Diagnostic accuracy of a simple qualitative ultrasound assessment for the diagnosis of high-risk gastric contents in the parturient. A prospective observational cohort study.

STUDY OBJECTIVE: Interpretation of gastric ultrasound relies on the use of a clinical algorithm that combines qualitative analysis of the gastric antrum contents with the calculation of the volume of fluid contents. This reference method may be difficult to apply in the parturient. We therefore aimed to assess the diagnostic accuracy of a simple qualitative assessment in the supine position for the diagnosis of high-risk gastric contents in the parturient. We also assessed the diagnostic accuracy of a composite scale and another clinical algorithm based on a mathematical model different to that used in the reference method. DESIGN: Prospective observational cohort study. SETTING: University hospital, Lyon, France. PATIENTS: Adult women admitted to the delivery room. INTERVENTIONS: Qualitative and quantitative gastric ultrasound examination within the first hour following admission. MEASUREMENTS: With respect to the reference method, the diagnostic accuracy of a simple qualitative assessment for the diagnosis of high-risk gastric contents was assessed. The diagnostic accuracy of a composite scale and another clinical algorithm, and the agreement between each approach were also assessed. MAIN RESULTS: A total of 235 parturients were included and analyzed. The simple qualitative assessment led to conclusive ultrasound assessment in 233 (99%) women, while the reference method led to conclusive assessment in 213 (91%) women (P < 0.05). The sensitivity and the specificity of the simple qualitative assessment were 97% (95%CI: 93 to 99%) and 96% (95%CI: 90 to 99%), respectively. These were not significantly different from those of the composite scale and the clinical algorithm. The four approaches showed almost perfect agreement with each other. CONCLUSIONS: These results suggest that simple qualitative assessment may be useful in clinical practice to help the anesthesiologist in the assessment of gastric contents status and risk of aspiration.

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.

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.

Non-invasive measurement of digital plethysmographic variability index to predict fluid responsiveness in mechanically ventilated children: A systematic review and meta-analysis of diagnostic test accuracy studies.

BACKGROUND: To date, the use of the plethysmographic variability index (PVI) has not been recommended to guide fluid management in the paediatric surgical population. This systematic review and meta-analysis aimed to summarise available evidence about the diagnostic accuracy of digital PVI to predict fluid responsiveness in mechanically ventilated children. METHODS: We searched the Pubmed, Embase and Web of Science databases, from inception to January 2022, to identify all relevant studies that investigated the ability of the PVI recorded at the finger to predict fluid responsiveness in mechanically ventilated children. Using a random-effects model, we calculated pooled values of diagnostic odds ratio, sensitivity, and specificity of PVI to predict the response to fluid challenge. RESULTS: Eight studies met the inclusion criteria with a total of 283 patients and 360 fluid challenges. All the studies were carried out in a surgical setting. The area under the summary receiver operating characteristic curve of PVI to predict fluid responsiveness was 0.82. The pooled sensitivity, specificity, and diagnostic odds ratio of PVI for the overall population were 72.4% [95% CI: 65.3-78.7], 65.9% [58.5-72.8], and 9.26 [5.31-16.16], respectively. CONCLUSION: Our results suggest that digital PVI is a reliable predictor for fluid responsiveness in mechanically ventilated children in the perioperative setting. The diagnostic performance of digital PVI reported in our work for discrimination between responders and non-responders to the fluid challenge was however not as high as previously reported in the adult population.

Diagnostic performance of qualitative ultrasound assessment for the interpretation of point-of-care gastric ultrasound to detect high gastric fluid volume: A prospective randomized crossover study.

STUDY OBJECTIVE: This study aimed to assess whether elevating the head of the bed to 45° was associated with sensitivity >90% of the qualitative ultrasound assessment for the diagnosis of gastric fluid volume > 1.5 ml.kg-1. We also assessed the performance of qualitative assessment, composite ultrasound scale, and clinical algorithm, for the diagnosis of fluid volume > 1.5 ml.kg-1 according to whether the head of the bed was elevated to 45° or not. DESIGN: Prospective randomized observer-blind crossover trial. SETTING: Hospices Civils de Lyon, France. PATIENT: Healthy adult volunteers. INTERVENTIONS: Two separate study sessions in fasting volunteers: with and without head-of-bed elevation to 45°, in a randomized order. Each session consisted of three tests, each corresponding to a randomized and different volume of water (either 0, 50, 100, 150 or 200 ml); the same volumes were used in both sessions and in a randomized order. Gastric ultrasounds were performed three minutes after the ingestion of water by an investigator blinded to the volume ingested. MEASUREMENTS: Diagnostic performance of each approach for the diagnosis of gastric fluid volume > 1.5 ml.kg-1. MAIN RESULTS: Twenty volunteers were included, and 120 measurements were analyzed. The sensitivity of the qualitative assessment for the diagnosis of gastric fluid volume > 1.5 ml.kg-1 with and without head-of-bed elevation was 91% (95%CI: 75-98) and 75% (95%CI: 57-89), respectively. The clinical algorithm with head-of-bed elevation had significantly better sensitivity than the qualitative assessment with no head-of-bed elevation; there was no significant difference for other comparisons. CONCLUSIONS: The results suggest that qualitative examination of gastric antrum in the supine position with head-of-bed elevation to 45° can discriminate between low and high gastric fluid volume with high sensitivity, while neither the composite ultrasound scale nor the clinical algorithm improved the diagnostic performance of gastric ultrasound for the diagnosis of gastric fluid volume > 1.5 ml.kg-1.

