Dual Defibrillation is Highly Variable: An Analysis of Pulse Interval Delivered in Dual Defibrillation.

Background: Dual defibrillation (DD) is a technique where two external defibrillators are applied with two different pad configurations and discharged to treat refractory ventricular fibrillation (RVF). Although commonly called dual sequential defibrillation (DSD), if the delivered electrical pulses overlap with no pulse interval, the shocks are actually dual simultaneous defibrillation (DSiD). Manual DD technique is not standardized and the effect that the method of activation has on the delivered pulse interval has never been studied. Objectives: This study measured the timing of four methods of DD and the resulting inter-shock intervals, frequency with which they were either DSiD or DSD, and frequency which the true DSDs delivered any previously reported optimum pulse interval. Methods: This was a single-blinded prospective evaluation of a convenience sample of volunteer physicians, nurses, and paramedics each performing DD in our simulation center on two types of defibrillators using four techniques: single operator-simultaneous with 2 hands (SOSI), two operators-simultaneous (TOSI), single operator-sequential with 1 hand (SOSE1), and single operator-sequential with 2 hands (SOSE2). Results: The four DD methods generated a variable set of pulse intervals depending on the technique and defibrillator employed. The pulse intervals ranged from 0 msec (i.e., overlapping waveforms or DSiD) to 1800 msec. Of all DD attempts, 85.9% met the definition of DSD, 14.1% were DSiD, and 49.4% delivered any one of the optimum pulse intervals previously described in the literature. SOSI and TOSI techniques resulted in DSD between 47.2 and 87.6% of the time, depending on the technique and defibrillator. Shocks delivered sequentially on purpose (SOSE2 and SOSE1) were always DSD but with widely variable pulse intervals. SOSI resulted in the shortest pulse intervals, SOSE1 resulted in the longest, and TOSI and SOSE2 were the least skewed. Conclusion: DD using the various methods currently employed produces a highly variable set of pulse intervals even within a single method. It is difficult to reach a conclusion about the efficacy of DD unless the delivered pulse interval is measured or the method of activation reproducibly produces a precise pulse interval.

Estimating the footprint of pollution on coral reefs with models of species turnover.

Ecological communities typically change along gradients of human impact, although it is difficult to estimate the footprint of impacts for diffuse threats such as pollution. We developed a joint model (i.e., one that includes multiple species and their interactions with each other and environmental covariates) of benthic habitats on lagoonal coral reefs and used it to infer change in benthic composition along a gradient of distance from logging operations. The model estimated both changes in abundances of benthic groups and their compositional turnover, a type of beta diversity. We used the model to predict the footprint of turbidity impacts from past and recent logging. Benthic communities far from logging were dominated by branching corals, whereas communities close to logging had higher cover of dead coral, massive corals, and soft sediment. Recent impacts were predicted to be small relative to the extensive impacts of past logging because recent logging has occurred far from lagoonal reefs. Our model can be used more generally to estimate the footprint of human impacts on ecosystems and evaluate the benefits of conservation actions for ecosystems.

Synthetic Cannabinoid Abuse Resulting in ST-Segment Elevation Myocardial Infarction Requiring Percutaneous Coronary Intervention.

BACKGROUND: Synthetic cannabinoids (SC) are recreational designer drugs intended to mimic delta-9-tetrahydrocannabinol while surreptitiously circumventing classification by the Drug Enforcement Administration. CASE REPORT: A 50-year-old black male arrived in the Emergency Department transported by Emergency Medical Services (EMS) for altered mental status after complaining of chest pain associated with smoking SCs. EMS found the patient with an empty foil pack labeled "Scooby Snax Limited Edition Blueberry Potpourri." The patient was somnolent, but became agitated when stimulated and complained of chest pain. Vital signs were blood pressure 87/52 mm Hg and pulse 52 beats/min. The electrocardiogram demonstrated an inferior wall myocardial infarction. Coronary angiography identified an occluded obtuse marginal second branch that was successfully opened with a drug-eluting stent. The patient recovered uneventfully. Urine drug screen was negative for cocaine, and gas chromatography/mass spectrometry testing of the smoked material identified PB-22 and AMB-FUBINACA as the active ingredients. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians and cardiologists need to be aware that the mechanism of action of synthetic cannabinoids on the endocannabinoid system may result in acute ST-segment elevation myocardial infarction requiring percutaneous coronary intervention.

