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The aim of this study was to produce a prognostic model to help predict posttransplant survival in patients transplanted with grade-3 acute-on-chronic liver failure (ACLF-3). Patients with ACLF-3 who underwent liver transplantation (LT) between 2007 and 2017 in 5 transplant centers were included (n = 152). Predictors of 1-year mortality were retrospectively screened and tested on a single center training cohort and subsequently tested on an independent multicenter cohort composed of the 4 other centers. Four independent pretransplant risk factors were associated with 1-year mortality after transplantation in the training cohort: age ≥53 years (P = .044), pre-LT arterial lactate level ≥4 mml/L (P = .013), mechanical ventilation with PaO2 /FiO2 ≤ 200 mm Hg (P = .026), and pre-LT leukocyte count ≤10 G/L (P = .004). A simplified version of the model was derived by assigning 1 point to each risk factor: the transplantation for Aclf-3 model (TAM) score. A cut-off at 2 points distinguished a high-risk group (score >2) from a low-risk group (score ≤2) with 1-year survival of 8.3% vs 83.9% respectively (P

The liver is frequently affected in patients with sickle cell disease (SCD), but few reports have described liver transplantation (LT) in patients with SCD. We present a thorough analysis of the largest single-center series of LT in patients with SCD and the first systematic review. There were 21 patients with a median age of 37.6 years. LT was performed for acute liver failure related to the sickling process (57%) or electively for end-stage liver disease (43%). Prior to LT, 13 patients (62%) were in the intensive care unit and required mechanical ventilation (33%), vasopressor therapy (24%), renal replacement therapy (10%), or molecular adsorbent recirculating system therapy (19%). Post-LT morbidity and mortality were 95% and 33%, respectively. Patient survival at 1 and 5 years were 58.3% and 41.7%, respectively, in the urgent group and 88.9% and 77.8%, respectively, in the elective group. A total of 22 transplant patients with SCD are described in 20 articles in the literature. The 1- and 5-year patient survival rates for the 18 evaluable patients were 75% and 65%, respectively. LT improves survival in patients with SCD and acute liver failure or end-stage liver disease but is associated with high morbidity during the early postoperative course.

Purpose Corynebacterium spp. (C. spp.) is commonly considered as a contaminant in respiratory specimens. No study has ever focused on its clinical relevance in the lower respiratory tract of patients admitted to the intensive care unit (ICU) and requiring mechanical ventilation. The aims were to describe the characteristics of ICU patients with a C. spp. positive deep respiratory specimen, to investigate the impact of C. spp. on the occurrence of pneumonia, and to evaluate the outcomes of these pneumonia. Methods We retrospectively included all adult patients admitted to ICU in a 1000-bed University Hospital (2007–2017) who had a C. spp. positive lower respiratory tract specimen at a significant quantitative level. We used clinical, radiological, and microbiological criteria to classify the likelihood of such pneumonia. Results Among the 31 patients included, acute respiratory failure and postoperative care after major surgery were the main reasons of admission. SAPS II was 47 [34–60]. C. spp. pneumonia was considered as probable, possible and unlikely in 10, 14, and 7 patients, respectively. Fifty-two and 94% of C. spp. strains were sensitive to amoxicillin, and vancomycin/linezolid, respectively. Seventeen patients had a complete course of antibiotic against C. spp. The overall ICU mortality was 58%. Conclusion Corynebacterium spp seems to be responsible for authentic pneumonia in mechanically ventilated patients. It should be considered as clinically relevant when predominantly present in respiratory specimen from patients suspected with pneumonia in ICU, and empirically treated.

International audience; Delayed hemolytic transfusion reaction (DHTR) is an unpredictable severe complication of transfusion in patients with sickle cell disease (SCD). It presents clinically as a vaso-occlusive crisis (VOC), often associated with the failure of one or more organs, after the transfusion of packed red blood cells (pRBC).1,2 Hyperhemolysis is encountered in the most severe forms. Both transfused and autologous red blood cells (RBC) are lysed.The mechanisms underlying DHTR remain unclear. Alloantibodies against RBC antigens were initially thought to underlie the pathophysiology, but no such antibodies are detected in about a third of the cases.3RBC degradation products, such as hemoglobin and heme, are released into the bloodstream during intravascular hemolysis. These elements and heme-loaded membrane microvesicles have recently been implicated in inflammation and organ injury in DHTR.4 Complement is activated via the classical pathway, by alloantibodies, and/or via the alternative pathway, by free heme.5 Hemedependent complement deposits on the endothelium contribute to organ damage.6 Due to these vascular lesions, hyperhemolysis often progresses to multiple organ failure and, in some cases, death.

