Mu-opioid receptors and dietary protein stimulate a gut-brain neural circuitry limiting food intake.

Intestinal gluconeogenesis is involved in the control of food intake. We show that mu-opioid receptors (MORs) present in nerves in the portal vein walls respond to peptides to regulate a gut-brain neural circuit that controls intestinal gluconeogenesis and satiety. In vitro, peptides and protein digests behave as MOR antagonists in competition experiments. In vivo, they stimulate MOR-dependent induction of intestinal gluconeogenesis via activation of brain areas receiving inputs from gastrointestinal ascending nerves. MOR-knockout mice do not carry out intestinal gluconeogenesis in response to peptides and are insensitive to the satiety effect induced by protein-enriched diets. Portal infusions of MOR modulators have no effect on food intake in mice deficient for intestinal gluconeogenesis. Thus, the regulation of portal MORs by peptides triggering signals to and from the brain to induce intestinal gluconeogenesis are links in the satiety phenomenon associated with alimentary protein assimilation.

Effective dose of ephedrine for treatment of hypotension after induction of general anaesthesia in neonates and infants less than 6 months of age: a multicentre randomised, controlled, open label, dose escalation trial.

BACKGROUND: The recommended dose of ephedrine in adults (0.1 mg kg-1) frequently fails to treat hypotension after induction of general anaesthesia in neonates and infants less than 6 months of age. The aim of this study was to determine the optimal dose of ephedrine in this population for the treatment of hypotension after induction of general anaesthesia with sevoflurane. METHODS: We conducted a multicentre, prospective, randomised, open-label, controlled, dose-escalation trial. Subjects were randomised if presenting a >20% change from baseline in MAP. Six cohorts of 20 subjects each were enrolled. Ten subjects in the first cohort received 0.1 mg kg-1 i. v. (reference dose). For each subsequent cohort, 10 subjects were assigned to the next higher dose (consecutively 0.6, 0.8, 1, 1.2, and 1.4 mg kg-1 i. v.), and the other subjects were assigned to one or more doses already investigated in previous cohorts. The primary outcome was the return of MAP to >80% of baseline at least once within 10 min after ephedrine administration. RESULTS: A total of 119 infants (25% females), with a mean age (standard deviation) of 2.7 (1.3) months, received their allocated dose of ephedrine. The optimal dose of ephedrine was 1.2 mg kg-1, with a percentage of success of 65.5% (95% confidence interval, 35.6-86.4). The doses of ephedrine investigated did not induce adverse events. CONCLUSIONS: Doses of ephedrine much higher (∼10-fold) than those used in adults are necessary in neonates and infants for the treatment of hypotension after induction of general anaesthesia with sevoflurane. CLINICAL TRIAL REGISTRATION: NCT02384876.

Association Between Anesthesia Provider Education and Carbon Footprint Related to the Use of Inhaled Halogenated Anesthetics.

BACKGROUND: Inhaled halogenated anesthetics are responsible for half of operating room total greenhouse gas emissions. Sustainable anesthesia groups were set up in 4 Lyon, France, university hospitals (Hospices Civils de Lyon) in January 2018 and have supported a specific information campaign about the carbon footprint related to the use of inhaled halogenated anesthetics in June 2019. We aimed to assess whether implementing such information campaigns was associated with a decrease in the carbon footprint related to inhaled halogenated anesthetics. METHODS: This retrospective cohort study was conducted from January 1, 2015, to February 29, 2020, in 4 hospitals of the Hospices Civils de Lyon in France. Information meetings on sustainable anesthesia practices were organized by sustainable anesthesia groups that were set up in January 2018. In addition, a specific information campaign about the carbon footprint related to inhaled halogenated anesthetics was conducted in June 2019; it was followed by a questionnaire to be completed online. The monthly purchase of sevoflurane, desflurane, and propofol was recorded, and the estimated monthly carbon footprint from desflurane- and sevoflurane-related perioperative emissions was calculated. The interrupted time-series data from January 2015 to February 2020 were analyzed by segmented regression, considering both interventions (setting up of the sustainable anesthesia groups and specific information campaign) in the analysis and adjusting for 2 confounding factors (seasonality of the data and number of general anesthesia uses). RESULTS: Among the 641 anesthesia providers from the study hospitals, 121 (19%) attended the information meetings about the carbon footprint of inhaled halogenated anesthetics, and 180 (28%) completed the questionnaire. The anesthetic activity from all 641 providers was considered in the analysis. After the sustainable anesthesia groups were set up, the carbon footprint of sevoflurane and desflurane started decreasing: the slope significantly changed ( P < .01) and became significantly negative, from -0.27 (95% confidence interval [CI], -1.08 to 0.54) tons.month -1 to -14.16 (95% CI, -16.67 to -11.65) tons.month -1 . After the specific information campaign, the carbon footprint kept decreasing, with a slope of -7.58 (95% CI, -13.74 to -1.41) tons.month -1 ( P = .02), which was not significantly different from the previous period ( P = .07). CONCLUSIONS: The setup of the sustainable anesthesia groups was associated with a dramatic reduction in the carbon footprint related to halogenated anesthetics. These results should encourage health care institutions to undertake information campaigns toward anesthesia providers so that they also take into account the environmental impact in the choice of anesthetic drugs, in addition to the benefits for the patient and economic concerns.

