Quantitative Ultrasound Assessment of Gastric Volume in Pregnant Women at Term

Study Overview
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Brief Summary
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Solid food or fluid residue in the stomach is always a major concern when patients need medical procedures under sedation or general anesthesia, due to the high risk of pulmonary aspiration of the stomach contents. This is especially important in emergency procedures, when a fasting period is not observed. The aspiration of the stomach contents into one's lungs can lead to serious complications (such as severe respiratory failure). Information from a bedside ultrasound assessment of the stomach may be a very useful tool to decide whether or not it's safe to proceed, cancel or delay a surgical procedure. The investigotrs hypothesize that a mathematical model can be constructed to predict clear fluid volume in the stomach of non-labouring pregnant patients, as it has been developed in healthy adult volunteers.

Detailed Description
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Food residue in the stomach of patients scheduled to have surgery is considered a major risk factor for pulmonary aspiration of gastric contents. The resulting respiratory compromise after aspiration is associated with significant morbidity and mortality. The risk of pulmonary aspiration is especially important in pregnant women, as they may often require surgery without having observed appropriate fasting. A bedside ultrasound assessment of the status of the gastric content would be of great value for the clinician. This technique has recently been shown very promising in non-pregnant patients and it is important to study its feasibility in the pregnant population. In this study, patients fast overnight and are randomized to the following groups: empty, or various volumes of fluid (50, 100, 200, 300 or 400mL of apple juice before scanning). Their gastric contents are then assessed by an anesthesiologist, using ultrasound. The investigators aim to evaluate a standardized quantitative ultrasound assessment of gastric volume in non-labouring pregnant women.

Official Title
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Quantitative Ultrasound Assessment of Gastric Volume in Pregnant Women at Term

Conditions
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Respiratory Aspiration, Pregnancy

Intervention / Treatment
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* Other: water


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Volunteer non-labouring pregnant women at term (≥ 36 weeks)- 18 years or older ASA Physical Status I-III 50-120 kg of weight 150 cm of height or taller Ability to understand the rationale of the study assessments and to provide signed informed consent Written informed consent Exclusion Criteria: Known pre-existing abnormal anatomy of the upper gastrointestinal tract History of upper GI tract surgical procedure

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: empty stomach<br>No fluid will be given to the patient prior to scanning. | |
| Experimental: 50mL<br>50mL of water will be given to the patient prior to scanning | Other: water<br>* water<br>|
| Experimental: 100mL<br>100mL of water will be given to the patient prior to scanning | Other: water<br>* water<br>|
| Experimental: 200mL<br>200mL of water will be given to the patient prior to scanning | Other: water<br>* water<br>|
| Experimental: 300mL<br>300mL of water will be given to the patient prior to scanning | Other: water<br>* water<br>|
| Experimental: 400mL<br>400mL of water will be given to the patient prior to scanning | Other: water<br>* water<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between ingested volume and CSA in antrum | The patient will ingest 0, 50, 100, 200, 300 or 400mL of apple juice, and then the cross-sectional area (CSA) will be measured. | 5-10 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pregnancy, Respiratory Aspiration, Gastric Contents, Ultrasound