Morbidity and mortality after anaesthesia in early life: results of the European prospective multicentre observational study, neonate and children audit of anaesthesia practice in Europe (NECTARINE)

Background: Neonates and infants requiring anaesthesia are at risk of physiological instability and complications, but triggers for peri-anaesthetic interventions and associations with subsequent outcome are unknown. Methods: This prospective, observational study recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. The primary aim was to identify thresholds of pre-determined physiological variables that triggered a medical intervention. The secondary aims were to evaluate morbidities, mortality at 30 and 90 days, or both, and associations with critical events. Results: Infants (n=5609) born at mean (standard deviation [SD]) 36.2 (4.4) weeks postmenstrual age (35.7% preterm) underwent 6542 procedures within 63 (48) days of birth. Critical event(s) requiring intervention occurred in 35.2% of cases, mainly hypotension (>30% decrease in blood pressure) or reduced oxygenation (SpO2 <85%). Postmenstrual age influenced the incidence and thresholds for intervention. Risk of critical events was increased by prior neonatal medical conditions, congenital anomalies, or both (relative risk [RR]=1.16; 95% confidence interval [CI], 1.04–1.28) and in those requiring preoperative intensive support (RR=1.27; 95% CI, 1.15–1.41). Additional complications occurred in 16.3% of patients by 30 days, and overall 90-day mortality was 3.2% (95% CI, 2.7–3.7%). Co-occurrence of intraoperative hypotension, hypoxaemia, and anaemia was associated with increased risk of morbidity (RR=3.56; 95% CI, 1.64–7.71) and mortality (RR=19.80; 95% CI, 5.87–66.7). Conclusions: Variability in physiological thresholds that triggered an intervention, and the impact of poor tissue oxygenation on patient's outcome, highlight the need for more standardised perioperative management guidelines for neonates and infants. Clinical trial registration: NCT02350348

Difficult tracheal intubation in neonates and infants. NEonate and Children audiT of Anaesthesia pRactice IN Europe (NECTARINE): a prospective European multicentre observational study

Background: Neonates and infants are susceptible to hypoxaemia in the perioperative period. The aim of this study was to analyse interventions related to anaesthesia tracheal intubations in this European cohort and identify their clinical consequences. Methods: We performed a secondary analysis of tracheal intubations of the European multicentre observational trial (NEonate and Children audiT of Anaesthesia pRactice IN Europe [NECTARINE]) in neonates and small infants with difficult tracheal intubation. The primary endpoint was the incidence of difficult intubation and the related complications. The secondary endpoints were the risk factors for severe hypoxaemia attributed to difficult airway management, and 30 and 90 day outcomes. Results: Tracheal intubation was planned in 4683 procedures. Difficult tracheal intubation, defined as two failed attempts of direct laryngoscopy, occurred in 266 children (271 procedures) with an incidence (95% confidence interval [CI]) of 5.8% (95% CI, 5.1e6.5). Bradycardia occurred in 8% of the cases with difficult intubation, whereas a significant decrease in oxygen saturation (SpO2<90% for 60 s) was reported in 40%. No associated risk factors could be identified among comorbidities, surgical, or anaesthesia management. Using propensity scoring to adjust for confounders, difficult anaesthesia tracheal intubation did not lead to an increase in 30 and 90 day morbidity or mortality. Conclusions: The results of the present study demonstrate a high incidence of difficult tracheal intubation in children less than 60 weeks post-conceptual age commonly resulting in severe hypoxaemia. Reassuringly, the morbidity and mortality at 30 and 90 days was not increased by the occurrence of a difficult intubation event. Clinical trial registration: NCT02350348

Morbidity and mortality after anaesthesia in early life: results of the European prospective multicentre observational study, neonate and children audit of anaesthesia practice in Europe (NECTARINE)

