Ultrasound Assessment Of Gastric Content Research Articles

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

BackgroundThis 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%). MethodsUltrasound 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. ResultsA 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. ConclusionsAround 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.

Ultrasound assessment of gastric content in patients undergoing laparoscopic cholecystectomy after preoperative oral carbohydrates: a prospective, randomized controlled, double-blind study.

To evaluate the gastric volume and nature after drinking preoperative oral carbohydrates in patients undergoing laparoscopic cholecystectomy via ultrasonography. One hundred patients who had been scheduled for elective laparoscopic cholecystectomy were enrolled and randomized into the traditional fasting group (Control group, n = 50) and the carbohydrate group (CHO group, n = 50). Patients in the Control group fasted solids and drink from midnight, the day before surgery. Patients in the CHO group drank 800 ml and 400 ml of oral carbohydrates 11 and 3 h before surgery, respectively. At 2 h after oral carbohydrates (T1), all patients underwent an ultrasound examination of residual gastric contents; if the patients had a full stomach, the assessment was performed again 1 h later (T2). A stomach containing solid contents or >1.5 ml/kg of liquid was considered "full". The primary outcome was full stomach incidences at the above time points. The secondary outcomes included gastric antral CSA in the right lateral decubitus (RLD) and semi-sitting positions, as well as gastric volume (GV), GV per weight (GV/kg), and Perla's grade at T1. Compared with the Control group, the incidence of entire stomach was significantly high in the CHO group 2 h after oral carbohydrates. At the T1 time point, 6 patients (13.3%) in the Control group and 14 patients (30.4%) in the CHO group presented with a full stomach [95% confidence interval (CI), (0.96-5.41), P = 0.049]. At T2, 3 patients (6.7%) in the Control group and 4 patients (8.7%) in the CHO group had a full stomach, with no marked differences between the two groups [95% CI, (0.31-5.50), P = 0.716]. Compared with the Control group, CSA in the semi-sitting and RLD positions, GV and GV/W were significantly high in the CHO group at T1 (P < 0.05). The median (interquartile range) of the Perlas grade was 1 (0-1) in the Control group and 1(1-1.25) in the CHO group (P = 0.004). Cholecystectomy patients experience a 2 h delay in gastric emptying after receiving preoperative carbohydrates. In LC patients, the fasting window for oral carbohydrates before surgery should be adequately prolonged. Chinese Clinical Trail Registry, No: ChiCTR2200055245.

Evaluation of ultrasound-measured gastric volume and content in type 2 diabetes mellitus patients undergoing elective surgery: a prospective observational study

Objectives: Delayed gastric emptying create a risk of pulmonary aspiration during anesthesia. We aim to assess the antral cross-sectional area (CSA) and gastric volume using ultrasound techniques and to investigate the relationship between these variables and both the duration and regulation of type 2 diabetes mellitus (DM). Methods: Gastric volume was estimated by measuring the antral CSA in the supine and right lateral decubitus (RLD) positions in 80 patients. The antral content was qualitatively classified according to Perlas et al. (grades 0, 1, and 2), and gastric volume was computed using a previously described formula. The presence of solid content or &amp;gt; 1.5 mL/kg fluid in the stomach was classified as indicative of a full stomach. Results: The mean duration of diabetes among the subjects was 9.4 ± 3.7 years. The mean fasting duration was 10.2 ± 2.1 hours for solids and 2.5 ± 0.7 for liquids. Twelve of the 80 patients exhibited grade 2 stomach. Age (p = 0.005), Body mass index (p = 0.001), solid fasting duration (p = 0.027), and supine and RLD CSA (p &amp;lt; 0.001 for both) were significantly associated with full stomach. A history of ≥8 years of diabetes (p &amp;lt; 0.001) and peripheral neuropathy (p = 0.005) was identified as a risk factor for a full stomach. Conclusions: Despite adherence to standard fasting protocols, 15% of the type 2 DM patients were identified with a 'full stomach' condition. Preoperative ultrasound assessment of gastric contents in patients with type 2 DM, especially with long-standing diabetes (≥ 8 years) and with peripheral neuropathy is recommended. The findings of this study necessitate additional investigation to support the conceptualization of specific guidelines for diabetes to mitigate the risk of pulmonary aspiration.