Background: Delayed hemolytic transfusion reaction (DHTR) is an unpredictable and severe complication of transfusion, especially in Sickle Cell Disease (SCD) patients (Habibi Am J Hematol 2016). The clinical presentation is a vaso occlusive crisis (VOC), often associated with one or more organ failures, after packed red blood cell transfusion (pRBC). The hypothesis of complement activation through the classical pathway by alloantibodies and/or the alternative pathway by free heme (released by hemolysis) suggests that an inhibitor of complement activation may be a treatment option for DHTR. Methods: This retrospective study focuses on the SCD patients who received anti-C5 monoclonal antibody during DHTR treatment after consulting with our French SCD referral center between 2013 and 2018. DHTR diagnosis associated VOC signs occurring 5 to 20 days after pRBC transfusion, with no other cause for intravascular hemolysis, and one or more of the following: - rapid decrease in, or unexpectedly low, hemoglobin A (HbA) concentration - hemoglobinuria defined by dark urines - direct antiglobulin test (DAT) positivity or new antibody formation. The treatment efficacy was evaluated through patients' clinical and biological data. Findings: Sixteen patients received anti-C5 for a DHTR defined by a VOC 5 to 20 days after a transfusion and the following criteria: 12 had low HbA or rapid decrease of HbA, 10 had hemoglobinuria, and 10 had positive DAT or antibody formation. One patient received anti-C5 for hyperhemolysis without being able to discriminate DHTR from hemolysis under Extracorporeal Membrane Oxygenation and was excluded from the analysis. The 16 patients included in the analysis had severe DHTR at diagnosis, with one or more organ failures (N=7), median hemoglobin concentration 57 g/L [30-97], LDH 2807 UI/L [510-12500], total bilirubin 92 mmol/L [15-730]. Two additional patients had organ failures during the follow-up. Lowest hemoglobin concentration was 32 g/L [19-58] and highest LDH 4238 UI/L [510-24000]. One to 3 anti-C5 doses were given at 1 week intervals, associated with symptomatic treatment (hydration, oxygen, analgesia; N=16), erythropoietin (N=15), pRBC transfusions (N=12), immunoglobulins (N=8), plasma exchange (N=4), steroids (N=1). The outcome was favorable for 13 patients. The number of pRBC transfused were limited as much as possible. Three patients died. All three had acute liver failure that required emergency liver transplant. Two patients improved after anti-C5 and could be grafted, but died of infectious complications unrelated to anti-C5: Klebsiella pneumoniae pulmonary infection 11 days after transplant for one, and digestive and urinary infection 47 days after transplant for the other. For the third patient, no compatible organ could be found. Conclusion: In association with other therapies (EPO, plasma exchange, limiting pRBC transfusions), anti-C5 can be a treatment option for severe DHTR despite its high cost, in the absence of effective alternatives. Disclosures Michel: Amgen: Consultancy; Rigel: Consultancy; Novartis: Consultancy. Bartolucci:Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; AddMedica: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; HEMANEXT: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Anti-C5 is currently used to treat paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS).

Cette etude retrospective (2013–2018) porte sur les patients drepanocytaires ayant recu un anticorps anti-C5 (Eculizumab) inhibant les voies d’activation du complement sur avis du Centre National de Reference des Pathologies du Globule Rouge (H. Mondor), au cours – d’une hemolyse post-transfusionnelle retardee (HPTR) associant : – crise vaso-occlusive 5 a 20 jours apres une transfusion de CGR – baisse rapide de l’HbA OU urines « Porto » ou « Coca Cola » (hemoglobinurie) ou nouvel anticorps a la RAI et/ou positivation du test de Coombs direct. Seize patients repondaient a ces criteres. Ils presentaient des signes de gravite d’emblee : hemoglobine 5,7 g/dL [3,0–9,7], bilirubine totale 92 μmol/L [15–730] (N

