Prevalence and factors associated with high-risk gastric contents in women admitted to the maternity unit for childbirth: a prospective multicentre cohort study.

BACKGROUND: This multicentre prospective observational study sought to determine the prevalence and the factors associated with high-risk gastric contents in women admitted to the maternity unit for childbirth, and to identify the clinical situations in which ultrasound assessment of gastric contents would be most helpful (i.e. when the prevalence of high-risk gastric contents is close to 50%). METHODS: Ultrasound assessments of gastric contents were performed within the first hour after admission to the maternity unit. The prevalence of high-risk gastric contents was calculated and variables associated with high-risk gastric contents were identified using logistic regression analyses. RESULTS: A total of 1003 parturients were analysed. The prevalence of high-risk gastric contents was 70% (379/544; 95% confidence interval: 66-74%) in women admitted in spontaneous labour and 65% (646/1003; 95% confidence interval: 61-67%) in the whole cohort. Lower gestational age, increased fasting duration for solids, and elective Caesarean delivery were independently associated with reduced likelihood of high-risk gastric contents. In women admitted in spontaneous labour and in the whole cohort, the prevalence of high-risk gastric contents ranged from 85% to 86% for fasting duration for solids <6 h, 63%-68% for fasting 6-8 h, 54%-55% for fasting 8-12 h, and 47%-51% for fasting ≥12 h. CONCLUSIONS: Around two-thirds of parturients had high-risk gastric contents within the first hour after admission to the maternity unit. Our results suggest that gastric emptying for solids continues in labouring women, and that gastric ultrasound would be most helpful when fasting duration is ≥8 h.

The Potential Role of Wearable Inertial Sensors in Laboring Women with Walking Epidural Analgesia.

There is a growing interest in wearable inertial sensors to monitor and analyze the movements of pregnant women. The noninvasive and discrete nature of these sensors, integrated into devices accumulating large datasets, offers a unique opportunity to study the dynamic changes in movement patterns during the rapid physical transformations induced by pregnancy. However, the final cut of the third trimester of pregnancy, particularly the first stage of labor up to delivery, remains underexplored. The growing popularity of "walking epidural", a neuraxial analgesia method allowing motor function preservation, ambulation, and free movement throughout labor and during delivery, opens new opportunities to study the biomechanics of labor using inertial sensors. Critical research gaps exist in parturient fall prediction and detection during walking epidural and understanding pain dynamics during labor, particularly in the presence of pelvic girdle pain. The analysis of fetal descent, upright positions, and their relationship with dynamic pelvic movements facilitated by walking during labor is another area where inertial sensors can play an interesting role. Moreover, as contemporary obstetrics advocate for less restricted or non-restricted movements during labor, the role of inertial sensors in objectively measuring the quantity and quality of women's movements becomes increasingly important. This includes studying the impact of epidural analgesia on maternal mobility, walking patterns, and associated obstetrical outcomes. In this paper, the potential use of wearable inertial sensors for gait analysis in the first stage of labor is discussed.

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.

Pre-operative distraction using electric ride-on cars for children undergoing elective ambulatory surgery: A randomised controlled trial.

BACKGROUND: Pre-operative anxiety occurs in 18 to 60% of children undergoing surgery and results in poor outcomes. Nonpharmacological methods of distraction are effective in alleviating peri-operative anxiety. In our institution, ride-on electric cars (ride-on e-cars) are routinely used by children undergoing ambulatory surgery as a mean of nonpharmacological distraction. OBJECTIVES: The aim of this study is to assess the effect of pre-operative distraction with ride-on e-cars on children's pre-operative anxiety when undergoing elective ambulatory surgery. DESIGN: This was a prospective, randomised, controlled, open-label study. SETTING: The study was carried out from September 2019 to September 2021 in the ambulatory paediatric surgery unit of our teaching hospital, in Marseille, France. PATIENTS: Children aged 2 to 10 years and weighing less than 35 kg undergoing elective ambulatory surgery were eligible. One hundred and fifteen children were included, 56 in the control group and 59 in the intervention group. INTERVENTION: Children in the control group were transported from the operating room (OR) waiting area to the OR using a trolley, while children in the intervention group used the ride-on e-cars, without pharmacological premedication or parental presence. MAIN OUTCOME MEASURES: The primary outcome was pre-operative anxiety at the end of the transport (prior going into the OR assessed by the modified Yale Preoperative Anxiety Score Short Form (mYPAS-SF). Secondary outcomes were the anxiety levels in children over time, as well as postoperative pain and agitation assessed with the Face Legs Activity Cry Consolability (FLACC) and Paediatric Anaesthesia Emergence Delirium (PAED) scales, respectively. RESULTS: The mYPAS-SF anxiety scores did not differ between the control group and the intervention group (39 ±â€Š19 vs. 37 ±â€Š21, P  = 0.574). The secondary outcomes were similar between the two groups. CONCLUSIONS: Our randomised controlled trial showed that the use of ride-on e-cars did not alter pre-operative anxiety as compared with standard transport in children undergoing elective ambulatory surgery. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT03961581.

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.

Pre-operative fasting in children: A guideline from the European Society of Anaesthesiology and Intensive Care.

