Effects of oral carbohydrate loading in patients scheduled for painless bidirectional endoscopy: a prospective randomized controlled trial

PURPOSE

Traditional fasting causes considerable discomfort without added assurance of security, whereas oral carbohydrate beverage offers an alternative to improve medical experience. This study aims to explore the impact of different types and dosages of oral fluids loading before painless bidirectional endoscopy on the gastric emptying and wellbeing.

METHODS

180 patients arranged for bidirectional endoscopy with intravenous anesthesia were randomized: patients in the control group (Group C) obeyed standard fasting; the 200 mL carbohydrate group (Group P1), 400 mL carbohydrate group (Group P2), 200 mL water group (Group W1) and 400 mL water group (Group W2) respectively consumed 200 mL or 400 mL corresponding clear liquids 2 h before the procedure. Gastric emptying metrics under ultrasound, subjective comfort indexes, periprocedural blood glucose and vital signs were contrasted among the groups.

RESULTS

No significant differences were detected in the gastric emptying including CSA (cross-sectional area), GV (gastric volume), cGV (corrected gastric volume) and the three-point grading system among groups, and none had a cGV > 1.5 mL/kg before anesthesia. Participants in Group P2 experienced less preprocedural thirst and mouth dryness, so as the postprocedural thirst, mouth dryness and hunger. Periprocedural blood glucose and MAP had the similar trend in all groups. The occurrence of hypotension, bradycardia, hypoxia, and the required norepinephrine was comparable among the groups.

CONCLUSIONS

Oral beverage loading with 200 mL or 400 mL can be safely applicated 2 h before painless bidirectional endoscopy without increasing the gastric volume. 400 mL carbohydrate solution effectively relieves the discomfort and could serve as a consideration.

TRIAL REGISTRATION

Registered in the Chinese Clinical Trial Registry on December 5, 2023 (ChiCTR2300078319).

Assessing Full Stomach Prevalence with Ultrasound Following Preoperative Fasting in Diabetic Patients with Dysautonomia: A Comparative Observational Study

BACKGROUND

Traditionally, diabetics have been considered patients with a high risk of aspiration due to having delayed gastric emptying; However, the evidence concerning residual gastric volume (GV) in fasting diabetic patients is inconsistent. This study aimed to compare the fasting GV of diabetic patients with or without dysautonomia with control patients scheduled for elective surgery using gastric ultrasound.

METHODS

This bicentric prospective single-blinded case-control study was conducted at 2 university hospitals in Spain. Patients aged over 18 years, classified as American Society of Anesthesiologists (ASA) physical statuses I to III and having similar fasting statuses, were included in the study. The primary outcome was to compare the prevalence of risk stomach using the Perlas gastric content grading scale evaluated by ultrasound in the 3 groups. Secondary outcomes included the measurement of cross-sectional area (CSA) and GV in the right lateral decubitus (RLD) position, as well as the prevalence of solid gastric residue.

RESULTS

A total of 289 patients were recruited for the study, comprising 145 diabetic patients (83 of whom had dysautonomia) and 144 patients in the control group. The percentage of patients classified as Perlas grade 2 was 13.2% in the control group, 16.1% in diabetic patients without dysautonomia, and 22.9% in diabetic patients with dysautonomia (P = .31). Antral CSA was significantly higher in diabetic patients with dysautonomia (6.5 [4.8-8.4]) compared to the control group (5.4 [4.0-7.2]; P = .04). However, no significant differences were observed between groups in residual GV. Among diabetic patients with dysautonomia, 12% exhibited solid gastric residue, which was twice the percentage observed in diabetic patients without dysautonomia (4.8%) and 3 times higher than that in the control group (3.5%; P = .03). The presence of dysautonomia was associated with an increased odds ratio of solid gastric residue (odds ratio [OR], 3.37; 95% confidence interval [CI], 1.28-8.87; P = .01) after adjusting for confounding factors.

CONCLUSIONS

This study offers insights into the relationship between dysautonomia in patients with diabetes mellitus and the presence of full stomach, underscoring the significance of preoperative gastric ultrasound evaluation in managing perioperative risks in this population.

The use of point of care gastric ultrasound and anesthesia management in pediatric patients with preoperative fasting non-adherence scheduled for elective surgical procedures: a retrospective study

BACKGROUND

Failure to adhere to perioperative fasting requirements increases aspiration risk and can lead to delay or cancellation of surgery. Point of care gastric ultrasound may guide decision-making to delay, cancel or proceed with surgery.

METHODS

This study aimed to describe gastric contents using point of care gastric ultrasound in pediatric patients with known fasting guideline violations presenting for elective surgery. This was a single-center retrospectivechart review of gastric ultrasound scans in patients presenting for elective surgeries with "nothing by mouth" violation (per fasting guidelines) or unclear fasting status. The primary outcome is description of gastric contents using point of care ultrasound. The ultrasound findings were classified as low-risk for aspiration (empty, clear fluid < 1.5 ml/kg), high-risk (solids, clear fluid > 1.5 ml/kg), or inconclusive study. Gastric ultrasound findings were communicated to the attending anesthesiologist. For patients proceeding without delay the estimated time saved was defined as the difference between ultrasound scan time and presumed case start time based on American Society of Anesthesiologists fasting guidelines.

RESULTS

We identified 106 patients with a median age of 4.8 years. There were 31 patients (29.2%) that had ultrasound finding of high-risk gastric contents. These patients had cases that were delayed, cancelled or proceeded with rapid sequence intubation. Sixty-six patients (62.3%) were determined to be low-risk gastric contents and proceeded with surgery without delay. For these patients, a median of 2.6 h was saved. No aspiration events were recorded for any patients.

CONCLUSIONS

It is feasible to use preoperative point of care gastric ultrasound to determine stomach contents and risk-stratify pediatric patients presenting for elective surgical procedures with fasting non-adherence. Preoperative gastric ultrasound may have a role in determining changes in anesthetic management in this patient population.

