First-principles evaluation of dopant impact on structural deformability and processability of Li7La3Zr2O12.

Li7La3Zr2O12 (LLZO) and related ceramic solid electrolytes feature excellent stability and reasonable ionic conductivity, but processing remains challenging. High-temperature co-sintering is required for successful integration with the electrode, which is energetically costly and can lead to unacceptable cathode degradation. The introduction of dopants can promote lower-temperature processing by improving deformability and disrupting lattice integrity; however, an unbiased, systematic study correlating these properties to the dopant chemistry and composition is lacking. Here, we rely on a set of static and dynamic metrics derived from first-principles simulations to estimate the impact of doping on LLZO processability by quantifying LLZO structural deformability. We considered three distinct dopants (Al, Ba, and Ta) as representatives of substitutional incorporation on Li, La, and Zr sites. Our descriptors indicate that doping in general positively impacts lattice deformability, although significant sensitivities to dopant identity and concentration are observed. Amongst the tested dopants, Al doping (on the Li site) appears to have the greatest impact, as signaled across nearly the entire set of computed features. We suggest that these proxy descriptors, once properly calibrated against well-controlled experiments, could enable the use of first-principles simulations to computationally screen new ceramic electrolyte compositions with improved processability.

[Standardisation of methods for dilution of intravenous medications in hospital]. / Standardisation des méthods de dilution des medications injectables en unites de soins intensifs et unites conventionnelles.

Introduction The administration of intravenous medications in hospital is a common practice. Although it may seem almost insignificant, this practice remains no less an act which involves risks, due to many factors identified. It is therefore important to gather, clarify and communicate the updated information on the modalities of the administration of these injections in order to facilitate and secure the work of the teams of care with a view of an optimal and standardized administration of intravenous medications. Method The tables of standardization of injectable drugs have been made on several occasions in the past and distributed in the care units. The latest version of these documents was reviewed and updated in the light of the recent editions of several sources. The data concerning each individual injectable medicine have individual as well been systematically updates. The updated data have been integrated into the electronic prescription of medicines, a standardized dilution is now proposed by default to the prescriber. For some drugs, special modalities of administration have been planned to meet the specific needs of patients hospitalized in the Intensive Care Unit (ICU). Results The methods for dilution of injections in classical hospitalization have been integrated in the electronic prescribing software (238 "packages" in total. The specific dilutions used in the ICU (48 in total, have been validated but may not be used in the conventional care units. Conclusion All of the information relating to the methods of preparation and administration have been gathered and clarified in order to facilitate and secure the work of the teams of care and thus enable optimal administration of intravenous medications. The information is accessible on paper file and via the internal computer network, the PC of intensive care units and the software Computerized prescription.

Another case of "European hantavirus pulmonary syndrome" with severe lung, prior to kidney, involvement, and diagnosed by viral inclusions in lung macrophages.

Puumala virus (PUUV) is considered a classic Old World etiologic agent of nephropathia epidemica (NE), or hemorrhagic fever with renal syndrome (HFRS). HFRS is considered to be distinct from hantavirus (cardio-)pulmonary syndrome (HPS or HCPS), described in the New World. Here, we report a severe case, which fulfilled most, if not all, Centers for Disease Control and Prevention (CDC) criteria for HPS, needing non-invasive ventilation and subsequent acute hemodialysis. However, the etiological agent was PUUV, as proved by serological testing, real-time polymerase chain reaction (PCR), and sequencing. Viral antigen was detected by specific anti-PUUV immunostaining, showing, for the first time, greenish intracytoplasmic inclusions in bronchoalveolar lavage (BAL) macrophages. This case definitely confirms that HPS can be encountered during PUUV infections. Interestingly, special findings could render the diagnosis easier, such as greenish homogeneous cytoplasmic inclusions, surrounded by a fine clear halo in BAL macrophages. Therefore, although the diagnosis remains difficult before the onset of renal involvement, the occurrence of severe respiratory failure mimicking community-acquired pneumonia must alert the clinician for possible HPS, especially in endemic areas.

Molecular Dynamics Modeling of the Structure and Na+-Ion Transport in Na2S + SiS2 Glassy Electrolytes.

