Association between elevated brain tissue glycerol levels and poor outcome following severe traumatic brain injury

OBJECT: Glycerol is considered to be a marker of cell membrane degradation and thus cellular lysis. Recently, it has become feasible to measure via microdialysis cerebral extracellular fluid (ECF) glycerol concentrations at the patient's bedside. Therefore the aim of this study was to investigate the ECF concentration and time course of glycerol after severe traumatic brain injury (TBI) and its relationship to patient outcome and other monitoring parameters. METHODS: As soon as possible after injury for up to 4 days, 76 severely head-injured patients were monitored using a microdialysis probe (cerebral glycerol) and a Neurotrend sensor (brain tissue PO2) in uninjured brain tissue confirmed by computerized tomography scanning. The mean brain tissue glycerol concentration in all monitored patients decreased significantly from 206 +/- 31 micromol/L on Day 1 to 9 +/- 3 micromol/L on Day 4 after injury (p < 0.0001). Note, however, that there was no significant difference in the time course between patients with a favorable outcome (Glasgow Outcome Scale [GOS] Scores 4 and 5) and those with an unfavorable outcome (GOS Scores 1-3). Significantly increased glycerol concentrations were observed when brain tissue PO2 was less than 10 mm Hg or when cerebral perfusion pressure was less than 70 mm Hg. CONCLUSIONS: Based on results in the present study one can infer that microdialysate glycerol is a marker of severe tissue damage, as seen immediately after brain injury or during profound tissue hypoxia. Given that brain tissue glycerol levels do not yet add new clinically significant information, however, routine monitoring of this parameter following traumatic brain injury needs further validation.

Outcome after acute traumatic subdural and epidural haematoma in Switzerland: a single-centre experience

BACKGROUND: Acute epidural and subdural haematomas remain among the most common causes of mortality and disability resulting from traumatic brain injury. In the last three decades improvements in rescue, neuromonitoring and intensive care have led to better outcomes. The purpose of this study was to evaluate the impact of these strategies on outcome in patients treated in a single institution in Switzerland. METHODS: A total of 76 consecutive patients who underwent emergency craniotomy for acute traumatic epidural and subdural haematoma at University Hospital Bern between January 2000 and December 2003 were included in this study. RESULTS: Thirty-seven patients presented with an epidural haematoma and 46 with a subdural haematoma. In seven patients both haematomas could be documented. The median age was 54 years (IQR 28). The median initial GCS score was 7 (IQR 6). The median time from primary injury to surgery was 3 hours (IQR 2.5 hours). The median stay in the ICU was 3 days (IQR: 3 days). The outcome was favourable (GOS 4 and 5) in 43 patients (57%). Thirteen patients (17%) remained severely or moderately disabled (GOS 3). Finally, a total of 21 patients (28%) died or remained in a persistent vegetative state (GOS 1 and 2). Mortality was 41% for acute subdural haematoma (19/46) and 3% (1/37) for patients with epidural haematoma. Only age, GCS at admission and pupil abnormalities seemed to be associated with outcome. Time to surgery was not. CONCLUSION: In patients admitted with acute traumatic epidural and subdural haematomas that are treated within a median of 3 hours after primary injury, factors such as age, initial GCS and pupil abnormalities still appear to be the most important factors correlating with outcome.

Sharing evidence of sustainable land management impacts

Ensuring sustainable use of natural resources is crucial for maintaining the basis for our livelihoods. With threats from climate change, disputes over water, biodiversity loss, competing claims on land, and migration increasing worldwide, the demands for sustainable land management (SLM) practices will only increase in the future. For years already, various national and international organizations (GOs, NGOs, donors, research institutes, etc.) have been working on alternative forms of land management. And numerous land users worldwide – especially small farmers – have been testing, adapting, and refining new and better ways of managing land. All too often, however, the resulting SLM knowledge has not been sufficiently evaluated, documented and shared. Among other things, this has often prevented valuable SLM knowledge from being channelled into evidence-based decision-making processes. Indeed, proper knowledge management is crucial for SLM to reach its full potential. Since more than 20 years, the international WOCAT network documents and promotes SLM through its global platform. As a whole, the WOCAT methodology comprises tools for documenting, evaluating, and assessing the impact of SLM practices, as well as for knowledge sharing, analysis and use for decision support in the field, at the planning level, and in scaling up identified good practices. In early 2014, WOCAT’s growth and ongoing improvement culminated in its being officially recognized by the UNCCD as the primary recommended database for SLM best practices. Over the years, the WOCAT network confirmed that SLM helps to prevent desertification, to increase biodiversity, enhance food security and to make people less vulnerable to the effects of climate variability and change. In addi- tion, it plays an important role in mitigating climate change through improving soil organic matter and increasing vegetation cover. In-depth assessments of SLM practices from desertification sites enabled an evaluation of how SLM addresses prevalent dryland threats. The impacts mentioned most were diversified and enhanced production and better management of water and soil degradation, whether through water harvesting, improving soil moisture, or reducing runoff. Among others, favourable local-scale cost-benefit relationships of SLM practices play a crucial role in their adoption. An economic analysis from the WOCAT database showed that land users perceive a large majority of the technologies as having benefits that outweigh costs in the long term. The high investment costs associated with some practices may constitute a barrier to adoption, however, where appropriate, short-term support for land users can help to promote these practices. The increased global concerns on climate change, disaster risks and food security redirect attention to, and trigger more funds for SLM. To provide the necessary evidence-based rationale for investing in SLM and to reinforce expert and land users assessments of SLM impacts, more field research using inter- and transdisciplinary approaches is needed. This includes developing methods to quantify and value ecosystem services, both on-site and off-site, and assess the resilience of SLM practices, as currently aimed at within the EU FP7 projects CASCADE and RECARE.