Perioperative point-of-care gastric ultrasound

Association of glucagon-like peptide receptor 1 agonist therapy with the presence of gastric contents in fasting patients undergoing endoscopy under anesthesia care: a historical cohort study

PURPOSE

We aimed to estimate the association of glucagon-like peptide 1 (GLP-1) receptor agonist therapy with the incidence of endoscopically visible gastric contents after preprocedural fasting.

METHODS

We reviewed the records of esophagogastroduodenoscopy (EGD) performed at our institution between 2019 and 2023 and determined the presence of residual gastric contents from the procedure notes and saved images. We compared patients taking GLP-1 agonists at the time of the procedure (GLP group, 90 procedures) with patients who started GLP-1 agonist therapy within 1,000 days after undergoing EGD (control, 102 procedures). We excluded emergent procedures without fasting, combined EGD/colonoscopy procedures, and patients with known gastroparesis or previous gastric surgery. We estimated the association between GLP-1 agonist therapy and residual gastric contents with a confounder-adjusted generalized linear mixed effect model.

RESULTS

Compared with controls, the GLP cohort had a higher age, American Society of Anesthesiologists' Physical Status, and incidence of nausea and diabetes mellitus. Body mass index and fasting duration were comparable between groups. Visible gastric content was documented in 17 procedures in the GLP group (19%) and in five procedures in the control group (5%), with an associated confounder adjusted odds ratio of 5.8 (95% confidence interval, 1.7 to 19.3; P = 0.004). There were five instances of emergent endotracheal intubation in the GLP group vs one case in control and one case of pulmonary aspiration vs none in control.

CONCLUSIONS

In fasting patients, GLP-1 agonist therapy was associated with an increased incidence of residual gastric contents, potentially posing an additional risk of periprocedural pulmonary aspiration.

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.

Point of Care Abdominal Ultrasound

Abdominal pain is a common emergency department complaint, and point-of-care ultrasound (POCUS) of the abdomen is increasingly being utilized to evaluate clinical manifestations. It aids in accurate diagnoses and assists in procedures, particularly in emergency and critical care settings. Imaging is often required to confirm the etiology of abdominal pain. POCUS provides the benefit of avoiding radiation exposure and enables quicker diagnosis compared to computed tomography scans. There is growing evidence of the diagnostic accuracy for numerous abdominal POCUS applications, including appendicitis, intussusception, diverticulitis, gastric ultrasound and contrast-enhanced ultrasound.

Beyond the Echo: The Evolution and Revolution of Ultrasound in Anesthesia

This article explores the evolving role of ultrasound technology in anesthesia. Ultrasound emerged decades ago, offering clinicians noninvasive, economical, radiation-free, and real-time imaging capabilities. It might seem that such an old technology with apparent limitations might have had its day, but this review discusses both the current applications of ultrasound (in nerve blocks, vascular access, and airway management) and then, more speculatively, shows how integration of advanced ultrasound modalities such as contrast-enhanced imaging with virtual reality (VR), or nanotechnology can alter perioperative patient care. This article will also explore the potential of robotics and artificial intelligence (AI) in augmenting ultrasound-guided anesthetic procedures and their implications for medical practice and education.

Gastric Ultrasound for Gastric Content Evaluation

Gastric content aspiration occurs once every 2000-3000 general anaesthetics. It is associated with a 20% incidence of in-hospital mortality. The incidence of pulmonary aspiration in patients undergoing surgery is at least three times more, up to 1 in 895 general anaesthetics. Pulmonary aspiration indeed is associated with half of our airway-related mortality linked with anaesthesia. The pulmonary aspiration causes significant morbidity including respiratory failure, acute lung injury, and multi-organ failure in adults. This review study aims to compare the stomach volume and contents in patients following standard fasting guidelines by Point of care gastric ultrasound measurements. Perioperative gastric ultrasound is a developing diagnostic modality that is modest, easy, non-invasive and efficient. It is very helpful to determine gastric contents in adult, obese, paediatric, and obstetric patients. It is a dependable and replicable tool that can be used for effective anaesthetic management. Gastric ultrasound is an irreplaceable procedure to complement the use of fasting guidelines, particularly when these guidelines have not been followed, or may not be relevant. Further series of research with metanalysis is required to understand the influence of point-of-care gastric ultrasound assessment on perioperative outcomes.

