Delayed gastric emptying after pediatric orthopedic trauma
Myron Yaster MD and Lynne G. Maxwell MD
It’s 1 AM and you are on call. You get a call from the orthopedic surgeon who wants to schedule a case of a 7 year old, otherwise healthy patient with a femur fracture. The child last ate at McDonald’s at 7 PM The orthopedist wants to know if she should schedule the case emergently in the middle of the night or defer to the morning to allow a full 8 hour NPO interval. Will waiting make any difference or will the pain, trauma and opioids used to treat the child’s pain delay gastric emptying regardless of the NPO time interval?
I’ve got to admit that I always treated these patients as a full stomach regardless of their NPO interval. Was I right or was my thinking yet another old wives’ tale (a bubbameisa)? Myron Yaster MD
Original article
Soneru CN, Reviere AN, Petersen TR, Paluska MR, Davis DD, Falcon RJ. An observational study of gastric contents in pediatric patients with long bone fracture using gastric ultrasound. Pediatr Anesth. 2024; 34: 768-772. doi:10.1111/pan.14923
“Delayed gastric emptying is known in the presence of opioid medication, pain, and trauma. However, less is known about the incidence of persistent stomach contents in orthopedic pediatric patients presenting for surgical repair of a single long bone fracture after an adequate fasting (nil per os, NPO) period, in which pain medications may or may not have been administered. Expectations about gastric contents necessarily influence airway management as clinicians seek to mitigate the risk and severity of gastric content aspiration. A 2022 study used preoperative gastric ultrasound (US) to evaluate the proportion of children with high-risk gastric contents (clear liquid with calculated gastric fluid volume >0.8 mL⋅kg−1, thick liquid, or solid)1 when presenting for acute extremity fracture repair. They found that at least one-third of children in their cohort with an acute isolated extremity fracture retained sufficient preoperative gastric contents to present a higher risk for pulmonary aspiration. We investigated a convenient metric for the duration of NPO status to further illustrate the persistence of non-trivial amounts of gastric contents in pediatric patients presenting for long bone fracture repair, and also examined the utility of gastric US in risk stratification.”2
In today’s PAAD, gastric contents were evaluated with ultrasound preoperatively (before anesthesia induction) and with suction of gastric contents after the induction of general anesthesia using an orogastric tube. “All patients met common NPO standards for all food types at the time of surgery: 8 h for solid foods, 6 h for milk/juice, 4 h for breastmilk, and 2 h for clear liquids. A sample size of 200 consecutive patients was chosen to permit relatively narrow 95% confidence intervals on the order of ±3%, assuming that the population incidence of full stomach at presentation would be near 5%.”2 They also recorded the duration of NPO status for all food types as well as preoperative opioid analgesic dosage (converted to morphine equivalents).
OK, what did they find? “Despite meeting typical NPO standards (median 14 h fasting), many patients retained nontrivial quantities of gastric contents at surgery. Weighted NPO units did not exhibit statistically-significant relationships with either suctioned volume or US grade. However, suctioned volume did correspond well to US grade.”2 They concluded “at anesthesia NPO status may be a less reliable predictor of gastric contents induction in this patient population than has been assumed. Bedside US screening appears to provide more useful information for the planning of airway management.”
I (MY) must admit that I am so relieved that the long standing teaching that trauma patients have full stomachs regardless of their NPO status turns out to be correct! Going back to the introduction, there may not be any reason other than scheduling and a desire to sleep to delay surgical correction. These patients need to be treated as a full stomach with a rapid sequence induction and awake extubation, regardless of NPO duration.
Another thought. This study once again demonstrates the power of point of care ultrasound (POCUS) to detect gastric fluid volume and maybe the quality of its content. We’ve discussed POCUS on several previous occasions in the PAADs and it definitely is not HOCUS POCUS. Are you routinely using POCUS to assess gastric volumes preoperatively in your practice? Do you feel adequately trained in using this newish technology in your practice? How is your practice gearing up to credential and maintain expertise with US? Send your thoughts to Myron who will post in a Friday reader response.
References
1. Evain JN, Durand Z, Dilworth K, et al. Assessing gastric contents in children before general anesthesia for acute extremity fracture: An ultrasound observational cohort study. Journal of clinical anesthesia 2022;77:110598. (In eng). DOI: 10.1016/j.jclinane.2021.110598.
2. Soneru CN, Reviere AN, Petersen TR, Paluska MR, Davis DD, Falcon RJ. An observational study of gastric contents in pediatric patients with long bone fracture using gastric ultrasound. Pediatric Anesthesia 2024;34(8):768-772. DOI: https://doi.org/10.1111/pan.14923.