Point-of-Care Ultrasound for Gastric Volume Measurement in a Pediatric Patient-Look Beyond the Antrum: A Case Report

Gastric ultrasound estimates stomach contents in perioperative patients. A 10-year-old boy with abdominal rhabdomyosarcoma, who received abdominal radiation, developed gastroparesis and was scheduled for endoscopic gastrointestinal pyloric dilation. Point-of-care gastric ultrasound revealed gastric antral cross-sectional area of 6.5 cm2 (estimated gastric content ~30 mL). However, dynamic right-to-left ultrasound revealed more hypoechoic material in the fundus of the stomach. On induction ~125 mL of stomach contents was suctioned. Antral measurements may not accurately predict the stomach contents in the setting of a stiff/fixed antrum. Scanning from antrum to fundus determined contents more accurately, especially with a prior history of abdominal radiation.

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.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part I

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Evaluation of the 'Sip Til Send' regimen before elective caesarean delivery using bedside gastric ultrasound: A paired cohort pragmatic study

BACKGROUND

Pre-operative fasting is routinely advocated to avoid pulmonary aspiration. The European Society of Anaesthesiology and Intensive Care (ESAIC) recommends a fasting period of 2 h for liquids before surgery. Liberal drinking policies such as the 'Sip Til Send' are a suggested alternative to maintain hydration before surgery.

OBJECTIVES

To compare residual gastric volumes in fully fasted nonlabouring parturients before elective caesarean delivery with the 'Sip Til Send' with water liberal drinking protocol. Our hypothesis was the 'Sip Til Send' would be noninferior to standard fasting at minimising the residual gastric volume immediately before surgery.

DESIGN

A paired cohort prospective observational pragmatic study using gastric ultrasound, analysed by an operator blinded to the fasting status of each scan.

SETTING

A tertiary maternity hospital in Dublin, Ireland. The study was conducted between January and June 2023.

PARTICIPANTS

Pregnant women about to undergo elective caesarean delivery who had followed ESAIC fasting guidelines before admission.

INTERVENTIONS

Each participant underwent two pairs (semi-recumbent and the semi-recumbent right lateral positions) of standardised ultrasound examinations of the gastric antrum: the order of these scans was randomised. The first pair of scans occurred on admission before the 'Sip Til Send' protocol commenced, the other pair just before spinal anaesthesia for caesarean delivery, after a variable time following the 'Sip Til Send' protocol.

MAIN OUTCOME MEASURE

The primary outcome was the difference in antral cross-sectional area (CSA) between the fully fasted women on admission and the same women after following the 'Sip Til Send' protocol until just before spinal anaesthesia.

RESULTS

Fifty-eight women were randomised for the study: 55 and 54 scans in the semi-recumbent position on admission, and 55 and 54 scans in the right lateral position just before spinal anaesthesia. The mean differences (95% CI) in CSA in the semi-recumbent and RL positions were 0.07 (-0.39 to 0.53) cm 2 and 0.04 (-0.60 to 0.68) cm 2 , respectively. Since the of 95% CIs did not cross the predefined noninferiority margin of 0.88 cm 2 , 'Sip Til Send' was noninferior to fully fasting in in terms of the antral CSA.

CONCLUSION

The 'Sip Til Send' protocol of liberal hydration with water was noninferior to standard fasting prior to elective caesarean delivery.

TRIAL REGISTRY NUMBER

NCT05783427 ClinicalTrials.gov.

An observational study of gastric content in women scheduled for cesarean section or operative hysteroscopy

BACKGROUND

The estimation of gastric content in third trimester pregnant women has already been studied, conclusions remain contradictory. The aim of this study was to compare gastric content in pregnant and non-pregnant women using gastric ultrasound. We performed an observational two-center study of women scheduled for a cesarean section (CS group) and of non-pregnant women scheduled for hysteroscopy (HS group).

METHODS

Ultrasound evaluation was performed before surgery with measurement of antral cross-sectional area (CSA) in the semi-recumbent position (SRP), primary outcome, and in the right lateral position (RLD). Gastric fluid volume (GFV) was calculated. Results are expressed as medians (25th and 75th percentiles). Perlas Score was evaluated and expressed as number (percentage).

RESULTS

Sixty patients in the CS group and 64 in the HS group were analyzed. Antral CSA (SRP) was greater in the CS group (350 mm2 [236-415] vs. 247 mm2 [180-318]; P=0.001). Antral CSA (RLD) was also significantly greater in the CS group (P=0.027). GFV was not different between groups whether expressed in absolute value (P=0.516) or relative to weight (P=0.946) mL.kg-1. Perlas Score repartition was similar in both groups (P=0.860). Kappa coefficients of concordance between CSA, GFV and Perlas Score were slight or at best fair.

CONCLUSIONS

Our study confirmed that antral CSA is increased among pregnant women and outlined that antral CSA should not be used alone in the decision-making process especially when the results of indicators (antral CSA, GFV, and Perlas Grading Score) are discordant.

Pre-operative gastric ultrasound in patients at risk of pulmonary aspiration: a prospective observational cohort study

Point-of-care gastric sonography offers an objective approach to assessing individual pulmonary aspiration risk before induction of general anaesthesia. We aimed to evaluate the potential impact of routine pre-operative gastric ultrasound on peri-operative management in a cohort of adult patients undergoing elective or emergency surgery at a single centre. According to pre-operative gastric ultrasound results, patients were classified as low risk (empty, gastric fluid volume ≤ 1.5 ml.kg-1 body weight) or high risk (solid, mixed or gastric fluid volume > 1.5 ml.kg-1 body weight) of aspiration. After sonography, examiners were asked to indicate changes in aspiration risk management (none; more conservative; more liberal) to their pre-defined anaesthetic plan and to adapt it if patient safety was at risk. We included 2003 patients, 1246 (62%) of which underwent elective and 757 (38%) emergency surgery. Among patients who underwent elective surgery, 1046/1246 (84%) had a low-risk and 178/1246 (14%) a high-risk stomach, with this being 587/757 (78%) vs. 158/757 (21%) among patients undergoing emergency surgery, respectively. Routine pre-operative gastric sonography enabled changes in anaesthetic management in 379/2003 (19%) of patients, with these being a more liberal approach in 303/2003 (15%). In patients undergoing elective surgery, pre-operative gastric sonography would have allowed a more liberal approach in 170/1246 (14%) and made a more conservative approach indicated in 52/1246 (4%), whereas in patients undergoing emergency surgery, 133/757 (18%) would have been managed more liberally and 24/757 (3%) more conservatively. We showed that pre-operative gastric ultrasound helps to identify high- and low-risk situations in patients at risk of aspiration and adds useful information to peri-operative management. Our data suggest that routine use of pre-operative gastric ultrasound may improve individualised care and potentially impact patient safety.

