Proposed Topic (Most preferred): :
Clinical Safety and Quality Service II (Projects aiming to enhance clinical safety and outcomes, clinical governance / risk management)
Proposed Topic (Second preferred): :
Clinical Safety and Quality Service III (Projects aiming at quality service to patients and their carers)
Authors (including presenting author) :
Fong KM (1), Lam LS (1)*, Ng WYG (1)
Affiliation :
(1) Intensive Care Unit, Queen Elizabeth Hospital
*Dr Lam has left the Hospital Authority at the time of submission
Introduction :
Fasting is a common practice in Intensive Care Units (ICU) prior to contrast imaging, surgical procedures, and extubations to prevent vomiting and aspiration. Critically ill patients, however, are at increased risk for malnutrition. The effectiveness of fasting in achieving an empty stomach in such patients remains uncertain. Ultrasound assessment of the stomach has been suggested to quantify the gastric content.
Objectives :
This study aims to stratify ICU patients into low, intermediate, and high-risk categories for stomach content after fasting by gastric ultrasound.
Methodology :
The antral cross-sectional area (CSA) was measured using a curvilinear ultrasound probe in a semi-upright position. According to a point-of-care algorithm reported by Bouvet et al. in 2019, a 'high-risk stomach' was defined by the presence of fluid or solid content in the gastric antrum. An 'intermediate-risk stomach' was identified by a gastric antral CSA of >300mm^2, while a 'low-risk stomach' was characterized by a gastric antral CSA of ≤300mm^2 and the absence of gastric content. Ultrasound assessments were conducted at fasting intervals of less than 3 hours, after 3 hours of fasting, and after 6 hours of fasting when available.
Result & Outcome :
From October 2022 to April 2023, 45 patients were included in the study. The most common indication for fasting was preparation for extubation (n=37). The 30-day mortality rate was 8.8%. A high-risk stomach (visible fluid) was observed in 5 patients who fasted for less than 3 hours, 5 patients who fasted between 3 to 6 hours, and 1 patient who fasted for more than 6 hours. Only 2 patients were categorized as low risk after 3 hours of fasting. The majority were classified as intermediate risk. No statistically significant differences were found in the antral CSA between fasting for less than 3 hours and fasting for over 3 hours (median CSA 6.3 [IQR 5.3 – 7.0] vs. 6.3 [IQR 5.0 – 6.6], p = 0.288, Wilcoxon signed-rank test), nor between fasting for less than 3 hours and fasting for over 6 hours (median CSA 6.3 [IQR 5.1 – 6.8] vs. 5.7 [IQR 4.8 – 6.7], p=0.155).
Ultrasound-assessed low-risk stomachs are uncommon after fasting. Prolonged fasting to ensure an empty stomach to prevent vomiting and aspiration may not be a realistic objective, with possible risk of underfeeding in ICU patients.
