibiotic choice and duration for community acquired pneumonia (CAP) and measured their impact on appropriate antibiotic use in children hospitalized for CAP. Methods: We performed a single center quasi-experimental study including children 6 months to 17 years hospitalized for CAP between 12/1/2021-11/30/2023. Children with chronic medical conditions, ICU stays >48 hours, and outside transfers were excluded. The intervention occurred in 11/2022 and included clinician education, a monthly group-level feedback report disseminated by email (Figure 1), and a monthly review of clinician performance during a virtual quality improvement meeting. Patient characteristics were compared using chi-square or Wilcoxon rank sum tests. Interrupted time series analysis (ITSA) was used to measure the immediate change in the proportion of CAP encounters receiving both the appropriate antibiotic choice and duration, as well as the change in slope from the preintervention to the postintervention periods. Choice and duration were analyzed separately using ITSA as a secondary analysis. Results: There were 817 CAP encounters, including 420 preintervention and 397 postintervention. Patients admitted in the postintervention period were older (median age 2 years vs 3 years, P=0.03), but otherwise there were no differences in race, ethnicity, sex, ICU admission, or complicated pneumonia. Preintervention, 52% of encounters received both the appropriate antibiotic choice and duration; 96% of encounters received the appropriate antibiotic choice and 54% received the appropriate duration. The ITSA demonstrated an immediate 16% increase in the proportion of patients receiving both appropriate antibiotic choice and duration (95% confidence interval, 1-31%; P = 0.047) and no significant further increase over time following the intervention (P = 0.84) (Figure 2). When antibiotic choice was analyzed separately by ITSA, there was no immediate change or change over time in the proportion of patients receiving the appropriate antibiotic choice. In the ITSA of duration alone, there was an immediate 17% increase in the proportion receiving the appropriate duration (95% confidence interval, 2-33%; P = 0.03) and no change over time. Conclusion: Feedback reports generated from electronically-derived metrics of antibiotic choice and duration, combined with ongoing clinician education, increased the proportion of children with CAP treated with the appropriate antibiotic duration. Electronic feedback reports are a scalable and impactful intervention to improve antibiotic use in children hospitalized with CAP.

Most theoretical descriptions of stresses induced by freezing are rooted in the (generalized) Clapeyron equation, which predicts the pressure that a solid can exert as it cools below its melting temperature. This equation is central for topics ranging beyond glaciology to geomorphology, civil engineering, food storage and cryopreservation. However, it has inherent limitations, requiring isotropic solid stresses and conditions near bulk equilibrium. Here, we examine when the Clapeyron equation is applicable by providing a rigorous derivation that details all assumptions. We demonstrate the natural extension for anisotropic stress states, and we show how the temperature and pressure ranges for validity depend on well-defined material properties. Finally, we demonstrate how the range of applicability of the (linear) Clapeyron equation can be extended by adding higher-order terms, yielding results that are in good agreement with experimental data for the pressure melting of ice.