To the editor: Delayed hemolytic transfusion reaction (DHTR) with hyperhemolysis is a potentially life-threatening complication of sickle cell disease (SCD) occurring 5 to 20 days after transfusion.[1][1] Patients display symptoms of severe vaso-occlusive crisis (VOC), associated with the

Invasive fungal infections (IFI) are complications after liver transplantation involving high morbidity and mortality. (1,3)-β-d-glucan (BG) is a biomarker for IFI, but its utility remains uncertain. This study was designed to evaluate the impact of BG following their diagnosis. Between January 2013 and May 2016, 271 liver transplants were performed in our institution. Serum samples were tested for BG (Fungitell®, Associates Cape Code Inc., Falmouth, MA, USA) at least weekly between liver transplantation and the discharge of patients. Nineteen patients (7%) were diagnosed with IFI, including 13 cases of invasive candidiasis (IC), eight cases of invasive pulmonary aspergillosis, and one case of septic arthritis due to Scedosporium apiospernum. Using a single BG sample for the primary analysis of IFI, 95% (21/22) of the subjects had positive BG (>80 pg/mL) at the time of IFI diagnosis. The area under the ROC curves to predict IFI was 0.78 (95% CI: 0.73–0.83). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of BG for IFI were 75% (95% CI: 65–83), 65% (62–68), 17% (13–21), and 96% (94–97), respectively. Based on their high NPV, the BG test appears to constitute a good biomarker to rule out a diagnosis of IFI.

Summary Background and objective We conducted a prospective double blind randomized study assessing ropivacaine end-of-surgery wound infiltration for pain relief in thyroid surgery after remifentanil-based intraoperative analgesia. Methods Fifty elective ASA I–II patients scheduled for thyroid surgery were included in this study. Balanced anesthesia was performed with propofol, remifentanil, N2O, isoflurane. Patients were randomized in two equal groups: ropivacaine (n = 25) and saline (n = 25) which respectively had end-of-surgery wound infiltration with 15 ml of ropivacaine 2% or the same volume of saline. Results Pain intensity, morphine requirement and the length of stay in PACU were significantly lower in ropivacaine group as compared to saline group (P Conclusions If remifentanil is used for intraoperative analgesia, end-of-surgery wound infiltration with 15 ml ropivacaine 2% is an efficient strategy to control postthyroidectomy pain.

We have investigated the effects of isotopic composition on the band gap of CuCl on a series of samples made out of the stable isotopes ${}^{63}\mathrm{Cu}$, ${}^{65}\mathrm{Cu}$, ${}^{35}\mathrm{Cl}$, and ${}^{37}\mathrm{Cl}$. Besides specimens containing elements with the natural abundances, we have measured samples with monoisotopic sublattices as well as artificial mixtures of isotopes. With nonlinear (two-photon absorption, second-harmonic generation) and linear (luminescence) optical spectroscopy we find that the fundamental gap of CuCl increases by 364(18) \ensuremath{\mu}eV/amu when increasing the Cl mass. However, it decreases by 76(5) \ensuremath{\mu}eV/amu when increasing the Cu mass. Using a two-oscillator model for the lattice dynamics of CuCl we show that these rates are consistent with the anomalous increase of the band gap with increasing temperature. These effects can be traced back to the strong $p$-$d$ mixing in the copper halides. From the temperature dependence of the band gap of CuBr we also estimate the changes of its gap with isotopic composition.

We have investigated the changes in the Raman spectra of CuCl resulting from isotope substitution. Our samples were made from the stable isotopes ${}^{63}\mathrm{Cu}$, ${}^{65}\mathrm{Cu}$, ${}^{35}\mathrm{Cl}$, and ${}^{37}\mathrm{Cl}$ as well as the natural elements. While the longitudinal-optic (LO) mode shifts according to the expected reduced mass behavior of a $\ensuremath{\Gamma}$-point phonon, the transverse-optic (TO) vibration shows pronounced deviations. Due to the strong anharmonicity of CuCl, the TO mode interacts with a two-phonon combination band of acoustic phonons and one obtains coupled excitations which have been attributed to a Fermi resonance. We describe this process using a shell model for the lattice dynamics of CuCl and only one cubic coefficient for the anharmonic interaction. The Fermi resonance results in an anomalous line shape of the TO phonon, which reflects properties of the zone center mode as well as of the two-phonon combination band. Isotope substitution allows us to discern the two contributions and to check the validity of the model. The off-center model proposed earlier to explain the TO anomaly cannot account for our findings.

