Gastric Ultrasound Assessment for Patients Taking Cannabis

Assessment of Preoperative Gastric Content With Ultrasound in Patients Reporting Cannabis Use

The aim of this study is to perform bedside gastric point of care ultrasound (POCUS) exams to assess the gastric volume and content (clear liquids vs solid food) perioperatively in patients who report cannabis use.

Study Overview

• Status: Completed
• Conditions: Cannabis Use; Gastric Ultrasound; Point of Care Ultrasound
• Intervention / Treatment: Other: Gastric Ultrasound Exam

Detailed Description

Cannabis use in the United States has continued to increase in recent years, particularly in the adult population. Ease of access through legalization paired with improved public perception has contributed to the uptick in cannabis use. The subset of cannabis users suffering from pain who present for surgery pose a risk for perioperative aspiration due to the slowing of gastric motility due to cannabis use. There is currently no adapted NPO guideline to account for cannabis use.

Gastric Ultrasound (GUS) can be used as a bedside tool for assessing a patient's stomach contents and risk of aspiration. GUS can identify whether a patient's stomach is empty or filled with clear liquid, thick liquid, or solid food. The volume of the stomach can be accurately calculated if there is clear liquid content. A full stomach is categorized as those with solid or thick liquid content or with clear liquid measuring more than 1.5 ml/kg body weight. As GUS is noninvasive and does not pose risk to patients, it is a useful tool assessing aspiration risk in the preoperative period.

• Study Type: Observational
• Enrollment (Actual): 40

Contacts and Locations

Study Locations

• United States
  • New York
    • New York, New York, United States, 10021
      • Hospital for Special Surgery

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population will be comprised of patients scheduled for surgery at HSS who meet the following inclusion criteria and none of the exclusion criteria.

Description

Inclusion Criteria:

• Any patient reporting preoperative cannabis usage within 1 month of surgery date

Exclusion Criteria:

• Patient refusal to participate
• Patient with gastric bypass or any other gastric surgery
• Large hiatal hernia
• Patients with large ascites
• Patients on peritoneal dialysis
• Emergency surgery
• Pre-existing diagnosis of gastroparesis
• Parkinson's disease
• Diabetes
• Currently taking metformin
• Chronic kidney disease stage 3 or higher
• Creatinine ≥ 1.2
• Esophageal surgery
• Currently taking GLP1 agonist medication

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Cannabis Users; The cannabis user group will be comprised of patients who report preoperative cannabis use within 1 month of surgery date. This group will receive the ultrasound exam to assess stomach contents.	Other: Gastric Ultrasound Exam; A gastric ultrasound is a simple, fast, non-invasive bedside diagnostic test that provides a qualitative and quantitative assessment of gastric contents. There are no known risks of a gastric ultrasound exam.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of delayed gastric emptying	A full stomach on gastric ultrasound is defined by the presence of either solid food, thick liquids, or a specific volume (>1.5 ml/kg) of clear liquids on gastric ultrasound.	This will be measured pre-operatively in the holding room area.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Nothing by mouth (NPO) intervals	Measure the NPO interval after last solid food and liquid consumption	This will be measured pre-operatively in the holding room area.
Presence of gastric peristalsis	Gastric peristalsis will be graded as absent, slow, or normal on gastric ultrasound	This will be measured pre-operatively in the holding room area.
Time interval since last cannabis use	Measure the time from last cannabis consumption to the time the gastric ultrasound was performed	This will be measured pre-operatively in the holding room area.

Collaborators and Investigators

• Sponsor: Hospital for Special Surgery, New York
• Investigators: Principal Investigator: Oliver Panzer, MD, Hospital for Special Surgery, New York

Publications and helpful links

General Publications

• King DD, Stewart SA, Collins-Yoder A, Fleckner T, Price LL. Anesthesia for Patients Who Self-Report Cannabis (Marijuana) Use Before Esophagogastroduodenoscopy: A Retrospective Review. AANA J. 2021 Jun;89(3):205-212.
• Cammarano CA, Villaluz JE. A Reason to Rethink Fasting Guidelines? Marijuana-Induced Gastroparesis and the Implications for Aspiration Risk in the Nil Per Os (NPO) Patient: A Case Report. Am J Case Rep. 2021 Nov 29;22:e934187. doi: 10.12659/AJCR.934187.
• McCallum RW, Soykan I, Sridhar KR, Ricci DA, Lange RC, Plankey MW. Delta-9-tetrahydrocannabinol delays the gastric emptying of solid food in humans: a double-blind, randomized study. Aliment Pharmacol Ther. 1999 Jan;13(1):77-80. doi: 10.1046/j.1365-2036.1999.00441.x.
• Esfandyari T, Camilleri M, Ferber I, Burton D, Baxter K, Zinsmeister AR. Effect of a cannabinoid agonist on gastrointestinal transit and postprandial satiation in healthy human subjects: a randomized, placebo-controlled study. Neurogastroenterol Motil. 2006 Sep;18(9):831-8. doi: 10.1111/j.1365-2982.2006.00834.x.

Study record dates

Study Major Dates

• Study Start (Actual): May 9, 2025
• Primary Completion (Actual): October 13, 2025
• Study Completion (Actual): October 14, 2025

Study Registration Dates

• First Submitted: August 20, 2024
• First Submitted That Met QC Criteria: August 20, 2024
• First Posted (Actual): August 23, 2024

Study Record Updates

• Last Update Posted (Actual): December 16, 2025
• Last Update Submitted That Met QC Criteria: December 9, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: cannabis; gastric ultrasound
• Additional Relevant MeSH Terms: Mental Disorders; Substance-Related Disorders; Chemically-Induced Disorders; Marijuana Abuse
• Other Study ID Numbers: 2024-1155

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No