Diagnostic accuracy of a simple qualitative ultrasound assessment for the diagnosis of empty stomach in the adult: A supplementary analysis of a prospective observer-blind randomized crossover study.

BACKGROUND: It has been reported that qualitative ultrasound assessment performed in the semi-upright position had high sensitivity to detect gastric fluid volume >1.5 mL.kg-1 . Nevertheless, the diagnostic accuracy of qualitative assessment for the diagnosis of empty stomach (fluid volume <0.8 mL.kg-1 ) has not been assessed. We aimed to assess the diagnostic accuracy of simple qualitative ultrasound assessment with and without head-of-bed elevation to 45° for the diagnosis of an empty stomach. We also aimed to determine the diagnostic accuracy of a composite ultrasound scale and clinical algorithm. METHODS: We performed a supplementary analysis of a prospective observer-blind randomized crossover trial in which adult fasting volunteers attended two distinct sessions, with the head-of-bed angled either at 0° or 45°, in a randomized order. Three tests were performed within each session, each corresponding to a different (either 0, 50, 100, 150 or 200 mL) and randomized volume of water; the same volumes were ingested in both sessions, in a randomized order. Ultrasounds were performed 3 min after water ingestion, blindly to the volume ingested. RESULTS: We included 20 volunteers in whom 120 measurements were analyzed. The sensitivity and specificity of the qualitative assessment in the semirecumbent position were 93% (95% CI: 68-100) and 89% (95% CI: 76-96), respectively. The composite scale and clinical algorithm did not have better diagnostic accuracy than the qualitative assessment performed with head-of-bed elevation. Without head-of-bed elevation, the clinical algorithm had significantly higher specificity (98% [95% CI: 88-100]) than qualitative assessment (67% [95% CI: 51-80]; p < 0.05). CONCLUSION: These results suggest that qualitative assessment in the semirecumbent position had high diagnostic accuracy for the diagnosis of fluid volume <0.8 mL.kg-1 ; this method can be used in clinical practice for reliable diagnosis of empty stomach.

Alveolar target ventilation and dead space in children under anaesthesia: The proventiped cohort study.

INTRODUCTION: Ventilator settings in children under anaesthesia remain difficult because of the changes in the physiology and the high dead space. OBJECTIVE: To determine the alveolar minute-volume to sustain normocapnia in children under mechanical ventilation. DESIGN: A prospective observational study. SETTINGS: This study was performed between May and October 2019 in a tertiary care children's hospital. PATIENTS: Children between 2 months and 12 years, weighing between 5 and 40 kg, admitted for general anaesthesia. INTERVENTION: Volumetric capnography was used to estimate the alveolar and dead space volume (Vd). MAIN OUTCOME MEASURES: Total and alveolar minute ventilation in (ml kg -1  min -1 ) over 100 breaths. RESULTS: Sixty patients were included comprising 20 per group: 5 to 10 kg (group 1), 10 to 20 kg (group 2), 20 to 40 kg (group 3). Seven patients were excluded for aberrant capnographic curves. After normalisation to weight, the median [IQR] tidal volume per kilogram was similar between the three groups: 6.5 ml kg -1 [6.0 to 7.5 ml kg -1 ], 6.4  ml kg -1 [5.7 to 7.3  ml kg -1 ], 6.4  ml kg -1 [5.3 to 6.8  ml kg -1 ]; P  = 0.3. Total Vd (in ml kg -1 ) was negatively correlated to weight ( r  = -0.62, 95% confidence interval -0.41 to -0.76, P  < 0.001). The total normalised minute ventilation (ml kg -1  min -1 ) to obtain normocapnia was higher in group 1 than in group 2 and in group 3; 203  ml kg -1  min -1 [175 to 219 ml kg -1  min -1 ], 150  ml kg -1  min -1 [139 to 181  ml kg -1  min -1 ] and 128  ml kg -1  min -1 [107 to 157  ml kg -1  min -1 ]; P  < 0.001 (mean ± SD), but (mean ± SD) alveolar minute ventilation was similar between the three groups; 68 ±â€Š21  ml kg -1  min -1 . CONCLUSION: Total dead space volume (including apparatus dead space) represents a major component of tidal volume in children less than 30 kg, when using large heat and moisture exchanger filters. The total minute ventilation necessary to achieve normocapnia decreased with increasing weight, while the alveolar minute ventilation remained constant. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT03901599.