Inter-observer and intra-observer variability in ultrasound assessment of gastric content and volume in critically ill patients receiving enteral nutrition

BackgroundThe assessment of gastric content and volume using bedside ultrasound (US) has become a useful tool in emergency departments, anesthesiology departments and inpatient wards, as it provides a rapid and dynamic assessment of the gastric content of patients, which, allows making decisions regarding the risk of regurgitation or the need to adjust the strategy used to induce general anesthesia in patients with a full stomach. This assessment consists of two evaluations: a qualitative one, in which the status of the antrum, in terms of gastric content, is classified into three categories (empty, liquid content and full), and a quantitative one, where gastric volume is estimated. The objective of this study was to estimate the intra-observer and inter-observer agreement in ultrasound assessment of gastric content and volume in critically ill patients receiving enteral nutrition.ResultsA total of 41 patients were included and each examiner performed 64 gastric US (n = 128). Participants’ average age was 56.5 years (SD ± 12.6) and 63.4% were men. Regarding the qualitative evaluation of the antrum, in supine position both examiners classified the gastric content as grade 0 in 1 gastric US (1.5%), grade 1 in 4 gastric US (6.2%) and grade 2 in 59 (92.1%). Regarding intra-observer variability in the measurement of the area of the antrum, Lin's concordance correlation coefficient (CCC), the difference of means between measurements and the 95% limits of agreement of Bland and Altman values were 0.95 (95% CI 0.940–0.977), − 0.47 cm2 (SD ± 1.64) and − 3.70 cm2 to 2.75 cm2, respectively, in EC1, and 0.94 (95% CI 0.922–0.973), − 0.18 cm2 (SD ± 2.18) and − 4.47 cm2 to 4.09 cm2 in EC2. Concerning to inter-observer variability (EC1 vs EC2) in the measurement of the area of the antrum and of gastric volume, the following CCC, mean difference between measurements and 95% limits of agreement of Bland and Altman values were obtained: measurement of the area of the antrum: 0.84 (95% CI 0.778–0.911), − 0.86 cm2 (SD ± 3.38) and − 7.50 cm2 to 5.78 cm2; gastric volume measurement: 0.84 (95% CI 0.782–0.913), − 12.3 mL (SD ± 49.2) and − 108.8 mL to 84.0 mL.ConclusionsThe assessment of gastric content and volume using bedside US in critically ill patients on mechanical ventilation and receiving enteral nutrition showed a good intra and inter-rater reliability. Most of the patients included in the study had a high risk of pulmonary aspiration, since, according to the results of the gastric US evaluation, they had gastric volumes > 1.5 mL/kg.

Ultrasound assessment of gastric contents and volume in patients undergoing endoscopic endonasal transsphenoidal surgery: a prospective observational study

