Outcomes following out-of-hospital cardiac arrest in the aeromedical retrieval population of the remote Top End of the Northern Territory, Australia.

OBJECTIVE: Out-of-hospital cardiac arrest is an event with an extremely poor prognosis. There is limited literature on the outcomes for regional Australia, with none specifically addressing remote populations. We aimed to assess out-of-hospital cardiac arrest outcomes in the aeromedical retrieval population of the Top End Medical Retrieval Service. DESIGN: We retrospectively identified all cardiac arrests, deaths and patients who had cardiopulmonary resuscitation within the aeromedical retrieval database for a 5-year period from January 2012 to December 2016. SETTING: Retrieval patients across the Top End of the Northern Territory, Australia. PARTICIPANTS: All patients within the cohort with a non-traumatic out-of-hospital cardiac arrest. MAIN OUTCOME MEASURES: Data were collected on outcomes as per Utstein definitions, along with patient demographics, retrieval timings and interventions. RESULTS: Seventy-five patients suffering cardiac arrest were identified, with 58 having a non-traumatic arrest in an out-of-hospital setting. The median age of the cohort was 40 years, and 53% had an initial shockable rhythm. Return of spontaneous circulation was achieved in 55% and 43% survived to hospital. The survival to hospital discharge and 28 days were 31% and 29%, respectively. CONCLUSIONS: Although the study has a small sample size and limitations on generalisability due to the restricted nature of the cohort selection, the results suggest a 28-day survival rate is potentially comparable to other regions of Australia and the rest of the world. Further research needs to be undertaken in out-of-hospital cardiac arrest in remote regions to establish a true population-based cohort and ascertain where improvements can be made.

Education Needs of Australian Flight Nurses: A Qualitative Study.

OBJECTIVE: Flight nurses work in physically challenging environments, often alone, in the confines of moving aircraft at altitudes with limited resources. Although this challenging environment has been previously described, there are no Australian studies that outline flight nurses' learning needs and the education activities they find useful in learning about their role. METHODS: This was a qualitative exploratory study using one-on-one interviews with 8 currently practicing flight nurses from 1 air medical retrieval organization. Data were analyzed thematically. RESULTS: Four key themes emerged: flight nurses need to learn how to work autonomously in a resource-constrained air medical environment, flight nurses need to learn how to develop physical and mental resilience to work in the air medical environment, flight nurses need to learn nontechnical skills such as flexibility and adaptability, and flight nurses learn how to perform in their role through formal and informal learning strategies. CONCLUSION: Existing clinical knowledge aids decision making as a sole practitioner in the resource-limited air medical environment. Previously unreported nontechnical skills of mental resilience, adaptability, and flexibility were highlighted. Flight nurses learn how to prepare for their role through simulation, case reviews, in situ observation through buddy flights, and a range of socially situated learning activities.

Is Nifedipine as a Tocolytic Effective in Facilitating In Utero Transfer?

OBJECTIVE: Previous studies have reported that air medical transfer of women in preterm labor can be safely accomplished, without preterm birth occurring; in fact, many women were later discharged without preterm birth occurring. The purpose of this study was to determine if nifedipine, when used as a tocolytic, is effective at facilitating in utero transfer of women in preterm labor in the Top End of the Northern Territory of Australia. METHODS: This was a retrospective descriptive study over a 3-year period of all women transported in preterm labor between 23 + 6 to 36 + 6 weeks' gestation of pregnancy (N = 325). RESULTS: The average gestation period was 32 + 2 weeks. The mean retrieval time was 6 hours. The mean time of birth from referral was 33 hours. A number of women gave birth to a preterm newborn in a remote health center (17%). There were 3 in-flight preterm births, and 49% of women were discharged without a preterm birth occurring. All women transported by air medical retrieval were admitted to the tertiary hospital for at least 24 hours. CONCLUSION: In this study, nifedipine was used successfully to facilitate in utero transfer in many cases. Nearly half of the women referred were discharged without preterm birth occurring. Findings compare favorably with other published studies.

Management of Septic Shock in the Remote Prehospital Setting.