Pregnancy and Labor Epidural Effects on Gastric Emptying: A Prospective Comparative Study.

BACKGROUND: The lack of reliable data on gastric emptying of solid food during labor has led to some discrepancies between current guidelines regarding fasting for solid food in the parturient. This prospective comparative study aimed to test the hypothesis that the gastric emptying fraction of a light meal would be reduced in parturients receiving epidural analgesia and with no labor analgesia compared with nonpregnant and pregnant women. METHODS: Ten subjects were enrolled and tested in each group: nonpregnant women, term pregnant women, parturients with no labor analgesia, and parturients with epidural labor analgesia. After a first ultrasound examination was performed to ensure an empty stomach, each subject ingested a light meal (125 g yogurt; 120 kcal) within 5 min. Then ultrasound measurements of the antral area were performed at 15, 60, 90, and 120 min. The fraction of gastric emptying at 90 min was calculated as [(antral area90 min / antral area15 min) - 1] × 100, and half-time to gastric emptying was also determined. For the Parturient-Epidural group, the test meal was ingested within the first hour after the induction of epidural analgesia. RESULTS: The median (interquartile range) fraction of gastric emptying at 90 min was 52% (46 to 61), 45% (31 to 56), 7% (5 to 10), and 31% (17 to 39) for nonpregnant women, pregnant women, parturients without labor analgesia, and parturients with labor epidural analgesia, respectively (P < 0.0001). The fraction of gastric emptying at 90 min was statistically significant and lower in the Parturient-Epidural group than in the Nonpregnant and Pregnant Control groups. In addition, the fraction of gastric emptying at 90 min was statistically significant and lower in the Parturient-No-Epidural group than in the Parturient-Epidural group. CONCLUSIONS: Gastric emptying in parturients after a light meal was delayed, and labor epidural analgesia seems not to worsen but facilitates gastric emptying. This should be taken into consideration when allowing women in labor to consume a light meal.

Stress Management Training Improves Overall Performance during Critical Simulated Situations: A Prospective Randomized Controlled Trial.

BACKGROUND: High-fidelity simulation improves participant learning through immersive participation in a stressful situation. Stress management training might help participants to improve performance. The hypothesis of this work was that Tactics to Optimize the Potential, a stress management program, could improve resident performance during simulation. METHODS: Residents participating in high-fidelity simulation were randomized into two parallel arms (Tactics to Optimize the Potential or control) and actively participated in one scenario. Only residents from the Tactics to Optimize the Potential group received specific training a few weeks before simulation and a 5-min reactivation just before beginning the scenario. The primary endpoint was the overall performance during simulation measured as a composite score (from 0 to 100) combining a specific clinical score with two nontechnical scores (the Ottawa Global Rating Scale and the Team Emergency Assessment Measure scores) rated for each resident by four blinded independent investigators. Secondary endpoints included stress level, as assessed by the Visual Analogue Scale during simulation. RESULTS: Of the 134 residents randomized, 128 were included in the analysis. The overall performance (mean ± SD) was higher in the Tactics to Optimize the Potential group (59 ± 10) as compared with controls ([54 ± 10], difference, 5 [95% CI, 1 to 9]; P = 0.010; effect size, 0.50 [95% CI, 0.16 to 0.91]). After specific preparation, the median Visual Analogue Scale was 17% lower in the Tactics to Optimize the Potential group (52 [42 to 64]) than in the control group (63 [50 to 73]; difference, -10 [95% CI, -16 to -3]; P = 0.005; effect size, 0.44 [95% CI, 0.26 to 0.59]. CONCLUSIONS: Residents coping with simulated critical situations who have been trained with Tactics to Optimize the Potential showed better overall performance and a decrease in stress level during high-fidelity simulation. The benefits of this stress management training may be explored in actual clinical settings, where a 5-min Tactics to Optimize the Potential reactivation is feasible prior to delivering a specific intervention.

