FastingNCT05674643
Gastric Assessment of Pediatric Patients Undergoing Surgery
An observational study of Fasting and Delayed Gastric Emptying, run by Boston Children's Hospital at 1 site in United States.
Trial summary
The goal of this pilot prospective cohort study is to examine the reproducibility of gastric volume and emptying as measured by gastric ultrasound and its correlation to a gold-standard test for gastric emptying in the perioperative period in pediatric patients. Read more about this study
- Who is it for?
- Ages 2 to 18 yearsHealthy volunteers can take part
- Conditions the study is for
- Fasting, Delayed Gastric Emptying, Aspiration Pneumonia
- What is being tested?
- Gastric Ultrasound Baseline Scans, Acetaminophen Absorption Test (AAT) and Gastric Ultrasound Serial Scans
- Type of treatment
- Injection or infusion
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Feb 2023to 31 Dec 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 2 to 18 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Study population: This study is enrolling healthy pediatric subjects ages 2 through 17 years of age who are undergoing surgery with anesthesia at Boston Children's Hospital.
Who may be able to join
- Perioperative patients with ASA classification 1-2
- Ages: 2 years- less than 18 years
- Locations: Longwood and Waltham campuses of Boston Childrens Hospital
Who cannot join
- History of gastrointestinal surgery
- Gastrostomy
- Known GI dysmotility (cohort 1 only)
- Acetaminophen allergy (cohort 1 only)
- Liver or renal dysfunction- pre-diagnosed or, if available, when serum biomarkers are 2 standard deviations above the highest value considered normal for age. (cohort 1 only)
- Consumption of acetaminophen in the 4 hours prior (cohort 1 only)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Boston Children's Hospital
Boston, Massachusetts, 02115
Jocelyn Booth, BSN, 18572184585, jocelyn.booth@childrens.harvard.edu
Rachel Bernier, MPH, 18572185348, rachel.bernier@childrens.harvard.edu
About this study
The goal of this pilot prospective cohort study is to examine the reproducibility of gastric volume and emptying as measured by gastric ultrasound and its correlation to a gold-standard test for gastric emptying in the perioperative period in pediatric patients. The main questions it aims to answer are:
- What is the reliability (inter-rater variability between expert and novice assessors, and intra-rater variability) of a) the gastric antral cross-sectional area (CSA) and b) gastric volume using the Perlas US qualitative grading assessment, measured by using an ultrasound device in pediatric patients undergoing general anesthesia for elective surgery?
- What is the correlation between ultrasound assessment of gastric emptying by the antral-CSA and gastric emptying determined by the acetaminophen absorption test (AAT), the gold standard?
Read more
The study will include two cohorts. Cohort assignment will be based on age and anesthesia induction plan. Subjects >7yrs of age and expected to get an IV induction will be assigned to Cohort #1. Subjects <7yrs of age and not expected to get an IV induction will be assigned to Cohort #2.
- Cohort 1 will include abdominal ultrasound for gastric assessment AND the acetaminophen absorption test which includes administering enteral acetaminophen (tylenol) with 6 oz of water and drawing of blood samples through a peripheral intravenous line.
- Cohort 2 will include subjects for whom a peripheral intravenous line placement is not part of routine pre-operative care. Procedures for Cohort 2 will include abdominal ultrasound only in the pre-op area (no tylenol). This cohort is included to examine the reliability of measurements across age groups.
- Conditions
- Fasting, Delayed Gastric Emptying, Aspiration Pneumonia, Respiratory Aspiration of Gastric Content
- Being tested
- Gastric Ultrasound Baseline Scans, Acetaminophen Absorption Test (AAT), Gastric Ultrasound Serial Scans
- Keywords
- gastric ultrasound, pre-operative fasting
- Medical subject headings
- Fasting, Gastroparesis, Pneumonia, Aspiration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Gastric Ultrasound Baseline ScansDiagnostic test
The patient's abdomen will be scanned using the ultrasound device by an expert scanner and novice scanner for baseline assessment of the antral CSA and gastric volume using Perlas US qualitative grading assessment.
Acetaminophen Absorption Test (AAT)Diagnostic test
Prior to starting the AAT, a baseline plasma acetaminophen level (250 microliters) will be obtained from the intravenous catheter. The subject will then be given 12.5 mg/kg or max 650mg of single batch 32mg/mL acetaminophen followed by 6oz of water PO. Up to 3 additional small volume blood samples will be drawn for acetaminophen levels.
These additional blood samples (250 microliters each) will be obtained to measure acetaminophen plasma levels at the following goal intervals after acetaminophen administration.T1:10-20 mins, T2:35-45 mins, T3: 60mins. At the time of each lab draw gastric ultrasound will be assessed by the expert scanner to correlate gastric ultrasound with the acetaminophen absorption test as a gold-standard of gastric emptying.