Intraoperative ingestion of blood, cerebrospinal fluid, and irrigation fluid can lead to an increase in gastric volume, resulting in the potential risk of aspiration in patients after endoscopic endonasal transsphenoidal surgery (EETS). In this prospective observational study, we aimed to assess the volume of gastric contents in patients undergoing this neurosurgical procedure using ultrasound, and to determine the factors associated with volume change. Eighty-two patients diagnosed with pituitary adenoma were recruited consecutively. Semi-quantitative (Perlas scores: 0, 1 and 2) and quantitative (cross-sectional area, CSA) ultrasound assessments of the gastric antrum were performed immediately before and after surgery in the semi-recumbent and semi-recumbent right-lateral positions. Seven (8.5%) patients had antrum scores from preoperative grade 0 to postoperative grade 2; nine (11%) patients had antrum scores from preoperative grade 0 to postoperative grade 1. The mean ± standard deviation (SD) of increased gastric volume was 71.0 ± 33.1 mL and 236.5 ± 32.4 mL in postoperative grade 1 and 2 groups, respectively. Subgroup analysis showed that 11 (13.4%) patients (4 in grade 1 and all in grade 2) had postoperative estimated gastric volume > 1.5 mL kg−1 (mean ± SD 3.08 ± 1.67, range 1.51–5.01 mL kg−1). Logistic regression analysis revealed that older age, diabetes mellitus, and long surgical duration were independent risk factors for significant volume change (all P < 0.05). Our results showed a significant increase in gastric volume in some patients who underwent EETS. Bedside ultrasound measurements of gastric volume can be used to assess the postoperative aspiration risk, particularly in older diabetic patients with a longer surgical duration.

Ultrasound assessment of gastric contents in children before general anaesthesia for acute appendicitis.

There is increasing evidence that a minority of adults with acute appendicitis have gastric contents, posing an increased risk of pulmonary aspiration. This study aimed to evaluate the proportion of children with acute appendicitis who have gastric contents considered to pose a higher risk of pulmonary aspiration. We analysed point-of-care gastric ultrasound data routinely collected in children before emergency appendicectomy in a specialist paediatric hospital over a 30-month period. Based on qualitative and quantitative antral assessment in the supine and right lateral decubitus positions, gastric contents were classified as 'higher-risk' (clear liquid with calculated gastric fluid volume > 0.8 ml.kg-1 , thick liquid or solid) or 'lower-risk' of pulmonary aspiration. The 115 children studied had a mean (SD) age of 11 (3) years; 37 (32%; 95%CI: 24-42%) presented with higher-risk gastric contents, including 15 (13%; 95%CI: 8-21%) with solid/thick liquid contents. Gastric contents could not be determined in 13 children as ultrasound examination was not feasible in the right lateral decubitus position. No cases of pulmonary aspiration occurred. This study shows that gastric ultrasound is feasible in children before emergency appendicectomy. This technique showed a range of gastric content measurements, which could contribute towards defining the risk of pulmonary aspiration.

Ultrasound assessment of the gastric content among diabetic and non-diabetic patients before elective surgery: a prospective multicenter study.

Although diabetic gastroparesis could be responsible for delayed gastric emptying, there is conflicting evidence about the volume of gastric content in diabetic patients after preoperative fasting. We hypothesized that diabetic patients had an increased gastric content before anesthesia induction despite the following of fasting recommendations. We used ultrasound assessment of gastric content to evaluate this risk. This multicenter prospective single-blinded case-control study was conducted in three teaching University hospital in France. Our primary outcome was the comparison of increased gastric content between the two groups and was defined either by a Perlas grade 2 antrum or an antral cross-sectional area (CSA)>340 mm2. Each diabetic patient was paired with three non-diabetic control patients. Forty-two diabetic and 126 control patients were included in the study. Eighteen (42.9%) diabetic patients reached the primary outcome versus 28 (22.2%) in the control group (P=0.009). Diabetic patients presented less frequently with an empty stomach. Indeed, ten (23.8%) diabetic patients had a grade 0 antrum versus 71 (56.3%) in the control group (P<0.001). Twenty-four (70.6%) diabetic patients had an antral CSA<340 mm2 versus 98 (86%) in the control group (P=0.039). Overall, diabetic patients and increased gastric content were associated with an Odds Ratio, 2.63; 95% confidence interval, 1.25-5.52, P=0.009. Our study documents that gastric content is increased among diabetic patients compared to control patients despite following appropriate fasting guidelines.

