Heparin versus 0.9% sodium chloride locking for prevention of occlusion in central venous catheters in adults

Background Intermittent locking of central venous catheters (CVCs) is undertaken to help maintain their patency. There are systematic variations in care: some practitioners use heparin (at different concentrations), whilst others use 0.9% NaCl (normal saline). This review looks at the effectiveness and safety of intermittent locking with heparin compared to 0.9% NaCl to see if the evidence establishes whether one is better than the other. This work is an update of a review first published in 2014. Objectives To assess the effectiveness and safety of intermittent locking of CVCs with heparin versus normal saline (NS) in adults to prevent occlusion. Search methods The Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (last searched 11 June 2018) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 5). Searches were also carried out in MEDLINE, Embase, CINAHL, and clinical trials databases (11 June 2018). Selection criteria We included randomised controlled trials in adults ≥ 18 years of age with a CVC that compared intermittent locking with heparin at any concentration versus NS. We applied no restriction on language. Data collection and analysis Two review authors independently selected trials, assessed quality, and extracted data. We contacted trial authors to retrieve additional information, when necessary.We carried out statistical analysis using ReviewManager 5 and assessed the overall quality of the evidence supporting assessed outcomes using GRADE. We carried out prespecified subgroup analysis. Main results We identified five new studies for this update (six prior studies were included in the original review), bringing the number of eligible studies to 11, with a total of 2392 participants. We noted differences in methods used by the included studies and variation in heparin concentrations (10 to 5000 IU/mL), time to follow-up (1 to 251.8 days), and the unit of analysis used (participant, catheter, line access). Combined results fromthese studies showed fewer occlusions with heparin than with NS (risk ratio (RR) 0.70, 95%confidence interval (CI) 0.51 to 0.95; P = 0.02; 1672 participants; 1025 catheters from 10 studies; I² = 14%) and provided very low-quality evidence. We carried out subgroup analysis by unit of analysis (testing for subgroup differences (P = 0.23; I² = 30.3%). When the unit of analysis was the participant, results show no clear differences in all occlusions between heparin and NS (RR 0.79, 95% CI 0.58 to 1.08; P = 0.15; 1672 participants; seven studies). Subgroup analysis using the catheter as the unit of analysis shows fewer occlusions with heparin use (RR 0.53, 95% CI 0.29 to 0.95; P = 0.03; 1025 catheters; three studies). When the unit of analysis was line access, results show no clear differences in occlusions between heparin and NS (RR 1.08, 95% CI 0.84 to 1.40; 770 line accesses; one study). We found no clear differences in the duration of catheter patency (mean difference (MD) 0.44 days, 95% CI -0.10 to 0.99; P = 0.11; 1036 participants; 752 catheters; six studies; low-quality evidence). We found no clear evidence of a difference in the following: CVC-related sepsis (RR 0.74, 95% CI 0.03 to 19.54; P = 0.86; 1097 participants; two studies; low-quality evidence); mortality (RR 0.76, 95% CI 0.44 to 1.31; P = 0.33; 1100 participants; three studies; low-quality evidence); haemorrhage at any site (RR 1.32, 95% CI 0.57 to 3.07; P = 0.52; 1245 participants; four studies; moderatequality evidence); or heparin-induced thrombocytopaenia (RR 0.21, 95% CI 0.01 to 4.27; P = 0.31; 443 participants; three studies; low-quality evidence). Themain reasons for downgrading the quality of evidencewere unclear allocation concealment, imprecision, and suspicion of publication bias. Authors’ conclusions Given the very low quality of the evidence, we are uncertain whether intermittent locking with heparin results in fewer occlusions than intermittent locking with NS. Low-quality evidence suggests that heparin may have little or no effect on catheter patency. Although we found no evidence of differences in safety (sepsis, mortality, or haemorrhage), the combined trials are not powered to detect rare adverse events such as heparin-induced thrombocytopaenia

Anomalies in the Charge Yields of Fission Fragments from the U(n,f)238 Reaction

Fast-neutron-induced fission of 238U at an energy just above the fission threshold is studied with a novel technique which involves the coupling of a high-efficiency γ-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via γ−γ coincidence spectroscopy. Experimental data and fission models are compared and found to be in reasonable agreement for many nuclei; however, significant discrepancies of up to 600% are observed, particularly for isotopes of Sn and Mo. This indicates that these models significantly overestimate the standard 1 fission mode and suggests that spherical shell effects in the nascent fission fragments are less important for low-energy fast-neutron-induced fission than for thermal neutron-induced fission. This has consequences for understanding and modeling the fission process, for experimental nuclear structure studies of the most neutron-rich nuclei, for future energy applications (e.g., Generation IV reactors which use fast-neutron spectra), and for the reactor antineutrino anomaly

