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Completed

NCT Number: NCT06292065

Gastric Ultrasound To Assess Gastric Contents In Patients On Semaglutide Therapy

Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1-RA) such as semaglutide (Ozempic™, Rybelsus™, Wegovy™) were first introduced as a therapeutic agent for type 2 diabetes mellitus but they are being increasingly used to target weight loss in obesity.

One of the mechanisms by which weight loss is achieved, is increased satiety and significantly delayed gastric emptying. Tachyphylaxis for this effect has been reported with chronic use of long acting GLP-1-RA (e.g. semaglutide) but this was based on the paracetamol absorption technique or 13C breath test. Recent clinical data suggests semaglutide use does increase perioperative gastric content.This creates uncertainty for anaesthetists who are, anecdotally, more frequently faced with patients who may or may not have full stomachs despite adhering to conventional fasting guidelines.

To address this issue the American Society of Anesthesiologists (ASA) has recently released guidelines in which it advises to hold GLP-1-RA for one day (if administered daily) or one week (if administered weekly).

However, these recommendations are based on sparse empirical evidence and they do not necessarily follow from the known pharmacokinetic properties of these drugs. Typically, GLP-1-RA are administered in increasing doses over several weeks until a therapeutic steady state is achieved. Meanwhile the elimination half-life of e.g. semaglutide is 7 days. This means that holding semaglutide for one day or even one week might not be enough to attenuate its therapeutic effect of delayed gastric emptying. On the other hand if semaglutide were to be held for e.g. 5 terminal half-lifes, this would mean an unpractical 5 weeks during which glycemic control may be worsened and after which semaglutide doses would have to be incrementally increased again. Besides, hyperglycaemia secondary to semaglutide cessation can also delay gastric emptying.

Further confounding the assessment of these patients there can be 'background' delayed gastric emptying in diabetic patients and more pronounced delayed gastric emptying in patients recently started on GLP-1-RA. The presence of gastro-intestinal symptoms (nausea, vomiting, dyspepsia, abdominal distension) might offer clinical information regarding increased gastric residue in this population.

Gastric ultrasound is a point-of-care clinical and research tool that has steadily gained popularity to assess gastric content in patients not compliant with fasting rules or with certain comorbidities. Clinical decisions can be made based on the visualised content (e.g. solids, fluids or nothing) or through calculation of gastric volume by measuring antral circumference. In this study the investigators will examine gastric contents in patients who are taking semaglutide and in patients who are not. The investigators will then evaluate whether there is a difference in the incidence of full stomachs and whether gastric ultrasound influenced the anaesthetic plan of the treating anaesthetist.

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Key information

Conditions

Gastroparesis Digestive System Diseases Gastrointestinal Diseases Neurologic Manifestations Paralysis Pathological Conditions, Signs and Symptoms Signs and Symptoms Stomach Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Antwerp University Hospital

Edegem, Antwerp, 2650, Belgium

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

for the semaglutide cohort are:

  • Adults (>=18 years old)
  • Semaglutide therapy for any indication (type 2 diabetes or weight loss)
  • Semaglutide therapy at any dose
  • Semaglutide therapy with any route of administration
  • Semaglutide therapy administered daily or weekly
  • Semaglutide therapy at any time since initiation
  • Elective surgery of any kind for which general anaesthesia was planned preoperatively
  • Adherence to current ASA recommendation regarding GLP-1-RA; i.e. holding semaglutide for 1 week if administered weekly or for 1 day if administered daily.
  • Adherence to current ESAIC fasting guidelines; i.e. >2 hours for liquids and >6 hours for solid foods.

Inclusion criteria

for the control cohort are:

  • Adults (>=18 years old)
  • Elective surgery of any kind for which general anaesthesia was planned preoperatively
  • Adherence to current ESAIC fasting guidelines; i.e. >2 hours for liquids and >6 hours for solid foods

Exclusion criteria

for the semaglutide cohort are:

  • Semaglutide not held in accordance with current ASA recommendation, i.e. held either longer or shorter than recommended.
  • No adherence to current ESAIC fasting guideline
  • Presence of a contra-indication to gastric ultrasound; i.e. previous gastric surgery (e.g. partial gastrectomy, gastric bypass) or hiatal hernias.
  • Presence of comorbidities associated with delayed gastric emptying: scleroderma, systemic lupus erythematosus, hypothyroidism, Parkinson disease, cerebral palsy, and multiple sclerosis.
  • Inability to assume the right lateral decubitus position
  • Initial anaesthetic plan did not involve general anaesthesia, e.g. neuraxial or locoregional cases

Exclusion criteria

for the control cohort are:

  • Semaglutide or other GLP-1-RA therapy
  • No adherence to current ESAIC fasting guideline
  • Presence of a contra-indication to gastric ultrasound; i.e. previous gastric surgery (e.g. partial gastrectomy, gastric bypass) or hiatal hernias
  • Presence of comorbidities associated with delayed gastric emptying: scleroderma, systemic lupus erythematosus, hypothyroidism, Parkinson disease, cerebral palsy, and multiple sclerosis
  • Inability to assume the right lateral decubitus position
  • Initial anaesthetic plan does not involve general anaesthesia, e.g. locoregional cases

Treatment and study plan

Point-of-care gastric ultrasound

Diagnostic Test

Using ultrasound to visualise the gastric antrum in supine position and right lateral decubitus.

