Gastric emptying is impaired in patients with spinal cord injury.

OBJECTIVES: The rate and completeness of gastric emptying (GE) are major determinants of the bioavailability of oral medication, and the efficiency of gastric emptying is highly dependent on an intact central nervous system. Hence, in spinal cord injury (SCI), an impairment in gastric emptying could significantly diminish drug efficacy.
METHODS: We evaluated posture-dependent (seated and supine) gastric emptying of an isotopically-labeled liquid meal in six quadriplegic subjects. The time-course profile of the gastric elimination of a radionuclide was followed for up to 120 min using serial anterior scintigraphy, and the disappearance of radioactivity from the stomach was described by both a mono- and biexponential fit of raw data. A half-time of gastric emptying (GEt1/2) was estimated from each curve and compared to GEt1/2 derived from able-bodied (intact neuraxis) experimental and historic control populations.
RESULTS: The mean GEt1/2 in quadriplegic subjects (monoexponential curve fit) was significantly increased to 43.4 +/- 26.0 min in seated SCI subjects (95% CI 13.5-73.2, p < 0.05) and to 50.5 +/- 48.0 min in supine SCI subjects compared to supine experimental and historic control values of 10.1 +/- 8.8 min (95% CI 2.3-18.0, p < 0.05) or 12.0 +/- 3.0 min (95% CI 9.4-14.8, p < 0.05), respectively. A small, non-significant trend towards an increased rate of GE (decreased GEt1/2) was observed in seated SCI subjects.
CONCLUSIONS: We conclude that gastric emptying is impaired in subjects with cervical SCI. Comparative studies of gastric emptying in subjects with SCI should incorporate concurrently studied, control subjects and employ experimental methods that are not constrained by truncated data collection periods. The convention of forcing GE data to conform to a monoexponential pattern of evacuation ignores time-dependent multiphasic patterns of GE and does not support serendipity.