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.

Assessing gastric contents in children before general anesthesia for acute extremity fracture: An ultrasound observational cohort study.

STUDY OBJECTIVE: Children with acute extremity fractures are commonly considered to be at risk of pulmonary aspiration of gastric contents during the induction of anesthesia. This study aimed to evaluate the proportion of such children with high-risk gastric contents using preoperative gastric ultrasound. DESIGN: Prospective observational cohort study. SETTING: Specialist pediatric center over a 30-month period. PATIENTS: Children undergoing surgery within 24 h of an acute extremity fracture. INTERVENTIONS: None. MEASUREMENTS: According to preoperative qualitative and quantitative ultrasound analysis of the antrum in the supine and right lateral decubitus positions, gastric contents were classified as high-risk (clear liquid with calculated gastric fluid volume > 0.8 mL.kg-1, thick liquid, or solid) or low-risk. Factors associated with high-risk gastric contents were identified by multivariable analysis. MAIN RESULTS: Forty-one children (37%; 95% CI: 28-47) of the 110 studied (mean(SD) age: 10(3) years) presented with high-risk gastric contents, including 26 (24%; 95% CI: 16-33) with solids/thick liquid contents. Scanning in the supine position alone allowed a diagnosis of high-risk gastric contents in 23 children out of the 63 for whom right lateral decubitus positioning was unfeasible. Gastric contents remained undetermined in 41 children, including one with a non-contributory gastric US (antrum non-visualized). Proximal limb fractures (OR: 2.5; 95% CI: 1.0-6.2), preoperative administration of opioids (OR: 3.9; 95% CI: 1.1-13), and the absence of bowel sounds (OR: 8.0; 95% CI: 1.4-44) were associated with high-risk gastric contents. Performing surgery the day following the trauma was a protective factor (OR: 0.1; 95% CI: 0.0-0.6). No cases of pulmonary aspiration occurred. CONCLUSIONS: At least one-third of children with an acute isolated extremity fracture had preoperative gastric contents identified as high risk for pulmonary aspiration. Although preoperative history can guide anesthetic strategy in this population, ultrasound allowed clear stratification of the risk of aspiration in most cases.

Ultrasound assessment of gastric contents prior to placental delivery: A prospective multicentre cohort study.

BACKGROUND: There is ongoing debate regarding the optimal general anaesthetic technique for manual removal of the placenta after vaginal delivery. Using ultrasound examination of the gastric antrum, this study aimed to assess the change in gastric contents during vaginal delivery and to determine the prevalence of stomach at risk for pulmonary aspiration in the immediate postpartum period before placental delivery. METHODS: In this prospective multicentre cohort study, antral ultrasonography was performed at full cervical dilatation within the thirty minutes preceding the beginning of expulsive efforts and after vaginal birth, before placental delivery. High-risk gastric content was defined as the visualisation of any solid content in the antrum or antral cross-sectional area in the semi-recumbent position (SR-CSA) > 608 mm². RESULTS: Twenty-six women were included and analysed. There was a significant decrease in both the proportion of patients with solid gastric content and the SR-CSA between the two-ultrasound examinations. Twenty-one patients (80.8%) exhibited a decrease in the SR-CSA during vaginal delivery. The prevalence of stomach at risk for pulmonary aspiration was significantly lower after vaginal delivery than before vaginal delivery (23.1% vs. 57.7%, P = 0.0004). CONCLUSION: Our results suggest that gastric emptying is at least partially preserved during vaginal birth. Nevertheless, almost a quarter of women did have high-risk gastric content in the immediate postpartum period. Point-of-care antral ultrasonography may be of interest for the fast assessment of the gastric content status when a general anaesthesia is required for manual removal of retained placenta.