Nuclear astrophysics with radioactive ions at FAIR

The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process, β-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes

Implications for maintaining vascular access device patency and performance: Application of science to practice

Introduction: Vascular access devices are commonly inserted devices that facilitate the administration of fluids and drugs, as well as blood sampling. Despite their common use in clinical settings, these devices are prone to occlusion and failure, requiring replacement and exposing the patient to ongoing discomfort/pain, local vessel inflammation and risk of infection. A range of insertion and maintenance strategies are employed to optimize device performance; however, the evidence base for many of these mechanisms is limited and the mechanisms contributing to the failure of these devices are largely unknown. Aims/objectives: (1) To revisit existing understanding of blood, vessel physiology and biological fluid dynamics; (2) develop an understanding of the implications that different clinical practices have on vessel health, and (3) apply these understandings to vascular access device research and practice. Method: Narrative review of biomedical and bioengineering studies related to vascular access practice. Results/outcomes: Current vascular access device insertion and maintenance practice and policy are variable with limited clinical evidence to support the theoretical assumptions underpinning these regimens. This review demonstrates the physiological response to vascular access device insertion, flushing and infusion on the vein, blood components and blood flow. These appear to be associated with changes in intravascular fluid dynamics. Variable forces are at play that impact blood componentry and the endothelium. These may explain the mechanisms contributing to vascular access failure. Conclusion: This review provides an update to our current knowledge and understanding of vascular physiology and the hemodynamic response, challenging some previously held assumptions regarding vascular access device maintenance, which require further investigation.</p

Atmospheric monitoring system of JEM-EUSO

JEM-EUSO telescope on International Space Station will detect UV fluorescence emission from Ultra High Energy Cosmic Rays (UHECR) induced Extensive Air Showers (EAS) penetrating in the atmosphere. The accuracy of reconstruction of the properties of the primary UHECR particles from the measurements of UV light depends on the extinction and scattering properties of the atmosphere at the location of the EAS and between the EAS and JEM-EUSO. The Atmospheric Monitoring system of JEM-EUSO will use the LIDAR, operating in the UV band, and an infrared camera to detect cloud and aerosol layer features across the entire 60? field of view of JEM-EUSO telescope, to measure the cloud top altitudes with the accuracy of 500 m and the optical depth profile of the atmosphere in the direction of each EAS with the accuracy 0.15 and resolution of 500 m. This should ensure that the energy of the primary UHECR particles and the depth of EAS maxima are measured with the accuracy better than 30% and 120 g/cm2, respectively

Appropriate Polypharmacy and Medicine Safety: When Many is not Too Many

The use of multiple medicines (polypharmacy) is increasingly common in middle-aged and older populations. Ensuring the correct balance between the prescribing of ‘many’ drugs and ‘too many’ drugs is a significant challenge. Clinicians are tasked with ensuring that patients receive the most appropriate combinations of medications based on the best available evidence, and that medication use is optimised according to patients’ clinical needs (appropriate polypharmacy). Historically, polypharmacy has been viewed negatively because of the associated medication safety risks, such as drug interactions and adverse drug events. More recently, polypharmacy has been identified as a risk factor for under-prescribing, such that patients do not receive necessary medications and this can also pose risks to patients’ safety and well-being. The negative connotations that have long been associated with the term polypharmacy could potentially be acting as a driving factor for under-prescribing, whereby clinicians are reluctant to prescribe necessary medicines for patients who are already receiving ‘many’ medicines. It is now recognised that the prescribing of ‘many’ medicines can be entirely appropriate in patients with several chronic conditions and that the risks of adverse drug events that have been associated with polypharmacy may be greatly reduced when patients’ clinical context is taken into consideration. In this article, we outline the current perspectives on polypharmacy and make the case for adopting the term ‘appropriate polypharmacy’ in differentiating between the prescribing of ‘many’ drugs and ‘too many’ drugs. We also outline the inherent challenges in doing so and provide recommendations for future clinical practice and research