MicroPET investigation of chronic long-term neurotoxicity from heavy ion irradiation

Positron emission tomography (PET) permits imaging of the regional biodistribution and pharmacokinetics of compounds labeled with short-lived positron-emitting isotopes. It has enabled evaluation of neurochemical systems in the living human brain, including effects of toxic substances. MicroPET devices allos studies of the rat brain with a spatial resolution of ∼2 mm. This is much poorer resolution than obtained using ex vivo autoradiography. However, animals need not be euthanized before imaging, so repeat studies are possible. This in principle allows the effects of toxic insults to be followed over the lifetime of an individual animal. We used microPET to evaluate brain metabolic effects of irradiation with high-energy heavy ions (HZE radiation), a component of the space radiation environment, on regional glucose metabolism. A significant fraction of neurons would be traversed by these densely ionizing particles during a Mars mission, and there is a need to estimate human neurological risks of prolonged voyages beyond the geomagnetosphere. Rats were irradiated with56Fe (600 MeV/n) ions at doses up to 240 cGy. At 9 months post-irradiation we did not detect alterations in regional accumulation of the glucose analog [18F]2-deoxy-2-fluoro-D-glucose. This may indicate that damage to the brain from HZE particles is less severe than feared. However, because radiation-induced alterations in some behaviors have been documented, it may reflect insensitivity of baseline cerebral glucose metabolism to HZE radiation. These studies will facilitate design of future studies of chronic, long-term exposure to both therapeutic and abused drugs using microPET

Infrastructure and Organization of Adult Intensive Care Units in Resource-Limited Settings

In this chapter, we provide guidance on some basic structural requirements, focusing on organization, staffing, and infrastructure. We suggest a closed-format intensive care unit (ICU) with dedicated physicians and nurses, specifically trained in intensive care medicine whenever feasible. Regarding infrastructural components, a reliable electricity supply is essential, with adequate backup systems. Facilities for oxygen therapy are crucial, and the choice between oxygen concentrators, cylinders, and a centralized system depends on the setting. For use in mechanical ventilators, a centralized piped system is preferred. Facilities for proper hand hygiene are essential. Alcohol-based solutions are preferred, except in the context of Ebola virus disease (chloride-based solutions) and Clostridium difficile infection (soap and water). Availability of disposable gloves is important for self-protection; for invasive procedures masks, caps, sterile gowns, sterile drapes, and sterile gloves are recommended. Caring for patients with highly contagious infectious diseases requires access to personal protective equipment. Basic ICU equipment should include vital signs monitors and mechanical ventilators, which should also deliver noninvasive ventilator modes. We suggest that ICUs providing invasive ventilatory support have the ability to measure end-tidal carbon dioxide and if possible can perform blood gas analysis. We recommend availability of glucometers and capabilities for measuring blood lactate. We suggest implementation of bedside ultrasound as diagnostic tool. Finally, we recommend proper administration of patient data; suggest development of locally applicable bundles, protocols, and checklists for the management of sepsis; and implement systematic collection of quality and performance indicators to guide improvements in ICU performance

Randomized controlled trials in central vascular access devices: A scoping review

Background Randomized controlled trials evaluate the effectiveness of interventions for central venous access devices, however, high complication rates remain. Scoping reviews map the available evidence and demonstrate evidence deficiencies to focus ongoing research priorities. Method A scoping review (January 2006–December 2015) of randomized controlled trials evaluating the effectiveness of interventions to improve central venous access device outcomes; including peripherally inserted central catheters, non-tunneled, tunneled and totally implanted venous access catheters. MeSH terms were used to undertake a systematic search with data extracted by two independent researchers, using a standardized data extraction form. Results In total, 178 trials were included (78 non-tunneled [44%]; 40 peripherally inserted central catheters [22%]; 20 totally implanted [11%]; 12 tunneled [6%]; 6 non-specified [3%]; and 22 combined device trials [12%]). There were 119 trials (68%) involving adult participants only, with 18 (9%) pediatric and 20 (11%) neonatal trials. Insertion-related themes existed in 38% of trials (67 RCTs), 35 RCTs (20%) related to post-insertion patency, with fewer trials on infection prevention (15 RCTs, 8%), education (14RCTs, 8%), and dressing and securement (12 RCTs, 7%). There were 46 different study outcomes reported, with the most common being infection outcomes (161 outcomes; 37%), with divergent definitions used for catheter-related bloodstream and other infections. Conclusion More high quality randomized trials across central venous access device management are necessary, especially in dressing and securement and patency. These can be encouraged by having more studies with multidisciplinary team involvement and consumer engagement. Additionally, there were extensive gaps within population sub-groups, particularly in tunneled devices, and in pediatrics and neonates. Finally, outcome definitions need to be unified for results to be meaningful and comparable across studies