The Mercury Planetary Orbiter will be a three-axis stabilized spacecraft and nadir pointing to Mercury center-of-mass. The pointing accuracy, needed for the very ambitious goals of the ESA space ...mission to Mercury denominated BepiColombo, is reached thanks to the onboard reaction wheels, and it is also required during the unobserved arcs. The unavoidable manoeuvres of desaturation of the reaction wheels, which are necessary to remove the accumulated angular momentum, represent a clear reduction of the accuracy of the objectives of the ESA space mission. Indeed, these manoeuvres are performed through the spacecraft thrusters and directly impact the accuracy of the propagated state-vector of the satellite at the beginning of the subsequent observed arc. Their impact is quantified by their number, position along the orbit and, especially, in the uncertainty in the linear momentum transferred to the spacecraft. The present paper is devoted to prove the feasibility of the speed variation measurements produced by the thruster thanks to the onboard accelerometer, ISA. Therefore, such measurements may be an essential ingredient in order to preserve the accuracy of the BepiColombo Radio Science Experiments and of other onboard instruments pointing accuracy, as is the case of BELA. This additional capability of ISA strengthens once more the key role of the accelerometer in the BepiColombo mission to Mercury.
Because of the wide range of etiologies which may provoke status epilepticus (SE), physical examination, laboratory tests and neuroimaging must be conducted according to a well-designed hierarchical ...system. While implementing intensive care management, clinicians must of course search for curable causes but also consider the possible interaction of multiple factors and hidden diseases favoring or triggering SE. Causes of SE in idiopathic or cryptogenic epilepsy and new-onset SE do not correlate but careful analysis of serum chemistry and neuroimaging abnormalities must nevertheless be conducted with the specific objective of establishing an etiological diagnosis.
Le traitement de l’état de mal épileptique (EME) réfractaire aux benzodiazépines et à d’autres antiépileptiques repose sur l’utilisation de médicaments induisant un coma pharmacologique, tels que le ...thiopental, le propofol ou le midazolam. Ces substances présentent des caractéristiques pharmacodynamiques et surtout pharmacocinétiques assez différentes, mais n’ont pas bénéficié d’une comparaison directe prospective. Leur utilisation est clairement conseillée lors d’EME généralisés convulsifs, alors que l’approche lors d’EME partiel–complexes ou d’absence est souvent moins radicale au vu du pronostic plus bénin de ces dernières conditions. L’aspect le plus important ne paraît donc pas être relatif au médicament spécifique utilisé, mais plutôt à la pose des bonnes indications et au choix des bons dosages. Il est conseillé de cibler un tracé électroencéphalographique de burst–suppression pendant au moins 24heures, avant de réduire progressivement le dosage sous contrôle EEG. En cas d’échec, l’utilisation d’autres substances, y compris des anesthésiques volatiles, a été rapportée.
Status epilepticus (SE) refractory to benzodiazepines and other antiepileptic agents is managed with intravenous anesthetic compounds, such as thiopental, propofol or midazolam. These drugs display quite different pharmacodynamic and pharmacokinetic properties, but have not been prospectively compared to date. Their use is clearly advocated for the treatment of generalized convulsive SE, whereas partial–complex, or absence SE are generally managed less aggressively, in consideration of their better prognosis. The most important aspect seems to be related to the correct use of these anesthetics in the right context, rather than the choice of one specific compound. An electroencephalographic burst–suppression should be targeted for about 24hour, before progressive weaning of the dosage under EEG monitoring. If this approach proves unsuccessful, the use of other drugs, including inhalational anesthetics, has been described.
L’extrême variété des étiologies pouvant provoquer un état de mal épileptique (EME) nécessite une hiérarchisation des examens complémentaires – guidée par l’examen clinique. Conjointement à la prise ...en charge réanimatoire, la recherche d’une cause curable ne doit pas faire occulter les possibles imbrications avec les nombreux facteurs d’entretien qui doivent eux aussi être diagnostiqués et traités. Les causes d’EME chez le patient épileptique connu diffèrent de celles liées à un EME inaugural mais la recherche de troubles métaboliques est incontournable et les indications de l’imagerie cérébrale doivent rester larges dans les deux cas. L’obtention d’un diagnostic est impérative.
Because of the wide range of etiologies which may provoke status epilepticus (SE), physical examination, laboratory tests and neuroimaging must be conducted according to a well-designed hierarchical system. While implementing intensive care management, clinicians must of course search for curable causes but also consider the possible interaction of multiple factors and hidden diseases favoring or triggering SE. Causes of SE in idiopathic or cryptogenic epilepsy and new-onset SE do not correlate but careful analysis of serum chemistry and neuroimaging abnormalities must nevertheless be conducted with the specific objective of establishing an etiological diagnosis.
