{
  "abstract": "Background and aims Ultrasound estimation of gastric volume is useful preoperatively for identifying those at increased risk of aspiration; however, studies to date have excluded subjects with prior gastric surgeries. We aimed to assess the performance of the current equation used in non-pregnant adults for patients who had undergone gastric sleeve and develop a new equation for this population if necessary. Secondarily, we determined if a 2-hour fast from clear fluids is sufficient to empty the stomach in this population.Methods 37 subjects who had undergone a gastric sleeve in the last 10 years were randomly assigned to drink 100, 200 or 300 mL of water after fasting 8 hours from solids and 2 hours from clear fluids. Pre-drink and 0, 30, 60, 90 and 120 min post-drink scans measured antral grade and cross-sectional area. Subjects participated in up to three study visits drinking different volumes.Results The existing equation was statistically suboptimal. A new equation was created with variables identified by LASSO regression (Volume (mL)=15.5×CSA (cm 2)−0.28×Weight (kg)−0.75×Height (cm)+97.9) with a mean bias of <1 mL (95% limits of agreement −51.2 to 51.2 mL). After 120 min, 93.2% of post-drink scans were grade 0, and all had a calculated volume <1.5 mL/kg.Conclusions The existing equation is likely still best suited for clinical use; however, the equation proposed here has superior accuracy in patients with prior gastric sleeve. A 2-hour fast from clear fluids is sufficient in this population.",
  "authors": [
    {
      "affiliations": [
        "Anesthesiology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA"
      ],
      "name": "Jacob R Wrobel"
    },
    {
      "affiliations": [
        "Anesthesiology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA"
      ],
      "name": "Justin C Magin"
    },
    {
      "affiliations": [
        "Anesthesiology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA"
      ],
      "name": "Yuka Koyama"
    },
    {
      "affiliations": [
        "Anesthesiology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA"
      ],
      "name": "David Gaston Sanders"
    },
    {
      "affiliations": [
        "Anesthesiology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA"
      ],
      "name": "Minakshi Pillai"
    },
    {
      "affiliations": [
        "Anesthesiology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA"
      ],
      "name": "Xinming An"
    },
    {
      "affiliations": [
        "Anesthesiology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA"
      ],
      "name": "Stuart Alan Grant"
    },
    {
      "affiliations": [
        "Anesthesiology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA"
      ],
      "name": "Alexander S Doyal"
    }
  ],
  "title": "Developing a method for ultrasound estimation of gastric volume in patients with previous gastric sleeve",
  "uid": "92bd30b1-18fa-5883-a4a4-b5af211b57b8"
}