Variational Problems with Fractional Derivatives: Euler-Lagrange Equations

We generalize the fractional variational problem by allowing the possibility that the lower bound in the fractional derivative does not coincide with the lower bound of the integral that is minimized. Also, for the standard case when these two bounds coincide, we derive a new form of Euler-Lagrange equations. We use approximations for fractional derivatives in the Lagrangian and obtain the Euler-Lagrange equations which approximate the initial Euler-Lagrange equations in a weak sense

Tight Glycemic Control After Pediatric Cardiac Surgery in High-Risk Patient Populations

Background—Our previous randomized, clinical trial showed that postoperative tight glycemic control (TGC) for children undergoing cardiac surgery did not reduce the rate of health care–associated infections compared with standard care (STD). Heterogeneity of treatment effect may exist within this population. Methods and Results—We performed a post hoc exploratory analysis of 980 children from birth to 36 months of age at the time of cardiac surgery who were randomized to postoperative TGC or STD in the intensive care unit. Significant interactions were observed between treatment group and both neonate (age ≤30 days; P=0.03) and intraoperative glucocorticoid exposure (P=0.03) on the risk of infection. The rate and incidence of infections in subjects ≤60 days old were significantly increased in the TGC compared with the STD group (rate: 13.5 versus 3.7 infections per 1000 cardiac intensive care unit days, P=0.01; incidence: 13% versus 4%, P=0.02), whereas infections among those \u3e60 days of age were significantly reduced in the TGC compared with the STD group (rate: 5.0 versus 14.1 infections per 1000 cardiac intensive care unit days, P=0.02; incidence: 2% versus 5%, P=0.03); the interaction of treatment group by age subgroup was highly significant (P=0.001). Multivariable logistic regression controlling for the main effects revealed that previous cardiac surgery, chromosomal anomaly, and delayed sternal closure were independently associated with increased risk of infection. Conclusions—This exploratory analysis demonstrated that TGC may lower the risk of infection in children \u3e60 days of age at the time of cardiac surgery compared with children receiving STD. Meta-analyses of past and ongoing clinical trials are necessary to confirm these findings before clinical practice is altered

Design and Rationale of Safe Pediatric Euglycemia After Cardiac Surgery (SPECS): A Randomized Controlled Trial of Tight Glycemic Control After Pediatric Cardiac Surgery

Objectives: To describe the design of a clinical trial testing the hypothesis that children randomized to tight glycemic control with intensive insulin therapy after cardiac surgery will have improved clinical outcomes compared to children randomized to conventional blood glucose management. Design: Two-center, randomized controlled trial. Setting: Cardiac ICUs at two large academic pediatric centers. Patients: Children from birth to those aged 36 months recovering in the cardiac ICU after surgery with cardiopulmonary bypass. Interventions: Subjects in the tight glycemic control (intervention) group receive an intravenous insulin infusion titrated to achieve normoglycemia (target blood glucose range of 80–110 mg/dL; 4.4–6.1 mmol/L). The intervention begins at admission to the cardiac ICU from the operating room and terminates when the patient is ready for discharge from the ICU. Continuous glucose monitoring is performed during insulin infusion to minimize the risks of hypoglycemia. The standard care group has no target blood glucose range. Measurements and Main Results: The primary outcome is the development of any nosocomial infection (bloodstream, urinary tract, and surgical site infection or nosocomial pneumonia). Secondary outcomes include mortality, measures of cardiorespiratory function and recovery, laboratory indices of nutritional balance, immunologic, endocrinologic, and neurologic function, cardiac ICU and hospital length of stay, and neurodevelopmental outcome at 1 and 3 yrs of age. A total of 980 subjects will be enrolled (490 in each treatment arm) for sufficient power to show a 50% reduction in the prevalence of the primary outcome. Conclusions: Pediatric cardiac surgery patients may recognize great benefit from tight glycemic control in the postoperative period, particularly with regard to reduction of nosocomial infections. The Safe Pediatric Euglycemia after Cardiac Surgery trial is designed to provide an unbiased answer to the question of whether this therapy is indeed beneficial and to define the associated risks of therapy