Recurrent acute chest syndrome (ACS) has been suggested as a risk factor for chronic lung dysfunction in sickle cell disease. To investigate this hypothesis, lung function tests were performed in 49 ...sickle cell disease outpatients whose condition was stable, including 23 patients with a history of two to four episodes of ACS (ACS+) and 26 with no history of ACS (ACS-). The two groups were comparable regarding the sex ratio, body mass index, smoking history, physical characteristics, clinical history and usual lung function tests. Respiratory resistance (Rrs), measured using the forced oscillation technique, increased with the number of ACS episodes (r=0.55, p<0.0001) and a significant relationship was observed between Rrs as an independent variable and the expiratory flow rates at 25, 50 and 25-75% of the forced vital capacity as explanatory variables (r= 0.36, p<0.02; r=0.35, p<0.02; and r=0.4, p<0.006, respectively), with higher Rrs being associated with lower expiratory flow rates. The transfer factor (TL,CO) and transfer coefficient (KCO) for CO were significantly higher in the ACS+ group than in the ACS-group (TL,CO=84+/-4 versus 71+/-3%, p<0.004 and KCO=102+/-5 versus 90+/-3%, p<0.05, respectively). The data demonstrate that obstructive lung dysfunction is fairly common in sickle cell disease and suggest that recurrent acute chest syndrome may contribute specific obstructive defects. The increase in respiratory resistance associated with acute chest syndrome was accompanied by an increase in diffusion capacity, suggesting that it may have been related to an increase in lung blood volume.
Stroke can produce irreversible brain damage of massive proportion leading to severe disability and poor quality of life. Resuscitation and mechanical ventilation of these patients remain ...controversial because of the high mortality and severe disability involved.
When prognosis is very poor, do-not-resuscitate orders (DNR orders) and withhold or withdrawal of treatment may be discussed. Studies have shown that DNR orders are relatively frequent in acute stroke: up to 30% of all patients, and 50% of which are given upon admission. DNR orders are closely associated with severity of the neurological deficit and age. Precise estimates of withhold and withdrawal of treatment are not available, but terminal extubations in severe stroke could contribute to 40,000 to 60,000 acute stage deaths per year. Little is known about the decision making process and palliative care in these situations. The neurological prognosis is the main explicit criterion. However, evaluation of neurological outcome is highly uncertain and difficult, and does not always reflect quality of life. Several studies have raised the issue of this disability paradox. Thus, physician estimation of prognosis has a profound impact on decisions for life sustaining therapies, and may lead to self-fulfilling prophecies in case of false appreciation of published evidence. Other criteria could influence the withhold and withdrawal of treatment decision, such as social conditions and patient values.
Decisions for life-sustaining therapies in severe stroke are always difficult and often based on subjective and uncertain criteria. We have to improve prognosis estimation and our understanding of patient preferences to promote patient-centered care. An ethical approach may guide these complex decisions.
We presents the results of an activity concerning the test of the Einstein Weak Equivalence Principle with an accuracy of about 5×10−15. The experiment will be performed in an “Einstein elevator” ...using a differential accelerometer with a final sensitivity of about 10−14g⊕/Hz1/2. The differential accelerometer is spun about an horizontal axis at a frequency in the range 0.5–1Hz in order to modulate, during the free fall, the signal from a possible violation of the Equivalence Principle. In the paper the perturbing effects with the same signature of the possible violation are analyzed and constrained. The experimental results obtained in the laboratory with a first prototype of the differential accelerometer are discussed, comparing this results with those obtained using a new prototype.
To better understand the epidemiology and patterns of tracheostomy practice for patients with acute respiratory distress syndrome (ARDS), we investigated the current usage of tracheostomy in patients ...with ARDS recruited into the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG-SAFE) study.
This is a secondary analysis of LUNG-SAFE, an international, multicenter, prospective cohort study of patients receiving invasive or noninvasive ventilation in 50 countries spanning 5 continents. The study was carried out over 4 weeks consecutively in the winter of 2014, and 459 ICUs participated. We evaluated the clinical characteristics, management and outcomes of patients that received tracheostomy, in the cohort of patients that developed ARDS on day 1-2 of acute hypoxemic respiratory failure, and in a subsequent propensity-matched cohort.
