NCT05674643 · Boston Children's Hospital
Gastric Assessment of Pediatric Patients Undergoing Surgery
What this study is about
The goal of this pilot forward-looking group of participants 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.
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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.
Interventions
DIAGNOSTIC_TEST
Gastric Ultrasound Baseline Scans
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.
DIAGNOSTIC_TEST
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
Gastric Ultrasound Serial Scans
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.
Primary outcome measures
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Perioperative patients with ASA classification 1-2
- Ages: 2 years- less than 18 years
- Locations: Longwood and Waltham campuses of Boston Childrens Hospital
Exclusion criteria
- 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)
Where
- Boston, Massachusetts
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
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Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
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Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
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Data: ClinicalTrials.gov · synced Apr 2, 2026 · Source of record for eligibility and locations