Increasing abdominal pressure with and without PEEP: effects on intra-peritoneal, intra-organ and intra-vascular pressures

Intra-organ and intra-vascular pressures can be used to estimate intra-abdominal pressure. The aim of this prospective, interventional study was to assess the effect of PEEP on the accuracy of pressure estimation at different measurement sites in a model of increased abdominal pressure.

Effects of non-ionic iodinated contrast media on patient heart rate and pressures during intra-cardiac or intra-arterial injection

PURPOSE: To compare the effects on heart rate (HR), on left ventricular (LV) or arterial pressures, and the general safety of a non-ionic low-osmolar contrast medium (CM) and a non-ionic iso-osmolar CM in patients undergoing cardiac angiography (CA) or peripheral intra-arterial digital subtraction angiography (IA-DSA). MATERIALS AND METHODS: Two double-blind, randomized studies were conducted in 216 patients who underwent CA (n=120) or peripheral IA-DSA (n=96). Patients referred for CA received a low-osmolar monomeric CM (iomeprol-350, n=60) or an iso-osmolar dimeric CM (iodixanol-320; n=60). HR and LV peak systolic and end-diastolic pressures were determined before and after the first injection during left and right coronary arteriography and left ventriculography. Monitoring for all types of adverse event (AE) was performed for 24 h following the procedure. t-tests were performed to compare CM for effects on HR. Patients referred for IA-DSA received iomeprol-300 (n=49) or iodixanol-320 (n=47). HR and arterial blood pressure (BP) were evaluated before and after the first 4 injections. Monitoring for AE was performed for 4 h following the procedure. Repeated-measures ANOVA was used to compare mean HR changes across the first 4 injections, whereas changes after the first injection were compared using t-tests. RESULTS: No significant differences were noted between iomeprol and iodixanol in terms of mean changes in HR during left coronary arteriography (p=0.8), right coronary arteriography (p=0.9), and left ventriculography (p=0.8). In patients undergoing IA-DSA, no differences between CM were noted for effects on mean HR after the first injection (p=0.6) or across the first 4 injections (p=0.2). No significant differences (p>0.05) were noted in terms of effects on arterial BP in either study or on LV pressures in patients undergoing CA. Non-serious AE considered possibly CM-related (primarily headache and events affecting the cardiovascular and digestive systems) were reported more frequently by patients undergoing CA and more frequently after iodixanol (14/60 [23.3%] and 2/47 [4.3%]; CA and IA-DSA, respectively) than iomeprol (10/60 [16.7%] and 1/49 [2%], respectively). CONCLUSIONS: Iomeprol and iodixanol are safe and have equally negligible effects on HR and LV pressures or arterial BP during and after selective intra-cardiac injection and peripheral IA-DSA. CLINICAL APPLICATION: Iomeprol and iodixanol are safe and equally well tolerated with regard to cardiac rhythm and clinical preference should be based on diagnostic image quality alone.

Finite element based estimation of contact areas and pressures of the human scaphoid in various functional positions of the hand

The scaphoid is the most frequently fractured carpal bone. When investigating fixation stability, which may influence healing, knowledge of forces and moments acting on the scaphoid is essential. The aim of this study was to evaluate cartilage contact forces acting on the intact scaphoid in various functional wrist positions using finite element modeling. A novel methodology was utilized as an attempt to overcome some limitations of earlier studies, namely, relatively coarse imaging resolution to assess geometry, assumption of idealized cartilage thicknesses and neglected cartilage pre-stresses in the unloaded joint. Carpal bone positions and articular cartilage geometry were obtained independently by means of high resolution CT imaging and incorporated into finite element (FE) models of the human wrist in eight functional positions. Displacement driven FE analyses were used to resolve inter-penetration of cartilage layers, and provided contact areas, forces and pressure distribution for the scaphoid bone. The results were in the range reported by previous studies. Novel findings of this study were: (i) cartilage thickness was found to be heterogeneous for each bone and vary considerably between carpal bones; (ii) this heterogeneity largely influenced the FE results and (iii) the forces acting on the scaphoid in the unloaded wrist were found to be significant. As major limitations, accuracy of the method was found to be relatively low, and the results could not be compared to independent experiments. The obtained results will be used in a following study to evaluate existing and recently developed screws used to fix scaphoid fractures.

Less Oxygen, Later Intubation and Reduced Respiratory Pressures for ELBW Infants from 1997 to 2011.

INTRODUCTION Evidence concerning delivery room management in extremely low birth weight infants (ELBW) has grown substantially within the last 20 years, leading to several guidelines and recommendations. However, it is unknown in which extent local treatment strategies have changed and if they reflect current recommendations. METHODS A detailed questionnaire about treatment strategies for ELBW infants was sent to all German neonatal intensive care units (NICUs) treating ELBW infants in 1997. A follow-up survey was conducted in 2011 and sent to all NICUs in Germany, Austria and Switzerland. RESULTS on delivery room management were compared to the first survey. RESULTS In 1997 and 2011, 63.6 and 66.2% of the approached hospitals responded. In 2011 similar results were observed between university and non-university hospitals as well as NICUs of different size. Differences between Germany, Austria and Switzerland were minimal. Changes over time were a lower initially applied fraction of inspired oxygen (FiO2) and peak inspiratory pressure (PiP) in 2011 compared to 1997. A longer time of apnea was tolerated before tracheal intubation is performed; the time of apnea was less frequently a sole criterion for intubation and surfactant was applied at lower FiO2 in 2011. The time of no thorax excursions and transport of the infant were considered an indication for intubation in 30.2 and 22.5%, and did not change in the observation period. CONCLUSION Treatment strategies for delivery room management in ELBW infants changed significantly between 1997 and 2011 and largely reflect current recommendations.

The American Myth of Markets in Social Policy: Ideological Roots of Inequality

The American Myth of Markets in Social Policy examines how implementing American tropes in policy design inadvertently frustrates policy goals. It investigates multiple market-oriented designs including funding for private organizations to deliver public services, funding for individuals to buy services, and policies incentivizing or mandating private actors to provide social policy. The author shows that these solutions often not only fail to achieve social goals, but, in fact, actively undermine them, for example saddling the poor with debt or encouraging discrimination. The book carefully details the mechanisms through which this occurs, for example a mismatch between program goals and either contract terms or individual preferences. The author examines several policies in depth, covering universal social insurance programs like healthcare and pensions, as well as smaller interventions like programs for the homeless. The author builds the argument using detailed empirical evidence as well as anecdote, keeping the book accessible and entertaining.