Segal J L, Milne N, Brunnemann S R
Nuclear Medicine Service, Department of Veterans Affairs Medical Center, Long Beach, California.
Am J Gastroenterol. 1995 Mar;90(3):466-70.
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.
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.
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.
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.
胃排空（GE）的速率和完整性是口服药物生物利用度的主要决定因素，而胃排空效率高度依赖于完整的中枢神经系统。因此，在脊髓损伤（SCI）中，胃排空受损可能会显著降低药物疗效。
我们评估了6名四肢瘫痪受试者在不同姿势（坐姿和仰卧位）下对同位素标记液体餐的胃排空情况。使用连续前位闪烁扫描法跟踪放射性核素胃清除的时间进程，最长达120分钟，并通过对原始数据进行单指数和双指数拟合来描述胃内放射性的消失情况。从每条曲线估计胃排空半衰期（GEt1/2），并与来自健全（神经轴完整）实验和历史对照人群的GEt1/2进行比较。
与仰卧位实验和历史对照值分别为10.1±8.8分钟（95%置信区间2.3 - 18.0，p<0.05）或12.0±3.0分钟（95%置信区间9.4 - 14.8，p<0.05）相比，四肢瘫痪受试者（单指数曲线拟合）的平均GEt1/2在坐姿SCI受试者中显著增加至43.4±26.0分钟（95%置信区间13.5 - 73.2，p<0.05），在仰卧位SCI受试者中增加至50.5±48.0分钟。在坐姿SCI受试者中观察到胃排空速率有轻微但不显著的增加趋势（GEt1/2降低）。
我们得出结论，颈髓损伤受试者存在胃排空受损。对SCI受试者胃排空的比较研究应纳入同时研究的对照受试者，并采用不受截断数据收集期限制的实验方法。将GE数据强制符合单指数排空模式的惯例忽略了GE随时间变化的多相模式，且不支持意外发现。