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.

Effect of early oral carbohydrate intake after elective Cesarean delivery on maternal body temperature and satisfaction: a randomized controlled trial

PURPOSE

Although the Enhanced Recovery After Cesarean Delivery (ERAC) consensus statement provides recommendations for early postoperative drinking and eating, evidence from high-quality clinical research directly addressing parturients is sparse. Our objective was to assess if early oral carbohydrate intake after elective Cesarean delivery improves maternal recovery.

METHODS

In this randomized controlled trial, we enrolled parturients undergoing elective Cesarean delivery under spinal anesthesia with tympanic membrane temperatures ≤ 36.5 °C immediately upon arrival at the postanesthesia care unit. Parturients were randomized to either 100 mL of oral complex carbohydrate intake (group CC) or 10 mL of water (group C). The primary outcome was maternal tympanic membrane temperature. Other outcomes included maternal thermal comfort score, degree of shivering, satisfaction, degree of thirst and hunger, and gastric emptying assessed by ultrasonography.

RESULTS

We included 90 participants in the final analysis. The mean (standard deviation [SD]) maternal body temperature at 120 min after ingestion was 36.7 (0.3) °C in group CC and 36.6 (0.3) °C in group C (difference in means, 0.14 °C; 95% confidence interval, 0.02 to 0.26; P = 0.02). Furthermore, using repeated measure models, the linear trends of temperature changes over time between groups CC and C were significantly different (P = 0.04). The thermal comfort scores at 120 min after ingestion were higher in group CC than in group C (P = 0.02), and the linear trends of shivering score changes over time between groups CC and C also were different (P = 0.003). The mean (SD) visual analogue scale scores for maternal satisfaction were 84 (13) mm in group CC and 47 (20) mm in group C (P < 0.001). Nevertheless, at 90 and 120 min after ingestion, there were no differences between the two groups in the number of participants with a gastric antrum cross-sectional area > 10.3 cm2.

CONCLUSIONS

Early oral carbohydrate intake after Cesarean delivery helped to restore maternal body temperature postoperatively and improve maternal satisfaction. Nevertheless, the clinical importance of these finding is unclear, given that most of the differences were small. In addition, there was no delay in maternal gastric emptying after consumption of a complex carbohydrate beverage in the early post-Cesarean period.

STUDY REGISTRATION

www.chictr.org.cn (ChiCTR2000031085); first submitted 13 November 2022.

Point of care gastric ultrasound to predict aspiration in patients undergoing urgent endotracheal intubation in the emergency medicine department

BACKGROUND

One significant cause of morbidity and mortality in patients undergoing endotracheal intubation is the aspiration of gastric contents. Its prevalence is more in the emergency than in elective settings. Point-of-care gastric ultrasound (GUS) is a non-invasive bedside ultrasonogram that provides both qualitative and quantitative information about the stomach contents. The diagnostic accuracy of GUS in terms of gastric parameters (measured antral diameters, antral cross-sectional area, and calculated gastric volume) to predict aspiration is yet unknown. We aim to determine this in the patients undergoing urgent emergency intubation (UEI) in the emergency department.

METHODOLOGY

A prospective observational study was conducted at the emergency department of a tertiary healthcare center in India. Patients requiring UEI were identified and a bedside gastric ultrasound was done in the right lateral decubitus position using low frequency curved array probe. The qualitative data and the antral diameters (anteroposterior and craniocaudal) were assessed. The patient's clinical parameters and history regarding the last meal were noted. The cross-sectional area of gastric antrum was calculated using CSA = (AP × CC) π/4. The gastric volume is estimated using Perla's formula: GV = 27.0 + 14.6(RLD CSA) -1.28(age).

RESULTS

A hundred patients requiring urgent endotracheal intubation were enrolled in the study. Visible aspiration was more in participants with a distended gastric status (χ2 = 16.880, p =  < 0.001). The median gastric volume in the patients who aspirated was 146.37 mL, and it ranged from 111.59 mL-201.01 mL. Using ROC analysis, a cut-off of CC diameter ≥ 2.35 cm (sensitivity 88%, specificity 91%) and AP diameter ≥ 5.15 cm (sensitivity 88%, specificity 87%) predicts aspiration. A calculated USG CSA cut-off ≥ 9.27cm2 (sensitivity 100%, specificity 87%) and an USG gastric volume ≥ 111.594 mL (sensitivity 100%, a specificity 92%) predicts aspiration.

CONCLUSION

Point-of-care gastric ultrasound is an useful non-invasive bedside tool for risk stratification for aspiration in busy emergency rooms. We present threshold gastric antral parameters that can be used to predict aspiration along with its diagnostic accuracy. This can help the treating ED physician take adequate precautions, decide on intubation techniques and treatment modifications to aid in better patient management.

Ultrasonographic Evaluation of Gastric Content and Volume in Pediatric Patients Undergoing Elective Surgery: A Prospective Observational Study

Anesthesia-related complications, such as pulmonary aspiration of gastric contents, occur in approximately 0.02-0.1% of elective pediatric surgeries. Aspiration risk can be reliably assessed by ultrasound examination of the gastric antrum, making it an essential non-invasive bedside tool. In this prospective observational study, since most of our patients are immigrants and have communication problems, we wanted to investigate gastric contents and the occurrence of "high risk stomach" in children undergoing elective surgery for the possibility of pulmonary aspiration, even if the children and/or parents reported their last oral intake time. This risk is defined by ultrasound findings of solid content in the antrum and/or a calculated gastric volume exceeding 1.25 mL/kg. Children aged 2-18 were included in the study. Both supine and right lateral decubitus (RLD) ultrasound examinations were performed on the antrum before surgery. Using a qualitative grading scale from 0 to 2, we evaluated the gastric fluid content. The cross-sectional area (CSA) of the antrum was measured in the RLD position, aiding the calculation of the gastric fluid volume according to an established formula by Perlas. Ultrasound measurements of 97 children were evaluated. The median fasting duration was 4 h for liquids and 9 h for thick liquids and solids. Solid content was absent in all the children. Five children (5.2%) exhibited a grade 2 antrum, implying that fluid content was visible in both the supine and RLD positions. The median antral CSA in the RLD was 2.36 cm2, with a median gastric volume of 0.46 mL/kg. For patients with a grade 0 antrum, a moderate and positive correlation was observed between the antral CSA and BMI, and a strong and positive correlation was evident between the antral CSA and age, similar to a grade 1 antrum. Only a single child (1%) had a potentially elevated risk of aspiration of gastric contents. Hence, the occurrence of a "high risk stomach" was 1% (95% confidence interval: 0.1-4.7%) and is consistent with the literature. As a necessary precaution, we propose the regular use of ultrasound evaluations of gastric contents, given their non-invasive, bedside-friendly, and straightforward implementation, for identifying risks when fasting times are uncertain and for ruling out unknown risk factors in each potential patient.