Background: Antibiotic overuse contributes to antibiotic resistance and unnecessary adverse drug effects. Antibiotic stewardship interventions have primarily focused on acute-care settings. Most antibiotic use, however, occurs in outpatients with acute respiratory tract infections such as pharyngitis. The electronic health record (EHR) might provide an effective and efficient tool for outpatient antibiotic stewardship. We aimed to develop and validate an electronic algorithm to identify inappropriate antibiotic use for pediatric outpatients with pharyngitis. Methods: This study was conducted within the Children’s Hospital of Philadelphia (CHOP) Care Network, including 31 pediatric primary care practices and 3 urgent care centers with a shared EHR serving >250,000 children. We used International Classification of Diseases, Tenth Revision (ICD-10) codes to identify encounters for pharyngitis at any CHOP practice from March 15, 2017, to March 14, 2018, excluding those with concurrent infections (eg, otitis media, sinusitis), immunocompromising conditions, or other comorbidities that might influence the need for antibiotics. We randomly selected 450 features for detailed chart abstraction assessing patient demographics as well as practice and prescriber characteristics. Appropriateness of antibiotic use based on chart review served as the gold standard for evaluating the electronic algorithm. Criteria for appropriate use included streptococcal testing, use of penicillin or amoxicillin (absent β-lactam allergy), and a 10-day duration of therapy. Results: In 450 patients, the median age was 8.4 years (IQR, 5.5–9.0) and 54% were women. On chart review, 149 patients (33%) received an antibiotic, of whom 126 had a positive rapid strep result. Thus, based on chart review, 23 subjects (5%) diagnosed with pharyngitis received antibiotics inappropriately. Amoxicillin or penicillin was prescribed for 100 of the 126 children (79%) with a positive rapid strep test. Of the 126 children with a positive test, 114 (90%) received the correct antibiotic: amoxicillin, penicillin, or an appropriate alternative antibiotic due to b-lactam allergy. Duration of treatment was correct for all 126 children. Using the electronic algorithm, the proportion of inappropriate prescribing was 28 of 450 (6%). The test characteristics of the electronic algorithm (compared to gold standard chart review) for identification of inappropriate antibiotic prescribing were sensitivity (99%, 422 of 427); specificity (100%, 23 of 23); positive predictive value (82%, 23 of 28); and negative predictive value (100%, 422 of 422). Conclusions: For children with pharyngitis, an electronic algorithm for identification of inappropriate antibiotic prescribing is highly accurate. Future work should validate this approach in other settings and develop and evaluate the impact of an audit and feedback intervention based on this tool.

Funding: None

Disclosures: None

Background: Antibiotic resistance has increased at alarming rates, driven predominantly by antibiotic overuse. Although most antibiotic use occurs in outpatients, antimicrobial stewardship programs have primarily focused on inpatient settings. A major challenge for outpatient stewardship is the lack of accurate and accessible electronic data to target interventions. We sought to develop and validate an electronic algorithm to identify inappropriate antibiotic use for outpatients with acute bronchitis. Methods: This study was conducted within the University of Pennsylvania Health System (UPHS). We used ICD-10 diagnostic codes to identify encounters for acute bronchitis at any outpatient UPHS practice between March 15, 2017, and March 14, 2018. Exclusion criteria included underlying immunocompromising condition, other comorbidity influencing the need for antibiotics (eg, emphysema), or ICD-10 code at the same visit for a concurrent infection (eg, sinusitis). We randomly selected 300 (150 from academic practices and 150 from nonacademic practices) eligible subjects for detailed chart abstraction that assessed patient demographics and practice and prescriber characteristics. Appropriateness of antibiotic use based on chart review served as the gold standard for assessment of the electronic algorithm. Because antibiotic use is not indicated for this study population, appropriateness was assessed based upon whether an antibiotic was prescribed or not. Results: Of 300 subjects, median age was 61 years (interquartile range, 50–68), 62% were women, 74% were seen in internal medicine (vs family medicine) practices, and 75% were seen by a physician (vs an advanced practice provider). On chart review, 167 (56%) subjects received an antibiotic. Of these subjects, 1 had documented concern for pertussis and 4 had excluding conditions for which there were no ICD-10 codes. One received an antibiotic prescription for a planned dental procedure. Thus, based on chart review, 161 (54%) subjects received antibiotics inappropriately. Using the electronic algorithm based on diagnostic codes, underlying and concurrent conditions, and prescribing data, the number of subjects with inappropriate prescribing was 170 (56%) because 3 subjects had antibiotic prescribing not noted based on chart review. The test characteristics of the electronic algorithm (compared to gold standard chart review) for identification of inappropriate antibiotic prescribing were the following: sensitivity, 100% (161 of 161); specificity, 94% (130 of 139); positive predictive value, 95% (161 of 170); and negative predictive value, 100% (130 of 130). Conclusions: For outpatients with acute bronchitis, an electronic algorithm for identification of inappropriate antibiotic prescribing is highly accurate. This algorithm could be used to efficiently assess prescribing among practices and individual clinicians. The impact of interventions based on this algorithm should be tested in future studies.

