Gastric emptying measurement of liquid nutrients using the (13)C-octanoate breath test in critically ill patients: a comparison with scintigraphy

Scintigraphy is considered the most accurate technique for the measurement of gastric emptying (GE) but, for patients in the intensive care unit, it is technically demanding, involves radiation and can interfere with care. The (13)C-octanoate breath test ((13)C-OBT) is a simple, non-invasive technique that does not involve radiation exposure. To evaluate the performance of the (13)C-OBT in the assessment of GE in critically ill patients. The GE was assessed in 33 mechanically ventilated patients (23 M; 54.3 ± 3.0 yrs; APACHE II: 22.0 ± 1.1). Following test meal administration (100 ml Ensure(®)), concurrent scintigraphic measurement and breath samples ((13)C-OBT) were collected over 4 h. Scintigraphic meal retention was determined and the gastric emptying coefficient (GEC) and half emptying time [t50(BT)] were calculated for the (13)C-OBT. Delayed GE was defined as meal retention >13 % at 180 min. Delayed GE was identified in 27/33 patients. Meal retention correlated modestly with t50(BT) (r = 0.55-0.66; P