Ultrasonographic Assessment of Gastric Volume in Fasted Patients Undergoing Gastrointestinal Endoscopy Under Sedation

Purpose

In this prospective observational study, an ultrasonographic measurement of antral cross-sectional area (ACSA) was conducted to evaluate the gastric content and volume as well as to identify high-risk stomach in non-pregnant adult surgical patients adhering to preanesthetic fasting guidelines.

Patients and Methods

Fasted patients undergoing gastrointestinal endoscopy under sedation were included. Ultrasonographic measurements of ACSA were conducted in both semi-recumbent and right lateral decubitus positions before endoscopic procedures. Gastroscopy was employed to guide the measurement of suctioned gastric volume (GV). Ultrasonography was performed to assess gastric contents and identify patients with high-risk stomach. The relationship between ACSA and suctioned GV was also evaluated.

Results

ACSA was evaluated in 736 out of 782 patients. A significant positive correlation was discovered between ACSA in the right lateral decubitus position and suctioned GV, which was more reliable than in the semi-recumbent position. To analyze high-risk stomach with a GV > 100 mL, the cutoff value of ACSA in the right lateral decubitus was found to be 7.5 cm2, with the AUC, sensitivity and specificity of 0.80 (95% CI, 0.76-0.82; P<0.001), 82.4% and 67.3%, respectively. A novel mathematical model based on ACSA to estimate GV in non-pregnant fasted adults was presented.

Conclusion

Ultrasonographic measurement of ACSA can assist anesthesiologists in estimating the risk of pulmonary aspiration of gastric contents during general anesthesia and sedation.

Influence of semaglutide use on the presence of residual gastric solids on gastric ultrasound: a prospective observational study in volunteers without obesity recently started on semaglutide

PURPOSE

Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) have become increasingly popular as both diabetic and weight loss therapies. One effect of this class of medication is delayed gastric emptying, which may impact the risk of aspiration during anesthesia delivery.

METHODS

In this prospective study, we used gastric ultrasound to evaluate the presence of solid gastric contents in both supine and lateral positions after an eight-hour fast in those taking GLP-1RA compared with controls. Participants underwent a second ultrasound evaluation two hours later after drinking 12 fluid ounces of water (approximately 350 mL).

RESULTS

Twenty adults voluntarily enrolled, giving a total of ten participants in each group. In the supine position, 70% of semaglutide participants and 10% of control participants had solids present on gastric ultrasound (risk ratio [RR], 3.50; 95% confidence interval [CI], 1.26 to 9.65; P = 0.02.) In the lateral position, 90% of semaglutide participants and 20% of control participants had solids identified on gastric ultrasound (RR, 7.36; 95% CI, 1.13 to 47.7; P = 0.005). Two hours after drinking clear liquids, the two groups did not differ in the lateral position, but in the supine position, 90% of control group participants were rated as empty compared with only 30% of semaglutide group participants (P = 0.02).

CONCLUSIONS

This study provides preliminary evidence that GLP-1RAs may affect gastric emptying and residual gastric contents following an overnight fast and two hours after clear liquids, which may have implications for aspiration risk during anesthetic care.

The correlation between patient satiety sensation and total gastric fluid volume: a prospective observational study

PURPOSE

Surgical patients are asked to adhere to preoperative fasting guidelines to minimize gastric contents. Large fluid volumes or solid content can still be present as shown with gastric ultrasound. It has been suggested that additional rating of patients' satiety, measured as the feeling of hunger and thirst, could help clinicians to better judge emptying of the stomach.

METHODS

We performed a prospective observational study in fasted elective surgical patients. The primary objective was to investigate the correlation between hunger measured on a 0-10 numeric rating scale and total gastric fluid volume measured with gastric ultrasonography. Secondary objectives included the correlation between 1) thirst and total gastric fluid volume and 2) hunger, thirst, and the Perlas grading scale score.

RESULTS

We included 515 patients. The exam was inconclusive in 14 individuals (2.7%). The Spearman correlation coefficient between gastric fluid volumes and hunger was 0.11 (95% confidence interval [CI], 0.02 to 0.20) (P = 0.01). The correlation between gastric fluid volumes and thirst was 0.11 (95% CI, 0.02 to 0.20) (P = 0.02). Between antral grades and numeric rating scale, the correlation coefficient was 0.00 (95% CI, -0.09 to 0.09) (P = 1.00) for thirst and 0.00 (95% CI, -0.08 to 0.09) (P = 0.94) for hunger. Ten patients (2.0%) had solid content, 24 presented a grade 2 antrum (4.8%).

CONCLUSION

This study suggests that the correlation between total gastric fluid volume and satiety sensation is very weak. Satiety did not reliably predict total gastric fluid volume.

STUDY REGISTRATION

ClinicalTrials.gov (NCT04884373); registered 13 May 2021.

Ultrasound Assessment of Gastric Volume in Parturients After High-Flow Nasal Oxygen Therapy

BACKGROUND

High-flow nasal oxygen (HFNO) therapy is widely used in critical care obstetrics to improve oxygenation. Much of the benefit of HFNO is linked to the creation of modest levels of positive airway pressure. Pregnant women are generally considered to be at high risk of regurgitation and aspiration. It is unknown whether HFNO may cause gas insufflation into the stomach and further increase this risk. Therefore, this study aimed to systematically evaluate the possible safety effects of HFNO on gastric volume in healthy fasted parturients.

