The effect of pre‐operative gastric ultrasound examination on the choice of general anaesthetic induction technique for non‐elective paediatric surgery. A prospective cohort study

Abstract

Ultrasound examination of the gastric antrum is a non-invasive tool that allows reliable estimation of gastric contents. We performed this prospective cohort study in non-elective paediatric surgery to assess whether gastric ultrasound may help to determine the best anaesthetic induction technique, whether rapid sequence or routine. The primary outcome was the reduction of inappropriate induction technique. A pre-operative clinical assessment was performed by the attending anaesthetist who made a provisional plan for induction. Gastric ultrasound was performed in the semirecumbent and right lateral decubitus positions for a qualitative assessment of gastric contents, using a 0-2 grading scale. A final induction plan was made based on this assessment. Immediately after tracheal intubation, gastric contents were suctioned through a multi-orifice nasogastric tube; these were defined as above risk threshold for regurgitation and aspiration if there was clear fluid > 0.8 ml.kg , and/or the presence of thick fluid and/or solid particles. Gastric ultrasound was feasible in 130 out of 143 (90%) of children, and led to a change in the planned induction technique in 67 patients: 30 from routine to rapid sequence, and 37 from rapid sequence to routine. An appropriate induction technique was therefore performed in 85% of children, vs. 49% planned after pre-operative clinical assessment alone (p < 0.00001). Our results suggest that gastric ultrasound is a useful guide to the general anaesthetic induction technique with respect to the risk of pulmonary aspiration, in comparison with pre-operative clinical assessment alone.

Ultrasound assessment of the prevalence of increased gastric contents and volume in elective pediatric patients: A prospective cohort study

“…Thus, the combination of the data of five studies using a three‐position blind aspiration technique to assess the gastric fluid volume in a total of 611 elective children found that the mean ± SD gastric fluid volume was 0.4 ± 0.45 mL/kg, and was <1.25 mL/kg in 95% of these children . Conversely, we recently reported that 66/143 (46%) of children undergoing urgent or emergency surgery had increased gastric contents volume as assessed by nasogastric aspiration . In the current study, the prevalence of gastric fluid volume >1.25 mL/kg ranged from 0.2%‐3.9% and was significantly lower than that of a gastric fluid volume >0.8 and >1 mL/kg.…”

Emerging trends, techniques, and equipment for airway management in pediatric patients

“…Gastric ultrasound resulted in the appropriate use of the indicated induction technique (RSI vs routine induction) in 85% of patients. The planned induction technique based on clinical assessment alone was consistent with postintubation findings following gastric suctioning (ie, RSI performed and gastric contents evacuated) in only 49% of patients . Further studies are needed to develop risk estimates for patients with radiographic evidence of residual gastric contents, such as high‐risk neonates or patients with difficult airways where it could be argued that the immediate risk of hypoxemia from strictly withholding ventilation may be greater than that of aspiration, as well as demonstrate actual risk reduction for pulmonary aspiration, which will be challenging, given aspiration is, fortunately, an infrequent event.…”

The link between gastric volume and aspiration risk. In search of the Holy Grail?

“…The recent introduction of point‐of‐care gastric ultrasound has rekindled the interest and discussion adding new perspectives and fresh human data to our understanding . There has been a burst of new publications recently, including two in this issue of Anaesthesia . Ultrasound studies confirm that gastric volumes of up to 1.5 ml.kg −1 are normal in healthy fasted individuals with baseline risk.…”