Gastric ultrasound to guide anesthetic management in elective surgical patients non-compliant with fasting instructions: a retrospective cohort study.

Abstract

Perioperative aspiration leads to significant morbidity and mortality. Standard fasting periods are used to ensure an empty stomach in patients. Anesthesiologists are frequently confronted with cases of dubious adherence to these guidelines. Point-of-care gastric ultrasound is a diagnostic tool that offers information on the type and volume of gastric contents. We performed a retrospective analysis of a departmental database containing clinical and sonographic information on elective surgical patients who had been non-compliant to the fasting guidelines. Primary outcome was the incidence of changes in aspiration risk stratification and anesthetic management when a point-of-care gastric ultrasound examination was added to a standard history-based clinical assessment. Secondary outcomes included type of changes (timing of the surgical procedure or change in anesthetic technique) and the incidence of aspiration. Differences in the management plan (history-based versus gastric ultrasound) were tested with McNemar-Bowker's Exact Test of symmetry. Thirty-seven patients met the inclusion criteria. Aspiration risk assessment and anesthetic management changed in 24 cases (64.9%) following gastric ultrasound. Additionally, there was a non-significant difference in the distribution of the pre- and post-test changes in timing (delay, cancel, proceed) (P=0.074) with a trend towards a lower number of surgical cancellations and a higher number of proceeds. No aspirations were documented. This retrospective study suggests that gastric ultrasound may be a useful diagnostic addition to standard patient assessment in cases of non-compliance to fasting guidelines. It allows to personalize aspiration risk assessment and to tailor anesthetic management to the individual patient.