METHODS

Sixty fasted parturients scheduled for elective cesarean delivery were enrolled in an observer-blinded, prospective, interventional study. We used ultrasonography to assess changes of antral cross-sectional area (CSA) and gastric volume before and after a 20-minute treatment with HFNO at a rate of 50 L·min -1 . The primary outcome was the change in gastric volume from before to after HFNO therapy, and the secondary outcome was the distribution of antral grades.

RESULTS

In semirecumbent right lateral position, the antral CSA at baseline and after treatment with HFNO was 3.81 (3.01-4.72) cm 2 and 3.79 (3.03-4.54) cm 2 , respectively. The estimated fluid volume at baseline and after treatment with HFNO was 38.51 (33.39-54.62) mL and 39.71 (32.00-52.82) mL, respectively. All participants had either a grade 0 or grade 1 antrum, and most of them had a grade 0 antrum. There was no significant difference in gastric volume and distribution of antral grades before and after HFNO therapy. Gastric air distension was not shown in any of the parturients either at baseline or after treatment with HFNO.

CONCLUSIONS

Treatment with HFNO for 20 minutes at flow rates up to 50 L·min -1 did not increase gastric volume in term pregnant women breathing spontaneously when evaluated by gastric ultrasonography.

Ultrasonic evaluation of metoclopramide's effect on gastric motility in emergency trauma patients

Objective: The present study aimed to use bedside ultrasound to evaluate the effects of metoclopramide on gastric motility in patients being treated for trauma in the emergency department. Methods: Fifty patients underwent an ultrasound immediately after attending the emergency department of Zhang Zhou Hospital due to trauma. The patients were randomly divided into two groups: a metoclopramide group (group M, n = 25) and a normal saline group (group S, n = 25). The cross-sectional area (CSA) of the gastric antrum was measured at 0, 30, 60, 90, and 120 min (T = time). The gastric emptying rate (GER, GER=-AareaTn/AareaTn-30-1×100), GER/min (GER divided by the corresponding interval time), gastric content properties, Perlas grade at different time points, T120 gastric volume (GV), and GV per unit of body weight (GV/W) were evaluated. The risk of vomiting, reflux/aspiration, and type of anesthetic treatment were also evaluated. Results: The differences between the two groups in the CSA of the gastric antrum at each time point were statistically significant (p < 0.001). The CSAs of the gastric antrum in group M were lower than those in group S, and the greatest difference between the two groups occurred at T30 (p < 0.001). The differences between the two groups in GER and GER/min were also statistically significant (p < 0.001); those differences in group M were higher than those in group S, and the greatest differences between the two groups occurred at T30 (p < 0.001). There were no obvious change trends in the properties of the gastric contents and the Perlas grades in either group, and the differences between the two groups were not statistically significant (p = 0.97). The differences between the two groups in the GV and GV/W at T120 were statistically significant (p < 0.001), as was the risk of reflux and aspiration at T120 (p < 0.001). Conclusion: When metoclopramide was used in satiated emergency trauma patients, it accelerated gastric emptying within 30 min and reduced the risk of accidental reflux. However, a normal gastric emptying level was not achieved, which can be attributed to the delaying effect of trauma on gastric emptying.

Ultrasound assessment of residual gastric volume in older adults undergoing staged-bilateral total knee arthroplasty after consuming carbohydrate-containing fluids: a prospective observational study

BACKGROUND

We compared preoperative residual gastric volume (GV) between the first and second stages of total knee arthroplasty (TKA) in older adults after drinking carbohydrate-containing fluid 2 h prior to surgery.

METHODS

In this study, 36 patients, aged > 65 years, scheduled for staged bilateral TKA with one-week interval, were enrolled. The patients consumed 400 ml of carbohydrate-containing fluid 2 h prior to surgery. Before the induction of spinal anesthesia, the gastric antral cross-sectional area was measured at the first and second TKA using ultrasound, and the residual GV was calculated. The primary outcome was the residual GV. Qualitative GV (grades 0, 1, and 2) and analgesic consumption after the first TKA were assessed as secondary outcomes.

RESULTS

The GV (median [Q1, Q3]) was greater in the second-stage TKA (41.1 [22.5, 62.8] ml) than in the first-stage TKA (10.3 [0.0, 27.1] ml) (P < 0.001). In the qualitative assessment, the distribution was not different between the two stages of TKA (P = 0.219) and only one patient showed grade 2 gastric content in the second TKA. When opioid consumption was converted to an equivalent dose of morphine, an average of 53.9 mg of morphine was required after the first TKA.

CONCLUSIONS

Residual GV after drinking carbohydrate-containing fluid differed according to the stage of TKA, showing a larger residual GV in the second TKA than in the first one. In older adults scheduled to undergo bilateral staged TKA, caution is required in preoperative fasting practice, especially in second-stage surgery.

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

BACKGROUND

The 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.

RESULTS

A 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.

CONCLUSIONS

The 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.

Prospective audit on fasting status of elective ambulatory surgery patients, correlated to gastric ultrasound

INTRODUCTION

Recent guidelines advocate a preoperative fasting interval of 6 h for solid food, 4 h for breast milk and 2 h for clear fluids. Long nil per mouth intervals give rise to complications and discomfort in the perioperative period. Gastric ultrasound is easily accessible and generates reliable information about gastric content.

PATIENTS AND METHODS

One hundred patients were offered a questionnaire regarding preoperative fasting. Important outcome measures were hour of last meal, last clear fluids intake, the source of preoperative information. Gastric ultrasound was performed in prone position and lateral decubitus.

RESULTS

The mean duration of fasting for solid food was 13h29 and 9h51 for clear fluids. 48% of patients were well aware of the correct fasting guidelines. The most frequent source of information was the preoperative phone call. Gastric ultrasound only found insignificant amounts of gastric content.

DISCUSSION

Too few patients are aware of the correct guidelines or fear complications and therefore adhere to the nil per mouth from midnight as most conservative measure. A phone call informing patients about the hour of surgery and allowing clear fluid intake until 2 h before surgery, is still not convincing enough. Some health care providers advise their patients the nil per mouth from midnight rule, due to risk of interfering with the operating room schedule.

CONCLUSION

It is still difficult to implement liberal intake of clear fluids according to current guidelines. Ambulatory surgery patients have long fasting intervals with decrease of subjective well-being and increased incidence of hunger and thirst.