Pilot Study of the Association of the DDAH2 −449G Polymorphism with Asymmetric Dimethylarginine and Hemodynamic Shock in Pediatric Sepsis

Genetic variability in the regulation of the nitric oxide (NO) pathway may influence hemodynamic changes in pediatric sepsis. We sought to determine whether functional polymorphisms in DDAH2, which metabolizes the NO synthase inhibitor asymmetric dimethylarginine (ADMA), are associated with susceptibility to sepsis, plasma ADMA, distinct hemodynamic states, and vasopressor requirements in pediatric septic shock.In a prospective study, blood and buccal swabs were obtained from 82 patients ≤ 18 years (29 with severe sepsis/septic shock plus 27 febrile and 26 healthy controls). Plasma ADMA was measured using tandem mass spectrometry. DDAH2 gene was partially sequenced to determine the -871 6g/7 g insertion/deletion and -449G/C single nucleotide polymorphisms. Shock type ("warm" versus "cold") was characterized by clinical assessment. The -871 7g allele was more common in septic (17%) then febrile (4%) and healthy (8%) patients, though this was not significant after controlling for sex and race (p = 0.96). ADMA did not differ between -871 6g/7 g genotypes. While genotype frequencies also did not vary between groups for the -449G/C SNP (p = 0.75), septic patients with at least one -449G allele had lower ADMA (median, IQR 0.36, 0.30-0.41 µmol/L) than patients with the -449CC genotype (0.55, 0.49-0.64 µmol/L, p = 0.008) and exhibited a higher incidence of "cold" shock (45% versus 0%, p = 0.01). However, after controlling for race, the association with shock type became non-significant (p = 0.32). Neither polymorphism was associated with inotrope score or vasoactive infusion duration.The -449G polymorphism in the DDAH2 gene was associated with both low plasma ADMA and an increased likelihood of presenting with "cold" shock in pediatric sepsis, but not with vasopressor requirement. Race, however, was an important confounder. These results support and justify the need for larger studies in racially homogenous populations to further examine whether genotypic differences in NO metabolism contribute to phenotypic variability in sepsis pathophysiology

Patient-reported quality of life outcomes for children with serious congenital heart defects

Objective To compare patient-reported, health-related quality of life (QoL) for children with serious congenital heart defects (CHDs) and unaffected classmates and to investigate the demographic and clinical factors influencing QoL. Design Retrospective cohort study. Setting UK National Health Service. Patients UK-wide cohort of children with serious CHDs aged 10–14 years requiring cardiac intervention in the first year of life in one of 17 UK paediatric cardiac surgical centres operating during 1992–1995. A comparison group of classmates of similar age and sex was recruited. Main outcome measures Child self-report of healthrelated QoL scores (Pediatric Quality of Life Inventory, PedsQL) and parental report of schooling and social activities. Results Questionnaires were completed by 477 children with CHDs (56% boys; mean age 12.1 (SD 1.0) years) and 464 classmates (55%; 12.0 (SD 1.1) years). Children with CHDs rated QoL significantly lower than classmates (CHDs: median 78.3 (IQR 65.0–88.6); classmates: 88.0 (80.2–94.6)) and scored lower on physical (CHDs: 84.4; classmates: 93.8; difference 9.4 (7.8 to 10.9)) and psychosocial functioning subscales (CHDs: 76.7, classmates: 85.0; difference 8.3 (6.0 to 10.6)). Cardiac interventions, school absence, regular medications and non-cardiac comorbidities were independently associated with reduced QoL. Participation in sport positively influenced QoL and was associated with higher psychosocial functioning scores. Conclusions Children with serious CHDs experience lower QoL than unaffected classmates. This appears related to the burden of clinical intervention rather than underlying cardiac diagnosis. Participation in sports activities is positively associated with increased emotional well-being. Child self-report measures of QoL would be a valuable addition to clinical outcome audit in this age group.RLK was awarded an MRC Special Training Fellowship in Health of the Public and Health Services Research (reference G106/1083). TD was supported by an NIHR Academic Clinical Fellowship. This work was supported by a British Heart Foundation project grant (reference PG/02/065/13934). The Centre for Paediatric Epidemiology and Biostatistics benefits from funding support from the Medical Research Council in its capacity as the MRC Centre of Epidemiology for Child Health (reference G04005546). Great Ormond St Hospital for Children NHS Trust and the UCL Institute of Child Health receives a proportion of funding from the Department of Health’s NIHR Biomedical Research Centres schem