Solid-state sodium batteries, a relatively safe and potentially cost-effective energy-storage technology, have attracted increasing scientific attention recently for application in stationary grid-scale energy storage. Identifying solid electrolytes with high electrochemical stability and high Na+-ion conductivity at room temperature is critically important to enable high energy densities with enhanced rate capabilities. We evaluated sodium sulfide-silicon sulfide, xNa2S + (1- x)SiS2, glasses as potential glassy solid electrolytes (GSEs) using molecular dynamics (MD) simulations. We employed ab initio MD to determine ion conduction mechanisms, to calculate energy barriers for ion hops, and to correlate these to the local short-range structure of 0.50Na2S + 0.50SiS2 glass. To simulate much larger systems for accurately calculating the ionic conductivity, we parameterized empirical Buckingham-type potential and performed classical MD simulations. After validating these calculations by comparing the structure obtained from MD to that from X-ray scattering data, we calculated the ionic conductivity of these glasses for the range of 0.33 ≤ x ≤ 0.67 compositions. The calculated ionic conductivities at room temperature were in the range of ∼10-5 S/cm for the x = 0.50 composition and increased significantly with sodium sulfide ( x) content. These calculations provide theoretical insights into the role of Na2S content on the ionic conductivity of GSEs aiding in the selection of specific compositions to enhance the ionic conductivity.

Gastric acid and pancreatic polypeptide responses to sham feeding are impaired in diabetic subjects with autonomic neuropathy.

To assess the relationship between cardiac and extra-cardiac dysfunction in diabetic autonomic neuropathy, the gastric acid output and the pancreatic polypeptide (hPP) secretion in response to sham feeding were evaluated in diabetic patients with (group 1) and without (group 2) cardiac autonomic neuropathy (CAN), and in normal subjects (group 3). All patients assigned to the group with CAN exhibited an impaired beat-to-beat heart rate variation during deep breathing. The basal gastric acid output was comparable in the three groups (1.3 +/- 0.5, 2.8 +/- 1.5, and 3.9 +/- 1.5 mmol/h, respectively). In contrast, the gastric acid output stimulated by sham feeding was significantly lower in patients with CAN (5.3 +/- 1.3 mmol/h) than in diabetic subjects without CAN (14.0 +/- 3.5 mmol/h; P less than 0.01) and in controls (10.9 +/- 3.1; P less than 0.05). The maximal gastric acid secretion capacity, determined after pentagastrin injection, was similar in all patients. Mean basal hPP concentrations were comparable in the three groups (185 +/- 53 pg/ml, 131 +/- 29 pg/ml, and 116 +/- 19 pg/ml). In the controls and diabetic subjects without CAN, a significant mean 60% increase of the hPP levels above basal values was observed during sham feeding. In contrast, no significant hPP response occurred in the group with CAN. These data suggest that diabetic CAN is associated with dysfunctions of the vagal pathways controlling the gastric acid output and the hPP secretion. Moreover, the results demonstrate a strong association between cardiac autonomic neuropathy and gastric vagal neuropathy (P less than 0.001).

Functional status and medium-term prognosis of very elderly patients after an ICU stay: a prospective observational study.

BACKGROUND: Because the proportion of elderly patients admitted to the intensive care unit (ICU) is increasing, the objective of this study was to test the hypothesis that very elderly patients with better preadmission functional status would have better medium-term survival and functional status after an ICU stay. METHODS: In this observational study, 96 patients (68% surgical and 32% medical) aged ≥80 years and admitted to the ICU between May 2008 and June 2009 were recruited. Functional status was assessed using a modified Katz Scale and the Lawton Scale. Primary outcomes were: one-year mortality and its independent predictive factors, one-year functional status and perceived quality of life. RESULTS: Multivariate analysis showed that type of admission (surgical vs. medical), existence of cancer, Sequential Organ Failure Assessment (SOFA) Score at ICU admission and occurrence of septic complications during the ICU stay were independent predictive factors for one-year mortality, but preadmission functional status was not. At one year, despite functional decline in 50% of survivors, 68% perceived their health status to be equivalent to or better than before and 82.6% would agree to a further ICU stay. CONCLUSION: One-year mortality of very elderly patients after an ICU stay is not related to preadmission functional status but to the type of admission, existence of cancer, SOFA Score at ICU admission and occurrence of septic complications during the ICU stay. Despite functional decline in half of these patients, one year after admission 82.6% would agree to another ICU stay.