Current paediatric anaesthetic fasting guidelines have recommended conservative fasting regimes for many years and have not altered much in the last decades. Recent publications have employed more liberal fasting regimes with no evidence of increased aspiration or regurgitation rates. In this first solely paediatric European Society of Anaesthesiology and Intensive Care (ESAIC) pre-operative fasting guideline, we aim to present aggregated and evidence-based summary recommendations to assist clinicians, healthcare providers, patients and parents. We identified six main topics for the literature search: studies comparing liberal with conservative regimens; impact of food composition; impact of comorbidity; the use of gastric ultrasound as a clinical tool; validation of gastric ultrasound for gastric content and gastric emptying studies; and early postoperative feeding. The literature search was performed by a professional librarian in collaboration with the ESAIC task force. Recommendations for reducing clear fluid fasting to 1 h, reducing breast milk fasting to 3 h, and allowing early postoperative feeding were the main results, with GRADE 1C or 1B evidence. The available evidence suggests that gastric ultrasound may be useful for clinical decision-making, and that allowing a 'light breakfast' may be well tolerated if the intake is well controlled. More research is needed in these areas as well as evaluation of how specific patient or treatment-related factors influence gastric emptying.

Women's dissatisfaction with inappropriate behavior by health care workers during childbirth care in France: A survey study.

BACKGROUND: Quality care during childbirth requires that health care providers have not only excellent skills but also appropriate and considerate attitudes and behavior. Few studies have examined the proportion of women in Western countries expressing dissatisfaction with such inappropriate or inconsiderate behavior. This study evaluated this proportion in a sample presumably representative of French maternity units. METHODS: This prospective multicenter study, using data from a selfadministered questionnaire, took place in 25 French maternity units during one week in September 2018. The primary outcome measure was mothers' self-reported dissatisfaction with blatantly inappropriate behavior (ie, inappropriate attitude, inadequate respect for privacy, insufficient gentleness of care, and/or inappropriate language) by health care workers in the delivery room. The secondary outcome was their self-reported dissatisfaction with these workers' inconsiderate behavior (ie, unclear and inappropriate information, insufficient participation in decision-making, or deficient consideration of pain). RESULTS: Of 803 potentially eligible women, 627 completed the questionnaire after childbirth; 5.62% (35/623, 95% CI: 3.94-7.73) reported dissatisfaction with blatantly inappropriate behaviors and 9.79% (61/623, 95% CI: 7.57-12.40) with inconsiderate behaviors. The main causes of dissatisfaction reported by women in this survey were the inadequate consideration of their pain and the failure to share decision-making. CONCLUSIONS: Most of the women were satisfied with how health care workers behaved towards them in the delivery room. Nonetheless, health care staff must be aware of women's demands for greater consideration of their expressions of pain and of their voice in decisions.

Oxygen desaturation and time burden during tracheobronchial endoscopy for suspected foreign body in toddlers.

Tracheobronchial endoscopy with general anaesthesia for suspected foreign body aspiration exposes toddlers to acute hypoxemia. Better quantification of intraoperative hypoxemia could help identify and manage the most severe patients. We explored the hypoxic burden approach to account for both duration and depth of desaturation episodes during the procedure and determined risk factors for high hypoxic burden. We retrospectively analysed tracheobronchial endoscopies performed from September 2015 to September 2018 in children ≤ 36 months for suspected foreign body aspiration, in two French university hospitals. The hypoxic burden (area under 90% of the SpO2/time curve) was calculated. The median of non-zero burdens was used to delineate a subgroup with high hypoxic burden. Risk factors for high hypoxic burden were identified using multivariable analysis. Of 96 procedures, 56 (58%) were associated with at least one SpO2 value < 90%. Of them, the median [interquartile] hypoxic burden was 25 [5-87] %.min. Bradycardia < 100 bpm occurred in 11 procedures (11%). Initial admission to general hospitals (OR 0.23, 95% CI 0.06-0.86) and airway anaesthesia with topical lidocaine (OR 0.15, 95% CI 0.03-0.62) were associated with a reduced risk of high hypoxic burden. High hypoxic burden was associated with an increased risk of postoperative invasive ventilation (OR 32, 95% CI 1.7-617) and of hospital stay > 24 h (OR 4.0, 95% CI 1.6-10). No postoperative neurological sequelae were found. The hypoxic burden approach, when applied in tracheobronchial endoscopy for suspected foreign body aspiration in toddlers, enabled the quantification of hypoxemia and the search for specific risk factors.

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.

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.

Comparison of cardiac output optimization with an automated closed-loop goal-directed fluid therapy versus non standardized manual fluid administration during elective abdominal surgery: first prospective randomized controlled trial.

An intraoperative automated closed-loop system for goal-directed fluid therapy has been successfully tested in silico, in vivo and in a clinical case-control matching. This trial compared intraoperative cardiac output (CO) in patients managed with this closed-loop system versus usual practice in an academic medical center. The closed-loop system was connected to a CO monitoring system and delivered automated colloid fluid boluses. Moderate to high-risk abdominal surgical patients were randomized either to the closed-loop or the manual group. Intraoperative final CO was the primary endpoint. Secondary endpoints were intraoperative overall mean cardiac index (CI), increase from initial to final CI, intraoperative fluid volume and postoperative outcomes. From January 2014 to November 2015, 46 patients were randomized. There was a lower initial CI (2.06 vs. 2.51 l min-1 m-2, p = 0.042) in the closed-loop compared to the control group. No difference in final CO and in overall mean intraoperative CI was observed between groups. A significant relative increase from initial to final CI values was observed in the closed-loop but not the control group (+ 28.6%, p = 0.006 vs. + 1.2%, p = 0.843). No difference was found for intraoperative fluid management and postoperative outcomes between groups. There was no significant impact on the primary study endpoint, but this was found in a context of unexpected lower initial CI in the closed-loop group.Trial registry number ID-RCB/EudraCT: 2013-A00770-45. ClinicalTrials.gov Identifier NCT01950845, date of registration: 17 September 2013.

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.