Preoperative decision-making based on gastric ultrasound

Abstract

A 46-year-old healthy woman weighing 61 kg and fasting for 10 hours was scheduled for a breast lumpectomy under general anesthesia. During the preoperative checklist, the patient reported that she had eaten a large dinner the night before and that she had been upset. A gastric ultrasound evaluation in the semi-recumbent supine position showed an empty stomach; however, the gastric antrum presented liquid content with air bubbles (antral area of 12.13 cm2 and estimated gastric volume using Perlas’ formula of 2.37 mL.kg-1] in right lateral decubitus [Figure 1a]. Surgery was delayed and intravenous metoclopramide (10 mg) was administered. The estimated gastric volume was 0.95 mL.kg-1 at 5 minutes and 0.6 mL.kg-1 at 30 minutes [Figure 1b]. The patient was operated on after 1 hour without incident.Figure 1: (a) Preoperative gastric ultrasound in semi-recumbent right lateral decubitus showed an antral area of 12.13 cm2 (estimated gastric volume of 2.37 mL.kg-1). (b) Gastric ultrasound 30 minutes after administration of metoclopramide. The antral area was 4.71 cm2 (estimated gastric volume of 0.6 mL.kg-1)The incidence of aspiration during anesthesia is close to 0.03%, with fatal outcomes in almost a third of cases.[1] Current guidelines suggest fasting for 2 hours for clear liquids, 6 hours for solid food and nonclear liquids, and 8 hours for a fatty meal or meat.[2] These recommendations are based on consensus opinion and may not be safe for a considerable number of patients; in fact, it has been described as full stomach up to 5% in elective surgeries and 56% in emergencies.[3] Point-of-care gastric ultrasound provides an objective and immediate assessment of the volume and character of stomach contents. Estimated gastric volume <1.5 mL.kg-1 of clear fluid is considered normal in a fasted patient (low risk); however, the presence of solid or thick particulate or a volume >1.5 mL.kg-1, as in our case, implies a high risk of aspiration. Gastric ultrasound supplements preoperative fasting guidelines to decision-making for a safe airway management strategy. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

The authors' abstract, as published at the source. Saudi Journal of Anaesthesia, 2024 · DOI ↗