Ventilation in pediatric anesthesia: A French multicenter prospective observational study (PEDIAVENT).

INTRODUCTION: Protective ventilation is now a standard of care in adults. However, management of ventilation is heterogeneous in children and little is known regarding the mechanical ventilation parameters actually used during pediatric anesthesia. AIM: The aim of the study was to assess current ventilatory practices during pediatric anesthesia in France and to compare them with pediatric experts' statements, with a specific focus on tidal volume. PATIENTS AND METHODS: We conducted a prospective multicenter observational study, regarding the ventilatory management and the mechanical ventilation parameters, over two days (21 and 22 June 2017) in 29 pediatric centers in France. All children undergoing general anesthesia during these 2 days were eligible; those who required extracorporeal circulation or one-lung ventilation were excluded. RESULTS: A total of 701 children were included; median [IQR] age was 60 [24-120] months. Among the patients in whom controlled ventilation was used, 254/515 (49.3%) had an expired tidal volume >8 mL/kg and 44 children (8.8%) an expired tidal volume ≥10 mL/kg. Lower weight and use of a supraglottic airway device were significantly associated with provision of a tidal volume ≥10 mL/kg (odds ratio 0.94, 95% confidence interval [0.92; 0.97], P < .001 and 2.28 [1.20; 4.31], P = .012, respectively). The positive end-expiratory pressure was set at a median [IQR] of 4 [3-5] cmH2 O; it was <3 cmH2 O in 15.7% of children and not used in 56/499 (9.3%). Among intubated children, 57 (18.3%) received a tidal volume < 10 mL/kg with a positive end-expiratory pressure ≥3 cmH2 O in association with recruitment maneuvers. CONCLUSIONS: Ventilatory practices in children were heterogenous, and a large proportion of children were not ventilated as it is currently recommended by some experts.

Does a two-minute mini-fluid challenge predict fluid responsiveness in pediatric patients under general anesthesia?

BACKGROUND: Very little evidence for predictive markers of fluid responsiveness has been reported in children as compared to adults. The impact of hypovolemia or hypervolemia on morbidity has driven interest in the fluid challenge titration strategy. AIM: The objective of this study was to explore the ability of a 3 mL kg-1 mini-fluid challenge over 2 minutes to predict fluid responsiveness in children under controlled ventilation. METHODS: Children scheduled for surgery under general anesthesia were included and received a fluid challenge of 15 mL kg-1 of crystalloid prior to incision administered over 10 minutes in two steps: 3 mL kg-1 over 2 minutes then 12 mL kg-1 over 8 minutes. Fluid responsiveness was defined as a change of ≥10% in cardiac output estimated by left ventricular outflow tract velocity time integral (VTI) as measured by transthoracic ultrasound before and after the fluid challenge of 15 mL kg-1 . RESULTS: Of the 55 patients included in the analysis, 43 were fluid responders. The increase in the VTI after the mini-fluid challenge (ΔVTIminiFC ) predicted fluid responsiveness with an area under the receiver operating characteristic curve of 0.77; 95% CI (0.63-0.87), P = .004. Considering the least significant change which was 7.9%; 95% CI (6-10), the threshold was 8% with a sensitivity of 53%; 95% CI (38-68); and a specificity of 77%; 95% CI (54-100). CONCLUSION: ΔVTIminiFC weakly predicted the effects of a fluid challenge of 15 mL kg-1 of crystalloid in anesthetized children under controlled mechanical ventilation.

European minimum standards for obstetric analgesia and anaesthesia departments: An experts' consensus.

