Can a simple blood test quantify brain injury?

Despite significant advances in neurocritical care, it remains difficult to precisely measure the extent of neurological injury in patients affected by stroke, trauma, or cardiac arrest. In the intensive care unit the extent of primary and secondary injury often eludes clinicians, making prognostication imprecise and difficult. Derwall and colleagues present their findings on the dynamics of serum S-100B protein levels in out-of-hospital cardiac arrest survivors. Their study suggests that elevation of S-100B reflects the severity of the primary hypoxic-ischemic insult

The effect of window rooms on critically ill patients with subarachnoid hemorrhage admitted to intensive care

Clinicians and specialty societies often emphasize the potential importance of natural light for quality care of critically ill patients, but few studies have examined patient outcomes associated with exposure to natural light. We hypothesized that receiving care in an intensive care unit (ICU) room with a window might improve outcomes for critically ill patients with acute brain injury. This was a secondary analysis of a prospective cohort study. Seven ICU rooms had windows, and five ICU rooms did not. Admission to a room was based solely on availability. We analyzed data from 789 patients with subarachnoid hemorrhage (SAH) admitted to the neurological ICU at our hospital from August 1997 to April 2006. Patient information was recorded prospectively at the time of admission, and patients were followed up to 1 year to assess mortality and functional status, stratified by whether care was received in an ICU room with a window. Of 789 SAH patients, 455 (57.7%) received care in a window room and 334 (42.3%) received care in a nonwindow room. The two groups were balanced with regard to all patient and clinical characteristics. There was no statistical difference in modified Rankin Scale (mRS) score at hospital discharge, 3 months or 1 year (44.8% with mRS scores of 0 to 3 with window rooms at hospital discharge versus 47.2% with the same scores in nonwindow rooms at hospital discharge; adjusted odds ratio (aOR) 1.01, 95% confidence interval (95% CI) 0.67 to 1.50, P = 0.98; 62.7% versus 63.8% at 3 months, aOR 0.85, 95% CI 0.58 to 1.26, P = 0.42; 73.6% versus 72.5% at 1 year, aOR 0.78, 95% CI 0.51 to 1.19, P = 0.25). There were also no differences in any secondary outcomes, including length of mechanical ventilation, time until the patient was able to follow commands in the ICU, need for percutaneous gastrostomy tube or tracheotomy, ICU and hospital length of stay, and hospital, 3-month and 1-year mortality. The presence of a window in an ICU room did not improve outcomes for critically ill patients with SAH admitted to the ICU. Further studies are needed to determine whether other groups of critically ill patients, particularly those without acute brain injury, derive benefit from natural light

Plant species selection by free-ranging cattle in southern Bolivian tropical montane forests

The frequency of selection of functional groups and plant species by free-ranging cattle foraging in a diverse environment and its changes during the dry and the following prehumid seasons were investigated using direct observations and bite counting. The study was conducted at two sites in the Bolivian-Tucuman montane forests in southern Bolivia, by including datasets of a total of 16 animals. Across both study sites and the entire observation period (May to October/November), the cattle were found to select a broad spectrum of plant species from different functional groups. However, just a limited number of species made up a considerable contribution to overall plant selection. The functional group of the graminoids was selected most frequently, but their contribution to plant selection decreased significantly from 63.5% of total bites in May to 15.9% in September/October, in accordance with a decrease in availability. Selection of woody plants (shrubs and tree parts, the latter mainly in the form of leaf litter and fruits) increased with time, reaching its peak at the beginning of the prehumid season, while the herbs showed a curvilinear pattern of selection which was highest in August. Plant species belonging to the functional groups of ferns, climbers and epiphytes were also selected by the cattle, but generally at low relative proportions. Plant selection might be influenced by temporal differences in nutritional quality and availability of the preferred plant species and functional groups. Sampling behaviour seems to be the most likely reason for the inclusion of a broad range of plant species with overall low contribution to plant selectio

Ethics roundtable: 'Open-ended ICU care: Can we afford it?'

The patient is a 27-year-old previously healthy male with a diagnosis of viral encephalitis with a lymphocytic pleocytosis on cerebrospinal fluid examination. For 3 months, he has been in status epilepticus (SE) on high doses of barbiturates, benzodiazepines, and ketamine and a ketogenic feeding-tube formula. He remains in burst suppression on continuous electroencephalography (EEG). He is trached and has a percutaneous endoscopic gastrostomy (PEG) feeding tube. He has been treated several times for pneumonia, and he is on a warming blanket and is on vasopressors to maintain his blood pressure. His vitals are stable and his lab work is within limits. The sedation is decreased under EEG guidance every 72 hours, after which he goes back into SE and heavy sedation is resumed. The latest magnetic resonance imaging (MRI) shows edema but otherwise no obvious permanent cortical damage. The family wants a realistic assessment of the likely outcome. The neurologist tells them the literature suggests the outlook is poor but not 100% fatal. As long as all of his other organs are functioning on life support, there is always a chance the seizures will stop at some time in the future, and so the neurologist recommends an open-ended intensive care unit (ICU) plan and hopes for that outcome. © 2010 BioMed Central Ltd