Effect of dopamine on gastrointestinal motility during critical illness.

OBJECTIVE: To document the action of dopamine on gastrointestinal motility in mechanically ventilated patients. DESIGN: Crossover, randomized, placebo-controlled study. SETTING: General intensive care unit (ICU) in a university hospital. PATIENTS: Twelve mechanically ventilated patients in a stable hemodynamic condition, with no contraindication to enteral feeding. INTERVENTIONS: Dopamine (4 microg/kg per minute) and placebo were infused over 8 h (4 h fasting, followed immediately by 4 h nasogastric feeding at 100 kcal per hour) on two consecutive days, in a random order. Pressure changes in the gastric antrum (four sites) and in the duodenum (two sites) were recorded by perfused catheter manometry. Each session started with the institution of dopamine or placebo infusion. MEASUREMENTS AND RESULTS: The migrating motor complex and its three successive phases were identified (phase I, period of quiescence; phase II, period of irregular contractile activity; phase III or activity front, period of high-frequency, regular contractions). Contractions and activity fronts at each site were quantified during fasting and feeding. The mean duration of the fasting migrating motor complex was determined in the duodenum, as well as the contribution of each phase (phases I, II, III) to the length of the complete cycle. The propagation characteristics of each activity front were assessed visually. The number of contractions was lower in the antrum (p = 0.024) and phase III motor activity higher in the duodenum [incidence of activity fronts (p = 0.008); number of phase III contractions (p = 0.009)] during dopamine infusion than with placebo. These modifications observed under dopamine were related to decreased antral contractions during fasting (p = 0.050), increased incidence of activity fronts during feeding (p = 0.031), and increased number of phase III contractions during fasting (p = 0.037). In both groups (placebo and dopamine) activity fronts rarely started in the antrum, and abnormally propagated activity fronts were found in the duodenum in some patients. CONCLUSIONS: Low-dose dopamine adversely affects gastroduodenal motility in mechanically ventilated critically ill patients.

Acute cardiogenic pulmonary edema and pregnancy: a ten-year experience.

We reviewed the cardiac emergencies that occurred during or soon after pregnancy and required admission in an intensive care unit. The study sample consisted of 22248 pregnant women representing the whole obstetrical population collected from 3 hospitals over a ten-year period. Among the 88 patients admitted to our ICU during this decade, only 5 suffered from a specific cardiac disorder. Acute pulmonary edema was the common clinical presentation in the 4 cases reported. Despite the severity of cardiac involvement on admission none had previous evidence of heart disease that could have heralded acute left ventricular failure. From these observations it can be concluded that preexisting cardiovascular disease and circulatory changes related to pregnancy should no longer be regarded as the unique contributors to the development of severe heart failure during pregnancy.

Gastric acidity and duodenogastric reflux during nasojejunal tube feeding in mechanically ventilated patients.

OBJECTIVE: In order to prevent gastric microbial overgrowth, which may complicate nasogastric feeding, administration of nutrients more distally into the gut has been advocated in intensive care patients, as it offers the advantage of keeping the stomach empty and acid. In this study, we assessed the impact of jejunal feeding upon gastic pH in a group of mechanically ventilated, critically ill patients, with special focus on duodenogastric reflux as a possible cause of gastric alkalinization during jejunal nutrition. DESIGN: Prospective experimental study. SETTING: Multidisciplinary intensive care unit of a university hospital. PATIENTS AND METHODS: Gastric pH was recorded by continuous pHmetry over a 4-h period of fasting followed by a 4-h period of nasojejunal feeding at 100 kcal/h in 21 mechanically ventilated, critically ill patients. To determine the contribution of duodenogastric reflux to modifications of gastric acidity, the diet was traced with [(111)In] DTPA (pentetic acid) in 11 of these 21 patients; gastric contents were aspirated every 30 min, then analysed for measurement of radioactivity, glucose, and bile acid concentration. MEASUREMENTS AND RESULTS: Median intragastric pH increased slightly from 1.59 (1.20-2.73; interquartile range) (fasting) to 2.33 (1.65-4.64) (feeding) (p = 0.013), and the length of time that the pH was 4 or above increased from 1 (0-24) to 9 (0-142) min (p = 0.026). The variability of pH values and the number of acute alkalinization episodes did not change between the two phases. In 10 of 11 patients in which the diet was labeled with [(111)In] DTPA, reflux was documented at a given time of the feeding period. Bile acid concentrations in the stomach increased from 392 (61-1076) (fasting) to 1446 (320-2770) micromol/l (feeding) (p = 0.010) and mean glucose concentration increased from 59 (28-95) to 164 (104-449) mg/dl (p = 0.006). CONCLUSION: Duodenogastric reflux is common in mechanically ventilated critically ill patients with nasojejunal feeding tubes. It occurs both during fasting and during nasojejunal feeding. During nasojejunal feeding, moderate alkalinization of the gastric contents occurs as a result of bile and nutrient reflux.