Funding: None

Disclosures: None

This study determined whether surrogate organisms can predict activity against Clostridium difficile spores and compared the efficacy of hand hygiene preparations against C. difficile. Our data suggest that surrogate organisms were not predictive of C. difficile spore removal. Four preparations were significantly more effective than tap water at removing C. difficile.

We compared the rates of exposure to blood in the operating room among third-year medical students during 2005-2006 with the rates reported in a study completed at the same institution during 1990-1991. The number of medical students exposed to blood decreased from 66 (68%) of 97 students during 1990-1991 to 8 (11%) of 75 students during 2005-2006 (P < .001)

Adult offspring of severely diabetic pregnant rats are insulin resistant and display cardiovascular dysfunction. When pregnant they develop mild hyperglycaemia. Diets high in saturated fat have been implicated in the development of cardiovascular disease and vascular dysfunction. In the present study we have determined vascular function in small mesenteric arteries from offspring of normal (OC) and diabetic (OD) rats fed standard chow and offspring of diabetic rats fed a diet high in saturated fats (OD-HF) from weaning to adulthood, and throughout their subsequent pregnancies. OD rats displayed an increased sensitivity to noradrenaline (P < 0·05) and impaired sensitivity to the endothelium-dependent vasodilator, acetylcholine. The component of acetylcholine-induced relaxation attributable to endothelium-derived hyperpolarizing factor was reduced in OD-HF rats. Pregnant OD rats also demonstrated impaired maximum relaxation to acetylcholine (pregnant OD rats v. pregnant OC rats P < 0·05). In pregnant OD-HF rats noradrenaline sensitivity was enhanced and endothelium-dependent relaxation further reduced (pregnant OD-HF rats v. pregnant OC rats P < 0·001). The isoprostane, 8-epi-prostaglandin F2α, a marker of oxidative stress, was increased in pregnant OD rats (pregnant OD rats v. pregnant OC rats P < 0·001) and further increased in pregnant OD-HF rats (pregnant OD-HF rats v. pregnant OD rats P < 0·05). We conclude that a high-saturated-fat diet leads to deterioration in specific components of vascular function in OD rats. When pregnant, vascular function of OD-HF rats is further compromised. Pregnancy in the OD rats is associated with a striking increase in a marker of oxidative stress, which increases further if the saturated fat intake is raised.

Food restriction during pregnancy in rats induces intrauterine growth retardation with consequences persisting into adulthood. In the present study we have investigated the hypothesis that malnutrition in pregnant rats may lead to altered cardiovascular function in adult female offspring. Perinatal growth retardation was induced by a 50 % reduction of normal dietary intake in rats during the second half of pregnancy. Systolic and diastolic blood pressure values and heart rate were recorded in conscious female offspring (100 d old) using a femoral artery probe. No significant differences in heart rate, or in systolic and diastolic blood pressures were recorded between control offspring and offspring of nutritionally deprived rats. In order to ascertain whether cardiovascular variables in the offspring were influenced by lactation, subgroups of offspring from food-restricted dams were fostered with lactating dams fed on a normal diet. Blood pressure and heart rate were also found to be normal in these offspring. The rise in blood pressure associated with NO inhibition was similar in all groups. Isolated resistance artery function was assessed in vitro in offspring (100–120 d old) of a second group of semi-starved dams. Small mesenteric arteries from these animals showed reduced endothelium-dependent relaxation (to acetylcholine and bradykinin), but enhanced sensitivity to exogenous NO (sodium nitroprusside). We conclude that food restriction during the second half of pregnancy and/or lactation does not induce hypertension in adult offspring, but may effect subtle changes in vascular function.

A program of accelerator mass spectrometry has been started at the Rehovot 14UD Pelletron Accelerator Laboratory. Part of the initial emphasis has been directed to the detection of the 36Cl radioisotope. We report here on the present status of our work and describe our experimental system. Preliminary results are presented, showing that 36Cl/Cl concentrations ranging down to 1×10−14 could be measured with our system.