Women's view on fasting during labor in a tertiary care obstetric unit. A prospective cohort study.

OBJECTIVE: Maternal satisfaction and comfort may in part depend on fasting instruction given during labor. This study aimed to assess the satisfaction and the wishes of parturients with regards to fasting during labor. STUDY DESIGN: This prospective cohort study was conducted among parturients assessing the fasting instructions they were given. We assessed whether women did have any oral intake during labor and focused on women's view of fasting during labor. Maternal discomfort related to thirst and hunger was assessed using 0-10 scales. RESULTS: A total of 193 women were included, among whom 71 (37 %) received spontaneously given instructions and 60 (31 %) received instruction upon request. One hundred sixteen (60 %) women were allowed to drink clear fluids, in a limited way for 106 women (91 % of those concerned); 119 women did drink clear fluids during labor. One hundred thirty-two (68 %) women had a thirst-related discomfort score ≥ 4 without any statistical difference whether they had or had not drunk clear fluids. Colder water, unrestricted volume of water and sweet drink were desired by 74 (64 %), 38 (33 %) and 28 (24 %) women who had been allowed to drink, respectively. CONCLUSION: These results emphasize that thirst contributes to maternal discomfort during labor. Permitting limited intake of water does not ensure high maternal satisfaction. Fresh clear fluids, unrestricted amounts of fluids and sweet fluids could contribute to improve maternal comfort.

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.

Relationship between the regurgitated and the aspirated volume of water. A manikin study.

BACKGROUND: The relationship between gastric fluid volume, volume of fluid regurgitated, and aspirated fluid volume remains unclear. Using a life-like manikin suitable for a pulmonary aspiration model, we aimed to assess the relationship between regurgitated and aspirated clear fluid volumes, and to determine the minimal value of the volume of liquid regurgitated that may lead to pulmonary aspiration of fluid volume ≥ 0.8 mL kg-1 (around 60 mL) that is likely to cause lung injury. METHODS: Several volumes of water ranging from 30 to 150 mL were injected in a randomized order, at a flow rate of 20 mL per second, into the esophagus of a manikin lying in the supine position on a non-tilted table, with the manikin head in the extension or in the sniffing position. Aspirated volumes were measured in the manikin bronchi, by an investigator blinded to the volume injected. Aspiration was defined as positive when the volume of collected water was ≥ 60 mL for at least one of the five injections of each volume of water. RESULTS: The minimal volume of water injected into the esophagus for an aspirated volume ≥ 0.8 mL kg-1 was 85 mL in the sniffing position, and was 150 mL in the extension position. CONCLUSIONS: These results suggest that the critical cut-off value of gastric fluid volume to be considered for the risk of significant pulmonary aspiration would be ≥ 85 mL (≥ 1 mL kg-1), in the sniffing position. These results should however be confirmed in further studies using other models.

Retrospective cohort study of decision-to-delivery interval and neonatal outcomes according to the type of anaesthesia for code-red emergency caesarean sections in a tertiary care obstetric unit in France.

BACKGROUND: Non-elective caesarean sections may be classified using a three-colour coding system, from code-green caesarean section corresponding to non-urgent delivery (no maternal of foetal compromise) to code-red caesarean section corresponding to emergency caesarean section due to immediate life-threatening maternal or foetal situations. Decision-to-delivery interval≤15min has been advocated in France for code-red caesarean section. This retrospective cohort study aimed to assess the decision-to-delivery interval and the neonatal outcomes according to the anaesthetic technique performed for code red caesarean section in a French tertiary care obstetric unit. METHODS: All women undergoing code-red caesarean section between January 2013 and December 2015 were included. Demographic characteristics and anaesthetic, obstetrical and neonatal outcomes were collected from the patient's electronic medical records. RESULTS: Among 194 code-red caesarean sections analysed, 127 (65%) were performed under epidural anaesthesia and 67 (35%) under primary general anaesthesia. The median decision-to-delivery interval was 10 [8-12.5] min, and the interval was≤15min in 174 (90%) women. Effective epidural top-up and epidural top-up requiring supplemental sedation were associated with the shortest decision-to-delivery interval. Primary general anaesthesia was independently associated with depressed 5minutes Apgar score. CONCLUSION: The decision-to-delivery interval was≤15min in most women, suggesting that optimised organisation ensures short decision-to-delivery interval independently of the anaesthetic technique performed. As general anaesthesia was associated with worse neonatal outcomes, our results support the early insertion of an epidural catheter whenever there is any potential concern that an emergency caesarean section may be required.

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.

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.