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A gastric ultrasound is performed to evaluate stomach contents before induction of anesthesia. This information allows practitioners to manage the risk of aspiration of gastric contents proactively. Information obtained from gastric ultrasound enables anesthesia providers to determine the optimal timing of procedures, type of anesthesia, and airway management technique. This activity reviews gastric ultrasound and highlights the role of the interprofessional team in evaluating gastric contents for patients undergoing procedures requiring sedation or anesthesia. Objectives: Assess the anatomy of the stomach and adjacent organs. Identify the necessary equipment and the proper technique to perform a gastric ultrasound exam. Evaluate the imaging findings associated with an empty stomach, liquid in the stomach, and solid food in the stomach. Access free multiple choice questions on this topic.

Aspiration of gastric contents is a common cause of perioperative morbidity and mortality. Aspiration can lead to hypoxia, bronchospasm, pneumonitis, pneumonia, acute respiratory distress syndrome, and death. Aspiration pneumonia among surgical patients is associated with a 4.0-fold increased risk of intensive care admission, a 9-day increase in length of stay, and a 7.6-fold increased risk of in-hospital mortality.[1] The presence of food or liquids in the stomach before the induction of anesthesia is 1 of the greatest risk factors for perioperative pulmonary aspiration.[2][3][4] The risk of gastric aspiration can be reduced by fasting before planned procedures. The American Society for Anesthesiologists Practice Guidelines for Preoperative Fasting is intended to reduce gastric aspiration risk. These guidelines recommend that healthy patients fast for at least 2 hours for clear liquids, 4 hours for human breastmilk, 6 hours for non-human breastmilk, infant formula, or light meals, and 8 hours for fried foods, fatty foods, and meat.[5][6] No clear guidance on appropriate fasting periods is provided for patients at increased risk of delayed gastric emptying or pulmonary aspiration, such as those with diabetes mellitus, gastroesophageal reflux disease, morbid obesity pregnancy, or recent opioid use. Providers also face the challenge of unclear NPO status, as seen in poor historians, patients with dementia, language barriers, and non-compliant patients.[7][8][9] Gastric ultrasound is a simple, fast, non-invasive bedside diagnostic test that provides a qualitative and quantitative assessment of gastric contents.[10][2] Gastric ultrasound allows anesthesia providers to differentiate between the full and empty stomach, determine the consistency of gastric contents (solids, thick liquids, clear liquids), and estimate the volume of gastric fluids. See Image. Gastric Ultrasound, Assessment of Gastric Contents. This information determines the most appropriate timing for elective procedures, anesthetic choice, and airway management approach.[11]

Gastric ultrasound is a useful diagnostic exam because it can reduce the risk of pulmonary aspiration of gastric contents. However, risk reduction requires effective communication and collaboration between all clinical members of each patient's care team. Surgical schedulers must ensure that patients receive instructions regarding appropriate fasting before surgery. On the day of a procedure, preoperative nurses should assess fasting status during the preoperative interview. The responsible provider (nurse practitioner, physician assistant, or physician) should ensure appropriate diet orders are placed the evening before a scheduled surgery for surgical inpatients. The anesthesiologist or nurse anesthetist is ultimately responsible for performing the final assessment and determining the most appropriate method for reducing the risk of aspiration. However, gastric ultrasound can be performed and interpreted by any qualified clinician.