This study aims to assess the management of septic shock by air medical retrieval teams in the remote setting. A retrospective observational study was performed over 36 months. Sixty-seven adult patients who met the criteria for septic shock were included. Respiratory sepsis was the working diagnosis for 53% of patients; this was confirmed on intensive care unit (ICU) discharge in 39% of patients. Intravenous antibiotics and oxygen were delivered in over 90% of patients. Central and arterial line insertions were performed in 48% and 40% of patients, respectively, and 79% of patients were catheterized. Thirty-three percent of patients required intubation, and 80% of patients received an initial crystalloid fluid bolus of 20 mL/kg. Vasopressors were started in 89% of patients. Upon reaching definitive care, 91% of patients were admitted to a high-dependency or ICU setting, with a median length of ICU stay of 4 days and a 30-day mortality of 13%. Of those admitted to the ICU, intubation was required in 48%, new renal support in 20%, and blood pressure support in 84% of patients, respectively. Septic shock was recognized early and managed aggressively by remote retrieval teams, which may have contributed to the low mortality rate observed.

A Case Review: In-Flight Births Over a 4-Year Period in the Northern Territory, Australia.

OBJECTIVE: There has been much newspaper and online news coverage of in-flight obstetric births on commercial aircraft over several decades. This case series reviews several cases of in-flight birth and immediate maternal and neonatal outcomes from air medical retrievals in the Northern Territory of Australia over a 4-year [corrected] period. METHODS: This is a retrospective written case note and electronic medical retrieval record analysis of 4 patients undergoing in-flight, at altitude, obstetric birth. RESULTS: Four premature births are recorded by CareFlight Operations over a 4-year period from January 2011 to January 2015. All patients involved were preterm; term ranged from 22 weeks to 36 weeks. Tocolysis was implemented on all 4 patients according to local obstetric guidelines. Maternal complications included 1 patient suffering antepartum hemorrhage and 2 patients suffering postpartum hemorrhage. Three neonates born at altitude needed neonatal resuscitation including positive-pressure ventilation. One neonate, 22 weeks' gestation, died approximately 2 hours after delivery. Maternal follow-up showed no morbidity or mortality at 1 to 6 days after birth. CONCLUSION: In-flight deliveries are rare events in air medical medicine. This case series includes patients of variable preterm gestation and correlates poor outcomes to prematurity of neonates. Close communication between remote clinics, obstetric centers, and air medical teams plus up-to-date early labor guidelines are essential for safe practice and to limit the risk of in-flight births.

The phenotype of a germline mutation in PIGA: the gene somatically mutated in paroxysmal nocturnal hemoglobinuria.

Phosphatidylinositol glycan class A (PIGA) is involved in the first step of glycosylphosphatidylinositol (GPI) biosynthesis. Many proteins, including CD55 and CD59, are anchored to the cell by GPI. Loss of CD55 and CD59 on erythrocytes causes complement-mediated lysis in paroxysmal nocturnal hemoglobinuria (PNH), a disease that manifests after clonal expansion of hematopoietic cells with somatic PIGA mutations. Although somatic PIGA mutations have been identified in many PNH patients, it has been proposed that germline mutations are lethal. We report a family with an X-linked lethal disorder involving cleft palate, neonatal seizures, contractures, central nervous system (CNS) structural malformations, and other anomalies. An X chromosome exome next-generation sequencing screen identified a single nonsense PIGA mutation, c.1234C>T, which predicts p.Arg412(∗). This variant segregated with disease and carrier status in the family, is similar to mutations known to cause PNH as a result of PIGA dysfunction, and was absent in 409 controls. PIGA-null mutations are thought to be embryonic lethal, suggesting that p.Arg412(∗) PIGA has residual function. Transfection of a mutant p.Arg412(∗) PIGA construct into PIGA-null cells showed partial restoration of GPI-anchored proteins. The genetic data show that the c.1234C>T (p.Arg412(∗)) mutation is present in an affected child, is linked to the affected chromosome in this family, is rare in the population, and results in reduced, but not absent, biosynthesis of GPI anchors. We conclude that c.1234C>T in PIGA results in the lethal X-linked phenotype recognized in the reported family.

Trends in stroke survival incidence rates in older Australians in the new millennium and forecasts into the future.