BACKGROUND: Neonates and infants requiring anaesthesia are at risk of physiological instability and complications, but triggers for peri-anaesthetic interventions and associations with subsequent outcome are unknown. METHODS: This prospective, observational study recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. The primary aim was to identify thresholds of pre-determined physiological variables that triggered a medical intervention. The secondary aims were to evaluate morbidities, mortality at 30 and 90 days, or both, and associations with critical events. RESULTS: Infants (n=5609) born at mean (standard deviation [sd]) 36.2 (4.4) weeks postmenstrual age (35.7% preterm) underwent 6542 procedures within 63 (48) days of birth. Critical event(s) requiring intervention occurred in 35.2% of cases, mainly hypotension (>30% decrease in blood pressure) or reduced oxygenation (SpO2 <85%). Postmenstrual age influenced the incidence and thresholds for intervention. Risk of critical events was increased by prior neonatal medical conditions, congenital anomalies, or both (relative risk [RR]=1.16; 95% confidence interval [CI], 1.04–1.28) and in those requiring preoperative intensive support (RR=1.27; 95% CI, 1.15–1.41). Additional complications occurred in 16.3% of patients by 30 days, and overall 90-day mortality was 3.2% (95% CI, 2.7–3.7%). Co-occurrence of intraoperative hypotension, hypoxaemia, and anaemia was associated with increased risk of morbidity (RR=3.56; 95% CI, 1.64–7.71) and mortality (RR=19.80; 95% CI, 5.87–66.7). CONCLUSIONS: Variability in physiological thresholds that triggered an intervention, and the impact of poor tissue oxygenation on patient's outcome, highlight the need for more standardised perioperative management guidelines for neonates and infants

Difficult tracheal intubation in neonates and infants. NEonate and Children audiT of Anaesthesia pRactice IN Europe (NECTARINE): a prospective European multicentre observational study

BACKGROUND: Neonates and infants are susceptible to hypoxaemia in the perioperative period. The aim of this study was to analyse interventions related to anaesthesia tracheal intubations in this European cohort and identify their clinical consequences. METHODS: We performed a secondary analysis of tracheal intubations of the European multicentre observational trial (NEonate and Children audiT of Anaesthesia pRactice IN Europe [NECTARINE]) in neonates and small infants with difficult tracheal intubation. The primary endpoint was the incidence of difficult intubation and the related complications. The secondary endpoints were the risk factors for severe hypoxaemia attributed to difficult airway management, and 30 and 90 day outcomes. RESULTS: Tracheal intubation was planned in 4683 procedures. Difficult tracheal intubation, defined as two failed attempts of direct laryngoscopy, occurred in 266 children (271 procedures) with an incidence (95% confidence interval [CI]) of 5.8% (95% CI, 5.1–6.5). Bradycardia occurred in 8% of the cases with difficult intubation, whereas a significant decrease in oxygen saturation (SpO2<90% for 60 s) was reported in 40%. No associated risk factors could be identified among co-morbidities, surgical, or anaesthesia management. Using propensity scoring to adjust for confounders, difficult anaesthesia tracheal intubation did not lead to an increase in 30 and 90 day morbidity or mortality. CONCLUSIONS: The results of the present study demonstrate a high incidence of difficult tracheal intubation in children less than 60 weeks post-conceptual age commonly resulting in severe hypoxaemia. Reassuringly, the morbidity and mortality at 30 and 90 days was not increased by the occurrence of a difficult intubation event

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

''Violences de genre et violences sexistes à l'école'', n°9 Edito.

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Vertically aligned carbon nanotubes growth on aluminum substrates at low temperature

International audienceEnergy storage is a major challenge for the next years, with the development of renewable energy, mobile devices (smartphones, tablets, computers,...) and electric vehicles. Supercapacitors have a great potential, with performance located between the capacitors and batteries. Their principle is based on rapid ion charge / discharge cycles, using the common activated carbon based electrodes. However, these systems have limitations in terms of energy density and cost which involves the development of new electrode materials. During the last five years, a strong interest has been devoted to electrodes based on vertically aligned carbon nanotubes (VACNT) thanks to their large specific surface area developed, their anisotropy and good electrical conductivity. In this context, our first results obtained in collaboration with the Universities of Cergy Pontoise and Tours have demonstrated a high increase of capacitance due to the implementation, in ionic liquid, of electrodes based on VACNT covered with conducting polymers and standing on Si substrates [1]. The development of ultra-capacitor by NawaTechnologies Company is based on this VACNT-based technology. One of the challenge to penetrate the market is to replace the silicon collector by a conductive and inexpensive substrate. In this context, the aim of this collaborative work is to develop the growth of VACNT on aluminum foil by aerosol assisted Chemical Vapor Deposition (CVD). This method is well controlled on substrates such as stainless steel or quartz for synthesis temperatures between 800 and 850°C [2, 3 and 4]. Taking into account the aluminum melting temperature of about 660°C, the synthesis of VACNT on aluminum requires a significant lowering of VACNT growth temperature. At low temperatures, the decomposition of catalytic and carbon precursors commonly used is insufficient. To overcome this problem, the nature of the gas phase has been changed in terms of both carbonaceous precursor and carrier gas. Indeed, the decomposition of the catalyst precursor at low temperatures and thus the synthesis yield are increased by the addition of hydrogen in the atmosphere [3]. Moreover, in order to limit the decrease in growth rate it is necessary to use precursors with a catalytic and thermal decomposition more favorable around 600 ° C, such as acetylene recently reported for CVD growth on aluminum [5]. Therefore, the approach in this work is first to identify the most relevant synthesis parameters to reach VACNT growth at such a low temperature by varying them and analyzing subsequently the products obtained with SEM, TEM, Raman, ATG, to have information on CNT length, density, diameter,… The first results obtained on pure aluminum, without any surface pretreatment show that growth in VACNT is strongly influenced by the flow of the reactive gas phase, composition and the synthesis temperature as represented on figure 1. Moreover, attention is paid on study of Al surface before growth or during the initial steps of VACNT growth, and of CNT / Al interface with various analysis technics: SEM, TEM, XPS, AFM… in order to understand VACNT formation mechanisms at lower temperatures which has a direct link towards the optimization of VACNT synthesis process

