An observational study of gastric contents in pediatric patients with long bone fracture using gastric ultrasound
Pediatric Anesthesia
Submitted November 2024 by Dr Su May Koh
Read by 68 Journal Watch subscribers
This prospective observational study involved 200 paediatric surgical patients and assessed the reliability of fasting with ultrasound (US) imaging and suction in paediatric patients presenting for single long-bone fracture repair after appropriate fasting intervals.
Methods
The authors appropriately excluded multi-trauma patients and patients who had gastric motility issues. All patients were fasted appropriately, even excessively by some standards; 8 hours for solid foods, 6 hours for milk/juice, 4 hours for breastmilk, and 2 hours for clear liquids. Certainly, many paediatric centres these days allow more liberal nil by mouth recommendations.
The authors used two techniques (imaging and suction) to evaluate gastric contents during surgery. US imaging was performed pre-induction with 2 views (supine and right lateral decubitus). A stomach with no visible contents in either supine or right lateral decubitus (RLD) positions was recorded as Grade 0, one with contents identified in RLD only was Grade 1, and cases with gastric contents visible in both positions were Grade 2. If gastric contents were identified with US, the patients then underwent a rapid sequence induction (RSI) and intubation. The authors placed an orogastric tube to suction gastric contents after induction and intubation for all patients and recorded the volume and pH of the suctioned gastric contents. The duration of fasting was also recorded for all food types as well as preoperative opioid analgesic use, age and BMI.
Results
Despite meeting typical fasting standards (median 14 hour fasting), many patients retained non-trivial quantities of gastric contents at surgery. Even with fasting, this study showed 27% with US Grade 0, 48% US Grade 1, and 26% US Grade 2. Concerningly over 70% of patients had gastric contents seen on ultrasound despite a prolonged fast. Interestingly, suctioned volume did correspond well to US grading in this study as well.
The median fasting interval was over 14 hours which is surprisingly long, and the median interval between accident and surgery presentation was almost 20 hours. However, even though many patients retained non-trivial quantities of gastric contents at surgery, there were no regurgitation or aspiration events. This is likely because in this study all patients were intubated.
The authors commented that the highest observed retained gastric contents were associated with relatively low opioid administration suggesting that opioids are not a primary driving factor in these results.
All patients with very large (>4 mL/kg) suctionable gastric contents presented as US Grade 2, and all of the US Grade 0 patients presented with low or very low quantities (<1ml/kg).
Conclusion
The authors conclude that fasting status is less predictive of gastric contents at time of surgery in patients with a fracture than previously assumed. However, bedside US screening may provide more useful information for the planning of airway management.
Take home messages
This study is interesting as it informs us that paediatric patients with long bone fractures are still likely to have persistent gastric contents despite prolonged fasting. It also suggests that in appropriately skilled hands, gastric ultrasound may be a useful tool in eliciting residual gastric content and helping the anaesthetist decide on appropriate airway management.
This study supports a flurry of recent studies in promoting the utility of gastric ultrasound in assessing paediatric patients perioperatively (Sever et al, 2024)(Sander et al, 2023). However, whilst the previous studies have all focussed on elective patients with minimal gastric contents, one of the strengths of this study is that it specifically assessed emergency patients and reinforces that we need to be cautious with this group of patients.