Commercial spaceflight participant G-force tolerance during centrifuge-simulated suborbital flight.

INTRODUCTION: Medical knowledge of the human body in microgravity and hypergravity is based upon studies of healthy individuals well-conditioned for such environments. Little data exist regarding the effects of spaceflight on untrained commercial passengers. We examined the responses of potential spaceflight participants (SFP) to centrifuge G-force exposure. METHODS: There were 77 individuals (65 men, 12 women), 22-88 yr old, who underwent 6 centrifuge runs over 48 h. Day 1 consisted of two +Gz runs (peak = 3.5+Gz, run 2) and two +Gx runs (peak = 6.0+Gx, run 4). Day 2 consisted of two runs approximating a suborbital spaceflight profile. Data included blood pressure, electrocardiogram, and postrun questionnaires regarding motion sickness, disorientation, greyout, and other symptoms. RESULTS: Of the 77 participants, average age was 50.4 +/- 12.7 yr. Average heart rate (HR) varied by sex and direction of G-exposure (+Gz: F 150 +/- 19, M 123 +/- 27; +Gx: F 135 +/- 30, M 110 +/- 27). Age and peak HR were inversely related (HR < 120 bpm: 60.2 +/- 12.2 yr, HR > 120: 47.1 +/- 10.9 yr). HR during peak G-exposure for the final run was associated with post-run imbalance (no imbalance: HR 126 +/- 26, imbalance: HR 145 +/- 21); no other significant hemodynamic change, sex, or age variation was associated with imbalance. Age and greyout were inversely associated; there was no association between greyout and vital sign change, sex, or G-force magnitude. Baseline/pretrial mean arterial pressure (MAP) was not associated with any symptoms. DISCUSSION: The results suggest that most individuals with well-controlled medical conditions can withstand acceleration forces involved in launch/landing profiles of commercial spaceflight vehicles. Further investigation will help refine which conditions present significant risk during suborbital flight and beyond.

The Hahnemann University Hospital Closure and What Matters: A Department Chair's Perspective.

The closure of Hahnemann University Hospital, which was announced on June 26, 2019, resulted in the most significant graduate medical education displacement in history, sending over 550 residents to new institutions within a month of the announcement. Over 2,000 physicians, nurses, and staff lost their jobs. While seemingly predictable in retrospect, the closure came as a cataclysmic event to all involved. In this Invited Commentary, a department chair reflects on the lessons learned from these unprecedented circumstances. These lessons cover areas that are not a typical concern for faculty who are focused on teaching their trainees, but are worthy of their attention. Corporate and organizational structure, leadership, and financing of the hospital were critical determining characteristics of the failure. The roles that the Accreditation Council for Graduate Medical Education and the Centers for Medicare and Medicaid Services played in this event were key stabilizers. However, examining their roles in this event offers opportunities to play a more active role in future events and alter how the next massive displacement unfolds, possibly preserving teaching programs. Highly competitive health systems should rethink noncollaborative strategies before allowing struggling institutions to succumb to market forces. Finally, a commitment by a hospital to the mission of academic medicine is a sacred trust with the faculty, trainees, and patients that it serves. It should not be undertaken by any enterprise that is not well resourced and equipped with the knowledge and expertise to meet this most serious of commitments.

Construct validity of the Motivated Strategies for Learning Questionnaire.