The thermalization of electrons in copper nanoparticles embedded in glass is investigated using femtosecond pump-probe spectroscopy. The time dependent induced transmission is enhanced near the surface plasmon resonance of the nanoparticles, as opposed to the static one obtained with thermomodulation measurements. In addition, a slowing of the process of electron cooling to the lattice temperature is observed at the plasmon resonance. These observations show the importance of quasiparticle collisions in confined metallic structures.

Difficult intubation management algorithms have proven efficacy in operating rooms but have rarely been assessed in a prehospital emergency setting. We undertook a prospective evaluation of a simple prehospital difficult intubation algorithm.All of our prehospital emergency physicians and nurse anesthetists were asked to adhere to a simple algorithm in all cases of impossible laryngoscope-assisted tracheal intubation. They received a short refresher course and training in the use of the gum elastic bougie (GEB) and the intubating laryngeal mask airway (ILMA), which were techniques to be used as a first and a second step, respectively. In cases of difficult ventilation with arterial desaturation, IMLA was to be used first. Cricothyroidotomy was the ultimate rescue technique when ventilation through ILMA failed. Patient characteristics, adherence to the algorithm, management efficacy, and early complications were recorded (August 2005-December 2009).An alternative technique to secure the airway was needed in 160 of 2,674 (6%) patients undergoing intubation. Three instances of nonadherence to the algorithm were recorded. GEB was used first in 152 patients and was successful in 115. ILMA was used first in 8 patients and second in the 37 GEB-assisted intubation failures. Forty-five patients were successfully mask-ventilated, and 42 were blindly intubated before reaching the hospital. Cricothyroidotomy was used successfully in a patient with severe upper airway obstruction as a result of pharyngeal neoplasia. Early intubation-related complications occurred in 52% difficult cases.Adherence to a simple algorithm using GEB, ILMA, and cricothyroidotomy solved all difficult intubation cases occurring in a prehospital emergency setting.

In patients with hepatocellular carcinoma (HCC), a previous liver resection (LR) may compromise subsequent liver transplantation (LT) by creating adhesions and increasing surgical difficulty. Initial laparoscopic LR (LLR) may reduce such technical consequences, but its effect on subsequent LT has not been reported. We report the operative results of LT after laparoscopic or open liver resection (OLR). Twenty-four LT were performed, 12 following prior LLR and 12 following prior OLR. The LT was performed using preservation of the inferior vein cava. Indication for the LT was recurrent HCC in 19 cases (salvage LT), while five patients were listed for LT and underwent resection as a neoadjuvant procedure (bridge resection). In the LLR group, absence of adhesions was associated with straightforward access to the liver in all cases. In the OLR group, 11 patients required long and hemorrhagic dissection. Median durations of the hepatectomy phase and whole LT were 2.5 and 6.2 h, and 4.5 and 8.3 h in the LLR and OLR groups, respectively (P

We discuss the validity of various theories of resonant light scattering by phonons. We specially consider the case of an exciton-phonon coupling which is small compared to the exciton-photon coupling. Thus, for a particular choice of additional boundary conditions (ABC) the scattered intensity can be calculated self-consistently with, parameters deduced from the experiments. We discuss several experiments, of the literature and the problem of ABC. Elastic scatterings by defects are also considered.