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Health-related quality of life in patients with congenitally corrected transposition of the great arteries

Objective: The study\u27s objectives were to survey the quality of life in patients with congenitally corrected transposition of the great arteries and to compare the responses of those who have undergone anatomic repair with those who have a systemic right ventricle. Methods: Thirty-eight patients who underwent anatomic repair and 13 patients after either conventional repair or no surgical procedure were enrolled. Subjects completed the PedsQL 4.0 Generic and 3.0 Cardiac Modules. Scores were also compared with those of patients from the literature with at least moderately severe cardiovascular disease. Mean differences between groups were compared, and the association between clinical variables and score in the anatomic repair subgroup was measured. Results: Caregivers of patients in the anatomic repair group reported similar scores compared with the non-anatomic repair group in all functional domains The anatomic repair group self-reported lower school function (63 vs 81, P = .02). On the Cardiac Module, patients in the anatomic repair group self-reported fewer problems related to residual heart disease (75 vs 63), appearance (81 vs 68), and treatment anxiety (74 vs 59), although the differences were not significant. Compared with patients with other heart disease, the anatomic repair group scored lower, with the largest differences in cognition and communication. Prolonged hospital stay and need for a pacemaker were associated with lower quality of life after anatomic repair. Conclusions: Patients in the anatomic repair group had similar quality of life compared with patients in the non-anatomic group, except in the domain of school functioning. Prolonged hospital stay and need for a pacemaker after anatomic repair may be risk factors for lower quality of life. Copyright © 2011 by The American Association for Thoracic Surgery

Personnel and unit factors impacting outcome after cardiac arrest in a dedicated pediatric cardiac intensive care unit

OBJECTIVE: To assess the impact of personnel and unit factors on outcome from cardiac arrest in a dedicated pediatric cardiac intensive care unit. DESIGN: Retrospective medical record review. SETTING: Dedicated cardiac intensive care unit at a quaternary academic children\u27s hospital. PATIENTS: Children and young adults who had cardiac arrest while cared for in the pediatric cardiac intensive care unit from January 1, 2006, to December 31, 2008. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred two index cardiac arrests over a 3-yr period in our pediatric cardiac intensive care unit were reviewed. We defined successful resuscitation as either return of spontaneous circulation or successful cannulation to extracorporeal membrane oxygenation. Differences in resuscitation rates were assessed across categorical systems variables using logistic regression. The rate of successful resuscitation was 84% (return of spontaneous circulation 74%, extracorporeal membrane oxygenation 10%). Survival to hospital discharge was 48% for patients who had a cardiac arrest. 11% of arrests during the week and 31% during weekends (odds ratio 3.8; 95% confidence interval 1.2-11.5) were not successfully resuscitated. Unsuccessful resuscitation was significantly more likely when the primary nurse had \u3c1 yr of experience in the pediatric cardiac intensive care unit (50% \u3c1 yr vs. 13% \u3e1 yr; odds ratio 6.8; confidence interval 1.5-31.0). Cardiac arrest on a weekend day and \u3c1-yr pediatric cardiac intensive care unit nursing experience were also associated with unsuccessful resuscitation in a multivariable model. Resuscitation outcomes were similar when senior intensive care unit attending physicians were on-call at the time of arrest compared with other intensive care unit staff (17% unsuccessful vs. 15%; odds ratio 1.2; confidence interval 0.4-3.7). Arrests where the attending physician was present at the onset resulted in unsuccessful resuscitation 18% of the time vs. 14% for events where the attending was not present (odds ratio 1.3; confidence interval 0.5-3.9). CONCLUSIONS: Our data suggest that personnel and unit factors may impact outcome after cardiac arrest in a pediatric cardiac intensive care unit. Weekend arrests and less experience of the primary nurse were risk factors for unsuccessful resuscitation. Neither presence at arrest onset nor experience of the attending cardiac intensivist was associated with outcome. Copyright © 2012 by the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies