Late-onset rapid gastric emptying: Identification of a new abnormal finding in patients with otherwise normal results on gastric emptying scintigraphy.

BACKGROUND

The 4-h gastric emptying (GE) scintigraphy protocol is the gold standard for assessing GE. Rapid gastric emptying (RGE) is >30% emptied by 30 min and >65% emptied at1 h. We observed that some GE studies demonstrated rapid emptying at a later time although interpreted as normal (NGE) at 4 h. We aimed to establish thresholds to characterize this subset of late-onset rapid gastric emptying (LRGE).

METHODS

We retrospectively analyzed 4-h GE studies of 425 patients with upper GI symptoms who fulfilled the criteria for NGE. We recruited 24 normal subjects to establish GE cutoff values (mean +/- 2SD) at 1-2, 2-3, and 3-4 h. These thresholds were applied to the 425 patients with NGE. During every GE study, patients graded their postprandial symptoms on a scale from 0 to 4.

KEY RESULTS

The mean upper threshold decrement limits were calculated from the normal volunteers as 67.6% at 1-2 h, 48.7% at 2-3 h, and 27.9% at 3-4 h. After applying these values to the NGE patients, 19 (4.5%) were classified as having LRGE; 6 patients (1.4%) for the 2- to 3-h; and 13 (3.1%) for the 3- to 4-h period. Patients with LRGE had abdominal pain, bloating, nausea, or diarrhea beginning more than 1-h postprandial.

CONCLUSION

5% of patients classified as "normal" at 4 h had an abnormal GE pattern based on the proposed criteria for LRGE. This highlights the importance of applying these hourly decrement thresholds to identify LRGE as a new diagnostic entity explaining postprandial symptoms.