: An important variability of anaesthetic standards of care was discovered in the obstetric departments of many European Union countries. After discussing this issue in various meetings of the European Society of Anaesthesiology (ESA) board and its obstetric subcommittee, European Board of Anaesthesiology of the European Union of Medical Specialists (EBA-UEMS) executive members, ESA obstetric subcommittee members and European experts in obstetric anaesthesiology have participated in the elaboration of this document. This experts' opinion is focused mainly on obstetric patients and safety concerns in terms of minimum standards of practice. An initial bibliographical search was performed in medical databases and general literature, searching for obstetric anaesthesiology standards to select the most important safety issues. After the initial presentation of the project during EBA-UEMS and ESA obstetric subcommittee meetings, participants were asked to review the document; several rounds of revisions were performed by the experts, to reach a common opinion concerning the topics considered central to patient safety in the obstetric setting. After three rounds of revision, a consensus was reached and is presented in this document, which includes the list of topics considered relevant by the involved areas, and the respective recommendations. These recommendations covered some EBA-UEMS strategic key areas, in addition to several clinical aspects of common obstetric practice.

Prevalence and prediction of higher estimated gastric content in parturients at full cervical dilatation: A prospective cohort study.

BACKGROUND: Emergent obstetrical procedures may require general anaesthesia in parturients at full cervical dilatation or immediately after vaginal birth. This study aimed to determine the prevalence and the predictive factors of higher estimated gastric content in parturients at full cervical dilatation with epidural analgesia and allowed to drink during the labour, and to assess the ability of the antral area measured in the semirecumbent position (SR-CSA) to identify higher estimated gastric content in this setting. METHODS: This prospective observational study was conducted between December 2016 and July 2017. Ultrasonographic examination of the antrum was performed at full cervical dilatation, within the hour preceding the beginning of expulsive efforts. Higher estimated gastric content was defined when solid content was observed and/or if the calculated gastric fluid volume was >1.5 mL/kg. RESULTS: Seventeen of 62 parturients (27%) presented higher estimated gastric content. Maximal pain intensity during the last hour of labour and time interval between the insertion of the epidural catheter and ultrasonographic examination were significantly increased in parturients with higher estimated gastric content. The threshold value of the SR-CSA to identify a higher estimated gastric content was 393 mm2 , with sensitivity = 88% and specificity = 87%. CONCLUSION: Around a quarter of parturients with epidural analgesia and free access to clear fluids during labour presented higher estimated gastric content at full cervical dilatation. The SR-CSA may be of interest for the fast ultrasound assessment of the gastric content status in case of emergent obstetrical procedures at full cervical dilatation.

Does programmed intermittent epidural bolus improve childbirth conditions of nulliparous women compared with patient-controlled epidural analgesia?: A multicentre, randomised, controlled, triple-blind study.

BACKGROUND: Epidural analgesia may change the mechanics of childbirth. These changes are related to the concentration of the local anaesthetic used epidurally but probably also to its mode of delivery into the epidural space. OBJECTIVE: To determine whether the administration of programmed intermittent epidural boluses (PIEB) improves the mechanics of second-stage labour compared with patient-controlled epidural analgesia (PCEA) with a background infusion. DESIGN: A randomised, controlled, triple-blind study. SETTING: Multicentre study including four level III maternity units, January 2014 until June 2016. PATIENTS: A total of 298 nulliparous patients in spontaneous labour were randomised to a PIEB or PCEA group. INTERVENTION: After epidural initiation with 15 ml of 0.1% levobupivacaine containing 10 µg of sufentanil, patients received either an hourly bolus of 8 ml (PIEB) or a continuous rate infusion of 8 ml h (PCEA): the drug mixture used was levobupivacaine 0.1% and sufentanil 0.36 µg ml. MAIN OUTCOME MEASURES: The primary outcome was a composite endpoint of objective labour events: a posterior occiput position in the second stage, an occiput position at birth, waiting time at full cervical dilatation before active maternal pushing more than 3 h, maternal active pushing duration more than 40 min, and foetal heart rate alterations. Vaginal instrumental delivery rates, analgesia and motor blockade scores were also recorded. RESULTS: From the 298 patients randomised, data from 249 (124 PIEB, 125 PCEA) were analysed. No difference was found in the primary outcome: 48.0% (PIEB) and 45.5% (PCEA) of patients, P = 0.70. In addition, no difference was observed between the groups for each of the individual events of the composite endpoint, nor in the instrumental vaginal delivery rate, nor in the degree of motor blockade. Despite an equivalent volume of medication in the groups, a significantly higher analgesia score at full dilatation was observed in the PIEB group, odds-ratio = 1.9 (95% confidence interval, 1.0 to 3.5), P = 0.04. CONCLUSION: The mechanics of the second stage did not differ whether PIEB or PCEA was used. Analgesic conditions appeared to be superior with PIEB, especially at full dilation. TRIAL REGISTRATION: NCT01856166.