Qualitative and quantitative gastric ultrasound assessment in highly skilled regional anesthesiologists

BackgroundPulmonary aspiration is a major complication in anesthesia, and various studies have shown that gastric sonography can reliably provide valuable information relative to both the qualitative and quantitative aspects of gastric content. This study aimed to determine the accuracy of ultrasound assessment of gastric content compared between two novice anesthesiologist gastric sonographers.MethodsThis prospective cohort study of two anesthesiologists learning to perform qualitative and quantitative ultrasound assessment of gastric content on healthy volunteers was conducted at Siriraj Hospital (Bangkok, Thailand). This trial was registered with ClinicalTrials.gov (reg. no. NCT04760106).ResultsOf the 50 enrolled participants, three were excluded due to study protocol violation. Each anesthesiologist performed a qualitative assessment on 47 participants for an overall total of 94 scans. There were 15 males and 32 females (age 42 ± 11.7 years, weight 61.2 ± 13.1 kg, height 160.7 ± 7.3 cm, and BMI 23.6 ± 4.3 kg/m2). The overall success rate for all gastric content categories was approximately 96%. From antral cross-sectional area measurement, as the ingested volume increased, there was a tendency toward increased deviation from the actual ingested volume. Interrater agreement between anesthesiologists was analyzed using intraclass correlation coefficients (ICCs). A larger fluid volume was found to be associated with a lower level of agreement between the two anesthesiologists. The ICCs were 0.706 (95% CI: −0.125 to 0.931), 0.669 (95% CI: −0.254 to 0.920), 0.362 (95% CI: −0.498 to 0.807) for the 100 ml, 200 ml, and 300 ml fluid volumes, respectively. The mean duration to perform an ultrasound examination for each gastric content category and for the entire examination did not differ significantly between anesthesiologists (p > 0.05).ConclusionOur results indicate that qualitative ultrasound assessment of gastric content is highly accurate and can be easily learned. In contrast, quantification of gastric volume by novice gastric sonographers is more complex and requires more training.Trial registrationClinicalTrials.gov no. NCT04760106 Date registered on Feb 11, 2021. Prospectively registered.

Oral fluid intake during the first stage of labour: A randomised trial.

Obstetric anaesthesia has been associated with concern for the inhalation of gastric contents for many years, justifying fasting during labour. However, many anaesthesiologists and obstetricians now allow fluid intake during labour. We hypothesised that allowing oral fluid intake during labour is not associated with increased gastric contents. We used ultrasound assessment of gastric contents to evaluate this hypothesis. A randomised, single-blind and intention-to-treat noninferiority trial comparing antral area measured by ultrasound in fasting parturients and in those who were allowed to drink fluid for 90 min after randomisation. Tenon University Hospital, Assistance Publique Hôpitaux de Paris, Paris, France. Pregnant women, aged from 18 to 40 years and from week 36 of an uncomplicated singleton gestation, were randomised into a fasting group and a fluid intake group after admission to the delivery room. Of the 184 patients screened, data from 125 were analysed: fasting group (62), fluid intake group (63). Women in the fluid intake group were allowed to drink up to 400 ml of apple juice for 90 min after randomisation. We compared the percentage of women with an 'empty stomach' between the two groups: empty stomach was defined as an antral cross-sectional area (CSA) less than 300 mm assessed in a semirecumbent position with a 45-degree head-up tilt. At full cervical dilatation an antral CSA less than 300 mm was measured in 76 and 79% of the parturients in the fasting group and the fluid intake groups respectively (P = 0.633). The current study reveals that the percentage of pregnant women with an 'empty stomach', defined by an antral CSA less than 300 mm in a semirecumbent position with a 45-degree head-up tilt, was comparable at full cervical dilation among those who remained nil by mouth and those allowed to drink up to 400 ml for 90 min after their randomisation. Clinicaltrials.gov identifier: NCT02362815.

Ultrasound assessment of gastric content in fasted patients before elective laparoscopic cholecystectomy: a prospective observational single-cohort study.

