Gastric Sonography in the Fasted Term Pregnant Patient for Elective Cesarean Delivery

Study Overview
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Brief Summary
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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. In pregnant patients scheduled for elective surgery, standard preoperative guidelines apply as the general non-pregnant surgical population (8-hour fasting of solid food and 2-hour fasting of clear fluids). A bedside ultrasound assessment of the status of the gastric content and volume would be of great value for the clinician. This technique has recently been shown very promising in fasted non-pregnant patients scheduled for elective surgery. Therefore, it is important to study its feasibility in the pregnant population scheduled for elective Cesarean Delivery. The investigators hypothesize that no residual solid contents will be found in the gastric sonography, and a small volume of gastric fluid will be observed in the antrum in both supine and right lateral decubitus.

Detailed Description
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The aim of this prospective study is to provide a qualitative and quantitative description of the sonographic appearance of the gastric antrum in fasted pregnant undergoing elective Cesarean delivery. The investigators expect that the information obtained from the systematic ultrasonographic qualitative/quantitative assessment of the gastric content may help anesthesiologist to better assess aspiration risk and guide anesthetic and airway management, particularly in pregnant women scheduled for elective Cesarean delivery after standard preoperative fasting guidelines.

Official Title
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Gastric Sonography in the Fasted Term Pregnant Patient for Elective Cesarean Delivery: a Prospective Descriptive Study

Conditions
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Respiratory Aspiration, Pregnancy

Intervention / Treatment
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* Device: Ultrasound


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Term pregnant patients<br>Term pregnant patients for scheduled elective cesarean section will be examined using a portable ultrasound machine to evaluate gastric contents. | Device: Ultrasound<br>* Two-dimensional portable ultrasound unit with a low frequency (2-5 MHz) curved array transducer<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Qualitative assessment of the antrum of the stomach | Patients will be classified as follows; Grade 0: the antrum appears empty on both supine and right lateral decubitus positions; grade 1: gastric fluid is visible on the right lateral decubitus position only, suggesting a small fluid volume; and grade 2: gastric fluid is observed in the antrum in both supine and right lateral decubitus, suggesting a larger fluid volume. | 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quantitative assessment of the antrum of the stomach | Three consecutive measures of the CSA (cross sectional area) of the antrum will be calculated via the ultrasound machine (free tracing method). | 10 minutes | 

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