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.

Prevalence of risk stomach in laboring women allowed to unrestrictive oral intake: a comparative cross-sectional study

Background

Although restricting food intake during labor is recommended by guidelines, intrapartum starvation has not been popular in some regions. We conducted this comparative cross-sectional study to determine the prevalence of risk stomach in non-fasted laboring women compared with fasted non-laboring women using gastric ultrasound.

Methods

Ultrasound examination of the antrum was performed in 50 term fasted non-laboring women before elective cesarean delivery and 50 laboring women allowed to eat and drink during active labor. Examinations consisted of the qualitative (antral grades, 0–3) and quantitative evaluation (antral cross-sectional area and calculated gastric volume) in the supine and right lateral decubitus (RLD) position. A risk stomach was defined as an antral grade ≥ 2 or grade 1 with gastric volume ≥ 1.5 ml· kg^− 1.

Results

No non-laboring women had grade ≥ 2, while 34 (68%) laboring women had grade ≥ 2. Nine (18%) non-laboring and 40 (80%) laboring women presented risk stomach (P < 0.001) (risk ratio: 4.4, 95% CI 2.4–8.2). Compared with non-laboring women, laboring women had larger antral area at “empty” stomach (grade 0) (437 mm² vs.350 mm² in supine, 571 mm² vs.480 mm² in RLD, P < 0.05) and cut-off values of antral area to discriminate a risk stomach (510 mm² vs. 453 mm² in supine, 670 mm² vs. 605 mm² in RLD).

Conclusions

This study confirms a higher prevalence of risk stomach presents in laboring women under a liberal eating policy, gastric ultrasound is therefore useful for this risk population if general anesthesia is required unexpectedly.

Qualitative and quantitative gastric ultrasound assessment in highly skilled regional anesthesiologists

BACKGROUND

Pulmonary 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.

METHODS

This 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).

RESULTS

Of 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).

CONCLUSION

Our 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 REGISTRATION

ClinicalTrials.gov no. NCT04760106 Date registered on Feb 11, 2021. Prospectively registered.

Point-of-Care Ultrasound to Assess Gastric Content in Pediatric Emergency Department Procedural Sedation Patients

OBJECTIVES

There is debate regarding the timing of procedural sedation and analgesia (PSA) in relation to fasting status. Point-of-care ultrasound (POCUS) provides the ability to measure gastric content and is being used as a surrogate for aspiration risk in anesthesia. We sought to evaluate the gastric content of pediatric emergency department (PED) patients undergoing PSA using POCUS.

METHODS

We performed a prospective observational study using a convenience sample of pediatric patients undergoing PSA between July 1, 2018, and June 30, 2019. Following a brief history, gastric content was measured using POCUS in both supine and right lateral decubitus positions at 2-hour intervals until the time of PSA. Qualitative content and calculated volume were classified based on the Perlas Model of anesthesia "Risk" assessment.

RESULTS

Ninety-three patients were enrolled with 61.3% male and mean age of 6.5 years. Gastric content was determined in 92 patients. There were 79.3% that had "high risk" content at the time of PSA, with a median fasting time of 6.25 hours and no serious adverse events. Fasting duration had a weak to moderate ability to predict "risk" category (area under the curve = 0.73), with no patient (n = 17) who underwent multiple evaluations awaiting PSA progressing from "high" to "low risk."

CONCLUSIONS

The majority of PED patients undergoing PSA at our institution had "high risk" gastric content with no clinically significant change occurring during serial evaluations. This calls into question the utility of delaying PSA based upon fasting status and lends support to a more comprehensive risk-benefit approach when planning pediatric PSA.

Point of Care Ultrasound on Labor and Delivery

Point of care ultrasound (POCUS) in the field of obstetric anesthesiology, including cardiac, pulmonary, neuraxial, gastric, and airway ultrasound, can facilitate rapid diagnosis, management, and clinical decision-making surrounding common maternal peripartum comorbidities, and obstetric complications. Routine and proficient utilization of POCUS can ultimately aid in anesthesiologists' role as critical care physicians in the multidisciplinary practice on labor and delivery, with potential future research aiming to determine the potential impact on maternal morbidity and mortality.

Fasting does not guarantee empty stomach in the intensive care unit: A prospective ultrasonographic evaluation (The NUTRIGUS study)

BACKGROUND

In the intensive care unit (ICU), a fasting period is usually respected to avoid gastric aspiration during airway management procedures. Since there are no recognised guidelines, intensive care physicians balance the aspiration risk with the negative consequences of underfeeding. Our objective was to determine the impact of fasting on gastric emptying in critically ill patients by using gastric ultrasound.

MATERIAL AND METHODS

Among the 112 patients that met the inclusion criteria, 100 patients were analysed. Gastric ultrasonography was performed immediately before extubation. Patients with either 1/ an absence of visualised gastric content (qualitative evaluation) or 2/ a gastric volume < 1.5 mll/kg in case of clear fluid gastric content (quantitative evaluation) were classified as having an empty stomach.

MAIN FINDINGS

In our study, twenty-six (26%) patients had a full stomach at the time of extubation. The incidence of full stomach was not significantly different between patients who fasted < 6 h or patients who fasted ≥ 6 h. Among the 57 patients receiving enteral nutrition (EN) within the last 48 h, there was no correlation between the duration of EN interruption and the GAA. The absence of EN was not associated with an empty stomach.

CONCLUSION

At the time of extubation, the incidence of full stomach was high and not associated with the fasting characteristics (duration/absence of EN). Our results support the notions that fasting before airway management procedures is not a universal paradigm and that gastric ultrasound might represent a useful tool in the tailoring process. CLINICALTRIALS.GOV: NCT04245878.

Anesthetic Management of Acute Ischemic Stroke in the Interventional Neuro-Radiology Suite: State of the Art

PURPOSE OF REVIEW

This review discusses the general anesthetic approach of endovascular stroke therapy and highlights recent advances and considerations for optimal intraoperative management of acute ischemic stroke.

RECENT FINDINGS

Recent randomized controlled trials have shown no differences in clinical outcomes between monitored anesthesia care with sedation compared with general anesthesia for endovascular stroke therapy. The COVID-19 pandemic has complicated decision-making in the neurointerventional setting. Advances in imaging techniques have extended the window of treatment for endovascular therapy.