Primary outcomes

  1. Prevalence of full stomach

    Time frame: Immediately preoperatively

    The prevalence of a full stomach based on gastric ultrasound (solids visible in any visualisation or calculated liquid gastric content exceeding 1.5 ml/kg of total body weight) in patients taking semaglutide compared to controls

Secondary outcomes

  1. Frequency of changes to the anaesthetic plan

    Time frame: Immediately preoperatively

    The frequency of changes to the anaesthetic plan (including postponement of surgery, change to locoregional or neuraxial technique, rapid sequence intubation, choice of airway, preoperative placement of nasogastric suctioning) after gastric ultrasound in semaglutide patients compared to controls

  2. Calculated gastric content

    Time frame: Immediately preoperatively

    The calculated gastric content (median) based on gastric ultrasound in semaglutide patients compared to controls.

  3. Prevalence of solid gastric content

    Time frame: Immediately preoperatively

    The prevalence of solid gastric content visible on gastric ultrasound in semaglutide patients compared to controls

  4. Association between fasting time for solids and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between fasting time for solids and 'full stomach' on gastric ultrasound

  5. Association between fasting time for liquids and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between fasting time for liquids and 'full stomach' on gastric ultrasound

  6. Frequency of perioperative aspiration

    Time frame: Immediately postoperatively

    The frequency of perioperative aspiration of gastric contents in semaglutide patients compared to controls

  7. Prevalence of gastric symptoms

    Time frame: Immediately preoperatively

    The prevalence of gastric symptoms (nausea, vomiting, dyspepsia, abdominal distension) in semaglutide patients compared to controls

  8. Association between nausea and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between nausea and 'full stomach' on gastric ultrasound

  9. Association between vomiting and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between vomiting and 'full stomach' on gastric ultrasound

  10. Association between dyspepsia and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between dyspepsia and 'full stomach' on gastric ultrasound

  11. Association between abdominal distension and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between abdominal distension and 'full stomach' on gastric ultrasound

  12. association between semaglutide dose and calculated gastric content

    Time frame: Immediately preoperatively

    The correlation between semaglutide dose and calculated gastric content on gastric ultrasound

  13. association between semaglutide dose and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between semaglutide dose and 'full stomach' on gastric ultrasound

  14. Association between frequency of semaglutide administration and calculated gastric content

    Time frame: Immediately preoperatively

    The correlation between frequency of semaglutide administration and calculated gastric content on gastric ultrasound

  15. Association between frequency of semaglutide administration and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between frequency of semaglutide administration and 'full stomach' on gastric ultrasound

  16. Association between duration of semaglutide therapy and calculated gastric content

    Time frame: Immediately preoperatively

    The correlation between duration of semaglutide therapy and calculated gastric content on gastric ultrasound

  17. Association between duration of semaglutide therapy at current dose and calculated gastric content

    Time frame: Immediately preoperatively

    The correlation between duration of semaglutide therapy at current dose and calculated gastric content on gastric ultrasound

  18. Association between duration of semaglutide therapy and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between duration of semaglutide therapy and 'full stomach' on gastric ultrasound

  19. Association between duration of semaglutide therapy at current dose and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between duration of semaglutide therapy at current dose and 'full stomach' on gastric ultrasound

  20. Association between duration of cessation of semaglutide and calculated gastric content

    Time frame: Immediately preoperatively

    The correlation between duration of cessation of semaglutide therapy and calculated gastric content on gastric ultrasound in patients administering semaglutide daily and weekly

  21. Association between duration of cessation of semaglutide and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between duration of cessation of semaglutide therapy and 'full stomach' on gastric ultrasound in patients administering semaglutide daily and weekly

  22. Association between preoperative blood glucose levels and calculated gastric content

    Time frame: Immediately preoperatively

    The correlation between preoperative blood glucose levels and calculated gastric content on gastric ultrasound

  23. Association between preoperative blood glucose levels and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between preoperative blood glucose levels and 'full stomach' on gastric ultrasound

  24. Association between HbA1c levels and calculated gastric content

    Time frame: Immediately preoperatively

    The correlation between HbA1c levels and calculated gastric content on gastric ultrasound

  25. Association between HbA1c levels and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between HbA1c levels and 'full stomach' on gastric ultrasound

  26. Association between time since onset of diabetes mellitus and calculated gastric content

    Time frame: Immediately preoperatively

    The correlation between time since onset of diabetes mellitus and calculated gastric content on gastric ultrasound

  27. Association between time since onset of diabetes mellitus and 'full stomach'

    Time frame: Immediately preoperatively

    The correlation between time since onset of diabetes mellitus and 'full stomach' on gastric ultrasound

Sponsors and collaborators

Lead sponsor

Nils Vlaeminck

Other

Registry information

Acronym: GUST

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Mar 4, 2024
Registry last updated
Sep 3, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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