Maternal Death Due to Amniotic Fluid Embolism: A National Study in France.

BACKGROUND: A structured definition of amniotic fluid embolism (AFE) based on 4 criteria was recently proposed for use in research by the Society for Maternal-Fetal Medicine (SMFM) and the Amniotic Fluid Embolism Foundation. The main objective of this study was to review all AFE-related maternal deaths in France during 2007-2011 according to the presence or not of all these 4 diagnostic criteria. METHODS: Maternal deaths due to AFE were identified by the national experts committee of the French Confidential Enquiry into Maternal Deaths during 2007-2011 (n = 39). The maternal mortality ratio for AFE was calculated. We applied the structured definition proposed by the Society for Maternal-Fetal Medicine and the Amniotic Fluid Embolism Foundation to AFE-related maternal deaths identified by the national experts committee. Characteristics of women, pregnancies and deliveries; clinical and biological features of AFE; and specific laboratory tests used were described by the presence or not of all 4 diagnostic criteria. Management of obstetric hemorrhage and quality of care according to the experts were also described. RESULTS: The maternal mortality ratio from AFE was 0.95/100,000 live births (95% confidence interval, 0.67-1.3). Detailed clinical data were collected for 36 women who died from AFE: 21 (58%) had all 4 proposed diagnostic criteria and 15 (42%) had 1 or more missing criterion. Documented early disseminated intravascular coagulopathy was missing for 14 women, and 2 women exhibited more than 1 missing criterion. Ten of the 15 women with missing criteria had clinical coagulopathy, with standard hemostasis tests performed in only 3. Specific diagnostic examinations for AFE were performed in similar proportions by the presence or not of all diagnostic criteria. Opportunities to improve care included timely performance of indicated hysterectomy (n = 13) and improved transfusion practices (n = 9). In the context of maternal cardiac arrest, for 5 of 13 women, fetal extraction was performed within 5 minutes. CONCLUSIONS: The structured definition of AFE for research studies would exclude more than one-third of AFE-related maternal deaths identified by the national experts committee. Inclusion of clinical coagulopathy as a diagnostic criterion for AFE would reduce this proportion to 14%. There is still room for improvement in the management of obstetric hemorrhage and timely fetal extraction in the context of maternal cardiac arrest, frequently observed in AFE-related maternal death.

Ultrasound assessment of the prevalence of increased gastric contents and volume in elective pediatric patients: A prospective cohort study.

BACKGROUND: Though pulmonary aspiration of gastric contents occurs mainly in the setting of emergency surgery, it may also occur in children scheduled for elective surgery without any obvious clinical risk factor. Increased gastric content volume is one the predisposing factors for pulmonary aspiration that could affect such children and may be identified using ultrasound examination of the gastric antrum. AIMS: We aimed to assess the prevalence of "at-risk stomach" defined by ultrasound visualization of any solid content in the antrum and/or by calculated gastric fluid volume > 1.25 mL/kg, in children scheduled for elective surgery. METHODS: Children scheduled for elective surgery were consecutively included into this prospective cohort study. Preoperative ultrasound examination of the antrum was performed in both the supine and the right lateral decubitus positions. Gastric fluid content was assessed using a 0-2 qualitative grading scale. The antral cross-sectional area was also measured in both the supine and the right lateral decubitus positions, allowing the calculation of the gastric fluid volume according to a formula previously described. RESULTS: We analyzed 200 elective children. Median duration of fasting was 4 hours for liquids and >13 hours for solids. None of the children included in this study had evidence of solid content. Six (3%) children had a Grade 2 antrum (fluid content seen in both the supine and the right lateral decubitus positions). Two children had a gastric fluid volume >1.25 mL/kg. The prevalence of "at-risk stomach" was 1% (95% confidence interval: 0.2%-3.9%). CONCLUSION: According to our results, only 1% of elective children had potentially increased risk for pulmonary aspiration. Further studies should be performed in order to define the target population of elective children for which ultrasound assessment of gastric content should be performed prior to general anesthesia.