Rapid Evaluation of Gastric Content With Ultrasound: An Educational Tool

Pulmonary aspiration is a severe complication in patients receiving anesthesia for surgical procedures. The risk and severity of aspiration are significantly higher in the presence of substantial gastric contents. Bedside ultrasound imaging of the gastric antrum is emerging as a rapid and valuable method to evaluate gastric contents before surgery. Rapid gastric ultrasound using a three-category grading system promotes timely decision-making to help in emergent or urgent surgeries by identifying patients with potentially high gastric volumes or solid food contents. In emergent cases with limited time, a single ultrasound view of the gastric antrum is still likely to yield helpful information. In this report, we argue that bedside ultrasound offers a more reliable assessment of gastric contents than assumptions based on time-based fasting guidelines.

Esophageal Stent Migration Diagnosed With Point-of-Care Ultrasound

This unique case depicts the first published report of a physician using point-of-care ultrasound to diagnose an esophageal stent migration. Discussed in this article are the sonographic findings that clinicians should be familiar with when evaluating patients with abdominal pain or chest pain who have a history of an esophageal stent. When coupled with a high index of suspicion, ultrasound can be one of the most portable, readily available, low-cost, and minimally invasive techniques for making a rapid diagnosis of esophageal stent migration.

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.

Semaglutide, delayed gastric emptying, and intraoperative pulmonary aspiration: a case report

PURPOSE

We report a case in which the use of semaglutide for weight loss was associated with delayed gastric emptying and intraoperative pulmonary aspiration of gastric contents.

CLINICAL FEATURES

A 42-yr-old patient with Barrett's esophagus underwent repeat upper gastrointestinal endoscopy and ablation of dysplastic mucosa. Two months earlier, the patient had started weekly injections of semaglutide for weight loss. Despite having fasted for 18 hr, and differing from the findings of prior procedures, endoscopy revealed substantial gastric content, which was suctioned before endotracheal intubation. Food remains were removed from the trachea and bronchi using bronchoscopy. The patient was extubated four hours later and remained asymptomatic.

CONCLUSION

Patients using semaglutide and other glucagon-like peptide 1 agonists for weight management may require specific precautions during induction of anesthesia to prevent pulmonary aspiration of gastric contents.

Comparative preoperative sonological assessment of gastric contents in patients with chronic kidney disease versus those with normal renal function - A prospective observational study

Background and Aims

Though the role of fasting preoperative gastric ultrasound has been validated in different patient populations, namely, obese, pregnant and diabetics, it has not been explored in patients with chronic kidney disease (CKD). This prospective, observational study compared the fasting sonological assessment of gastric contents in patients with CKD versus those with normal renal function scheduled for elective surgery.

Methods

After ethical approval and trial registration were obtained, preoperative gastric ultrasound was done in 115 CKD patients and 115 with normal renal function. Qualitative and quantitative assessment of residual gastric volume was done. Also, the patients were administered the Porto Alegre Dyspeptic Symptoms Questionnaire (PADYQ) to evaluate gastroparesis objectively. The researcher was not blinded to the patient groups. Data analyses were done using the Statistical Package for Social Sciences (SPSS) for Windows software (version 22.0).

Results

Gastric volumes exceeding 1.5 ml/kg or particulate or solid contents were found in 57 patients with CKD and 36 patients with normal renal function (P = 0.004). The PADYQ scores were 6.54 ± 8.49 for CKD and 2.15 ± 5.71 for normal renal function (P < 0.0001) groups. CKD patients had a higher age (P < 0.001), lower body mass index (P = 0.005) and higher incidence of diabetes mellitus (P < 0.001). There were no incidents of gastric aspiration.

Conclusion

Renal dysfunction contributes to delayed gastric emptying. PADYQ can also help identify those at high risk of gastroparesis. Combining the questionnaire and preoperative gastric ultrasound must be considered in these patients to ensure optimum safety.

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.

An analysis of enhanced recovery pathways for bariatric surgery-preoperative fasting, carbohydrate loading, and aspiration risk: a position statement from the International Society for the Perioperative Care of Patients with Obesity

Enhanced recovery pathways (ERPs) and recommendations have become widely accepted for metabolic and bariatric surgery, including recommendations for preoperative carbohydrate loading and duration of fasting status. There is still a lack of consensus regarding such protocols and the underlying issues of gastric emptying time, resting gastric volume and pH, and risk of aspiration in patients with severe obesity and in patients undergoing bariatric surgery. The goal of this position statement by the International Society for the Perioperative Care of Patients with Obesity (ISPCOP) is to provide an analysis of available data on preoperative fasting and loading with oral complex clear carbohydrate drinks as well its potential effects on perioperative risk of aspiration in the context of Enhanced Recovery Pathways for Metabolic and Bariatric Surgery (ERAMBS).

