Using a mobile Y camera radionuclide decay of a tracer (for example 20 MBq 00m Technetium sulphur colloid) and scatter can be measured. From this, gastric emptying after given timepoints can be measured [1].
Feasibility/Equipment: Scintigraphy for gastric emptying is not being performed outside of research. The equipment (radioactive tracers & camera) is expensive and handling of that equipment requires specific training.
Scoring information: Gastric emptying can be quantified in % of initial volume and emptying half time. Retention is defined from healthy subjects as a percentage after a given amount of time (e.g. >32% after 120 minutes) [1].
Cost: Cost may be high due to equipment and tracers. The technique is time-consuming and analysis may be cumbersome.
Evidence: One prospective study who used scintigraphy in critically ill patients compared to healthy subjects to assess gastric emptying [1]. Impact of sedation strategy in critically ill patients was assessed retrospectively using scintigraphy [2]. The impact of highly selective 5-hydroytryptamine type 4 receptor agonist was assessed using scintigraphy [3].
Accuracy / measurement properties: Retention of 51 (7-99) % occurred in critically ill patients after 60 minutes compared to 34 (11-80) % in healthy subjects [1]. At 240 minutes, no healthy subjects showed any retention while critically ill patients showed 14 (0 – 97)% retention. Patients with delayed GE had greater severity of illness on admission to the ICU. Scintigraphy correlated with aspiration measurements of GRV (R2 0.77 (p < 0.001) at 240 minutes) [1]. Gastric half-emptying time and meal retention was higher in patients sedated with midazolam (t1/2 135 (IQR 72-434) min) than with propofol (t1/2 58 (34-166) min) [2]. Following treatment with selective 5-hydroytryptamine type 4 receptor agonist, patients receiving TAK-954 had normal GR (<13% retention at 180 minutes) than those receiving metoclopramide (6/7 vs 3/6 patients, respectively) [3].
References
1. Chapman MJ, Besanko LK, Burgstad CM, Fraser RJ, Bellon M, O’Connor S, Russo A, Jones KL, Lange K, Nguyen NQ et al: Gastric emptying of a liquid nutrient meal in the critically ill: relationship between scintigraphic and carbon breath test measurement. Gut 2011, 60(10):1336-1343.
2. Nguyen NQ, Chapman MJ, Fraser RJ, Bryant LK, Burgstad C, Ching K, Bellon M, Holloway RH: The effects of sedation on gastric emptying and intra-gastric meal distribution in critical illness. Intensive Care Medicine 2008, 34(3):454-460.
3. Chapman MJ, Jones KL, Almansa C, Barnes CN, Nguyen D, Deane AM: Blinded, Double-Dummy, Parallel-Group, Phase 2a Randomized Clinical Trial to Evaluate the Efficacy and Safety of a Highly Selective 5-Hydroxytryptamine Type 4 Receptor Agonist in Critically Ill Patients With Enteral Feeding Intolerance. JPEN J Parenter Enteral Nutr 2021, 45(1):115-124.