Rethinking pediatric ethics consultations

Johnson and colleagues (2015) report a retrospective review of the experience of an ethics consultation service at a single, highly specialized children's hospital over an 11-year period. Despite its methodologic limitations, the results of this study are worthy of note. The St. Jude Children's Research Hospital ethics consultation service consulted on a range of complex cases, including the management of conflict between parents and physicians, futility, parental demands, treatment nonadherence, and, less commonly, end-of-life issues. The number of case consultations was small, fewer than five per year, and did not increase over time. The retrospective nature of the study prevented eliciting how often consultations altered treatment or other decisions. No record was kept of clinical staff, parent, or patient perception of the value of the ethics consultation, nor of the frequency or value of informal (curb side) ethics consultations. The St. Jude ethics consultation process is consistent with “standard” models in the field. An ethics team comprising two to five staff members, including an ethicist, performs the initial ward consultation, which is then discussed with the formal clinical ethics committee of 21 people. Other involved services participate via interdisciplinary meetings. The types of consultation are consistent with many other services, including both formal and informal consultations using a range of methods to assist resolution of cases, including mediation and arbitration. Despite open access to requesting consultations, including anonymous enquiries, almost all requests came from physicians, often the same ones. Only a few came from nurses and none from parents or patients. Importantly, nurses appeared to be subject to repercussions from physicians if they requested consultations, an important issue that requires further attention but goes beyond the scope of our commentary. We suggest that the experience of the St. Jude service illustrates both the limitations of ethics consultation and the need to evaluate the importance and impact of an ethics service using metrics other than simply the number of case consultations

The management of children with Spinal Muscular Atrophy Type 1 in Australia

Aims: To (1) estimate the prevalence of Spinal Muscular Atrophy Type 1 (SMA 1); (2) describe what practices characterise end-of-life care of patients with SMA 1; (3) ascertain whether a consistent approach to the management of these patients exists in Australia. Methods: An audit of the Australasian pathology laboratories offering the diagnostic SMN1 deletion test was conducted for patients diagnosed with SMA in Australia for 2010 and 2011. In addition, a retrospective clinical audit was conducted in eight major Australian paediatric hospitals of the end-of-life care provided to children with confirmed SMA 1 from 2005 to 2010. Results: 35 children were included in the clinical audit, accounting for an estimated 61% of children diagnosed with SMA 1 from 2005-2010. 26% were ventilated invasively, only two of whom were intubated after the diagnosis was confirmed. No children were ventilated long-term (>90 days) or had a tracheostomy performed. Nasogastric tube feeding was a common measure to support adequate nutritional intake. Total parenteral nutrition, gastrostomy and fundoplication were not provided for any children. Conflict over end-of-life care decisions was documented in one instance, without the involvement of a guardianship tribunal. Conclusion: There appears to be a consistent approach in the management of children with SMA 1 in Australia, which can be characterised as ‘actively managed dying.’ This study could contribute to the development of Australian consensus guidelines for the management of these children. These results also highlight a number of ethical issues related to the management of children with SMA 1

The influence of the frequency of periodic disturbances on the maintenance of phytoplankton diversity

The influence of periodic disturbances of various frequency on the maintenance of the phytoplankton diversity was studied by semicontinuous competition experiments. Disturbances consisted of dilution events, which meant both addition of fresh nutrients and elimination of organisms. The intervals between dilution events varied from 1 to 14 days. Diversity was found to increase with increasing intervals between disturbances. coexisting species belonged to different strategy types: (a) species with rapid growth under enriched conditions, (b) species with good competitive abilities under impoverished conditions, (c) species with the ability to build up storage pools of the limiting nutrient. An increase of the number of coexisting species over the number that would have coexisted in steady state was only found when the interval exceeded one generation time

Phytoplankton competition along a gradient of dilution rates

Natural phytoplankton from Lake Constance was used for chemostat competition experiments performed at a variety of dilution rates. In the first series at high Si:P ratios and under uniform phosphorus limitation for all species, Synedra acus outcompeted all other species at all dilution rates up to 1.6 d-1, only at the highest dilution rate (2.0 d-1) Achnanthes minutissima was successful. In the second series in the absence of any Si a green algal replacement series was found, with Mougeotia thylespora dominant at the lowest dilution rates, Scenedesmus acutus at the intermediate ones, and Chlorella minutissima at the highest ones. The outcome of interspecific competition was not in contradiction with the Monod kinetics of P-limited growth of the five species, but no satisfactorily precise prediction of competitive performance can be derived from the Monod kinetics because of insufficient precision in the estimate of k s

Nitrate- and silicate-competition among antarctic phytoplankton

Natural phytoplankton from antarctic waters in the Drake Passage were used for competition experiments in semicontinuous cultures. The outcome of interspecific competition for silicate and nitrate was studied at a range of Si:N ratios (from 2.6:1 to 425:1) and at three different dilution rates. For five species Monod kinetics of silicate-and nitrate-limited growth has been established. Comparison between theoretical predictions derived from Monod kinetics and the outcome of competition experiments showed only minor deviations. Contrary to literature data, considerable depletion of nitrate was found in antarctic seawater. Both the concentrations of soluble silicate and of nitrate were too low to support maximum growth rates of some of the diatom species under investigation

Settling for second best: when should doctors agree to parental demands for suboptimal medical treatment?