This study examined the construct validity of the motivational component of the Motivated Strategies for Learning Questionnaire using both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). 327 students enrolled in Bachelor of Education and Graduate Diploma Education courses at the University of Auckland participated in this study (278 women, 49 men). The results of the EFA did not generate support for either a six-factor or three-factor model. The CFA tested a six-factor correlated original model and a respecified model and found a good fit for the respecified model and a better fit of the original 31-item model in comparison with previous studies. In addition, alternative second-order and hierarchical models were tested, none of which showed better fit than the six-factor correlated models. The reasons for the lack of fit of the original model are discussed in light of nonnormality condition, specification error, and latent variables. Finally, possible explanations for the slight variation in patterns of subscale correlations are discussed.

Giant coral reef fishes display markedly different susceptibility to night spearfishing.

The humphead wrasse (Cheilinus undulatus) and bumphead parrotfish (Bolbometopon muricatum) are two of the largest, most iconic fishes of Indo-Pacific coral reefs. Both species form prized components of subsistence and commercial fisheries and are vulnerable to overfishing. C. undulatus is listed as Endangered and B. muricatum as Vulnerable on the IUCN Red List of Threatened Species. We investigated how night spearfishing pressure and habitat associations affected both species in a relatively lightly exploited setting; the Kia fishing grounds, Isabel Province, Solomon Islands. We used fisheries-independent data from underwater visual census surveys and negative binomial models to estimate abundances of adult C. undulatus and B. muricatum as a function of spearfishing pressure and reef strata. Our results showed that, in Kia, night spearfishing pressure from free divers had no measurable effect on C. undulatus abundances, but abundances of B. muricatum were 3.6 times lower in areas of high spearfishing pressure, after accounting for natural variations due to habitat preferences. It is likely the species' different nocturnal aggregation behaviors, combined with the fishers' use of night spearfishing by spot-checking underpin these species' varying susceptibility. Our study highlights that B. muricatum is extremely susceptible to night spearfishing; however, we do not intend to draw conservation attention away from C. undulatus. Our data relate only to the Kia fishing grounds, where human population density is low, the spot-checking strategy is effective for reliably spearing large numbers of fish, particularly B. muricatum, and fisheries have only recently begun to be commercialized; such conditions are increasingly rare. Instead, we recommend that regional managers assess the state of their fisheries and the dynamics affecting the vulnerability of the fishes to fishing pressure based on local-scale, fisheries-independent data, where resources permit.

Restricted grouper reproductive migrations support community-based management.

Conservation commonly requires trade-offs between social and ecological goals. For tropical small-scale fisheries, spatial scales of socially appropriate management are generally small-the median no-take locally managed marine area (LMMA) area throughout the Pacific is less than 1 km(2). This is of particular concern for large coral reef fishes, such as many species of grouper, which migrate to aggregations to spawn. Current data suggest that the catchment areas (i.e. total area from which individuals are drawn) of such aggregations are at spatial scales that preclude effective community-based management with no-take LMMAs. We used acoustic telemetry and tag-returns to examine reproductive migrations and catchment areas of the grouper Epinephelus fuscoguttatus at a spawning aggregation in Papua New Guinea. Protection of the resultant catchment area of approximately 16 km(2) using a no-take LMMA is socially untenable here and throughout much of the Pacific region. However, we found that spawning migrations were skewed towards shorter distances. Consequently, expanding the current 0.2 km(2) no-take LMMA to 1-2 km(2) would protect approximately 30-50% of the spawning population throughout the non-spawning season. Contrasting with current knowledge, our results demonstrate that species with moderate reproductive migrations can be managed at scales congruous with spatially restricted management tools.

Solomon Islands largest hawksbill turtle rookery shows signs of recovery after 150 years of excessive exploitation.