Serum glutamine and hospital-acquired infections after aneurysmal subarachnoid hemorrhage

OBJECTIVE: To understand nutritional and inflammatory factors contributing to serum glutamine levels and their relationship to hospital-acquired infections (HAIs) after aneurysmal subarachnoid hemorrhage (SAH). METHODS: A prospective observational study of patients with SAH who had measurements of daily caloric intake and C-reactive protein, transthyretin, tumor necrosis factor α receptor 1a (TNFαR1a), glutamine, and nitrogen balance performed within 4 preset time periods during the 14 days after SAH. Factors associated with glutamine levels and HAIs were analyzed with multivariable regression. HAIs were tracked daily for time-to-event analyses. Outcome 3 months after SAH was assessed by the Telephone Interview for Cognitive Status and modified Rankin Scale. RESULTS: There were 77 patients with an average age of 55 ± 15 years. HAIs developed in 18 (23%) on mean SAH day 8 ± 3. In a multivariable linear regression model, negative nitrogen balance ( CONCLUSIONS: Declining glutamine levels in the first 14 days after SAH are influenced by inflammation and associated with an increased risk of HAI

Dissemination and Sustainability of a Hospital-Wide Hand Hygiene Program Emphasizing Positive Reinforcement

Objective. To increase and sustain hospital-wide compliance with hand hygiene through a long-term ongoing multidimensional improvement program emphasizing behavioral factors. Design. Quasi-experimental short study (August 2000-November 2001) and descriptive time series (April 2003-December 2006). Setting. A 450-bed teaching tertiary-care hospital. Interventions. An initial intervention bundle was introduced in pilot locations that addressed cognitive behavioral factors, which included access to alcohol sanitizer, education, and ongoing audit and feedback. The bundle was subsequently disseminated hospital-wide, along with a novel approach focused on behavior modification through positive reinforcement and annually changing incentives. Results. A total of 36,123 hand hygiene opportunities involving all categories of healthcare workers from 12 inpatient units were observed from October 2000 to October 2006. The rate of compliance with hand hygiene significantly improved after the intervention in 2 cohorts over the first year (from 40% to 64% of opportunities and from 34% to 49% of opportunities; P< .001, compared with the control group). Mean compliance rates ranged from 19% to 41% of 4174 opportunities (at baseline), increased to the highest levels of 73%-84% of 6,420 opportunities 2 years after hospital-wide dissemination, and remained improved at 59%-81% of 4,990 opportunities during year 6 of the program. Conclusion. This interventional cohort study used a behavioral change approach and is one of the earliest and largest institution-wide programs promoting alcohol sanitizer from the United States that has shown significant and sustained improvements in hand hygiene compliance. This creative campaign used ongoing frequent audit and feedback with novel use of immediate positive reinforcement at an acceptable cost to the institutio

Nutritional support and brain tissue glucose metabolism in poor-grade SAH: a retrospective observational study

INTRODUCTION: We sought to determine the effect of nutritional support and insulin infusion therapy on serum and brain glucose levels and cerebral metabolic crisis after aneurysmal subarachnoid hemorrhage (SAH). METHODS: We used a retrospective observational cohort study of 50 mechanically ventilated poor-grade (Hunt-Hess 4 or 5) aneurysmal SAH patients who underwent brain microdialysis monitoring for an average of 109 hours. Enteral nutrition was started within 72 hours of admission whenever feasible. Intensive insulin therapy was used to maintain serum glucose levels between 5.5 and 7.8 mmol/l. Serum glucose, insulin and caloric intake from enteral tube feeds, dextrose and propofol were recorded hourly. Cerebral metabolic distress was defined as a lactate to pyruvate ratio (LPR) > 40. Time-series data were analyzed using a general linear model extended by generalized estimation equations (GEE). RESULTS: Daily mean caloric intake received was 13.8 ± 6.9 cal/kg and mean serum glucose was 7.9 ± 1 mmol/l. A total of 32% of hourly recordings indicated a state of metabolic distress and < 1% indicated a state of critical brain hypoglycemia (< 0.2 mmol/l). Calories received from enteral tube feeds were associated with higher serum glucose concentrations (Wald = 6.07, P = 0.048), more insulin administered (Wald = 108, P < 0.001), higher body mass index (Wald = 213.47, P < 0.001), and lower body temperature (Wald = 4.1, P = 0.043). Enteral feeding (Wald = 1.743, P = 0.418) was not related to brain glucose concentrations after accounting for serum glucose concentrations (Wald = 67.41, P < 0.001). In the presence of metabolic distress, increased insulin administration was associated with a relative reduction of interstitial brain glucose concentrations (Wald = 8.26, P = 0.017), independent of serum glucose levels. CONCLUSIONS: In the presence of metabolic distress, insulin administration is associated with reductions in brain glucose concentration that are independent of serum glucose levels. Further study is needed to understand how nutritional support and insulin administration can be optimized to minimize secondary injury after subarachnoid hemorrhage