La transplantation hepatique est le traitement de reference de l’insuffisance hepatique terminale et de ses complications. La survie a un an des patients transplantes est superieure a 85 %. Cependant, il existe une inadequation croissante entre l’offre et la demande de greffons qui est en augmentation constante. La prevention et la gestion des complications postoperatoires doivent donc etre attentives afin d’optimiser les resultats de cette greffe. Les complications infectieuses sont frequentes de l’ordre de 27 % et associees a une importante morbidite allant jusqu’a une mortalite attribuable. Parmi ces complications, les infections fongiques invasives (IFI) ont une incidence allant de 7 a 42 % selon les etudes. La transplantation hepatique possede l’un des plus haut taux d’infections fongiques invasives parmi les greffes d’organes. Parmi les IFI, les candidoses invasives (candidemie, candidose intra-abdominales…) sont les plus frequentes et surviennent principalement dans les premiers mois d’une transplantation hepatique. Parmi les especes fongiques impliquees, Candida spp. est le genre majoritaire. Historiquement, Candida albicans etait l’espece principalement mise en cause mais l’epidemiologie des candidoses invasives change avec recemment l’emergence actuelle des especes de Candida non- albicans . Des facteurs de risque ont ete identifies (la transplantation hepatique pour hepatite fulminante, la re-transplantation ou le recours a une epuration extrarenale pour insuffisance renale aigue). La presence d’au moins un facteur de risque motive l’utilisation d’un traitement preventif chez le receveur, qui a participe a la diminution de l’incidence des candidoses invasives ces dernieres annees. Cependant, le choix de l’antifongique utilise dans le cadre de cette prevention est variable selon la toxicite (renale, hepatique), les interactions medicamenteuses, l’ecologie et le cout. De plus, un traitement precoce des infections fongiques est indispensable pour ameliorer le pronostic vital de ces patients mais il est dependant de tests diagnostiques rapides et fiables. Meme si le gold standard pour le diagnostic de candidose invasive reste l’hemoculture, de nouvelles methodes diagnostiques (s-D-glucanes, PCR…) se developpent visant a ameliorer la prise en charge globale de ces patients. Cependant, la place de ces nouveaux outils diagnostiques reste a definir dans la population des transplantes hepatiques.

Background and Objectives: The authors conducted a scanographic study in order to characterize the local anesthetic spread of injectate resulting from a single-injection technique of deep cervical plexus block. Methods: Six consecutive American Society of Anesthesiologists II and III patients scheduled for elective carotid endarterectomy under regional anesthesia were enrolled. Deep cervical plexus block was placed via an anterolateral approach using a nerve stimulator to guide the injection on contact with the levator scapulae nerve. With specific contractions evoked at a stimulating current intensity ≤0.5 mA, a 40-mL mixture containing local anesthetics and iopamidol was injected. Thirty minutes after the block was placed, sensory and motor neural blockade was evaluated, and a helicoidal scanner of the head-neck and upper thorax was completed. Sequential cross sections spaced at 5 mm were performed from the base of the skull down to T1. A 3-dimensional volume-rendering technique was used to characterize spread of injectate, which calculated volume. Results: All patients completed C2-C4 dermatomal sensory blockade. None of the patients experienced anesthesia of the C8 and T1 dermatomes. The spread of injectate extended in a cephalocaudal direction from C1 to C7; its wider dimensions were systematically observed at the C3-C4 level. Fascia of the carotid sheath and sternocleidomastoid muscle limited the anterior spread of injectate. The trapezius limited lateral and posterior diffusion of injectate. Spread of injectate had a large volume exceeding twice that of the injectate. It has roughly a hemi cylinder shape with both ends stretched toward C1 and C7. Conclusion: The authors showed that deep cervical plexus block was associated with a wide spread of injectate. The data show that the spread of injectate is enclosed within to the prevertebral layer of the deep cervical fascia.

ObjectiveCarotid artery stenting (CAS) has been introduced as an alternative to carotid endarterectomy (CEA) for the treatment of carotid artery stenosis. Both techniques seem to be associated with postoperative hemodynamic lability. Both may induce baroreceptor dysfunction, possibly leading to transient impairment of cardiovascular autonomic activity and resulting in hemodynamic instability. This instability might contribute to postoperative morbidity. To elucidate these phenomena, we studied the cardiac baroreflex and autonomic cardiovascular control after CAS and CEA.MethodIn 20 patients scheduled for CAS (n = 10) or CEA (n = 10), intra-arterial pressures and electrocardiograms were recorded during 10 minutes before and 8 and 24 hours after the procedure. Spontaneous cardiac baroreflex sensitivity was assessed using the sequence method and cross-spectral analysis. In addition, cardiovascular autonomic activity was investigated using spectral analysis of heart rate variability and systolic arterial pressure variability.ResultsAfter CAS, we demonstrated an increase of the spontaneous baroreflex sensitivity median (interquartile range) from 5.6 (5.1 to 6.2) ms/mm Hg before the procedure to 8.8 (6.8 to 10.5) ms/mm Hg and 7.7 (3.9 to 8.6) ms/mm Hg (P < .001), 8 and 24 hours after the procedure. This was consistent with the increase of the high frequency component of heart rate variability reflecting cardiac parasympathetic activity and a decrease of the low frequency of systolic arterial pressure variability reflecting sympathetic vascular activity. The postoperative period was also associated with decreased systolic arterial pressure from 173 (162 to 190) mm Hg at baseline to 122 (109 to 143) mm Hg and 136 (121 to 143) mm Hg at 8 and 24 hours after CAS (P < .001). No changes in baroreflex sensitivity or in autonomic activity were observed after CEA.ConclusionsThese preliminary data suggest that CAS is associated with parasympathetic predominance postoperatively and may probably explain the lower systolic arterial pressure observed after CAS.

