Search

Over the course of human life, health care decision-making is often interdependent. In this article, we use "interdependence" to refer to patients' engagement of nonclinicians-for example, family members or trusted friends-to reach health care decisions. Interdependence, we suggest, is common for patients in all stages of life, from early childhood to late adulthood. This view contrasts with the common bioethical assumption that medical decisions are either wholly independent or dependent and that independence or dependence is tightly coupled with a person's decision-making capacity. In this article, we array various approaches to decision-making along a continuum of interdependence. An appreciation of this continuum can empower patients and elucidate ethical challenges that arise when people transition between different kinds of interdependence across the life span.

This trial is aimed at studying the utility and interventional outcomes of rescue transesophageal echocardiography (RescueTEE) to aid in diagnosis, change in management, and outcomes during CPR by using a point of care RescueTEE protocol in the evaluation of in-hospital cardiac arrest (IHCA). This is an interventional prospective convenience sampled partially blinded phase II clinical trial with primary outcomes of survival to hospital discharge (SHD) with RescueTEE image guided ACLS versus conventional ACLS.

Recent arguments in aging and dementia research suggest that “terminal lucidity”—defined as unexpected communication or connectedness occurring shortly before death—is distinct from “paradoxical lucidity”—defined as an episode of communication or connectedness in a person who is assumed to have lost these capacities due to progressive neurodegeneration. We disagree with this distinction and argue that terminal lucidity is a special subtype of paradoxical lucidity. We suggest that specifying the relationship between terminal and paradoxical lucidity is important for investigating the underlying mechanism of lucidity in dementia.

Until recently, molecular imaging using magnetic resonance (MR) has been limited by the modality's low sensitivity, especially with non-proton nuclei. The advent of hyperpolarized (HP) MR overcomes this limitation by substantially enhancing the signal of certain biologically important probes through a process known as external nuclear polarization, enabling real-time assessment of tissue function and metabolism. The metabolic information obtained by HP MR imaging holds significant promise in the clinic, where it could play a critical role in disease diagnosis and therapeutic monitoring. This review will provide a comprehensive overview of the developments made in the field of hyperpolarized MR, including advancements in polarization techniques and delivery, probe development, pulse sequence optimization, characterization of healthy and diseased tissues, and the steps made towards clinical translation.

This study tested the ability of a multibreath hyperpolarized HP (3) He MRI protocol to increase the accuracy of regional alveolar oxygen tension (PA O2 ) measurements by lessening the influence of gas-flow artifacts. Conventional single-breath PA O2 measurement has been susceptible to error induced by intervoxel gas flow, particularly when used to study subjects with moderate-to-severe chronic obstructive pulmonary disease (COPD).Both single-breath and multibreath PA O2 imaging schemes were implemented in seven human subjects (one healthy, three asymptomatic smokers, and three COPD). The number and location of voxels with nonphysiologic PA O2 values generated by intervoxel gas flow were compared between the two protocols.The multibreath scheme resulted in a significantly lower total percentage of nonphysiologic PA O2 values (6.0%) than the single-breath scheme (13.7%) (P = 0.006). PA O2 maps showed several patterns of gas-flow artifacts that were present in the single-breath protocol but mitigated by the multibreath approach. Multibreath imaging also allowed for the analysis of slow-filling areas that presented no signal after a single breath.A multibreath approach enhances the accuracy and completeness of noninvasive PA O2 measurement by significantly lessening the proportion of nonphysiologic values generated by intervoxel gas flow. Magn Reson Med 76:1092-1101, 2016. © 2015 Wiley Periodicals, Inc.

To present a new cryogenic technique for preparing gaseous compounds in solid mixtures for polarization using dynamic nuclear polarization (DNP).(129) Xe and (15) N2 O samples were prepared using the presented method. Samples were hyperpolarized at 1.42K at 5 Tesla. (129) Xe was polarized at 1.65K and 1.42K to compare enhancement. Polarization levels for both samples and T1 relaxation times for the (129) Xe sample were measured. Sample pulverization for the (129) Xe and controlled annealing for both samples were introduced as additional steps in sample preparation.Enhancement increased by 15% due to a temperature drop from 1.65K to 1.42K for the (129) Xe sample. A polarization level of 20 ± 3% for the (129) Xe sample was achieved, a two-fold increase from 10 ± 1% after pulverization of the sample at 1.42K. T1 of the (129) Xe sample was increased by more than three-fold by means of annealing. In the case of (15) N2 O, annealing led to a ∼two-fold increase in the signal level after DNP.The presented technique for producing and manipulating solid gas/glassing agent/radical mixtures for DNP led to high polarization levels in (129) Xe and (15) N2 O samples. These methods show potential for polarizing other gases using DNP technology. Magn Reson Med 76:1007-1014, 2016. © 2015 Wiley Periodicals, Inc.