Intradialytic hypotension prevention and management knowledge and practices: Results from a survey of Australian and New Zealand nephrology nurses

Intradialytic hypotension (IDH) remains the most frequent serious side effect of hemodialysis, increasing morbidity in patients on hemodialysis. Nephrology nurses have a critical role in the prevention and management of IDH. The aim of this study was to investigate nephrology nurse knowledge and practice habits in the prevention and management of IDH. This was an explorative cross-sectional design, web-based survey of Australian and New Zealand nephrology nurses (n = 173). IDH definitions, blood pressureinterpretation, and IDH interventions were inconsistent and not always evidencebased.Demographic characteristics had little impact on the variation in responses. A universal definition for IDH may improve early recognition of the problem. Formal guidelines in considering individualized interventional strategies for asymptomaticepisodes prior symptomatic IDH occurrence may improve outcomes for patients on hemodialysis

Small reptile community responses to rotational logging

Timber harvesting is a common global disturbance that has important effects on the ability of forests to provide ecosystems services and retain biodiversity. Using predictive frameworks to examine biodiversity responses to logging could assist in retaining natural forest values. The intermediate disturbance hypothesis (IDH) and the habitat accommodation model (HAM) potentially offer frameworks for explaining different coarse scale community responses to logging. We used a 60. year post-logging chronosequence to investigate small reptile community responses to age post-logging in temperate forests using three metrics (species richness, evenness and relative abundance). First, we evaluated if variation in these metrics adhered to prior predictions, including the IDH. Second, we evaluated how age post-logging influence community responses through fine scale vegetation elements. Third, we evaluated support for the HAM by measuring compositional change (species turnover) of small reptile community to age post-logging. Reptile relative abundance exhibited a curvilinear relationship to age since logging, contradicting our prior prediction of sustained increase. Species richness and evenness were unrelated to age since logging thus providing no support to IDH and other prior predictions. Relative abundance and richness did not relate to any vegetation characteristic tested. These metrics were also unrelated to logging method. Community composition was marginally significantly influenced by age since logging, thus supporting the HAM. Our results suggest that forest reptiles exposed to logging exhibit variable changes depending on the community metric in question, and that different approaches, including those based on species traits, are needed to improve evaluating disturbance related biodiversity responses.

Evaluating the role of fire disturbance in structuring small reptile communities in temperate forests

Fire is an integral disturbance shaping forest community dynamics over large scales. However, understanding the relationship between fire induced habitat disturbance and biodiversity remain equivocal. Ecological theories including the intermediate disturbance hypothesis (IDH) and the habitat accommodation model (HAM) offer predictive frameworks that could explain faunal responses to fire disturbances. We used an 80 year post-fire chronosequence to investigate small reptile community responses to fires in temperate forests across 74 sites. First, we evaluated if changes in species richness, abundance and evenness post-fire followed trends of prior predictions, including the IDH. Second, using competing models of fine scale habitat elements we evaluated the specific ways which fire influenced small reptiles. Third, we evaluated support for the HAM by examining compositional changes of reptile community post-fire. Relative abundance was positively correlated to age post-fire while richness and evenness showed no associations. The abundance trend was as expected based on the prior prediction of sustained population increase post-disturbance, but the trend for richness contradicted the prediction of highest diversity at intermediate levels of disturbance (according to IDH). Abundance changes were driven mainly by changes in overstorey, ground layer, and shelter, while richness and evenness did not associate with any vegetation parameter. Community composition was not strongly correlated to age since fire, thus support for the HAM was weak. Overall, in this ecosystem, frequent fire disturbances can be detrimental to small reptiles. Future studies utilizing approaches based on species traits could enhance our understanding of biodiversity patterns post-disturbance.

Asymptomatic intradialytic hypotension: the need for pre-emptive intervention

Intradialytic hypotension (IDH) remains the most common severe side effect of hemodialysis despite numerous technological advancements. Recent evidence emphasises the significance of asymptomatic hypotensive episodes, as well as the hypoperfusive consequences of both relative blood pressure drops and repetitive, symptomatic events. This article reviews the physiological importance of rapid blood pressure decrease during hemodialysis, and highlights the pathological consequences of repeated asymptomatic and symptomatic hypoperfusive episodes. In proposing a view concerned with asymptomatic IDH, a practicalpre-emptive intervention is offered to improve the long-term outcomes of patients on hemodialysis. Ongoing monitoring of individual patient's mean arterial pressure (MAP) throughout the dialysis treatment can facilitate the identification of an asymptomatic hypotensive episode. A brief pause in ultrafiltration enables vascular refill and subsequent increase in MAP, allowing resumption of safe fluid removal. Such enhanced assessment results in a reduction off patient risk, allowing safe and optimal fluid removal.