Hemodynamic alterations during balloon carotid angioplasty (BCA) and stenting have been ascribed to the consequences of direct carotid baroreceptor stimulation during balloon inflation. BCA with stenting in patients with carotid atheromatous stenoses offers a unique opportunity for elucidating the cardiovascular autonomic response to direct transient intravascular stimulation of the baroreceptors. We analysed the consequences of BCA on the autonomic control of heart rate and on breathing components in nine patients with atheromatous stenoses involving the bifurcation and the internal carotid. A time–frequency domain method, the smoothed pseudo-Wigner–Ville transform (SPWVT), was used to evaluate the spectral parameters (i.e., the instantaneous amplitude and centre frequency (ICF) of the cardiovascular and respiratory oscillations). Those parameters and their dynamics (8 and 24 h later) were evaluated during and after the procedure. BCA stimulates baroreceptors in all patients, which markedly reduces heart rate and blood pressure. Vagal baroreflex activation altered the respiratory sinus arrhythmia in terms of amplitude and frequency (ICF HF RR shifted from 0.27 ± 0.03 to 0.23 ± 0.04 Hz pre-BCA vs. BCA, respectively; p < 0.01). Both the high- and low-frequency amplitudes of heart rate oscillations were altered during carotid baroreceptor stimulation, strongly supporting a contribution of the baroreflex to the generation of both oscillations of heart rate. Carotid baroreceptors stimulation increased the inspiratory time (Ti) (1.5 ± 0.5 to 2.3 ± 0.6 s pre-BCA vs. BCA, respectively; p < 0.01). In awake patients, BCA with stenting of atheromatous stenosis involving the bifurcation and internal carotid causes marked changes in the cardiac autonomic and respiratory control systems.Key words: carotid angioplasty, heart rate variability, autonomic nervous system, respiration, spectral analysis.

The dynamics of electrons heated with femtosecond optical pulses is investigated in silver nanoparticles. The electron-lattice relaxation is compared for particles in various surrounding matrixes.

We study the effect of a magnetic field H oriented along [ 1 10] on the hyper-Raman spectrum obtained in a backward scattering geometry from a [110] surface of a CuBr crystal. We investigate the energy E( k , H ) being not symmetric with respect to H, we fixed wave vector k . The energies E( k , H ) being not symmetric with respect to H , we conclude that the k-linear term plays an important role in the exciton dispersion.

We present new experimental results concerning the optical nonlinearities of CuCl microcrystallites embedded in a glass matrix. Using a "pump and probe" technique, the induced absorption is measured in the spectral range of the Z3 exciton. We observe two phenomena: first, a bleaching of the excitonic resonance accompanied by the generation of a new absorption band at higher photon energies when the test probes the sample during the pump pulse; secondly, a weak shift of the excitonic resonance towards higher photon energies when probing the sample during and after the pump excitation. We vary the intensity and the photon energy of the pump beam as well as the delay between the pump and the probe pulses. Thus we can show that the pump beam populates excitonic states, which leads to a complete bleaching of the excitonic absorption. In addition, excitons can be created at higher energies, inducing the new absorption band. Its energy depends on the number of states already occupied in the microcrystallites. The shift of the excitonic resonance, on the contrary, can be explained by the heating of the microcrystallites through this high population of excitons and its non radiative decay during and after the excitation pulse.