Gastric Ultrasound Serial ScansDiagnostic test
Cohort 1 will have multiple scans as part of assessing gastric emptying. These sequential scans after the baseline assessment will be done in line with the Acetaminophen Absorption Test timeline (T1:10-20 mins, T2:35-45 mins, T3: 60mins) and will be performed by an expert scanner only.
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1 - ultrasound and acetaminophen | Cohort 1 will include subjects who have a peripheral intravenous line placed in the pre-op area per routine care. This cohort is on average age 7 years and older. Procedures for cohort 1 will include: (a) gastric US measurement of the antral CSA and gastric volume using the Perlas US qualitative grading assessment by an expert and a novice operator to determine the inter-rater class reliability and repeat measurements by each operator to assess the intra-rater reliability (Aim 1), and (b) serial abdominal ultrasounds for gastric assessment and the acetaminophen absorption test to determine the correlation between gastric US and a gold-standard for gastric emptying (Aim 2). The acetaminophen absorption test requires administering a single weight-based enteral dose of acetaminophen with 6 oz of water and drawing of blood samples through a peripheral intravenous line. Receives: Diagnostic Test: Gastric Ultrasound Baseline Scans; Diagnostic Test: Acetaminophen Absorption Test (AAT); Diagnostic Test: Gastric Ultrasound Serial Scans | |
| Cohort 2 - ultrasound only | Cohort 2 will include subjects for whom a peripheral intravenous line placement is not part of routine pre-operative care. Average age for cohort 2 is age less than 7 years old. Procedures for Cohort 2 will include a gastric US measurement of the antral CSA and gastric volume using Perlas US qualitative grading assessment by an expert and a novice operator to determine the inter-rater class reliability and repeat measurements by each operator for the intra-rater reliability (Aim 1). This cohort is included to examine the reliability of measurements across age groups. Receives: Diagnostic Test: Gastric Ultrasound Baseline Scans |
What is being measured
The primary outcome is the main question the study is designed to answer.
Inter-rater reliability
Measured using the following quantitative and qualitative ultrasound assessments between a novice and an expert gastric ultrasound operator:
- Qualitative using the previously published Perlas' US qualitative grading assessment
- Grade 0- no contents visualized in supine and lateral position
- Grade 1- contents visualized in the lateral decubitus position (RLD) only
- Grade 2- contents visualized in the supine and RLD.
- Quantitative assessment using the cross-sectional area as published by Spencer AO et al.
- Measurement of the CSA: longitudinal diameter (D1), and the antero-posterior diameter (D2) in both supine and RLD. Then these will be used to calculate the cross-sectional area (CSA) = (π*D1*D2)/4.
- Quantitative assessment using the cross-sectional area as published by Spencer AO et al.
- Measurement of the CSA: longitudinal diameter (D1), and the antero-posterior diameter (D2) in both supine and RLD. Then these will be used to calculate the cross-sectional area (CSA)
Measured: 1 year
Intra-rater reliability
Measured using the following quantitative and qualitative ultrasound assessments between a novice and an expert gastric ultrasound operator:
- Qualitative using the previously published Perlas' US qualitative grading assessment
- Grade 0- no contents visualized in supine and lateral position
- Grade 1- contents visualized in the lateral decubitus position (RLD) only
- Grade 2- contents visualized in the supine and RLD.
- Quantitative assessment using the cross-sectional area as published by Spencer AO et al.
- Measurement of the CSA: longitudinal diameter (D1), and the antero-posterior diameter (D2) in both supine and RLD. Then these will be used to calculate the cross-sectional area (CSA) = (π*D1*D2)/4.
Measured: 1 year
Gastric Emptying
Outcome will be gastric emptying assessed by the change in antral CSA (measured in cm2) over time after acetaminophen administration, and this will be correlated to gastric emptying over the same period of time by the acetaminophen absorption test PK parameter, AUC60 mcg*min/mL. As such, each patient will act as their own control. Correlation analysis will be applied to examine the performance of CSA measurements overtime using gastric ultrasound to determine gastric emptying compared to the acetaminophen absorption test as the gold standard.
Measured: 1 year
Secondary outcomes (1)
Post-anesthetic outcomes
Fasting times have been correlated to post-anesthetic outcomes such as post-operative nausea/ vomiting, and discomfort, and it is known that some patients fast longer than required by their clinical team, which can result in adverse effects. Reported fasting times for all patients and confirmatory assessment by gastric US will be examined along with data pulled from the medical record about post-operative nausea/ vomiting, post-operative discomfort, satisfaction, and whether the patient met their expected post-operative trajectory or not (e.g. unplanned admission).
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Jan 2023
- Study start1 Feb 2023
- Primary completion31 Dec 2028 (estimated)
- Study completion31 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for FastingStudies of the same condition, open and under way.