SUMMARY

Optimal time to intervention, hemodynamic stability, novel imaging techniques, and careful consideration of anesthetic plan can impact patient outcomes in reperfusion stroke therapy.

Ultrasound: The New Stethoscope (Point-of-Care Ultrasound)

Advances in technology have led to more user-friendly ultrasound devices that allow for easy incorporation into daily perioperative practice, with the anesthesiologist serving as the sonographer. With appropriate knowledge and training, bedside ultrasound examinations can be used to better diagnose pathology and guide perioperative strategies. Cardiac ultrasound examination was the initial emphasis in anesthesiology, with now expansion into lung and gastric ultrasound imaging. In this review, the indications, procedural description, and clinical findings for lung and gastric ultrasound examinations are discussed to demonstrate its importance and build confidence in the user.

A protocol implementation to determine aspiration risk in patients with multiple risk factors for gastroparesis

Patients with risk factors for gastroparesis are at increased risk for aspiration into the tracheobronchial tree. Current American Society of Anesthesiologists fasting guidelines use subjective measures to determine aspiration risk. A gastric ultrasound protocol can identify patients with risk factors for gastroparesis and determine the need to perform a point-of-care gastric ultrasound to objectively assess gastric antral contents. This enables the anaesthesia provider to assess patients at increased risk for aspiration. Additionally, many patients who present for surgery with risk factors for gastroparesis have an empty gastric antrum. Thus, the gastric ultrasound protocol checklist saves time and manpower requirements of anaesthesia staff without impacting patient safety or perioperative efficiency. A convenience sample of 40 patients consented for surgery was assessed using a screening tool to identify those at risk for gastroparesis and possible aspiration. Patients deemed at risk received a gastric ultrasound examination to evaluate for the presence of gastric contents. Over 12% of these patients had solid food gastric contents on exam. All patients with solid food gastric contents had an American Society of Anesthesiologists Physical Status Classification of 3 or higher, and two or more risk factors for gastroparesis.

Gastric content and perioperative pulmonary aspiration in patients with diabetes mellitus: a scoping review

BACKGROUND

Gastric emptying may be delayed in patients with diabetes mellitus (DM). However, the incidence of full stomach in fasting patients with DM and their risk of pulmonary aspiration under anaesthesia is not well understood.

METHODS

A scoping review was undertaken to map the literature on aspiration risk in DM. A search was conducted in seven bibliographic databases, including MEDLINE and Embase, for original articles that studied aspiration risk, gastric emptying, or gastric content and volume. Selection and characterisation were performed by two independent reviewers using a predefined protocol registered externally.

RESULTS

The search identified 5063 unique records, and 16 studies (totalling 775 patients with DM) were selected: nine studied gastric emptying and seven studied gastric content or volume. There were no studies reporting the incidence of aspiration in subjects with DM. All nine studies reported delayed emptying in patients with DM compared with healthy controls. Amongst the seven studies that compared gastric residual content/volume (GRV) in the perioperative period, five reported clinically negligible GRV in both patients with DM and controls, whereas two observed a higher incidence of 'full' stomach in patients with DM.

CONCLUSIONS

The evidence concerning the aspiration risk for surgical patients with DM is based on a limited number of studies, mostly unblinded, reporting physiological data on gastric emptying and gastric volume as surrogate markers of aspiration risk. Data on fasting gastric content and volume in patients with DM are limited and contradictory; hence, the true risk of aspiration in fasting patients with DM is unknown.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part II: recommendations

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine Society (ASRA) commissioned this narrative review to provide recommendations for POCUS. The recommendations were written by content and educational experts and were approved by the guidelines committee and the Board of Directors of the ASRA. In part II of this two-part series, learning goals and objectives were identified and outlined for achieving competency in the use of POCUS, specifically, airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma exam, and focused cardiac ultrasound, in the perioperative and chronic pain setting. It also discusses barriers to POCUS education and training and proposes a list of educational resources. For each POCUS section, learning goals and specific skills were presented in the Indication, Acquisition, Interpretation, and Medical decision-making framework.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part I: clinical indications

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine (ASRA) commissioned this narrative review to provide recommendations for POCUS. The guidelines were written by content and educational experts and approved by the Guidelines Committee and the Board of Directors of the ASRA. In part I of this two-part series, clinical indications for POCUS in the perioperative and chronic pain setting are described. The clinical review addresses airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma examination and focused cardiac ultrasound for the regional anesthesiologist and pain physician. It also provides foundational knowledge regarding ultrasound physics, discusses the impact of handheld devices and finally, offers insight into the role of POCUS in the pediatric population.

The Obese Patient: Facts, Fables, and Best Practices

The prevalence of obesity continues to rise worldwide, and anesthesiologists must be aware of current best practices in the perioperative management of the patient with obesity. Obesity alters anatomy and physiology, which complicates the evaluation and management of obese patients in the perioperative setting. Gastric point-of-care ultrasound (PoCUS) is a noninvasive tool that can be used to assess aspiration risk in the obese patient by evaluating the quantity and quality of gastric contents. An important perioperative goal is adequate end-organ perfusion. Standard noninvasive blood pressure (NIBP) is our best available routine surrogate measurement, but is vulnerable to greater inaccuracy in patients with obesity compared to the nonobese population. Current NIBP methodologies are discussed. Obese patients are at risk for wound and surgical site infections, but few studies conclusively guide the exact dosing of intraoperative prophylactic antibiotics for them. We review evidence for low-molecular-weight heparins and weight-based versus nonweight-based administration of vasoactive medications. Finally, intubation and extubation of the patient with obesity can be complicated, and evidence-based strategies are discussed to mitigate danger during intubation and extubation.

Point-of-Care Ultrasound (POCUS) for the Cardiothoracic Anesthesiologist

Point-of-Care Ultrasound (POCUS) is a valuable bedside diagnostic tool for a variety of expeditious clinical assessments or as guidance for a multitude of acute care procedures. Varying aspects of nearly all organ systems can be evaluated using POCUS and, with the increasing availability of affordable ultrasound systems over the past decade, many now refer to POCUS as the 21^st-century stethoscope. With the current available and growing evidence for the clinical value of POCUS, its utility across the perioperative arena adds enormous benefit to clinical decision-making. Cardiothoracic anesthesiologists routinely have used portable ultrasound systems for nearly as long as the technology has been available, making POCUS applications a natural extension of existing cardiothoracic anesthesia practice. This narrative review presents a broad discussion of the utility of POCUS for the cardiothoracic anesthesiologist in varying perioperative contexts, including the preoperative clinic, the operating room (OR), intensive care unit (ICU), and others. Furthermore, POCUS-related education, competence, and certification are addressed.

