Ultrasound Assessment of Gastric Content and Gastric Volume Before Crash Induction for Appendectomy

Performing anesthetic induction for appendicectomy has two main risks : first aspiraion of gastric content causing pneumonia. Otherwise, anaphylactic risk to drugs used during anesthetic induction. Indeed, the guidelines recommend an anesthetic induction protocol qualified "full stomach" whatever the patient and the preoperative fasting period are. This protocol provides the use of fast-acting neuromuscular blocking agents (succinylcholine or rocuronium). However, these neuromuscular blocking agents are ten times more at allergic risk than others. Ultrasound assessment of gastric content before rapid sequence induction of anesthesia is a reproducible, non-invasive, inexpensive and quickly achievable bedside technique. Furthermore, the correlations between gastric volume and risk of a full stomach and also between the cross-section antral area (CSA) and the risk of a full stomach have been validated on several patient cohorts. We formulate the hypothesis that the achievement of a gastric ultrasound before anesthetic induction for appendectomy could allow to identify "full stomach" patients who actually justify rapid sequence induction of anesthesia with exposure to fast-acting neuromuscular blocking agents that implies.

Primary endpoint is to determine te percentage of patients who have a gastric content before appendectomy. Secondary endpoint is to determine the incidenc of aspiration pneumonia and anaphylactic shock. Another secondary endpoint is to determine the percentage of patient with gastric content with the antral grading system (Perlas method) and to evaluate the concordance between this methode and the cross-section antral area.