- More trials run by Boston Children's HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Boston Children's Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Walid Alrayashi, Boston Children's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05674643
- Sponsor's protocol ID
- IRB-P00040829
- Status last verified
- Mar 2026
- First submitted
- 18 Oct 2022
- Last updated
- 2 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Spencer AO, Walker AM, Yeung AK, Lardner DR, Yee K, Mulvey JM, Perlas A. Ultrasound assessment of gastric volume in the fasted pediatric patient undergoing upper gastrointestinal endoscopy: development of a predictive model using endoscopically suctioned volumes. Paediatr Anaesth. 2015 Mar;25(3):301-8. doi: 10.1111/pan.12581. Epub 2014 Dec 11.
PubMed 25495405
Study at a glance
From the registry record, last updated by the sponsor on 2 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Gastric Assessment of Pediatric Patients Undergoing Surgery
- ClinicalTrials.gov ID
- NCT05674643
- Acronym / sponsor ID
- IRB-P00040829
- Conditions
- Fasting, Delayed Gastric Emptying, Aspiration Pneumonia, Respiratory Aspiration of Gastric Content
- Keywords
- gastric ultrasound, pre-operative fasting
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Boston Children's HospitalUniversity, hospital or other
- Study start
- 1 Feb 2023 (actual)
- Primary completion
- 31 Dec 2028 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 6 Jan 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this pilot prospective cohort study is to examine the reproducibility of gastric volume and emptying as measured by gastric ultrasound and its correlation to a gold-standard test for gastric emptying in the perioperative period in pediatric patients. The main questions it aims to answer are:
- What is the reliability (inter-rater variability between expert and novice assessors, and intra-rater variability) of a) the gastric antral cross-sectional area (CSA) and b) gastric volume using the Perlas US qualitative grading assessment, measured by using an ultrasound device in pediatric patients undergoing general anesthesia for elective surgery?
- What is the correlation between ultrasound assessment of gastric emptying by the antral-CSA and gastric emptying determined by the acetaminophen absorption test (AAT), the gold standard?
The study will include two cohorts. Cohort assignment will be based on age and anesthesia induction plan. Subjects >7yrs of age and expected to get an IV induction will be assigned to Cohort #1. Subjects <7yrs of age and not expected to get an IV induction will be assigned to Cohort #2.
- Cohort 1 will include abdominal ultrasound for gastric assessment AND the acetaminophen absorption test which includes administering enteral acetaminophen (tylenol) with 6 oz of water and drawing of blood samples through a peripheral intravenous line.
- Cohort 2 will include subjects for whom a peripheral intravenous line placement is not part of routine pre-operative care. Procedures for Cohort 2 will include abdominal ultrasound only in the pre-op area (no tylenol). This cohort is included to examine the reliability of measurements across age groups.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Cohort 1 - ultrasound and acetaminophen | – | Diagnostic Test: Gastric Ultrasound Baseline Scans, Diagnostic Test: Acetaminophen Absorption Test (AAT), Diagnostic Test: Gastric Ultrasound Serial ScansCohort 1 will include subjects who have a peripheral intravenous line placed in the pre-op area per routine care. This cohort is on average age 7 years and older. Procedures for cohort 1 will include: (a) gastric US measurement of the antral CSA and gastric volume using the Perlas US qualitative grading assessment by an expert and a novice operator to determine the inter-rater class reliability and repeat measurements by each operator to assess the intra-rater reliability (Aim 1), and (b) serial abdominal ultrasounds for gastric assessment and the acetaminophen absorption test to determine the correlation between gastric US and a gold-standard for gastric emptying (Aim 2). The acetaminophen absorption test requires administering a single weight-based enteral dose of acetaminophen with 6 oz of water and drawing of blood samples through a peripheral intravenous line. |
| Cohort 2 - ultrasound only | – | Diagnostic Test: Gastric Ultrasound Baseline ScansCohort 2 will include subjects for whom a peripheral intravenous line placement is not part of routine pre-operative care. Average age for cohort 2 is age less than 7 years old. Procedures for Cohort 2 will include a gastric US measurement of the antral CSA and gastric volume using Perlas US qualitative grading assessment by an expert and a novice operator to determine the inter-rater class reliability and repeat measurements by each operator for the intra-rater reliability (Aim 1). This cohort is included to examine the reliability of measurements across age groups. |
Who may qualify
- Ages
- 2 to 18 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
- Study population
- This study is enrolling healthy pediatric subjects ages 2 through 17 years of age who are undergoing surgery with anesthesia at Boston Children's Hospital.