Background Doctors sometimes encounter parents who object to prescribed treatment for their children, and request suboptimal substitutes be administered instead (suboptimal being defined as less effective and/or more expensive). Previous studies have focused on parental refusal of treatment and when this should be permitted, but the ethics of requests for suboptimal treatment has not been explored. Methods The paper consists of two parts: an empirical analysis and an ethical analysis. We performed an online survey with a sample of the general public to assess respondents’ thresholds for acceptable harm and expense resulting from parental choice, and the role that religion played in their judgement. We also identified and applied existing ethical frameworks to the case described in the survey to compare theoretical and empirical results. Results Two hundred and forty-two Mechanical Turk workers took our survey and there were 178 valid responses (73.6%). Respondents’ agreement to provide treatment decreased as the risk or cost of the requested substitute increased (p<0.001). More than 50% of participants were prepared to provide treatment that would involve a small absolute increased risk of death for the child (<5%) and a cost increase of US$<500, respectively. Religiously motivated requests were significantly more likely to be allowed (p<0.001). Existing ethical frameworks largely yielded ambiguous results for the case. There were clear inconsistencies between the theoretical and empirical results. Conclusion Drawing on both survey results and ethical analysis, we propose a potential model and thresholds for deciding about the permissibility of suboptimal treatment requests

The evolution of saline lake waters: gradual and rapid biogeochemical pathways in the Basotu Lake District, Tanzania

The biogeochemical evolution of solutes markedly alters the chemistry in the closed-basin maar lakes that comprise the Basotu Lake District (Tanzania, East Africa). Examination of 11 (out of 13) lakes in the Basotu Lake District identified two distinct evolutionary pathways: a gradual path and a rapid path. During the course of biogeochemical evolution these waters follow either the gradual path alone or a combination of the gradual and rapid paths. Solute evolution along the gradual path is determined by all of the biogeochemical processes that for these waters appear to be tightly coupled to evaporative concentration (e.g. mineral precipitation, sorption and ion exchange, C0 2 degassing, and sulfate reduction). Rapid evolution occurs when mixing events suddenly permit H 2 S to be lost to the atmosphere. The chemistry of waters undergoing rapid evolution is changed abruptly because loss of every equivalent of sulfide produces an equivalent permanent alkalinity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42881/1/10750_2004_Article_BF00026937.pd

Increased risk of phosphorus limitation at higher temperatures for Daphnia magna

Invertebrate herbivores frequently face growth rate constraints due to their high demands for phosphorus (P) and nitrogen (N). Temperature is a key modulator of growth rate, yet the interaction between temperature and P limitation on somatic growth rate is scarcely known. To investigate this interaction, we conducted a study on the somatic growth rate (SGR) of the cladoceran Daphnia magna, known to be susceptible to P-limitation. We determined the SGR across a broad range of dietary P content of algae (carbon (C):P ratios (125–790), and at different temperatures (10–25°C). There was a strong impact of both temperature and C:P ratio on the SGR of D. magna, and also a significant interaction between both factors was revealed. The negative effect of dietary C:P on growth rate was reduced with decreased temperature. We found no evidence of P limitation at lowest temperature, suggesting that enzyme kinetics or other measures of food quality overrides the demands for P to RNA and protein synthesis at low temperatures. These findings also indicate an increased risk of P limitation and thus reduced growth efficiency at high temperatures

Loss of Sexual Reproduction and Dwarfing in a Small Metazoan

Asexuality has major theoretical advantages over sexual reproduction, yet newly formed asexual lineages rarely endure. The success, or failure, of such lineages is affected by their mechanism of origin, because it determines their initial genetic makeup and variability. Most previously described mechanisms imply that asexual lineages are randomly frozen subsamples of a sexual population.We found that transitions to obligate parthenogenesis (OP) in the rotifer Brachionus calyciflorus, a small freshwater invertebrate which normally reproduces by cyclical parthenogenesis, were controlled by a simple Mendelian inheritance. Pedigree analysis suggested that obligate parthenogens were homozygous for a recessive allele, which caused inability to respond to the chemical signals that normally induce sexual reproduction in this species. Alternative mechanisms, such as ploidy changes, could be ruled out on the basis of flow cytometric measurements and genetic marker analysis. Interestingly, obligate parthenogens were also dwarfs (approximately 50% smaller than cyclical parthenogens), indicating pleiotropy or linkage with genes that strongly affect body size. We found no adverse effects of OP on survival or fecundity.This mechanism of inheritance implies that genes causing OP may evolve within sexual populations and remain undetected in the heterozygous state long before they get frequent enough to actually cause a transition to asexual reproduction. In this process, genetic variation at other loci might become linked to OP genes, leading to non-random associations between asexuality and other phenotypic traits