The implausibility of ‘usual care’ in an open system: sedation and weaning practices in Paediatric Intensive Care Units (PICUs) in the United Kingdom (UK)

Background: The power of the randomised controlled trial depends upon its capacity to operate in a closed system whereby the intervention is the only causal force acting upon the experimental group and absent in the control group, permitting a valid assessment of intervention efficacy. Conversely, clinical arenas are open systems where factors relating to context, resources, interpretation and actions of individuals will affect implementation and effectiveness of interventions. Consequently, the comparator (usual care) can be difficult to define and variable in multi-centre trials. Hence outcomes cannot be understood without considering usual care and factors that may affect implementation and impact on the intervention. Methods: Using a fieldwork approach, we describe PICU context, ‘usual’ practice in sedation and weaning from mechanical ventilation, and factors affecting implementation prior to designing a trial involving a sedation and ventilation weaning intervention. We collected data from 23 UK PICUs between June and November 2014 using observation, individual and multi-disciplinary group interviews with staff. Results: Pain and sedation practices were broadly similar in terms of drug usage and assessment tools. Sedation protocols linking assessment to appropriate titration of sedatives and sedation holds were rarely used (9 % and 4 % of PICUs respectively). Ventilator weaning was primarily a medical-led process with 39 % of PICUs engaging senior nurses in the process: weaning protocols were rarely used (9 % of PICUs). Weaning methods were variably based on clinician preference. No formal criteria or use of spontaneous breathing trials were used to test weaning readiness. Seventeen PICUs (74 %) had prior engagement in multi-centre trials, but limited research nurse availability. Barriers to previous trial implementation were intervention complexity, lack of belief in the evidence and inadequate training. Facilitating factors were senior staff buy-in and dedicated research nurse provision. Conclusions: We examined and identified contextual and organisational factors that may impact on the implementation of our intervention. We found usual practice relating to sedation, analgesia and ventilator weaning broadly similar, yet distinctively different from our proposed intervention, providing assurance in our ability to evaluate intervention effects. The data will enable us to develop an implementation plan; considering these factors we can more fully understand their impact on study outcomes

Intranasal melanoma treated with radiation therapy in three dogs

Three dogs were investigated for chronic unilateral nasal discharge. In all cases CT imaging showed an intranasal mass causing turbinate lysis and no evidence of metastasis. Cytology in cases 1 (a 14-year-old neutered male crossbreed dog) and 2 (a five-year-old neutered male German Shepherd dog) demonstrated a pleomorphic cell population with variable intracellular pigment suspicious of melanocytic neoplasia. Histopathology with immunohistochemistry (Melan-A and vimentin, plus PNL-2 in one case) confirmed the diagnosis of melanoma in all dogs. All dogs were treated with megavoltage radiotherapy using linear accelerators. Cases 1 and 3 (a nine-year-old neutered female beagle dog) received a hypofractionated (4 × 8 Gy) protocol and case 2 received a definitive (12 × 4 Gy) protocol. Complete remission was demonstrated on repeat CT scan five months after diagnosis in case 1 and seven months in case 2. Stable disease was documented on CT at four months for case 3; however, clinical signs in this dog remained controlled for 10 months in total. Case 1 died of unrelated causes five months after diagnosis, case 2 was euthanased due to the development of seizures 13 months after diagnosis, and case 3 was lost to follow-up 12 months after diagnosis. Melanoma should be considered as a rare differential diagnosis for primary nasal neoplasia in the dog and radiation therapy can be used as effective local therapy

Barrier and Sacrificial Protection Mechanisms of Zinc Rich Primers

A specific type of Zinc-Rich Paint was scratched and exposed in salt fog chamber for various exposure times up to 1,000 hours. The corrosion products that developed within the scratched region were studied by optical microscopy, scanning electron microscopy, and Electrochemical Impedance Spectroscopy (EIS). Bode plots were used to obtain the total resistance of the coating by salt spray exposure time. The results suggest that the mechanism of protection of zinc rich paints may not be simply as only sacrificial action followed by only barrier action, but rather an iteration of these two mechanisms exist. Although at very short times, prior to deposition of zinc corrosion products in the scratch, sacrificial action is the only mechanism of protection, once the corrosion products start to form there is a conjunction of the two protection actions with one dominating from time to time. This dual protection mechanism continues until all the available free zinc within the throwing power distance of the scratch has been consumed, at which point only barrier protection remains in action

A Comparison of Miranda Procedures: The Effects of Oral and Written Administrations on Miranda Comprehension

Millions of custodial suspects waive their rights each year without the benefit of legal counsel. The question posed to psychologists in disputed Miranda waivers is whether this waiver decision was, knowing, intelligent, and voluntary. Mental health professionals must be aware of potential barriers to Miranda comprehension to provide expert opinions regarding a defendant's competency to waive rights. The current study examined how Miranda warning reading level, length, and method of administration affects Miranda comprehension. Recently arrested detainees at Grayson County Jail were administered oral and written Miranda warnings from the Miranda Statements Scale (MSS; Rogers, 2005) to measure their comprehension of the warnings. Surprisingly low levels of Miranda comprehension were found for most warnings. For all warnings at or above 8th grade, a substantial minority (27.1% - 39.6%) of defendants exhibited failed (i.e., < 50% understanding) Miranda comprehension. Regardless of other variables, oral administrations resulted in a substantially larger number of defendants with failed Miranda comprehension. Implications for public policy and clinical practice are discussed

Spin flip from dark to bright states in InP quantum dots

We report measurements of the time for spin flip from dark (non-light emitting) exciton states in quantum dots to bright (light emitting) exciton states in InP quantum dots. Dark excitons are created by two-photon excitation by an ultrafast laser. The time for spin flip between dark and bright states is found to be approximately 200 ps, independent of density and temperature below 70 K. This is much shorter than observed in other quantum dot systems. The rate of decay of the luminescence intensity, approximately 300 ps, is not simply equal to the radiative decay rate from the bright states, because the rate of decay is limited by the rate of conversion from dark excitons into bright excitons. The dependence of the luminescence decay time on the spin flip time is a general effect that applies to many experiments.Comment: 3 figure

A comparison of the different anisometropic testing procedures as done at Pacific University

A comparison of the different anisometropic testing procedures as done at Pacific Universit