Patients with symptomatic gallbladder diseases exhibit delayed gastric emptying. We evaluated the residual gastric content in fasted patients scheduled for elective laparoscopic cholecystectomy because of symptomatic gallbladder disease using ultrasonography. This prospective observational single-cohort study was approved by the Institutional Review Board, and written informed consent was obtained from all included patients. Before anesthesia induction, the gastric antrum was examined by ultrasound. Once the presence of solid content was excluded, the patients were classified using a three-point grading system (grade 0: no fluid; grade 1: fluid in the right lateral decubitus position; grade 2: fluid in both the supine and right lateral decubitus positions), and the fluid volume was measured. A stomach was considered empty if it had no contents or ≤ 1.5 mL·kg-1 of fluid, and was considered full if solid content or > 1.5 mL·kg-1 of fluid was detected. Among 138 patients, 18 patients (13%) presented with a full stomach, 12 (9%) of whom had solid content, and six (4%) of whom had >1.5 mL·kg-1 of fluid in their stomach. Among the remaining 120 patients with an empty stomach, 65 patients presented with a grade 0 antrum, and 55 patients with a grade 1 or 2 antrum with ≤ 1.5 mL·kg-1 of fluid. The gastric ultrasound assessment revealed that 13% of patients scheduled for elective cholecystectomy because of symptomatic gallbladder disease had a full stomach despite following the fasting guidelines. This was higher than the reported incidence of a full stomach among the general surgical population. Further studies are required to delineate the clinical implications of our findings. www.ClinicalTrials.gov (NCT03259841); registered 4 August, 2017.

Ultrasound Assessment of Gastric Content in Fasted Pregnant Women

Ultrasound Assessment of Gastric Content in Fasted Pregnant Women

Point-of-care ultrasound defines gastric content in elective surgical patients with type 2 diabetes mellitus: a prospective cohort study

BackgroundDelayed gastric emptying and the resultant “full stomach” is the most important risk factor for perioperative pulmonary aspiration. Using point-of-care gastric sonography, we aimed to investigate the prevalence of full stomach and its risk factors in elective surgical patients with type 2 diabetes.MethodsType 2 diabetic and non-diabetic elective surgical patients were included from July 2017 to April 2018 in a 1:1 ratio. The study was retrospectively registered at July 2017, after enrollment of the first participant. Gastric ultrasound was performed 2 h after ingesting clear fluid or 6 h after a light meal. Full stomach was defined by the presence of gastric content in both semi-recumbent and right lateral decubitus positions. For patients with full or intermediate stomach, consecutive ultrasound scan was performed until empty stomach was detected. Logistic regression analyses were used to identify risk factors associated with full stomach.ResultsFifty-two type 2 diabetic and fifty non-diabetic patients were analyzed. The prevalence of full stomach was 48.1% (25/52) in diabetic patients, with 44.0% for 2-h fast after clear fluid and 51.9% for 6-h fast after a light meal, significantly higher than 8% (4/50) in non-diabetic patients (P = 0.000). The average time to empty stomach in diabetic patients was 146.50 ± 40.91 mins for clear liquid and 426.50 ± 45.25 mins for light meal, respectively. Further analysis indicated that presence of diabetes-related eye disease was an independent risk factor of full stomach in diabetic patients (OR = 4.83, P = 0.010).ConclusionsAlmost half of type 2 diabetic patients have a full stomach following the current preoperative fasting guideline. Preoperative ultrasound assessment of gastric content in type 2 diabetic patients is suggested, especially for those with diabetes -related eye disease.Trial registrationThe trial was registered at www.clinicaltrials.gov with registration number NCT03217630. Retrospectively registered on 14th July 2017.