Ultrasound measurements for evaluation of changes in upper airway during anaesthesia induction and prediction difficult laryngoscopy: a prospective observational study

Upper airway collapsibility after anaesthesia induction may be associated with unpredictable difficult airway. However, most works on airway anatomy are tended to morphological description before anaesthesia. This study aimed to evaluate the changes of upper airway after anaesthesia induction and using pre-anesthetic ultrasound measurements to predict Difficult Laryngoscopy (DL). We included 104 eligible subjects with complete data, who were performed tracheal intubations under general anaesthesia in the study. The upper airway changes before and after anaesthesia induction were determined by seven neck ultrasound measurements, included as follow: (1) Distance from skin to under surface of Tongue (DT), (2) Thickness of the thickest part of Tongue body (TT), (3) Hyoid Mental Distance (HMD), (4) Depth of Hyoid (DH), (5) Width of Hyoid (WH), (6) Distance from Skin to Epiglottis (DSE), (7) Depth of the anterior combination of the Vocal Cords (DVC). DL was evaluated with Cormack-Lehane (CL). Data regarding HMD [from 45.3 (42.4-48.5) to 41.1 (38.5-44.9) mm], DH [from 8.7 (6.6-10.9) to 7.0 (5.3-9.1) mm], DSE [from 20.1 (16.6-22.5) to 19.5 (16.5-21.6) mm] and the DVC [from 7.1 (5.7-8.3) to 6.8 (5.7-7.9) mm] were decreased (P < 0.05), while the DT [from 15.9 (13.1-18.4) to 17.4 (14.5-19.8) mm] was increased (P > 0.05) after anaesthesia induction. Additionally, when cut-off value of DSE was 21.25 mm before anaesthesia, it may be better predicted to DL [sensitivity 80.0% (95% CI: 60.7-91.6%) and specificity 83.8% (95% CI: 73.0-91.0%)]. The upper airway after induction showed the propensity of collapsibility by ultrasound measurements. Compared with other indicators, the DSE assessed by ultrasound might be considered to a valuable predictor of DL.Trial registration: The study was registered in ClinicalTrials.gov on 23th Jan 2019, ChiCTR1900021123.

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.

Head to toe ultrasound: a narrative review of experts’ recommendations of methodological approaches

Critical care ultrasonography (US) is widely used by intensivists managing critically ill patients to accurately and rapidly assess different clinical scenarios, which include pneumothorax, pleural effusion, pulmonary edema, hydronephrosis, hemoperitoneum, and deep vein thrombosis. Basic and advanced critical care ultrasonographic skills are routinely used to supplement physical examination of critically ill patients, to determine the etiology of critical illness and to guide subsequent therapy. European guidelines now recommend the use of US for a number of practical procedures commonly performed in critical care. Full training and competence acquisition are essential before significant therapeutic decisions are made based on the US assessment. However, there are no universally accepted learning pathways and methodological standards for the acquisition of these skills.

Therefore, in this review, we aim to provide a methodological approach of the head to toe ultrasonographic evaluation of critically ill patients considering different districts and clinical applications.

Pre-induction Ultrasonographic Evaluation of Gastric Residual Volume in Elective Gastrointestinal Cancer Surgeries

Pulmonary aspiration of gastric contents during elective surgery remains a major cause of airway-related mortality and morbidity. The preoperative fasting times for solids and liquids have been standardized across various anesthesia society guidelines. Enhanced Recovery After Surgery (ERAS) guidelines now advocate liberal clear fluid intake with carbohydrate loading up to 2 h preoperatively. The aim of the study was to assess whether practicing both ASA fasting guidelines and ERAS protocol makes the patients prone to a full stomach. The supine position standard curvilinear ultrasound probe (2-5 MHz) with Sonosite M-Turbo ©system was used to obtain the images. Gastric residual volume (GRV) was derived from the cross-sectional area (CSA) using the Perlas and colleagues model. A total of 102 patients were recruited and analyzed. The mean age and BMI were 50.65 years ± 13.35 years and 22.23 kg/m² ± 3.7 kg/m², respectively. A total of four patients (3.92%) had gastric volume > 1.5 ml/kg; out of these four patients, three were female and one was male. We did not observe any case of pulmonary aspiration in any of our patients. In conclusion, even though for elective surgeries, the current fasting guidelines are adequate, these findings cannot be extrapolated to patients with risk factors for high gastric residual volume where further studies need to be performed.