Ultrasound examination of the antrum to predict gastric content volume in the third trimester of pregnancy as assessed by MRI: A prospective cohort study.

BACKGROUND: Ultrasound examination of the gastric antrum allows reliable pre-operative assessment of gastric contents and volume in adult patients. However, during pregnancy, the change in the anatomical position of the stomach due to the gravid uterus leads to a change in the measured value of the antral area. Therefore, current mathematical models predicting gastric content volume (GCV) in the adult may not apply in term pregnant women. OBJECTIVE: To propose a mathematical model which is predictive of GCV in pregnant women and to assess the performance of an ultrasound qualitative grading scale (0 to 2) for the diagnosis of clear fluid volumes more than 0.8 and 1.5 ml kg. DESIGN: Prospective cohort study. SETTING: Hospices Civils de Lyon, Hôpital Femme Mère Enfant, Lyon and Assistance Publique - Hôpitaux de Marseille, Hôpital Nord, Marseille, France. PATIENTS: Pregnant women in the third trimester of pregnancy. MAIN OUTCOME MEASURES: Comparison of the GCV as measured by MRI and the ultrasound measured antral cross-sectional area, and an assessment of gastric contents according to a 0 to 2 qualitative grading scale. RESULTS: Data from 34 women were analysed. A linear model predictive of GCV was constructed with a 95% agreement band of ±95 ml, with a mean polar angle of -8.7°. Performance of the qualitative grading scale to detect fluid volumes >0.8 and >1.5 ml kg was improved when used in a composite scale including a 505 mm antral area cut-off value in the semirecumbent supine position. CONCLUSION: We report a new mathematical model predictive of GCV in women in the third trimester of pregnancy. Furthermore, the combination of the qualitative and the quantitative ultrasound examination of the gastric antrum might be useful to assess gastric fluid volume in pregnant women. TRIAL REGISTRATION: ANSM Register N°2015-A00800-49.

Suprasternal notch echocardiography: a potential alternative for the measurement of respiratory variation in aortic blood flow peak velocity in mechanically ventilated children.

We conducted a prospective, observational study to investigate the relationship between the respiratory variation in aortic blood flow peak velocity (ΔVPeak) measured by echocardiography in the proximal ascending aorta from the suprasternal notch window and the ΔVPeak measured at the level of the aortic annulus from the classical apical five-chamber view. We studied children aged from 1 to 10 years referred for surgery under general anesthesia with positive pressure ventilation, after induction of general anesthesia. Twenty-two children (mean age = 5 ± 3 years) were recruited. There was a significant relationship between the ΔVPeak recorded via the suprasternal notch view and the ΔVPeak recorded via the apical five-chamber view (r = 0.62 [95% confidence interval 0.25-0.84], P = 0.003). The ΔVPeak measured using the suprasternal notch route could be considered to predict fluid responsiveness in children under mechanical ventilation, notably when the access to the chest wall is limited during surgery.

Intravenous Amisulpride for the Prevention of Postoperative Nausea and Vomiting: Two Concurrent, Randomized, Double-blind, Placebo-controlled Trials.

BACKGROUND: Two essentially identical, randomized, double-blind, placebo-controlled, parallel-group phase III studies evaluated the efficacy of intravenous amisulpride, a dopamine D2/D3 antagonist, in the prevention of postoperative nausea and vomiting in adult surgical patients. METHODS: Adult inpatients undergoing elective surgery during general anesthesia and having at least two of the four Apfel risk factors for postoperative nausea and vomiting were enrolled at 9 U.S. and 10 European sites. A single 5-mg dose of amisulpride or matching placebo was given at induction of anesthesia. The primary endpoint was complete response, defined as no vomiting/retching and no use of antiemetic rescue medication in the 24-h postoperative period. Nausea incidence was a secondary endpoint. RESULTS: Across the two studies, 689 patients were randomized and dosed with study medication, of whom 626 were evaluable per protocol. In the U.S. study, 46.9% (95% CI, 39.0 to 54.9) of patients achieved complete response in the amisulpride group compared to 33.8% (95% CI, 26.2 to 42.0) in the placebo group (P = 0.026). In the European study, complete response rates were 57.4% (95% CI, 49.2 to 65.3) for amisulpride and 46.6% (95% CI, 38.8 to 54.6) for placebo (P = 0.070). Nausea occurred less often in patients who received amisulpride than those who received placebo. There was no clinically significant difference in the safety profile of amisulpride and placebo; in particular, there were no differences in terms of QT prolongation, extrapyramidal side effects, or sedation. CONCLUSIONS: One of the two trials demonstrated superiority, while pooling both in a post hoc change to the plan of analysis supported the hypothesis that amisulpride was safe and superior to placebo in reducing the incidence of postoperative nausea and vomiting in a population of adult inpatients at moderate to high risk of postoperative nausea and vomiting.