Preoperative ultrasound assessment of gastric content in obese patients

Preoperative ultrasound assessment of gastric content in obese patients

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

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. 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>1.25mL/kg, in children scheduled for elective surgery. 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. We analyzed 200 elective children. Median duration of fasting was 4hours for liquids and >13hours 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 >1.25mL/kg. The prevalence of "at-risk stomach" was 1% (95% confidence interval: 0.2%-3.9%). 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 assessment of gastric contents in children undergoing elective ear, nose and throat surgery: a prospective cohort study.

Ultrasound examination of the gastric antrum allows reliable assessment of gastric contents and volume. Postoperative assessment of gastric contents before recovery from anaesthesia could help the physician to choose the most appropriate extubation technique after surgery in children. In this prospective observational study, we assessed whether significant changes occurred in gastric contents during the intra-operative period in children undergoing elective ear, nose and throat (ENT) surgery. Children aged between six months and 16 years were recruited consecutively. Ultrasound examination of the antrum was performed before induction of anaesthesia and at the end of surgery before tracheal extubation, and included quantitative and qualitative assessment of gastric contents. The mean (SD) gastric volume was 0.28 (0.30) ml.kg-1 before surgery and 0.27 (0.30) ml.kg-1 after surgery, p = 0.82. No solid contents were identified in the antrum, and the gastric volume was < 1.5 ml.kg-1 in all patients during both ultrasound examinations. Our results suggest that, after elective ENT surgery, children are not at risk of a full stomach before tracheal extubation, and that pulmonary aspiration of blood that may occur after elective ENT surgery is probably not related to regurgitation of ingested blood from the stomach.

Prevalence and Factors Predictive of Full Stomach in Elective and Emergency Surgical Patients

Abstract Background This prospective observational study sought to assess the rate of full and empty stomach in elective and emergency patients and to determine the factors associated with full stomach. Methods Non-premedicated patients were consecutively included between May 2014 and October 2014. Ultrasound examination of the gastric antrum was performed by an operator blinded to the history of the patient. It included measurement of the antral cross-sectional area, performed in the supine position with the head of the bed elevated to 45°, and qualitative assessment of the gastric antrum, performed in both semirecumbent and right lateral decubitus positions. Full stomach was defined by the appearance of any gastric content in both positions (Grade 2). Empty stomach was defined either by empty antrum in both positions (Grade 0) or by empty antrum in the semirecumbent position only (Grade 1) with measured antral area 340 mm2 defined intermediate stomach. Logistic regression analyses were performed for the identification of factors associated with full stomach. Results Four hundred and forty patients were analysed. The prevalence of full stomach was 5% (95% confidence interval: 2–9) in elective patients and 56% (95% confidence interval: 50–62) in emergency patients (P Conclusions The results suggest that preoperative ultrasound assessment of gastric content should be performed in all emergency patients, and in elective patients with identified predictive factors for full stomach.

Ultrasound assessment of gastric content in the immediate postpartum period: a prospective observational descriptive study.

Pulmonary aspiration of gastric contents in pregnant women undergoing general anesthesia or sedation/analgesia in the peripartum period is a feared complication in obstetric anesthesia. We assessed the changes in antral cross-sectional area (CSA) with ultrasonography in laboring women and in the immediate postpartum period. In an observational study in a university-affiliated maternity, gastric ultrasonography examinations were performed in non-consecutive laboring women, after epidural analgesia insertion and after childbirth. Assessment of antral CSA, difficulty of performance on a numerical scale, and factors that could influence gastric content were noted. A cut-off value of 381mm2 was taken for the diagnosis of empty stomach. One hundred women were enrolled in the study. Median antral CSA was 469mm2 [25th-75th] [324-591] after epidural insertion and 427mm2 [316-574] after delivery. Antral CSA was ≥381mm2 in 59 of 90 women (65%) after epidural insertion vs. 48 of 100 women (48%) after delivery (P=0.59). Median variation of antral CSA between two measurements was 36mm2 [-42 to 114]. Gastric ultrasonography was significantly more difficult to perform during labor than immediately post-delivery (median difficulty score 5 [2-7] vs. 2 [1-4], P<0.0001). No risk factors (pain, anxiety, diabetes, smoking) were significantly associated with the occurrence of full stomach post-delivery. This study demonstrated that 48% of parturients in the immediate postpartum period presented an antral CSA≥381mm2 , cut-off being accepted for diagnosis of empty stomach and emphasizes the need for re-assessing before any general anesthetic procedure.

