Airway Bundle With Gastric Ultrasound Guidance for Aspiration Prevention During Emergency Intubation in Assiut University Hospital.

Emergency endotracheal intubation is a high-risk procedure performed frequently in critically ill patients, with major complications, including pulmonary aspiration, reported across a substantial proportion of cases (1). Reported aspiration incidence after ED intubation varies widely with definition and case-mix, from as low as 3.5% in early retrospective series (2) up to 22% in trauma-heavy cohorts (3). Aspiration pneumonia specifically has been documented in roughly 8% of contemporary prospective ED intubation cohorts (4), and failure on the first intubation attempt is independently associated with a higher likelihood of aspiration and other adverse events (5).

Aspiration is one of the must-pay-attention-to risk factors in patients undergoing endotracheal intubation due to its linked mortality and morbidity (6). The induction and paralytic agents used in endotracheal intubation weaken the protective airway reflexes and the lower esophageal sphincter tone that can lead to aspiration of the gastric content (6).

Point-of-care gastric ultrasound (GUS) has been a reliable tool to assess gastric content preoperatively and in the Emergency Department (7). Previous studies mentioned the use of GUS as a qualitative tool (Perlas criteria) and as a quantitative tool using the Cross-Sectional Area of the Antrum (CSA) in the supine and right lateral decubitus (RLD) positions (7,8). CSA can be calculated by a known formula, CSA = (AP × CC) x π/4, where AP is the anteroposterior diameter and CC is the craniocaudal diameter (7). Gastric volume can be calculated with CSA and the age of the patient using the Perlas formula, GV = 27.0 + (14.6 × CSA) - (1.28 × Age) (7). The Perlas formula applies only to non-pregnant adults whose BMI is less than 40 (8). The Perlas grading system and CSA-based volume model have subsequently been validated against gastroscopically-suctioned gastric volumes in adult surgical patients (9), and combining the qualitative grade with the CSA-derived volume has been shown to sharply improve discrimination of a full stomach, with a pre-test probability of 50% rising to roughly 98% following a positive scan (10). GUS has multiple studies assessing its diagnostic accuracy and its association to aspiration (11); nevertheless, it hasn't been studied as a guide to the airway management of patients with the risk of aspiration undergoing endotracheal intubation.

The present trial asks the next question: among ED trauma patients found to have a high risk of aspiration during endotracheal intubation, does a focused, low-resource bundle lower the rate of aspiration, compared with standard unstructured practice?