AIMS: The objective of this study is (i) to evaluate trends in the incidence rates of stroke survivors aged 60 years and older over a 11-year period in the Australian Capital Territory (ACT) and (ii) to forecast future trends in Australia until 2051. METHODS: Analysis of age- and sex-specific standardized incidence rates of older first-ever stroke survivors in ACT from 1999-2000 to 2009-2010 and projections of number of stroke survivors (NSS) in 2021 and 2051 using 2 models based only on (i) demographic changes and (ii) assuming changing of both incidence rates and demography. RESULTS: In the ACT in the first decade of the 21st century, the absolute numbers and age-adjusted standardized incidence rates of stroke survivors (measured as a function of age and period) increased among both men and women aged 60 years or older. The trend toward increased survival rates in both sexes was driven mainly by population aging, whereas the effect of stroke year was more pronounced in men compared with women. The absolute NSS (and the financial burden to the society) in Australia is predicted to increase by 35.5%-59.3% in 2021 compared with 2011 and by 1.6- to 4.6-fold in 2051 if current only demographic (first number) or both demographic and incidence trends (second number) continue. CONCLUSIONS: Our study demonstrates favorable trends in stroke survivor rates in Australia in the first decade of the new millennium and projects in the foreseeable future significant increases in the absolute numbers of older stroke survivors, especially among those aged 70 years or older and men.

Reciprocal modulation of internal and external factors determines individual movements.

Movement is fundamental to individual and population dynamics, as it allows individuals to meet their basic requirements. Although movement patterns reflect interactions between internal and external factors, only few studies have examined the effects of these factors on movement simultaneously, and they generally focused on particular biological contexts (e.g. dispersal, foraging). However, the relative importance of these factors in driving individual routine movements might reflect a species' potential flexibility to cope with landscape changes and therefore buffer their potential impact on fitness. We used data from GPS collars on Scandinavian brown bears to investigate the relative role of these factors, as well as an additional factor (period of the year) on routine movements at two spatial scales (hourly and daily relocations). As expected, internal factors played a major role in driving movement, compared to external factors at both scales, but its relative importance was greater at a finer scale. In particular, the interaction between reproductive status and period of the year was one of the most influential variables, females being constrained by the movement capacity of their cubs in the first periods of the year. The effect of human disturbance on movement was also greater for females with cubs than for lone females. This study showed how reciprocal modulation of internal and external factors is shaping space use of brown bears. We stress that these factors should be studied simultaneously to avoid the risk of obtaining context-dependent inferences. Moreover, the study of their relative contribution is also highly relevant in the context of multiple-use landscapes, as human activities generally affect the landscape more than they affect the internal states of an individual. Species or individuals with important internal constraints should be less responsive to changes in their environment as they have less freedom from internal constraints and should thus be more sensitive to human alteration of the landscape, as shown for females with cubs in this study.

Predator-prey spatial game as a tool to understand the effects of protected areas on harvester-wildlife interactions.

No-take reserves are sometimes implemented for sustainable population harvesting because they offer opportunities for animals to spatially avoid harvesters, whereas harvesters can benefit in return from the reserve spillover. Here, we used the framework of predator-prey spatial games to understand how protected areas shape spatial interactions between harvesters and target species and determine animal mortality. In these spatial games, the "predator" searches for "prey" and matches their habitat use, unless it meets spatial constraints offering the opportunity for prey to avoid the mortality source. However, such prey refuges could attract predators in the surroundings, which questions the potential benefits for prey. We located, in the Geneva Basin (France), hunting dogs and wild boar Sus scrofa L. during hunting seasons with global positioning systems and very-high-frequency collars. We quantified how the proximity of the reserve shaped the matching between both habitat uses using multivariate analyses and linked these patterns to animals' mortality with a Cox regression analysis. Results showed that habitat uses by both protagonists disassociated only when hunters were spatially constrained by the reserve. In response, hunters increased hunting efforts near the reserve boundary, which induced a higher risk exposure for animals settled over the reserve. The mortality of adult wild boar decreased near the reserve as the mismatch between both habitat uses increased. However the opposite pattern was determined for younger individuals that suffered from the high level of hunting close to the reserve. The predator-prey analogy was an accurate prediction of how the protected area modified spatial relationships between harvesters and target species. Prey-searching strategies adopted by hunters around reserves strongly impacted animal mortality and the efficiency of the protected area for this harvested species. Increasing reserve sizes and/or implementing buffer areas with harvesting limitations can dampen this edge effect and helps harvesters to benefit durably from source populations of reserves. Predator-prey spatial games therefore provide a powerful theoretical background for understanding wildlife-harvester spatial interactions and developing substantial application for sustainable harvesting.