Chronic obstructive pulmonary disease patients with invasive pulmonary aspergillosis: benefits of intensive care?

OBJECTIVES: Invasive pulmonary aspergillosis (IPA) is increasingly recognized as a cause of acute respiratory failure in patients with chronic obstructive pulmonary disease (COPD) treated with corticosteroids. For these patients admission in intensive care unit (ICU) is often required for life-support and mechanical ventilation. Whether this approach improves outcome is unknown. DESIGN AND SETTING: Retrospective study in a university hospital intensive care unit. PATIENTS: Between November 1993 and December 1997, 23 COPD patients were admitted in our ICU and received antifungal agents for possible IPA. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The clinical features and the outcome were reviewed. Diagnosis of IPA was classified as confirmed (positive lung tissue biopsy and/or autopsy) or probable (repeated isolation of Aspergillus from the airways with consistent clinical and radiological findings). Among the 23 patients treated for Aspergillus, 16 fulfilling these criteria for IPA were studied. Steroids had been administered at home to all patients but one and were increased during hospitalization in all. Twelve patients suffered a worsening of their bronchospasm precipitating acute respiratory failure. During ICU stay all patients required mechanical ventilation for acute respiratory failure. Although amphotericin B deoxycholate was started when IPA was suspected (0.5-1.5 mg/kg per day), all patients died in septic shock (n = 5) or in multiple-organ failure. CONCLUSIONS: The poor prognosis of intubated COPD patients with IPA, in spite of antifungal treatment suggests that further studies are required to define the limits and indications for ICU management of these patients.

Duodenal motor response to continuous enteral feeding is impaired in mechanically ventilated critically ill patients.

In order to investigate the duodenal motor response to continuous enteral feeding during critical illness, we recorded the duodenal contractions of 12 mechanically ventilated critically ill patients during a 4 h fasting period immediately followed by another 4 h period of continuous (100 kcal/h) nasogastric feeding with a polymeric diet. Duodenal motility was recorded by manometry (perfused catheter technique) and the migrating motor complexes (MMC) were identified by their activity front (period of high frequency, regular contractions). The incidence and the mean duration of activity fronts as well as the mean duration of the MMC (time interval separating two successive activity fronts) recorded during both periods were compared. The incidence of activity fronts (fasting: median: 2.5, interquartile range: 5.5; feeding: median: 2, interquartile range: 3.5), their duration (fasting: 6.2 +/- 1.6 min; feeding: 5.8 +/- 1.6 min), and the mean duration of the MMC (fasting: 50.9 +/- 24.7 min; feeding: 49.1 +/- 20.3 min) were similar during both periods. We conclude that in these patients, the fasting pattern of motility is not interrupted by the continuous nasogastric administration of a polymeric diet. Since the activity fronts of the MMCs are highly propulsive, we suggest that their abnormal persistence during feeding may play a role in the pathophysiology of unexplained diarrhoea in some critically ill patients.

Unusual manifestations after malathion poisoning.

We report a case of organophosphate poisoning with a commercial preparation of malathion (deliberate ingestion of Malathane Garden Spray: malathion 15% in isopropyl alcohol) in which the initial cholinergic crisis was followed by cardiac, pulmonary, neurological and renal manifestations. They occurred when erythrocyte and plasma cholinesterases were reactivating. A chemical analysis of the pesticide preparation revealed, apart from malathion itself, the presence of isopropylmalathion and O,O,S-trimethylphosphorothioate. Although pure malathion is regarded as one of the safest organophosphate insecticides, this observation underlines the possibility of severe complications after exposure to a preparation which has been stored for a long period of time.

