A Case of Back to The Future: Paediatric Abdominal Pain. Thorough History, Examination And Senior Clinician Involvement Remain Imperative For Successful Management

INTRODUCTION: The inherent variability of the history and exam in paediatrics make acute abdominal pain a diagnostic challenge. Investigations such as white-cell-count (WCC), C-reactive-protein and radiological studies have been advocated to help objectify management. Whilst Computed Tomography is accurate, the amount of radiation involved renders it unacceptable and thus many view ultrasonographyas an acceptable alternative. But do these tests add value? METHODS: Retrospective review between 2002–2012. Data was collected for children under sixteen with acute abdominal pain undergoing investigation with ultrasound and haematological testing. For 2005,a retrospective review was conducted for children presenting with abdominal pain to obtain data on demographics, history and examination findings. Analysis for diagnostic accuracy was undertaken. RESULTS: 5000 records were reviewed, and 1744 records included. 6% of children developed appendicitis. Findings of worsening pain, associated with nausea or vomiting yielded moderate sensitivities and specificities (combined values over 70%). Fever was non-specific. Localised tenderness is the most sensitive exam finding and rebound tenderness is the most specific, both having values over 90%. WCC and CRP offer similar sensitivities and specificities, both producing results under 80%. Only 30% of ultrasounds visualised the appendix, significantly dampening the sensitivity below 75%. The incidence of appendicitis in the non-visualised group was 8%. Conclusion No test is useful for ruling out appendicitis. Given that the incidence of appendicitis is higher in the non-visualised group, this is especially so with ultrasonography. Clinical examination with senior input is the most sensible strategy for managing children with acute abdominal pain

Numerical prediction of turbulent boundary layer noise from a sharp-edged flat plate

© 2019 John Wiley & Sons, Ltd. An efficient hybrid uncorrelated wall plane waves–boundary element method (UWPW-BEM) technique is proposed to predict the flow-induced noise from a structure in low Mach number turbulent flow. Reynolds-averaged Navier-Stokes equations are used to estimate the turbulent boundary layer parameters such as convective velocity, boundary layer thickness, and wall shear stress over the surface of the structure. The spectrum of the wall pressure fluctuations is evaluated from the turbulent boundary layer parameters and by using semi-empirical models from literature. The wall pressure field underneath the turbulent boundary layer is synthesized by realizations of uncorrelated wall plane waves (UWPW). An acoustic BEM solver is then employed to compute the acoustic pressure scattered by the structure from the synthesized wall pressure field. Finally, the acoustic response of the structure in turbulent flow is obtained as an ensemble average of the acoustic pressures due to all realizations of uncorrelated plane waves. To demonstrate the hybrid UWPW-BEM approach, the self-noise generated by a flat plate in turbulent flow with Reynolds number based on chord Rec = 4.9 × 105 is predicted. The results are compared with those obtained from a large eddy simulation (LES)-BEM technique as well as with experimental data from literature

Idiopathic slow transit constipation is rare - but delayed passage of meconium is common in the constipation clinic

We hypothesise that constipated children would be more likely to come from a socially deprived background. We also hypothesise that a percentage of children with resistant constipation would have a congenital gut motility problem that might be recognise

Uncertainty Analysis in Airfoil–Turbulence Interaction Noise Using Polynomial Chaos Expansion

Airfoil–turbulence interaction noise is a known source of environmental disturbance and acoustic performance loss in aeroacoustics and hydroacoustics. This noise can be predicted using semi-analytical models that require input measurements of the incoming turbulent flow parameters. However, the turbulence parameters are inherently difficult to measure accurately. These parameters, which include the turbulence kinetic energy and its dissipation rate, have a stochastic nature. This study aims to investigate how small variations in the measurements of turbulence parameters affect the uncertainty of the predicted airfoil–turbulence interaction noise. This is achieved by applying polynomial chaos expansion (PCE) to the semi-analytical model of Amiet’s theory for airfoil-interaction noise. The validity of the deterministic and stochastic simulations is ensured by comparisons against available experimental data from the literature, and Monte Carlo simulations, respectively. Uncertainty quantification is then performed using a stochastic collocation technique, where the aerodynamic noise is evaluated at specific collocation points to estimate the coefficients required for PCE. Both the individual and combined effects of varying the uncertain input turbulence parameters are simulated to quantify the uncertainty of the output aerodynamic noise. The insights gained from the results suggest it is important to incorporate the stochastic behavior of the incoming turbulent flow in operational models for airfoil–turbulence interaction noise predictions. </jats:p

Interpretation of heart rate variability via detrended fluctuation analysis and alpha-beta filter

Detrended fluctuation analysis (DFA), suitable for the analysis of nonstationary time series, has confirmed the existence of persistent long-range correlations in healthy heart rate variability data. In this paper, we present the incorporation of the alpha-beta filter to DFA to determine patterns in the power-law behaviour that can be found in these correlations. Well-known simulated scenarios and real data involving normal and pathological circumstances were used to evaluate this process. The results presented here suggest the existence of evolving patterns, not always following a uniform power-law behaviour, that cannot be described by scaling exponents estimated using a linear procedure over two predefined ranges. Instead, the power law is observed to have a continuous variation with segment length. We also show that the study of these patterns, avoiding initial assumptions about the nature of the data, may confer advantages to DFA by revealing more clearly abnormal physiological conditions detected in congestive heart failure patients related to the existence of dominant characteristic scales.Comment: 18 pages, 14 figure

International Study of the Epidemiology of Paediatric Trauma : PAPSA Research Study

Objectives: Trauma is a significant cause of morbidity and mortality worldwide. The literature on paediatric trauma epidemiology in low- and middle-income countries (LMICs) is limited. This study aims to gather epidemiological data on paediatric trauma. Methods: This is a multicentre prospective cohort study of paediatric trauma admissions, over 1&nbsp;month, from 15 paediatric surgery centres in 11 countries. Epidemiology, mechanism of injury, injuries sustained, management, morbidity and mortality data were recorded. Statistical analysis compared LMICs and high-income countries (HICs). Results: There were 1377 paediatric trauma admissions over 31&nbsp;days; 1295 admissions across ten LMIC centres and 84 admissions across five HIC centres. Median number of admissions per centre was 15 in HICs and 43 in LMICs. Mean age was 7&nbsp;years, and 62% were boys. Common mechanisms included road traffic accidents (41%), falls (41%) and interpersonal violence (11%). Frequent injuries were lacerations, fractures, head injuries and burns. Intra-abdominal and intra-thoracic injuries accounted for 3 and 2% of injuries. The mechanisms and injuries sustained differed significantly between HICs and LMICs. Median length of stay was 1&nbsp;day and 19% required an operative intervention; this did not differ significantly between HICs and LMICs. No mortality and morbidity was reported from HICs. In LMICs, in-hospital morbidity was 4.0% and mortality was 0.8%. Conclusion: The spectrum of paediatric trauma varies significantly, with different injury mechanisms and patterns in LMICs. Healthcare structure, access to paediatric surgery and trauma prevention strategies may account for these differences. Trauma registries are needed in LMICs for future research and to inform local policy