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.

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. To calculate the cut-off value of the antral area, measured in the supine position during established labour, for the diagnosis of 'empty' stomach. A prospective cohort study. Hospices Civils de Lyon, Hôpital Femme Mère Enfant, Lyon, France. Seventy-three women in established labour. 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. 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. 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%). 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.

Prevalence and factors predictive of full stomach in elective and emergency surgical patients: a prospective cohort study

BackgroundThis prospective observational study sought to assess the rate of full and empty stomach in elective and emergency patients and to determine the factors associated with full stomach. MethodsNon-premedicated patients were consecutively included between May 2014 and October 2014. Ultrasound examination of the gastric antrum was performed by an operator blinded to the history of the patient. It included measurement of the antral cross-sectional area, performed in the supine position with the head of the bed elevated to 45°, and qualitative assessment of the gastric antrum, performed in both semirecumbent and right lateral decubitus positions. Full stomach was defined by the appearance of any gastric content in both positions (Grade 2). Empty stomach was defined either by empty antrum in both positions (Grade 0) or by empty antrum in the semirecumbent position only (Grade 1) with measured antral area <340 mm2. The combination of Grade 1 and antral area >340 mm2 defined intermediate stomach. Logistic regression analyses were performed for the identification of factors associated with full stomach. ResultsFour hundred and forty patients were analysed. The prevalence of full stomach was 5% (95% confidence interval: 2–9) in elective patients and 56% (95% confidence interval: 50–62) in emergency patients (P<0.0001). Obesity, diabetes mellitus, emergency surgery, and preoperative consumption of opiates were independent factors predictive of full stomach. ConclusionsThe results suggest that preoperative ultrasound assessment of gastric content should be performed in all emergency patients, and in elective patients with identified predictive factors for full stomach.

Interrater Reliability of Qualitative Ultrasound Assessment of Gastric Content in the Third Trimester of Pregnancy

Background Pulmonary aspiration of gastric contents in pregnant women undergoing general anaesthesia is one of the most feared complications in obstetric anaesthesia. Bedside gastric ultrasonography is a feasible imaging tool to assess the gastric content. The purpose of this study was to investigate the reliability of qualitative bedside assessment of the gastric content performed by anaesthesiologists on third trimester pregnant women. Methods Pregnant women (≥32 weeks gestational age) were randomized to undergo ultrasound (US) assessments of their stomach in a fasting state (>8 h), or after ingestion of clear fluids only, or solid food. Three anaesthesiologists trained in gastric ultrasonography performed the assessments using a low-frequency curved-array US transducer (5–2 MHz). Primary outcome of the study was the consistency of raters in diagnosing the correct status of the gastric content, which was used to determine the interrater reliability among the three anaesthesiologists. Secondary outcomes were overall proportion of correct and incorrect diagnoses and the specific proportions of correct diagnosis across the three gastric content groups. Results We analysed 32 pregnant women. The interrater reliability displayed a kappa statistic of 0.74 (bias corrected 95% CI: 0.68–0.84). The overall proportion of correct diagnosis was 87.5% (84 of 96). The odds of correct diagnosis for ‘solid contents' were 16.7 times the odds for ‘empty', and 14.3 times for ‘clear fluid'. Conclusions Our results show the consistency of the qualitative US assessment of gastric contents of pregnant women in the third trimester by anaesthesiologists. A kappa of 0.74 suggests substantial agreement in terms of interrater reliability for this diagnostic measurement. Clinical trial registration ClinicalTrials.gov identifier: NCT01564030.