The largest rookery for hawksbill turtles in the oceanic South Pacific is the Arnavon Islands, which are located in the Manning Strait between Isabel and Choiseul Province, Solomon Islands. The history of this rookery is one of overexploitation, conflict and violence. Throughout the 1800s Roviana headhunters from New Georgia repeatedly raided the Manning Strait to collect hawksbill shell which they traded with European whalers. By the 1970s the Arnavons hawksbill population was in severe decline and the national government intervened, declaring the Arnavons a sanctuary in 1976. But this government led initiative was short lived, with traditional owners burning down the government infrastructure and resuming intensive harvesting in 1982. In 1991 routine beach monitoring and turtle tagging commenced at the Arnavons along with extensive community consultations regarding the islands' future, and in 1995 the Arnavon Community Marine Conservation Area (ACMCA) was established. Around the same time national legislation banning the sale of all turtle products was passed. This paper represents the first analysis of data from 4536 beach surveys and 845 individual turtle tagging histories obtained from the Arnavons between 1991-2012. Our results and the results of others, reveal that many of the hawksbill turtles that nest at the ACMCA forage in distant Australian waters, and that nesting on the Arnavons occurs throughout the year with peak nesting activity coinciding with the austral winter. Our results also provide the first known evidence of recovery for a western pacific hawksbill rookery, with the number of nests laid at the ACMCA and the remigration rates of turtles doubling since the establishment of the ACMCA in 1995. The Arnavons case study provides an example of how changes in policy, inclusive community-based management and long term commitment can turn the tide for one of the most charismatic and endangered species on our planet.

Complications of ultrarapid opioid detoxification with subcutaneous naltrexone pellets.

UNLABELLED: Rapid and ultrarapid opioid detoxification (ROD and UROD) centers promise quick, painless, same-day detoxification treatment for patients with opioid addiction. The goal of ROD and UROD is to provide a rapid transition from opioid dependency to oral naltrexone therapy. The patient is given general anesthesia and high-dose opioid antagonists. This induces a severe withdrawal but spares the patient the experience. In theory, the process is complete within four to five hours. The patient awakens without opioid dependency and is started on oral naltrexone. Any subsequent, persistent withdrawal symptoms are treated symptomatically. A novel, unapproved approach is to compound a pellet of naltrexone and implant it in the subcutaneous tissue. In theory, this should result in continuous therapeutic levels for this drug, and avoid issues with noncompliance. CASE SERIES: This article reports six cases of complications from the same detoxification center that performed UROD with naltrexone pellet implantation, including pulmonary edema, prolonged withdrawal, drug toxicity, withdrawal from cross-addiction to alcohol and benzodiazepines, variceal rupture, aspiration pneumonia, and death. CONCLUSIONS: The risks of this procedure are great and further studies should assess its safety and the novel use of naltrexone.

Material appropriate processing and elaboration: The impact of balanced and complementary types of processing on learning concepts from text.

BACKGROUND: The Material Appropriate Processing (MAP) framework suggests that the influence of a text adjunct on the learning and transfer of textual information will be moderated by the overlap between type of processing induced by the adjunct and by the organisation of the text. The two types of processing are item specific processing and relational processing. Although complementary types of processing have been found to produce superior concept learning effects in previous research, there is some question as to the effects of complementary but unbalanced processing. AIMS: This study examined the effects of different combinations of two types of text adjuncts (i.e., elaborative activities) and two types of text on learning concepts from text. The four combined treatments differed as to the degree to which they were balanced and/or complementary. SAMPLE: Participants were 80 undergraduate students who were enrolled in a Year 3 education paper. METHODS: Students studied a passage that included adjuncts which asked them to either: (a) create personal examples of target concepts, or (b) contrast the target concepts. In addition, two versions of text were paired with these adjuncts: specific-only text and specific/relational text. Subjects took a criterion test that consisted of cued recall of definitions, free recall of text, classification of novel examples, and problem solving. RESULTS: Best performance occurred within the condition that included balanced and complementary processing of text/adjunct information, and worst performance occurred in the condition that included non-complementary processing. CONCLUSION: Although these results are consistent with a MAP perspective, the results are equivocal about the potential interfering effects of complementary and unbalanced processing on learning of concepts from text.

