Respiratory Aspiration of Gastric Contents

Examining the effectiveness of cricoid pressure using ultrasound imaging. Pulmonary aspiration of gastric contents during tracheal intubation, although rare in pediatrics, is a potentially catastrophic complication of anesthesia. Cricoid pressure is applied during rapid sequence induction to occlude the esophagus and prevent aspiration of gastric contents. Accumulating evidence in adults suggests that cricoid pressure often is not effective, either because the esophagus normally lies lateral to the cricoid cartilage, or because downward pressure on the cricoid cartilage laterally displaces (rather than compresses) the esophagus. The investigator proposes to examine the effectiveness of cricoid pressure in children in the peri-operative setting using non-invasive ultrasound imaging. Using this approach, the investigator will investigate the normal anatomical relationship of the esophagus and the cricoid cartilage, as well as how cricoid pressures influences this relationship. Further, the investigator will examine whether alternatives to downward cricoid pressure, such as laterally directed pressure, are more effective at occluding the esophagus.

The aim of this randomised controlled trial is to determine the effect of a 24-hour liquid diet compared to standard fasting guidelines on the proportion of participants who present with increased residual gastric contents during their study visit. It also aim to determine the effect of a 24-hour liquid diet compared to standard fasting guidelines on:
* Solid content, defined as a grade 3 antrum.
* Patient-reported outcome measures (PROMs), including thirst, hunger, nausea, fatigue, and anxiety.
* Compliance measures, including adherence with the intervention, time since last oral intake of solid foods, and time since last oral intake of clear liquids.
We will enrol adults who are currently using any once-weekly glucagon-like peptide-1 receptor agonist (GLP-1RA) medication. Participants will be allocated in a 1:1 ratio to follow a 24-hour clear liquid diet or standard fasting guidelines prior to attending a study visit where participants will undergo a blinded gastric ultrasound assessment.

The risk of pulmonary aspiration of gastric contents remains a significant risk during anesthesia, especially 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 prospective observational study aimed to (1) qualitatively and quantitatively describe the sonographic appearance of the gastric antrum in fasted high-risk pregnant women during the third trimester and (2) evaluate the relationship between demographic and clinical variables and the gastric antral cross-sectional area (CSA).