Point-of-care ultrasound for the pediatric regional anesthesiologist and pain specialist: a technique review

Point-of-care ultrasound (PoCUS) has been well described for adult perioperative patients; however, the literature on children remains limited. Regional anesthesiologists have gained interest in expanding their clinical repertoire of PoCUS from regional anesthesia to increasing numbers of applications. This manuscript reviews and highlights emerging PoCUS applications that may improve the quality and safety of pediatric care.

In infants and children, lung and airway PoCUS can be used to identify esophageal intubation, size airway devices such as endotracheal tubes, and rule in or out a pulmonary etiology for clinical decompensation. Gastric ultrasound can be used to stratify aspiration risk when nil-per-os compliance and gastric emptying are uncertain. Cardiac PoCUS imaging is useful to triage causes of undifferentiated hypotension or tachycardia and to determine reversible causes of cardiac arrest. Cardiac PoCUS can assess for pericardial effusion, gross ventricular systolic function, cardiac volume and filling, and gross valvular pathology. When PoCUS is used, a more rapid institution of problem-specific therapy with improved patient outcomes is demonstrated in the pediatric emergency medicine and critical care literature.

Overall, PoCUS saves time, expedites the differential diagnosis, and helps direct therapy when used in infants and children. PoCUS is low risk and should be readily accessible to pediatric anesthesiologists in the operating room.

Effects of a Preoperative Carbohydrate-Rich Drink Before Ambulatory Surgery: A Randomized Controlled, Double-Blinded Study

Background

The guidelines recommend oral carbohydrates up to 2 hr before elective surgery. The objective of this study was to explore the safety and feasibility of preoperative carbohydrate drink in patients undergoing ambulatory surgery.

Material/Methods

Patients undergoing ambulatory surgery under general anesthesia were enrolled. They were fasted from midnight and randomly assigned to a study group (200 mL of a carbohydrate beverage) or the control group (pure water) and received the assigned drink 2 hr before surgery. Bedside ultrasonography was performed to monitor gastric emptying at T₀ (before liquid intake), T₁ (5 min after intake), T₂ (1 hr after intake), and T₃ (2 hr after intake). Subjective feelings of thirst, hunger, anxiety, and fatigue were assessed 1 hr after liquid intake using the visual analogue scale (VAS).

Results

In both groups, gastric antrum cross-sectional area, gastric content volume, and weight-corrected gastric content volume increased at T₁ and returned to baseline at T₃. These parameters were significantly higher in the study group at T₂ (6.28±1.38 vs. 4.98±0.78, 67.22±29.49 vs. 49.04±15.4, 1.10±0.51 vs. 0.85±0.37, P<0.05). Thirst and hunger VAS scores were reduced in both groups. The study group suffered significantly less hunger (28.44±10.41 vs. 36.03±14.42, P<0.05). Blood electrolytes (sodium, potassium, calcium) and glucose concentration levels were similar in both groups at T₂. No gastric regurgitation or pulmonary aspiration was recorded.

Conclusions

Administration of 200 mL of oral carbohydrate beverage 2 hr before ambulatory surgery is safe, effective, and can be used for preoperative management of fasting patients.

Point-of-Care Gastric Ultrasound in a Pediatric Patient After Bowel Preparation: A Case Report

Polyethylene glycol electrolyte solutions (PEG, NuLYTELY^®) are widely used to prepare the GI tract before colonoscopy or barium enema examinations. Although PEG appears as a clear liquid, the optimal interval for sedation or general anesthesia after the last administration of these solutions is unclear and controversial in the anesthetic literature. We present a 3-year-old patient with intermittent bloody stools who required anesthetic care for esophagogastroduodenoscopy (EGD) and colonoscopy. Given the controversial nil per os time with the use of PEG-containing solutions, point-of-care gastric ultrasound was performed to evaluate gastric contents and gastric volume before the induction of anesthesia.

Point-of-Care Ultrasound to Assess Gastric Content

Gastric ultrasound (US) is a growing modality within the point-of-care ultrasound (POCUS) field. It provides the ability to directly measure an individual patient's gastric content and has potential use as both a clinical and a research tool. Here, we review the historical development of current gastric US models and their clinical application within the field of general anesthesia, describe the US findings and technique for using POCUS to assess gastric content, and discuss the current and potential applications of gastric POCUS within the emergency department.

Gastric point-of-care ultrasound (PoCUS) during pregnancy and the postpartum period: a systematic review

Personalised risk assessment of the likelihood of pulmonary aspiration is recommended for pregnant women undergoing general anaesthesia and gastric point-of-care ultrasound (PoCUS) may help to achieve this. Traditionally, risk assessment is based upon adherence to fasting times, but gastric emptying may vary during pregnancy and surgery often needs to be expedited. We systematically reviewed the evidence for gastric PoCUS up to August 2018 in pregnant and postpartum women to determine whether it can identify and quantify stomach contents, provide aspiration risk assessment via qualitative or quantitative means, and determine how gastric emptying is affected by pregnancy. Twenty-two articles comprising 1050 participants were included and studies were classified by qualitative or quantitative findings. The evidence suggests that gastric PoCUS is a reliable and feasible method of imaging the stomach in pregnancy in clinical practice. Qualitative assessment via the Perlas grading system can provide rapid assessment of gastric volume states. If fluid is visible, identification of patients at high risk of pulmonary aspiration requires measurement of antral cross-sectional area. Cut-off values of 608 mm² and 960 mm² are recommended in the semi-recumbent and right lateral semi-recumbent positions, respectively. Validated methods to quantify stomach volumes are available, however their usefulness is currently restricted to research. Gastric PoCUS also provides evidence that gastric emptying of ingested food is delayed by term pregnancy, labour and during the early postpartum period. However, the passage of fluids through the stomach appears unaffected throughout the peripartum period.