End-expiratory breath samples are collected prior to test meal and then at given time intervals. 14CO2 is added to the test meal and the percentage of recovery/hour is used as a surrogate for gastric emptying [1].
Feasibility/Equipment: Breath test measurements are performed using 14CO2samples with special equipment for analysis and processing. 14CO2 must be available. Processing of data must be performed by a specially trained analyst. Radioactivity may be a security issue.
Scoring information: Gastric emptying is expressed using half emptying time and gastric emptying coefficient.
Cost: Due to the necessary material, equipment and training costs are high. The technique is time-consuming.
Evidence: Gastric emptying was measured in multiple studies using breath test measurements of CO2 [1-4]. It has been shown to be accurate compared to scintigraphy [2]. It has been used as an outcome measurement for interventions testing gastric emptying [3, 4], but no relevant data in the field of critical care medicine exist.
Accuracy / measurement properties: Gastric emptying assessed by breath test was slower in critically ill patients compared with volunteers: gastric emptying coefficient 2.93 (2.17-3.39) vs. 3.58 (3.18-3.79), p <.001 and gastric half emptying time, derived from the area under the 13CO2 curve, 155 min (130-220) vs. 133 min (120-145), p <.008 [1]. Breath test of gastric emptying correlated well with scintigraphy tests (r2=0.56; p≤0.002) [2]. Camicinal (GSK962040, a motilin agonist) did not affect gastric emptying significantly as assessed by breath testing [3]. Breath testing was used to demonstrate that 70mg of Erythromycin accelerates gastric emptying as effectively as 200mg: The initial gastric emptying measurements were comparable among the three patient groups before treatment. After treatment with both 70 mg and 200 mg doses of erythromycin, there was a significant reduction in gastric t1/2 compared to the placebo group: 70 mg, 98 min (IQR 88–112); 200 mg, 86 min (75–104); vs. placebo, 122 min (102–190) (p<0.05). Additionally, the GEC was higher in both erythromycin groups compared to the placebo group: 70 mg, 3.8 (3.3–4.0); 200 mg, 4.0 (3.6–4.2); vs. placebo, 2.9 (2.5–3.7) (p<0.05) [4].
References
1. Ritz MA, Fraser R, Edwards N, Di Matteo AC, Chapman M, Butler R, Cmielewski P, Tournadre JP, Davidson G, Dent J: Delayed gastric emptying in ventilated critically ill patients: measurement by 13 C-octanoic acid breath test. Crit Care Med 2001, 29(9):1744-1749.
2. 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.
3. Chapman MJ, Deane AM, O’Connor SL, Nguyen NQ, Fraser RJL, Richards DB, Hacquoil KE, Vasist Johnson LS, Barton ME, Dukes GE: The effect of camicinal (GSK962040), a motilin agonist, on gastric emptying and glucose absorption in feed-intolerant critically ill patients: a randomized, blinded, placebo-controlled, clinical trial. Critical Care 2016, 20(1).
4. Ritz MA, Chapman MJ, Fraser RJ, Finnis ME, Butler RN, Cmielewski P, Davidson GP, Rea D: Erythromycin dose of 70 mg accelerates gastric emptying as effectively as 200 mg in the critically ill. Intensive Care Medicine 2005, 31(7):949-954.