Point-of-Care Ultrasound to Assess Gastric Content

Abstract

Gastric ultrasound (US) is a growing modality within the point-of-care ultrasound (POCUS) field. It provides the ability to directly measure an individual patient's gastric content and has potential use as both a clinical and a research tool. Here, we review the historical development of current gastric US models and their clinical application within the field of general anesthesia, describe the US findings and technique for using POCUS to assess gastric content, and discuss the current and potential applications of gastric POCUS within the emergency department.

Ultrasound assessment of gastric contents in children before general anaesthesia for acute appendicitis

“…Although the availability of sonographers determined whether gastric ultrasound was performed or not, the sample included a significant proportion of children operated on outside normal working hours. Second, the threshold of gastric fluid volume above which aspiration risk becomes significant remains a matter of debate [11, 34]. The risk of aspiration is generally considered high when gastric fluid volume is >1.5 ml.kg −1 [35] and low when it is < 0.8 ml.kg −1 [9], but there is a ‘grey zone’ between these two values.…”

Point-of-Care Ultrasound to Assess Gastric Content in Pediatric Emergency Department Procedural Sedation Patients

“…1) following the technique described by Perlas [31][32][33][34][35] and previously reviewed by our group. 42 All patients were imaged with the curvilinear probe to establish a wide view of abdominal anatomy, with addition of the high-frequency linear probe to allow for increased resolution of gastric anatomy and content when patient habitus was amenable. A minimum of one live clip and 3 still images were obtained in each position.…”

“…Prior studies have debated this cutoff and used anywhere between 0.8 and 1.5 mL/kg. [33][34][35]37,38,42,44,46,56,71,72 We chose our cutoff of 1.25 ml/kg based on data by Cook-Sather 71 in which 95% of 611 fasting pediatric patients undergoing elective surgery demonstrated a volume less than 1.25 mL/kg. Implications of various quality and quantity of solid content have also not been quantified.…”

“…Gastric volume was determined via average of 3 individual CSA measurements using the pediatric equation 38 : Volume = −7.8 + (3.5 Â RLD CSA) + (0.127) Â age (months). Final "grade" and "risk" category were assigned for all studies per the Perlas Model 34,35,42 (Fig. 3) using a volume cutoff of 1.25 ml/kg.…”

“…29,30 Over the past decade the field of general anesthesia has evaluated the use of point-of-care US (POCUS) to assess gastric content in both adult and pediatric patients. [31][32][33][34][35][36][37][38][39][40][41][42] This work has resulted in development of a model (the Perlas Model) to define the "at-risk" stomach for purposes of preoperative general anesthesia planning, 34,35 which is now being used to better understand peri-operative gastric content [43][44][45][46] and to guide anesthesia airway management. [47][48][49][50][51] Additionally, gastric POCUS has been used to assess stomach content in critically-ill ICU patients 52,53 and more recently in emergency department patients.…”