Common drivers of seasonal movements on the migration - residency behavior continuum in a large herbivore.

This study aimed to (1) identify the scale of environmental drivers of seasonal movements on the migration - residency behavior continuum in a large herbivore species and to (2) test the hypothesis that the same environmental drivers and spatio-temporal scaling should influence spatial processes in both migrants (long distance migration) and residents (short distance range shifts). We performed a comparative analysis of the influence of plant phenology and snow cover duration on seasonal movements of five partially migrating red deer populations with contrasting environmental conditions, at the seasonal range scale and at the study area scale. The five populations presented varying proportions of migrants, large gradients of migration distances and seasonal range shifts. The probability for a red deer to migrate was strongly influenced by large-scale environmental conditions, consistent with the resource heterogeneity hypothesis (high spatio-temporal scaling favors migration). Distances moved by both migrants and residents were strongly related to large-scale environmental conditions as well. We showed that similar proximal causes influenced these seasonal movements, reinforcing the idea of a continuum from migration to residency in response to seasonal environmental changes. Together, our findings suggest that global warming, by homogenizing large-scale environmental conditions, may thus decrease migratory tactics.

Identifying Space Use at Foraging Arena Scale within the Home Ranges of Large Herbivores.

An intermediate spatiotemporal scale of food procurement by large herbivores is evident within annual or seasonal home ranges. It takes the form of settlement periods spanning several days or weeks during which foraging activity is confined to spatially discrete foraging arenas, separated by roaming interludes. Extended by areas occupied for other activities, these foraging arenas contribute towards generating the home range structure. We delineated and compared the foraging arenas exploited by two African large herbivores, sable antelope (a ruminant) and plains zebra (a non-ruminant), using GPS-derived movement data. We developed a novel approach to specifically delineate foraging arenas based on local change points in distance relative to adjoining clusters of locations, and compared its output with modifications of two published methods developed for home range estimation and residence time estimation respectively. We compared how these herbivore species responded to seasonal variation in food resources and how they differed in their spatial patterns of resource utilization. Sable antelope herds tended to concentrate their space use locally, while zebra herds moved more opportunistically over a wider set of foraging arenas. The amalgamated extent of the foraging arenas exploited by sable herds amounted to 12-30 km2, compared with 22-100 km2 for the zebra herds. Half-day displacement distances differed between settlement periods and roaming interludes, and zebra herds generally shifted further over 12h than sable herds. Foraging arenas of sable herds tended to be smaller than those of zebra, and were occupied for period twice as long, and hence exploited more intensively in days spent per unit area than the foraging arenas of zebra. For sable both the intensity of utilization of foraging arenas and proportion of days spent in foraging arenas relative to roaming interludes declined as food resources diminished seasonally, while zebra showed no seasonal variation in these metrics. Identifying patterns of space use at foraging arena scale helps reveal mechanisms generating the home range extent, and in turn the local population density. Thereby it helps forge links between behavioural ecology, movement ecology and population ecology.

Coping with spatial heterogeneity and temporal variability in resources and risks: adaptive movement behaviour by a large grazing herbivore.

Movement is a key mean for mobile species to cope with heterogeneous environments. While in herbivorous mammals large-scale migration has been widely investigated, fine-scale movement responses to local variations in resources and predation risk remain much less studied, especially in savannah environments. We developed a novel approach based on complementary movement metrics (residence time, frequency of visits and regularity of visits) to relate movement patterns of a savannah grazer, the blue wildebeest Connochaetes taurinus, to fine-scale variations in food availability, predation risk and water availability in the Kruger National Park, South Africa. Wildebeests spent more time in grazing lawns where the grass is of higher quality but shorter than in seep zones, where the grass is of lower quality but more abundant. Although the daily distances moved were longer during the wet season compared to the dry season, the daily net displacement was lower, and the residence time higher, indicating a more frequent occurrence of area-concentred searching. In contrast, during the late dry season the foraging sessions were more fragmented and wildebeests moved more frequently between foraging areas. Surprisingly, predation risk appeared to be the second factor, after water availability, influencing movement during the dry season, when resources are limiting and thus expected to influence movement more. Our approach, using complementary analyses of different movement metrics, provided an integrated view of changes in individual movement with varying environmental conditions and predation risk. It makes it possible to highlight the adaptive behavioral decisions made by wildebeest to cope with unpredictable environmental variations and provides insights for population conservation.