Predictive factors of maternal hypothermia during Cesarean delivery: a prospective cohort study.

PURPOSE: Although perioperative hypothermia may increase maternal morbidity, active warming is infrequently performed to maintain normothermia during Cesarean delivery (CD). The aim of this prospective observational study was to determine the factors associated with maternal hypothermia in this setting. METHODS: Women scheduled for elective or emergency CD were consecutively included in this study from November 2014 to October 2015. Maternal temperature was measured using an infrared tympanic thermometer on the patient's arrival in the operating room, at skin incision, and at the end of skin suture. Maternal hypothermia was defined by tympanic temperature < 36°C at the end of skin suture. Univariate analysis was performed, followed by multivariate logistic regression analysis, in order to determine the factors associated with maternal hypothermia at the end of the surgery. RESULTS: Three hundred fifty-nine women were included and analyzed during this study. The incidence of hypothermia was 23% (95% confidence interval, 18 to 27) among the total population included. According to multivariate analysis, obesity, oxytocin augmentation of labour, and use of active forced-air warming were associated with a decreased risk of maternal hypothermia, while maternal temperature < 37.1°C on arrival in the operating room, maternal temperature < 36.6°C at skin incision, and an infused volume of fluids > 650 mL were significantly associated with maternal hypothermia. Both goodness of fit and predictive value of multivariate analysis were high. CONCLUSION: Several predictive factors for maternal hypothermia during CD were identified. These factors should be taken into account to help prevent maternal hypothermia during CD.

Determination of a cut-off value of antral area measured in the supine position for the fast diagnosis of an empty stomach in the parturient: A prospective cohort study.

BACKGROUND: Ultrasound measurement of the antral cross-sectional area of the stomach, performed in the supine position, has been described for preoperative assessment of gastric content in the adult, but, to date, no study has determined the cut-off value of the antral area for the diagnosis of an empty stomach in the parturient. Nevertheless, previous studies in parturients have reported that the use of a simple qualitative grading scale (0 to 2) was reliable for the estimation of the gastric fluid volume. However, this qualitative grading score requires turning the parturient into the right lateral decubitus position for the ultrasound examination, something which may not be easily feasible, particularly in the case of an obstetric emergency. OBJECTIVE: To calculate the cut-off value of the antral area, measured in the supine position during established labour, for the diagnosis of 'empty' stomach. DESIGN: A prospective cohort study. SETTING: Hospices Civils de Lyon, Hôpital Femme Mère Enfant, Lyon, France. PATIENTS: Seventy-three women in established labour. INTERVENTIONS: For each parturient, ultrasound assessment of gastric contents was performed in the supine and right lateral decubitus position and scored 0 to 3 on a qualitative grading scale. This assessment was followed by ultrasound measurement of the antral cross-sectional area in both the supine and right lateral positions. MAIN OUTCOME MEASURES: To assess the performance of the antral area measured in the supine position for the diagnosis of an 'empty' stomach (gastric antrum grade 0), a receiver operating characteristic curve was plotted, and the area under the receiver operating characteristic curve was calculated. RESULTS: Data from 73 women were analysed. For the diagnosis of grade 0, the cut-off value for the antral area measured in the supine position was 381 mm (sensitivity, 81%; specificity, 76% and negative predictive value, 80%). CONCLUSION: With a parturient lying in the supine position, a single assessment of the antral cross-sectional area may be used for the fast diagnosis of an empty stomach. This tool could be useful in assessing the risk of aspiration for parturients who require emergency anaesthesia during labour.