Of the 2377 patients with ARDS that fulfilled the inclusion criteria, 309 (13.0%) underwent tracheostomy during their ICU stay. Patients from high-income European countries (n = 198/1263) more frequently underwent tracheostomy compared to patients from non-European high-income countries (n = 63/649) or patients from middle-income countries (n = 48/465). Only 86/309 (27.8%) underwent tracheostomy on or before day 7, while the median timing of tracheostomy was 14 (Q1-Q3, 7-21) days after onset of ARDS. In the subsample matched by propensity score, ICU and hospital stay were longer in patients with tracheostomy. While patients with tracheostomy had the highest survival probability, there was no difference in 60-day or 90-day mortality in either the patient subgroup that survived for at least 5 days in ICU, or in the propensity-matched subsample.
Most patients that receive tracheostomy do so after the first week of critical illness. Tracheostomy may prolong patient survival but does not reduce 60-day or 90-day mortality.
ClinicalTrials.gov, NCT02010073 . Registered on 12 December 2013.
Recent guidelines have emphasized actively avoiding fever to improve outcomes in patients who are comatose following resuscitation from cardiac arrest (ie, out-of-hospital cardiac arrest). However, ...whether targeted temperature management between 32 °C and 36 °C (TTM32-36) can improve neurologic outcome in some patients remains debated.
Is there an association between the use of TTM32-36 and outcome according to severity assessed at ICU admission using a previously derived risk score?
Data prospectively collected in the Sudden Death Expertise Center (SDEC) registry (France) between May 2011 and December 2017 and in the Resuscitation Outcomes Consortium Continuous Chest Compressions (ROC-CCC) trial (United States and Canada) between June 2011 and May 2015 were used for this study. Severity at ICU admission was assessed through a modified version of the Cardiac Arrest Hospital Prognosis (mCAHP) score, divided into tertiles of severity. The study explored associations between TTM32-36 and favorable neurologic status at hospital discharge by using multiple logistic regression as well as in tertiles of severity for each data set.
A total of 2,723 patients were analyzed in the SDEC data set and 4,202 patients in the ROC-CCC data set. A favorable neurologic status at hospital discharge occurred in 728 (27%) patients in the French data set and in 1,239 (29%) patients in the North American data set. Among the French data set, TTM32-36 was independently associated with better neurologic outcome in the tertile of patients with low (adjusted OR, 1.63; 95% CI, 1.15-2.30; P = .006) and high (adjusted OR, 1.94; 95% CI, 1.06-3.54; P = .030) severity according to mCAHP at ICU admission. Similar results were observed in the North American data set (adjusted ORs of 1.36 95% CI, 1.05-1.75; P = .020 and 2.42 95% CI, 1.38-4.24; P = .002, respectively). No association was observed between TTM32-36 and outcome in the moderate groups of the two data sets.
TTM32-36 was significantly associated with a better outcome in patients with low and high severity at ICU admission assessed according to the mCAHP score. Further studies are needed to evaluate individualized temperature control following out-of-hospital cardiac arrest.
This study sought to assess the relationship between an immediate invasive strategy and survival after an out-of-hospital cardiac arrest (OHCA) of presumed cardiac cause, according to prognosis ...evaluated on hospital arrival.
An immediate coronary angiogram (CAG) may be associated with better outcome after OHCA in neurologically preserved patients but could be futile in other cases.
From May 2011 to May 2015, we collected data for all patients admitted in hospital after OHCA in Paris and its suburbs (France). Risk of in-hospital death was retrospectively calculated using the validated Cardiac Arrest Hospital Prognosis score, which includes age, setting, initial rhythm, durations from collapse to basic life support and from basic life support to return of spontaneous circulation, pH, and epinephrine dose. Independent predictors of survival at discharge (including immediate CAG) were assessed in multivariate logistic regression in each of the 3 pre-defined subgroups of Cardiac Arrest Hospital Prognosis score: low risk (<150 points), medium risk (150 to 200 points), and high risk (>200 points) for in-hospital death.
A total of 1,410 patients were included and overall survival rate at hospital discharge was 32%. Distribution in the low-, medium-, and high-risk Cardiac Arrest Hospital Prognosis subgroups was 667 (47%), 469 (33%), and 274 patients (20%), respectively. The rate of early CAG was 86%, 66%, and 47% in the low-, medium-, and high-risk subgroups, respectively (p < 0.001). Early invasive strategy was independently associated with better survival in low-risk patients (odds ratio: 2.3; 95% confidence interval: 1.4 to 3.9; p = 0.001), but not in medium-risk (p = 0.55) and high-risk (p = 0.43) patients. Sensitivity analysis found consistent results.
In cardiac arrest patients, our results suggest that investigations regarding early CAG after OHCA should focus on patients with preserved neurological status.
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