Seismological expression of the iron spin crossover in ferropericlase in the Earth's lower mantle.

The two most abundant minerals in the Earth's lower mantle are bridgmanite and ferropericlase. The bulk modulus of ferropericlase (Fp) softens as iron d-electrons transition from a high-spin to low-spin state, affecting the seismic compressional velocity but not the shear velocity. Here, we identify a seismological expression of the iron spin crossover in fast regions associated with cold Fp-rich subducted oceanic lithosphere: the relative abundance of fast velocities in P- and S-wave tomography models diverges in the ~1,400-2,000 km depth range. This is consistent with a reduced temperature sensitivity of P-waves throughout the iron spin crossover. A similar signal is also found in seismically slow regions below ~1,800 km, consistent with broadening and deepening of the crossover at higher temperatures. The corresponding inflection in P-wave velocity is not yet observed in 1-D seismic profiles, suggesting that the lower mantle is composed of non-uniformly distributed thermochemical heterogeneities which dampen the global signature of the Fp spin crossover.

Emergency department management and follow-up of children with bicycle spoke injuries.

BACKGROUND: Evidence for a standard x-ray study and cast immobilization in emergency department (ED) management and follow-up of children with bicycle spoke injury (BSI) is absent. OBJECTIVE: To describe the injury pattern and outpatient follow-up and care of ED patients with BSI. In addition, patient characteristics predicting the presence of a fracture and long-term follow-up were assessed. METHODS: This was a retrospective study including BSI patients < 9 years of age. Kruskal-Wallis test was used to compare groups with a fracture, soft tissue injury, and mild skin abrasion. Multivariable logistic regression analysis was used to identify independent predictors of a fracture and long-term outpatient follow-up. RESULTS: Twenty-three percent of 141 included patients had a fracture, with a median (interquartile range) follow-up of 27 (23-40) days. For soft tissue injury and mild abrasions this was 9 (6-14) and 7 (5-9) days, respectively (p < 0.001). No clinical variables could predict a fracture. Fifty-six (40%) patients required no further care after the first outpatient visit at ∼1 week. Triage category yellow and swelling were independent predictors for more than one outpatient visit, besides presence of fracture. Corrected odds ratios (95% confidence interval) were 2.42 (0.99-5.88) and 4.76 (1.38-16.39), respectively. Only 12% of 141 patients had none of these predictors at ED presentation. CONCLUSIONS: A quarter of ED patients with BSI have a fracture with no clinical signs that could predict the presence of a fracture, justifying a standard x-ray study in ED management. Only 12% of ED patients with BSI have no fracture and no signs that predict long-term follow-up. In this group, further studies are warranted to investigate the benefit of cast immobilization for fractures and soft tissue injury.

Impact of the diagnostic process on the accuracy of source identification and time to antibiotics in septic emergency department patients.

OBJECTIVE: Timely administration of effective antibiotics is important in sepsis management. Source-targeted antibiotics are believed to be most effective, but source identification could cause time delays. OBJECTIVES: First, to describe the accuracy/time delays of a diagnostic work-up and the association with time to antibiotics in septic emergency department (ED) patients. Second, to assess the fraction in which source-targeted antibiotics could have been administered solely on the basis of patient history and physical examination. METHODS: Secondary analysis of the prospective observational study on septic ED patients was carried out. The time to test result availability was associated with time to antibiotics. The accuracy of the suspected source of infection in the ED was assessed. For patients with pneumosepsis, urosepsis, and abdominal sepsis, combinations of signs and symptoms were assessed to achieve a maximal positive predictive value for the sepsis source, identifying a subset of patients in whom source-targeted antibiotics could be administered without waiting for diagnostic test results. RESULTS: The time to antibiotics increased by 18 (95% confidence interval: 12-24) min/h delay in test result availability (n=323). In 38-79% of patients, antibiotics were administered after additional tests, whereas the ED diagnosis was correct in 68-85% of patients. The maximal positive predictive value of signs and symptoms was 0.87 for patients with pneumosepsis and urosepsis and 0.75 for those with abdominal sepsis. Use of signs and symptoms would have led to correct ED diagnosis in 33% of patients. CONCLUSION: Diagnostic tests are associated with delayed administration of antibiotics to septic ED patients while increasing the diagnostic accuracy to only 68-85%. In one-third of septic ED patients, the choice of antibiotics could have been accurately determined solely on the basis of patient history and physical examination.

[Acute pain at the emergency department: better treatment required]. / Acute pijn op de Spoedeisende Hulp: beter behandelen.

Acute pain is common among patients at the emergency department and is still not being treated adequately. Repeated measurement and documentation of pain is essential for adequate pain treatment. The patient determines how much analgesia is needed. Pharmacological pain relief should not be delayed during the diagnostic process, not even in cases of abdominal pain. Opioids play a central role in the treatment of acute pain. Opiophobia is not justified. Adequate pain relief started at the emergency department must be continued throughout both hospital admission and discharge to home.

Medical student disaster medicine education: the development of an educational resource.

BACKGROUND: Disaster medicine education is an enormous challenge, but indispensable for disaster preparedness. AIMS: We aimed to develop and implement a disaster medicine curriculum for medical student education that can serve as a peer-reviewed, structured educational guide and resource. Additionally, the process of designing, approving and implementing such a curriculum is presented. METHODS: The six-step approach to curriculum development for medical education was used as a formal process instrument. Recognized experts from professional and governmental bodies involved in disaster health care provided input using disaster-related physician training programs, scientific evidence if available, proposals for education by international disaster medicine organizations and their expertise as the basis for content development. RESULTS: The final course consisted of 14 modules composed of 2-h units. The concepts of disaster medicine, including response, medical assistance, law, command, coordination, communication, and mass casualty management, are introduced. Hospital preparedness plans and experiences from worldwide disaster assistance are reviewed. Life-saving emergency and limited individual treatment under disaster conditions are discussed. Specifics of initial management of explosive, war-related, radiological/nuclear, chemical, and biological incidents emphasizing infectious diseases and terrorist attacks are presented. An evacuation exercise is completed, and a mass casualty triage is simulated in collaboration with local disaster response agencies. Decontamination procedures are demonstrated at a nuclear power plant or the local fire department, and personal decontamination practices are exercised. Mannequin resuscitation is practiced while personal protective equipment is utilized. An interactive review of professional ethics, stress disorders, psychosocial interventions, and quality improvement efforts complete the training. CONCLUSIONS: The curriculum offers medical disaster education in a reasonable time frame, interdisciplinary format, and multi-experiential course. It can serve as a template for basic medical student disaster education. Because of its comprehensive but flexible structure, it should also be helpful for other health-care professional student disaster education programs.