Key inclusion criteria (3 listed)
- Perioperative patients with ASA classification 1-2
- Ages: 2 years- less than 18 years
- Locations: Longwood and Waltham campuses of Boston Childrens Hospital
Key exclusion criteria (6 listed)
- History of gastrointestinal surgery
- Gastrostomy
- Known GI dysmotility (cohort 1 only)
- Acetaminophen allergy (cohort 1 only)
- Liver or renal dysfunction- pre-diagnosed or, if available, when serum biomarkers are 2 standard deviations above the highest value considered normal for age. (cohort 1 only)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Gastric Ultrasound Baseline ScansThe patient's abdomen will be scanned using the ultrasound device by an expert scanner and novice scanner for baseline assessment of the antral CSA and gastric volume using Perlas US qualitative grading assessment. | Diagnostic test | Cohort 1 - ultrasound and acetaminophen, Cohort 2 - ultrasound only |
| Acetaminophen Absorption Test (AAT)Prior to starting the AAT, a baseline plasma acetaminophen level (250 microliters) will be obtained from the intravenous catheter. The subject will then be given 12.5 mg/kg or max 650mg of single batch 32mg/mL acetaminophen followed by 6oz of water PO. Up to 3 additional small volume blood samples will be drawn for acetaminophen levels. These additional blood samples (250 microliters each) will be obtained to measure acetaminophen plasma levels at the following goal intervals after acetaminophen administration.T1:10-20 mins, T2:35-45 mins, T3: 60mins. At the time of each lab draw gastric ultrasound will be assessed by the expert scanner to correlate gastric ultrasound with the acetaminophen absorption test as a gold-standard of gastric emptying. | Diagnostic test | Cohort 1 - ultrasound and acetaminophen |
| Gastric Ultrasound Serial ScansCohort 1 will have multiple scans as part of assessing gastric emptying. These sequential scans after the baseline assessment will be done in line with the Acetaminophen Absorption Test timeline (T1:10-20 mins, T2:35-45 mins, T3: 60mins) and will be performed by an expert scanner only. | Diagnostic test | Cohort 1 - ultrasound and acetaminophen |
Primary outcome
Inter-rater reliability
Time frame: 1 year
Measured using the following quantitative and qualitative ultrasound assessments between a novice and an expert gastric ultrasound operator: * Qualitative using the previously published Perlas' US qualitative grading assessment * Grade 0- no contents visualized in supine and lateral position * Grade 1- contents visualized in the lateral decubitus position (RLD) only * Grade 2- contents visualized in the supine and RLD. * Quantitative assessment using the cross-sectional area as published by Spencer AO et al. * Measurement of the CSA: longitudinal diameter (D1), and the antero-posterior diameter (D2) in both supine and RLD. Then these will be used to calculate the cross-sectional area (CSA) = (π*D1*D2)/4. * Quantitative assessment using the cross-sectional area as published by Spencer AO et al. * Measurement of the CSA: longitudinal diameter (D1), and the antero-posterior diameter (D2) in both supine and RLD. Then these will be used to calculate the cross-sectional area (CSA)
Intra-rater reliability
Time frame: 1 year
Measured using the following quantitative and qualitative ultrasound assessments between a novice and an expert gastric ultrasound operator: * Qualitative using the previously published Perlas' US qualitative grading assessment * Grade 0- no contents visualized in supine and lateral position * Grade 1- contents visualized in the lateral decubitus position (RLD) only * Grade 2- contents visualized in the supine and RLD. * Quantitative assessment using the cross-sectional area as published by Spencer AO et al. * Measurement of the CSA: longitudinal diameter (D1), and the antero-posterior diameter (D2) in both supine and RLD. Then these will be used to calculate the cross-sectional area (CSA) = (π*D1*D2)/4.
Gastric Emptying
Time frame: 1 year
Outcome will be gastric emptying assessed by the change in antral CSA (measured in cm2) over time after acetaminophen administration, and this will be correlated to gastric emptying over the same period of time by the acetaminophen absorption test PK parameter, AUC60 mcg*min/mL. As such, each patient will act as their own control. Correlation analysis will be applied to examine the performance of CSA measurements overtime using gastric ultrasound to determine gastric emptying compared to the acetaminophen absorption test as the gold standard.
1 secondary outcome
Post-anesthetic outcomes
Time frame: 1 year
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Apr 2026.
- Results publication: PubMed 25495405Spencer AO, Walker AM, Yeung AK, Lardner DR, Yee K, Mulvey JM, Perlas A. Ultrasound assessment of gastric volume in the fasted pediatric patient undergoing upper gastrointestinal endoscopy: development of a predictive model using endoscopically suctioned volumes. Paediatr Anaesth. 2015 Mar;25(3):301-8. doi: 10.1111/pan.12581. Epub 2014 Dec 11.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Fasting and Delayed Gastric Emptying, run by Boston Children's Hospital at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jocelyn Booth, BSN (857-218-4585, jocelyn.booth@childrens.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Inter-rater reliability (time frame: 1 year). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05674643, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Apr 2026; AzTrials last refreshed its copy on 7 Nov 2026.