Legal and Ethical Considerations for Requiring Consent for Apnea Testing in Brain Death Determination

Abstract

The past decade has witnessed escalating legal and ethical challenges to the diagnosis of death by neurologic criteria (DNC). The legal tactic of demanding consent for the apnea test, if successful, can halt the DNC. However, US law is currently unsettled and inconsistent in this matter. Consent has been required in several trial cases in Montana and Kansas but not in Virginia and Nevada. In this paper, we analyze and evaluate the legal and ethical bases for requiring consent before apnea testing and defend such a requirement by appealing to ethical and legal principles of informed consent and battery and the right to refuse medical treatment. We conclude by considering and rebutting two major objections to a consent requirement for apnea testing: (1) a justice-based objection to allocate scarce resources fairly and (2) a social utility objection that halting the diagnosis of brain death will reduce the number of organ donors.     

Subjective and physiological responses to the 35% carbon dioxide challenge in healthy and non-clinical control populations: a meta-analysis and systematic review

Background/Rationale: The carbon dioxide (CO₂) challenge has been reliably used in laboratory settings as a panicogen in clinical populations. However, the magnitude of these effects on healthy and non-clinical control populations are not clear. The aim of this meta-analysis and systematic review is to provide quantitative estimates of those effects. Specifically, the current paper will evaluate the relative efficacy of the CO₂ challenge in eliciting both subjective and physiological arousal in healthy and non-clinical control populations.

Method: A total of 16 articles with 35 independent samples were included in the meta-analysis, while 37 studies with 74 independent samples were included in the systematic review.

Results: Both the meta-analysis and systematic review found the CO₂ challenge to elicit an increase in subjective distress via self-reported anxiety and fear. Physiological responses via blood pressure and heart rate were heterogeneous in studies sampled, with no significant changes observed across studies. Moderator analyses revealed the variations in findings may be attributed to participant screening and invasive sampling.

Discussion: Findings highlight the CO₂ challenge as a useful tool in the provocation of subjective distress. Implications for both the use of the CO₂ challenge and its anticipated effects in healthy and non-clinical control populations are discussed.     

Factor structure of the CNS Vital Signs computerized cognitive battery in youth with neurological diagnoses

Computerized cognitive batteries, such as CNS Vital Signs (CNSVS), can provide valuable information in clinical and research settings. However, psychometric properties, especially in children and adolescents, remain relatively understudied. The aim of this study was to investigate the factor structure of CNSVS in children and adolescents with neurological diagnoses.

Participants with neurological diagnoses (N = 280) age 7–19 years were assessed as part of their clinical care at a tertiary hospital. All participants received the full CNSVS computerized cognitive battery, which contains seven subtests designed to measure attention, executive functioning, psychomotor speed, and memory. Principal components analyses were used to examine factor structure.

Scores from CNSVS subtests loaded onto a three-component solution and accounted for 46% of the variance. The three components were deemed to best represent (1) speed, (2) memory, and (3) inhibition, with subtest scores loading differently than the original 11 primary and secondary domain scores would have suggested.

Although the CNSVS program generates numerous primary and secondary domain scores, a three-component solution represents a more parsimonious approach to interpreting performance on the CNSVS in youth with neurological diagnoses. Confirmation of this factor solution in other samples is warranted.     

Model Selection of Nested and Non-Nested Item Response Models Using Vuong Tests

Abstract

In this paper, we apply Vuong’s general approach of model selection to the comparison of nested and non-nested unidimensional and multidimensional item response theory (IRT) models. Vuong’s approach of model selection is useful because it allows for formal statistical tests of both nested and non-nested models. However, only the test of non-nested models has been applied in the context of IRT models to date. After summarizing the statistical theory underlying the tests, we investigate the performance of all three distinct Vuong tests in the context of IRT models using simulation studies and real data. In the non-nested case we observed that the tests can reliably distinguish between the graded response model and the generalized partial credit model. In the nested case, we observed that the tests typically perform as well as or sometimes better than the traditional likelihood ratio test. Based on these results, we argue that Vuong’s approach provides a useful set of tools for researchers and practitioners to effectively compare competing nested and non-nested IRT models.     

The development of creativity in Chilean kindergarten and school children / Desarrollo de la creatividad en párvulos y escolares chilenos

Abstract

The purpose of this study is to explore the development of creativity in Chilean kindergarten and school children. For this, we evaluated non-verbal divergent and convergent thinking skills in a sample of 320 Chilean kindergarten, second-, fourth- and sixth-grade school children. We found that kindergarten and second-grade children showed a lower performance in creative fluency and originality than fourth-grade and sixth-grade children. In addition, we found that kindergarten and second-grade children had a low performance in creative elaboration, which worsened in the fourth and sixth grades. We did not find differences between the different educational levels in convergent thinking skills. Our results contradict previous international studies that report a stable development of creativity throughout the first few years of schooling, with a transitory slump in the fourth or sixth grade, revealing an early slump of creative skills in Chilean children, which rebound after the fourth grade. We discuss the potential relationship between the academization and rigidization of Chilean early childhood education and the early slump in creativity.