Dispersal of grouper larvae drives local resource sharing in a coral reef fishery.

In many tropical nations, fisheries management requires a community-based approach because small customary marine tenure areas define the spatial scale of management [1]. However, the fate of larvae originating from a community's tenure is unknown, and thus the degree to which a community can expect their management actions to replenish the fisheries within their tenure is unclear [2, 3]. Furthermore, whether and how much larval dispersal links tenure areas can provide a strong basis for cooperative management [4, 5]. Using genetic parentage analysis, we measured larval dispersal from a single, managed spawning aggregation of squaretail coral grouper (Plectropomus areolatus) and determined its contribution to fisheries replenishment within five community tenure areas up to 33 km from the aggregation at Manus Island, Papua New Guinea. Within the community tenure area containing the aggregation, 17%-25% of juveniles were produced by the aggregation. In four adjacent tenure areas, 6%-17% of juveniles were from the aggregation. Larval dispersal kernels predict that 50% of larvae settled within 14 km of the aggregation. These results strongly suggest that both local and cooperative management actions can provide fisheries benefits to communities over small spatial scales.

Improving patient safety with ultrasonography guidance during internal jugular central venous catheter placement by novice practitioners.

INTRODUCTION: This study compared ultrasonography-guided (USG) placement with anatomic placement during internal jugular (IJ) central venous catheter (CVC) insertion by novice practitioners using a simulation model. METHODS: A prospective, randomized, crossover study of 28 fourth year medical students was conducted with institutional review board approval. Participants viewed an instructional material before participation, and supervision was standardized. Participants were randomly assigned to either USG or traditional landmark method first, and each group served as its own crossover comparison. Paired t tests and χ analysis were performed on matched-pair data. RESULTS: Fifty-four percent of participants had at least one arterial stick without USG compared with 0% when using USG. Significant differences were shown in the USG versus no-USG groups in number of needle advances until successful cannulation of the vein: mean with USG = 1.5 advances (95% CI, 1.0-1.9), mean without USG = 10.4 advances (95% CI, 7.8-13), P < 0.001; time to successful cannulation: mean with USG = 58 seconds (95% CI, 48-72 seconds), mean without USG = 338 seconds (95% CI, 286-390 seconds), P < 0.001; and success rates: 100% with USG and 42.8% without USG (95% CI, 24.5%-61.1%). The number needed to treat to avoid an arterial stick by using USG during IJ insertion by novice practitioners is ∼2. CONCLUSIONS: The USG during IJ CVC placement by novice practitioners is essential to improve patient safety. If these data are extrapolated to impact on patient care, an arterial stick may be avoided in one of every two IJ CVCs placed by novice practitioners. The USG technology should be made available to novice practitioners needing to place CVCs.

Co-worker fatalities from hydrogen sulfide.

BACKGROUND: Hydrogen sulfide is a colorless, odorless gas that may cause rapid loss of consciousness and respiratory depression without warning. It has produced toxicity in workers in numerous industries and occupations. METHODS: A review of the United States Bureau of Labor Statistics (USBLS) Census of Fatal Occupational Injuries (CFOI) for occupational deaths related to hydrogen sulfide from 1993 to 1999 was performed. RESULTS: Fifty-two workers died of hydrogen sulfide toxicity in this 7-year period. Deaths were most commonly reported in workers who were white (85%), male (98%), and in their first year of employment with the company (48%). Common industries included waste management, petroleum, and natural gas. In 21% of cases, a co-worker died simultaneously or in the attempt to save the workers. CONCLUSIONS: Hydrogen sulfide toxicity is uncommon, but potentially deadly. Toxicity is predominantly in new workers and co-worker fatalities occur in a significant minority of cases. Proper training and education on the warning signs of hydrogen sulfide toxicity may help reduce worker fatalities.