Selecting habitat to survive: the impact of road density on survival in a large carnivore.

Habitat selection studies generally assume that animals select habitat and food resources at multiple scales to maximise their fitness. However, animals sometimes prefer habitats of apparently low quality, especially when considering the costs associated with spatially heterogeneous human disturbance. We used spatial variation in human disturbance, and its consequences on lynx survival, a direct fitness component, to test the Hierarchical Habitat Selection hypothesis from a population of Eurasian lynx Lynx lynx in southern Norway. Data from 46 lynx monitored with telemetry indicated that a high proportion of forest strongly reduced the risk of mortality from legal hunting at the home range scale, while increasing road density strongly increased such risk at the finer scale within the home range. We found hierarchical effects of the impact of human disturbance, with a higher road density at a large scale reinforcing its negative impact at a fine scale. Conversely, we demonstrated that lynx shifted their habitat selection to avoid areas with the highest road densities within their home ranges, thus supporting a compensatory mechanism at fine scale enabling lynx to mitigate the impact of large-scale disturbance. Human impact, positively associated with high road accessibility, was thus a stronger driver of lynx space use at a finer scale, with home range characteristics nevertheless constraining habitat selection. Our study demonstrates the truly hierarchical nature of habitat selection, which aims at maximising fitness by selecting against limiting factors at multiple spatial scales, and indicates that scale-specific heterogeneity of the environment is driving individual spatial behaviour, by means of trade-offs across spatial scales.

MRI features of 4 female patients with pyruvate dehydrogenase E1 alpha deficiency.

Pyruvate dehydrogenase complex is a key intramitochondrial multienzyme complex required for the conversion of pyruvate to acetyl-CoA. Most patients with pyruvate dehydrogenase deficiency have a defect in the E1 alpha subunit, associated with mutations in the PDHA1 gene. In this report, we submit detailed magnetic resonance images in 4 affected female patients with PDHA1 mutations who had with severe cortical atrophy, dilated ventricles, and an incomplete corpus callosum. In one of these patients, the magnetic resonance imaging pattern prompted molecular diagnostic testing when enzymatic testing was normal. We underscore that this constellation of features, which may be misdiagnosed as periventricular leukomalacia, illustrates a pattern highly suggestive of a deficiency of pyruvate dehydrogenase E1 alpha in female patients and should trigger appropriate diagnostic investigations.

Bisphosphonate use and hip fracture epidemiology: ecologic proof from the contrary.

AIM: The objective of this article is to evaluate the relationship between the changes in prescriptions of antiosteoporotic drugs (mainly the rapid fall in the use of bisphosphonates [BPs]) and standardized hip fracture (HF) rates over the period 2005-2008 in the Australian Capital Territory (ACT). METHODS: Annual sex- and age-specific HF rates (per 100,000 population) were determined and standardized using the Australian 2006 population census. Data on the annual prescriptions of BPs (mainly alendronate and risedronate), strontium ranelate, and hormone replacement therapy were obtained from the Australian Pharmaceutical Benefits Scheme (PBS) and Repatriation Australian Pharmaceutical Benefits Scheme (RPBS) databases. RESULTS: In the ACT, the peak annual number of prescriptions for BPs was observed in 2006. Following reports linking osteonecrosis of the jaw with BP use, the number of BP prescriptions dropped by 14% in 2007-2008 compared with 2005, when the lowest HF rates were recorded. The reduction in BP prescriptions coincided with increased HF rates in females in 2007 (+22.6%) and in 2008 (+25.2%) compared with 2005; in males, HF incidence declined by 6.6% and 16.7%, respectively. The proportion of filled prescriptions for strontium ranelate, risedronate, and alendronate in 2007-2008 was 1:8.4:15.5, indicating that BPs were the dominant antiosteoporotic drugs. There was an inverse statistically significant relationship between the total annual number of BP prescriptions and standardized HF incidence rates for the 10-year period 1999-2008. CONCLUSION: Although currently there is no clear understanding of factors contributing to changing HF epidemiology, the available evidence suggests that much of the decline in HF rates is due to the use of BPs. The fall in the use of BPs is associated with an increase in HF rates in females, indicating that BPs should still be considered the first-line medications for the prevention and treatment of osteoporosis. Our results need to be confirmed in other populations and countries.