Agricultural adjuvants: impact on the microbial toxicity and biodegradation of the pesticide active substance

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Growth of vertically aligned carbon nanotubes on aluminum foils

International audienceForests of vertically aligned carbon nanotubes (VACNTs) are attractive nanomaterials because of their unique structural, electrical and thermal properties. However, many applications require their growth on metallic substrates. Catalytic chemical vapor deposition (CCVD) is the best method to grow them but the catalytic particles can diffuse rapidly into the metal subsurface and thus become inactive. In this communication, I will address this issue through the recent results obtained in our laboratory. I will show how it is possible to grow VACNT on carbon fibers, stainless steel and aluminum surfaces by a single-step process, namely the aerosol assisted CCVD, where the catalyst and carbon precursors are injected simultaneously. In the case of aluminum, due to its low melting temperature, the synthesis of VACNT requires a significant reduction in the growth temperature as compared to conventional substrates. Our results show that, with our single-step process, it is possible to obtain clean, long and dense VACNTs, with a growth rate at the best state of the art level for such a low temperature. A particular attention has been paid to the study of the CNT/Al interface. The results suggest the crucial role of the interface for an efficient and reproducible VACNT growth. Finally, I will show that the aerosol-assisted CCVD process can be scaled-up to enable the fabrication of innovative ultracapacitors based on VACNTs grown on aluminum foils

Vertically Aligned Carbon Nanotube Growth on Aluminium Substrate at Low Temperature

International audienceThis communication addresses the growth of VACNT on aluminium by a single-step process (simultaneously injecting catalyser and carbon source precursors), namely the thermal aerosol assisted CCVD. The aim is to get a scalable process to fabricate ultracapacitor electrodes exhibiting a great potential thanks to VACNT specific surface area, anisotropy and good electrical conductivity. Considering the aluminium melting temperature (c.a. 660°C), the synthesis of VACNT on such substrates requires a significant reduction in the growth temperature as compared to conventional substrates [1-3]. According to our previous work, when hydrogen is added in the gas phase, the decomposition of the catalyst precursor will be more efficient at low temperature [2]. Moreover, the use of acetylene as carbon source is more favourable for a decomposition at low temperature [4]. Our approach is first to identify the most relevant synthesis parameters to reach VACNT growth at such a low temperature by analysing the VACNT properties such as CNT length, density, diameter, … This optimization study, involving no surface pre-treatment of aluminium substrate, shows clean, long and dense VACNTs (Fig.1 A,B,C), with a growth rate (ca. 5µm/min) on par with the state of art the state of the art. Secondly, the objective is to understand VACNT growth mechanisms on Al substrate occurring at low temperature in order to optimise the VACNT synthesis process. Indeed, attention is paid on the Al surface prior and past the initial step of VACNT growth, and on the CNT/Al interface, with various analysis technics: SEM, TEM, EDX, XPS, GDOES … The results of the chemical analysis of the interface by STEM/EDX (Fig.2 D) exhibit clearly identifiable catalytic particles located at the CNT base within a well-defined oxide interface layer suggesting the crucial role of the interface for an efficient and reproducible VACNT growth