Pyroglutamic acid-induced metabolic acidosis: a case report.

High anion gap metabolic acidosis due to pyroglutamic acid (5-oxoproline) is a rare complication of acetaminophen treatment (which depletes glutathione stores) and is often associated with clinically moderate to severe encephalopathy. Acquired 5-oxoprolinase deficiency (penicillins) or the presence of other risk factors of glutathione depletion such as malnutrition or sepsis seems to be necessary for symptoms development. We report the case of a 55-year-old women who developed a symptomatic overproduction of 5-oxoproline during flucloxacillin treatment for severe sepsis while receiving acetaminophen for fever control. Hemodialysis accelerated the clearance of the accumulated organic acid, and was followed by a sustained clinical improvement.

Polyurethane does not protect better than polyvinyl cuffed tracheal tubes from microaspirations.

BACKGROUND: Mechanically ventilated patients are prone to develop ventilator associated pneumonia due to microaspirations of subglottic secretions around the endotracheal tube cuff (usually constructed of polyvinyl material). A novel polyurethane cuff has been designed to minimize these leakages. The aim of the study was to compare the tracheal sealing capacities between the two tubes. METHODS: Twenty-nine consecutive patients from whom tracheal intubation was necessary as part of their care were randomized to receive either a polyvinyl HI-LO Evac® or a polyurethane SEALGUARD Evac® endotracheal tube. Patients requiring emergency intubation, with unstable hemodynamics or history of tracheal/laryngeal disease were excluded. For the entire study, cuff pressure was set at 30 cmH2O, and ventilator parameters were adjusted for a plateau pressure ≤30 cmH2O; Patients were fasting, placed in a strict 45° position during 12 hours and sedated if needed. After injection of 74 MBq 99mTc-DTPA diluted in 5 mL 0.9% NaCl just above the cuff, tracheal radioactivity was assessed sequentially (hourly from T0 to T6, then T8 and T12 hours) using a scintillation camera. RESULTS: Sixteen polyurethane and 13 polyvinyl tubes were compared. Leakages were observed in 11/29 patients (38%) (5/16 polyurethane and 6/13 polyvinyl tubes [P=NS]). Leakages occurred more often in female (7/8) than in male patients (4/21) (P<0.001). Microaspirations were decreased with larger tubes (size 9 vs. ≤8.5: 24% vs. 75%; P=0.01), whatever the cuff membrane. CONCLUSION: These preliminary results suggest that both tubes are poorly effective in preventing microaspirations.

Invasive pulmonary aspergillosis in patients with chronic obstructive pulmonary disease.

Aspergillus spp. cultured in specimens from the airways of chronic obstructive pulmonary disease (COPD) patients are frequently considered as a contaminant. However, growing evidence suggests that severe COPD patients are at higher risk of developing invasive pulmonary aspergillosis (IPA), although IPA incidence in this population is poorly documented. Some data report that COPD is the underlying disease in 1% of patients with IPA. Definitive diagnosis of IPA in COPD patients is often difficult as tissue samples are rarely obtained before death. Diagnosis is therefore usually based on a combination of clinical features, radiological findings (mostly thoracic computed tomography scans), microbiological results and, sometimes, serological information. Of 56 patients with IPA reported in the literature, 43 (77%) were receiving corticosteroids on admission to hospital. Breathlessness was always a feature of disease and excess wheezing was present in 79% of patients. Fever (>38 degrees C) was present in only 38.5%. Chest pain and haemoptysis were uncommon. Six out of 33 (18%) patients had tracheobronchitis observed during bronchoscopy. The median delay between symptoms and diagnosis was 8.5 days. The mortality rate was high: 53 out of 56 (95%) patients died despite invasive ventilation and antifungal treatment in 43 (77%) of them. In chronic obstructive pulmonary disease patients, invasive pulmonary aspergillosis currently carries a very poor prognosis. Outcome could perhaps be improved by more rapid diagnosis and prompt therapy with voriconazole.

Trichloroethylene and cardiac toxicity: report of two consecutive cases.

About two consecutive cases of acute intoxication by trichloroethylene, the authors want to point out the possible occurrence of serious disturbances in cardiac conduction which are less frequently described in the literature than disturbances in myocardial excitability.