Evaluation of gastric contents using ultrasound in full-term pregnant women fasted for 8 h: a prospective observational study

BACKGROUND

We aimed to evaluate the gastric volume and contents after an 8-h fasting period in full-term, non-laboring, pregnant women following a standardized meal.

METHODS

In this prospective observational study, we included full-term pregnant women scheduled for elective cesarean delivery. The participants were instructed to fast after a standardized meal (apple juice, bread, and cheese). Participants were scanned in the semi-recumbent and right-lateral positions 8 h after the standardized meal. The primary outcome was the proportion of patients with gastric volume > 1.5 mL kg^-1 calculated by two equations. Secondary outcomes included the antral cross-sectional area and gastric volume. Data are expressed as frequency (%, 95% confidence interval [CI]), mean ± standard deviation (95% CI of the mean), or median (quartiles) as appropriate.

RESULTS

Forty-one women were available for the final analysis. For the primary outcome, one participant (2.4%, 95% CI of 0.06 to 12.8%) had gastric volume > 1.5 mL kg^-1, and none had solids in the antrum. For the secondary outcomes, the mean (95% CI of the mean) of the antral cross-sectional area was 2.11 ± 0.72 (1.88 to 2.34) cm² and 4.08 ± 1.80 (3.51 to 4.65) cm² during the semi-recumbent and right-lateral position, respectively. The median (quartiles) gastric volume was 0.53 (0.32, 0.66) mL kg^-1 and 0.33 (0.13, 0.52) mL kg^-1 as estimated by Perlas et al. and Roukhomovsky et al. equations, respectively.

CONCLUSION

After 8-h fasting following a standardized meal, full-term pregnant non-laboring women are less likely to have a high residual gastric volume.

The effects of diabetes mellitus on gastric emptying: A prospective observational cohort study

STUDY OBJECTIVE

Our goal was to evaluate the effect of diabetic severity and duration on preoperative residual gastric volume. Secondarily we compared ultrasonic estimates of residual gastric volume with actual volume determined by aspiration during endoscopy.

DESIGN

This was a prospective, observational cohort study that included adults with a history of diabetes mellitus and/or opioid use scheduled for gastrointestinal endoscopic procedures.

SETTING

Endoscopy unit at Cleveland Clinic Main Campus from 2017 to 2019.

PARTICIPANT

Adults scheduled for upper endoscopy with or without colonoscopy.

INTERVENTION AND MEASUREMENTS

Residual gastric volumes were primarily determined by aspiration during endoscopy, and secondarily estimated with ultrasound. We evaluated the relationship between gastric residual volume and preoperative HBA1C concentration and duration of diabetes. Secondarily, we conducted an agreement analysis between the two gastric volume measurement techniques.

MAIN RESULTS

Among 145 enrolled patients, 131 were diabetic and 17 were chronic opioid users. Among 131 diabetic patients, the mean ± SD HbA1c was 7.2 ± 1.5% and the median (Q1, Q3) duration of diabetes was 8.5 (3, 15) years. Neither HbA1c nor duration of diabetes was associated with residual gastric volume. The adjusted mean ratio of residual gastric volume was 1.07 (98.3% CI: 0.89, 1.28; P = 0.38) for 1% increase in HbA1c concentration, and 0.84 (98.3% CI: 0.63, 1.14; P = 0.17) for each 10-year increase induration of diabetes. The median [Q1-Q3] absolute difference between gastric ultrasound measurement and endoscopic measurement was 25 [15, 65] ml.

CONCLUSIONS

In this prospective observational cohort study, neither the duration nor severity of diabetes influenced preoperative residual gastric volume. Gastric ultrasound can help identify patients who have excessive residual volumes despite overnight fasting.

Utility of gastric ultrasound in evaluating nil per os status in a child

Although rare, the aspiration of gastric contents can lead to significant morbidity or even mortality in pediatric patients receiving anesthetic care. For elective cases, routine preoperative practices include the use of standard nil per os times to decrease the risk of aspiration. However, patients may fail to adhere to provided NPO guidelines or other patient factors may impact the efficacy of standard NPO times. Gastric point-of-care ultrasound provides information on the volume and quality of gastric contents and may allow improved patient management strategies. We present a 4-year-old patient who presented for bilateral myringotomy with tympanostomy tube insertion, who was found to have evidence of a full stomach during preoperative gastric ultrasound examination. The use of preoperative gastric point-of-care ultrasound in evaluating stomach contents and confirming NPO times is reviewed and its application to perioperative practice discussed.