International audience; Objectives: Prone positioning and venovenous extracorporeal membrane oxygenation (ECMO) are both useful interventions in acute respiratory distress syndrome (ARDS). Combining the two therapies is feasible and safe, but the effectiveness is not known. Our objective was to evaluate the potential survival benefit of prone positioning in venovenous ECMO patients cannulated for COVID-19-related ARDS.Design: Retrospective analysis of a multicenter cohort.Patients: Patients on venovenous ECMO who tested positive for severe acute respiratory syndrome coronavirus 2 by reverse transcriptase polymerase chain reaction or with a diagnosis on chest CT were eligible.Interventions: None.Measurements and main results: All patients on venovenous ECMO for respiratory failure in whom prone position status while on ECMO and in-hospital mortality were known were included. Of 647 patients in 41 centers, 517 were included. Median age was 55 (47-61), 78% were male and 95% were proned before cannulation. After cannulation, 364 patients (70%) were proned and 153 (30%) remained in the supine position for the whole ECMO run. There were 194 (53%) and 92 (60%) deaths in the prone and the supine groups, respectively. Prone position on ECMO was independently associated with lower in-hospital mortality (odds ratio = 0.49 [0.29-0.84]; p = 0.010). In 153 propensity score-matched pairs, mortality rate was 49.7% in the prone position group versus 60.1% in the supine position group (p = 0.085). Considering only patients alive at decannulation, propensity-matched proned patients had a significantly lower mortality rate (22.4% vs 37.8%; p = 0.029) than nonproned patients.Conclusions: Prone position may be beneficial in patients supported by venovenous ECMO for COVID-19-related ARDS but more data are needed to draw definitive conclusions.

Background Despite expanding use, knowledge on extracorporeal membrane oxygenation support during the COVID-19 pandemic remains limited. The objective was to report characteristics, management, and outcomes of patients receiving extracorporeal membrane oxygenation with a diagnosis of COVID-19 in France and to identify pre-extracorporeal membrane oxygenation factors associated with in-hospital mortality. A hypothesis of similar mortality rates and risk factors for COVID-19 and non–COVID-19 patients on venovenous extracorporeal membrane oxygenation was made. Methods The Extracorporeal Membrane Oxygenation for Respiratory Failure and/or Heart failure related to Severe Acute Respiratory Syndrome-Coronavirus 2 (ECMOSARS) registry included COVID-19 patients supported by extracorporeal membrane oxygenation in France. This study analyzed patients included in this registry up to October 25, 2020, and supported by venovenous extracorporeal membrane oxygenation for respiratory failure with a minimum follow-up of 28 days after cannulation. The primary outcome was in-hospital mortality. Risk factors for in-hospital mortality were analyzed. Results Among 494 extracorporeal membrane oxygenation patients included in the registry, 429 were initially supported by venovenous extracorporeal membrane oxygenation and followed for at least 28 days. The median (interquartile range) age was 54 yr (46 to 60 yr), and 338 of 429 (79%) were men. Management before extracorporeal membrane oxygenation cannulation included prone positioning for 411 of 429 (96%), neuromuscular blockage for 419 of 427 (98%), and NO for 161 of 401 (40%). A total of 192 of 429 (45%) patients were cannulated by a mobile extracorporeal membrane oxygenation unit. In-hospital mortality was 219 of 429 (51%), with a median follow-up of 49 days (33 to 70 days). Among pre-extracorporeal membrane oxygenation modifiable exposure variables, neuromuscular blockage use (hazard ratio, 0.286; 95% CI, 0.101 to 0.81) and duration of ventilation (more than 7 days compared to less than 2 days; hazard ratio, 1.74; 95% CI, 1.07 to 2.83) were independently associated with in-hospital mortality. Both age (per 10-yr increase; hazard ratio, 1.27; 95% CI, 1.07 to 1.50) and total bilirubin at cannulation (6.0 mg/dl or more compared to less than 1.2 mg/dl; hazard ratio, 2.65; 95% CI, 1.09 to 6.5) were confounders significantly associated with in-hospital mortality. Conclusions In-hospital mortality was higher than recently reported, but nearly half of the patients survived. A high proportion of patients were cannulated by a mobile extracorporeal membrane oxygenation unit. Several factors associated with mortality were identified. Venovenous extracorporeal membrane oxygenation support should be considered early within the first week of mechanical ventilation initiation. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New