Independent lung ventilation in a newborn with asymmetric acute lung injury due to respiratory syncytial virus: a case report

<p>Abstract</p> <p>Introduction</p> <p>Independent lung ventilation is a form of protective ventilation strategy used in adult asymmetric acute lung injury, where the application of conventional mechanical ventilation can produce ventilator-induced lung injury and ventilation-perfusion mismatch. Only a few experiences have been published on the use of independent lung ventilation in newborn patients.</p> <p>Case presentation</p> <p>We present a case of independent lung ventilation in a 16-day-old infant of 3.5 kg body weight who had an asymmetric lung injury due to respiratory syncytial virus bronchiolitis. We used independent lung ventilation applying conventional protective pressure controlled ventilation to the less-compromised lung, with a respiratory frequency proportional to the age of the patient, and a pressure controlled high-frequency ventilation to the atelectatic lung. This was done because a single tube conventional ventilation protective strategy would have exposed the less-compromised lung to a high mean airways pressure. The target of independent lung ventilation is to provide adequate gas exchange at a safe mean airways pressure level and to expand the atelectatic lung. Independent lung ventilation was accomplished for 24 hours. Daily chest radiograph and gas exchange were used to evaluate the efficacy of independent lung ventilation. Extubation was performed after 48 hours of conventional single-tube mechanical ventilation following independent lung ventilation.</p> <p>Conclusion</p> <p>This case report demonstrates the feasibility of independent lung ventilation with two separate tubes in neonates as a treatment of an asymmetric acute lung injury.</p

American College of Critical Care Medicine Clinical Practice Parameters for Hemodynamic Support of Pediatric and Neonatal Septic Shock

OBJECTIVES: The American College of Critical Care Medicine provided 2002 and 2007 guidelines for hemodynamic support of newborn and pediatric septic shock. Provide the 2014 update of the 2007 American College of Critical Care Medicine “Clinical Guidelines for Hemodynamic Support of Neonates and Children with Septic Shock.” DESIGN: Society of Critical Care Medicine members were identified from general solicitation at Society of Critical Care Medicine Educational and Scientific Symposia (2006–2014). The PubMed/Medline/Embase literature (2006–14) was searched by the Society of Critical Care Medicine librarian using the keywords: sepsis, septicemia, septic shock, endotoxemia, persistent pulmonary hypertension, nitric oxide, extracorporeal membrane oxygenation, and American College of Critical Care Medicine guidelines in the newborn and pediatric age groups. MEASUREMENTS AND MAIN RESULTS: The 2002 and 2007 guidelines were widely disseminated, translated into Spanish and Portuguese, and incorporated into Society of Critical Care Medicine and American Heart Association/Pediatric Advanced Life Support sanctioned recommendations. The review of new literature highlights two tertiary pediatric centers that implemented quality improvement initiatives to improve early septic shock recognition and first-hour compliance to these guidelines. Improved compliance reduced hospital mortality from 4% to 2%. Analysis of Global Sepsis Initiative data in resource rich developed and developing nations further showed improved hospital mortality with compliance to first-hour and stabilization guideline recommendations. CONCLUSIONS: The major new recommendation in the 2014 update is consideration of institution—specific use of 1) a “recognition bundle” containing a trigger tool for rapid identification of patients with septic shock, 2) a “resuscitation and stabilization bundle” to help adherence to best practice principles, and 3) a “performance bundle” to identify and overcome perceived barriers to the pursuit of best practice principles

Stimuli-SoS: a model-based approach to derive stimuli generators for simulations of systems-of-systems software architectures

Abstract Background Systems-of-systems (SoS) are alliances of independent and interoperable software-intensive systems. SoS often support critical domains, being required to exhibit a reliable operation, specially because people’s safety relies on their services. In this direction, simulations enable the validation of different operational scenarios in a controlled environment, allowing a benchmarking of its response as well as revealing possible breaches that could lead to failures. However, simulations are traditionally manual, demanding a high level of human intervention, being costly and error-prone. A stimuli generator could aid in by continuously providing data to trigger a SoS simulation and maintaining its operation. Methods We established a model-based approach termed Stimuli-SoS to support the creation of stimuli generators to be used in SoS simulations. Stimuli-SoS uses software architecture descriptions for automating the creation of such generators. Specifically, this approach transforms SoSADL, a formal architectural description language for SoS, into dynamic models expressed in DEVS, a simulation formalism. We carried out a case study in which Stimuli-SoS was used to automatically produce stimuli generators for a simulation of a flood monitoring SoS. Results We run simulations of a SoS architectural configuration with 69 constituent systems, i.e., 42 sensors, 9 crowdsourcing systems, and 18 drones. Stimuli generators were automatically generated for each type of constituent. These stimuli generators were capable of receiving the input data from the database and generating the expected stimuli for the constituents, allowing to simulate constituent systems interoperations into the flood monitoring SoS. Using Stimuli-SoS, we simulated 38 days of flood monitoring in little more than 6 h. Stimuli generators correctly forwarded data to the simulation, which was able to reproduce 29 flood alerts triggered by the SoS during a flooding event. In particular, Stimuli-SoS is almost 65 times more productive than a manual approach to producing data for the same type of simulation. Conclusions Our approach succeeded in automatically deriving a functional stimuli generator that can reproduce environmental conditions for simulating a SoS. In particular, we presented new contributions regarding productivity and automation for the use of a model-based approach in SoS engineering

Decade-long unsustainable vegetation management practices increase macronutrient losses from the plant-soil system in the Taklamakan Desert

Arid ecosystems are characterized by low availability and mobility of soil nutrients and slow geochemical cycles. Management of native vegetation in such ecosystems for fuel, livestock grazing, and other agricultural activities (burning and cutting) may threaten semi-natural communities due to the changes in nutrient cycles and soil fertility. Alhagi sparsifolia is a dominant perennial legume in the Taklamakan Desert of northwestern China and has been used as fodder for livestock and plays a crucial ecological role in stabilizing dunes in the oasis-desert ecotone. We evaluated the effects of long-term (12 years) burning and cutting of plant biomass on the mineral nutrition of A. sparsifolia and associated soils at two depths (0–50 and 50–100 cm) in the field conditions following the block design experiment. We found that burning effects tended to be restricted to the topsoil (0–50 cm), and the concentration of many micro-and macronutrients was increased. Burning was associated with a decrease in plant nitrogen (N) and phosphorus (P) concentration, whereas concentrations of other micro-and macronutrients increased; overall, burning reduced foliar stocks of N, P, and potassium (K). Annual cutting elicited smaller increases in soil mineral (total sulfur, total P, calcium, magnesium, and available P and K) concentrations than burning, and soil enzymatic activities increased. There were contrasting response patterns of leaf N and P concentration and macro-and micronutrients between the two management approaches. Burning and cutting reduced leaf N and P concentrations, while changes in root and shoot N and P concentrations depended on treatments. Thus, burning and cutting of A. sparsifolia impact organ nutrient stoichiometry (increased losses of macronutrients from arid plant-soil ecosystems) and nutritional quality (for feeding livestock), particularly due to predicted rises in extreme climatic events under climate change that are expected to increase risks of soil erosion, however, impacts on native trophic webs remain unclear