O'Sullivan G, Sear J W, Bullingham R E, Carrie L E
Anaesthesia. 1985 Mar;40(3):246-53. doi: 10.1111/j.1365-2044.1985.tb10750.x.
Eighty women (40 for elective Caesarean section and 40 for elective gynaecological surgery) were randomly assigned to one of five treatment groups and received pre-operatively either no medication; magnesium trisilicate mixture (BP) 30 ml; metoclopramide 10 mg intramuscularly; ranitidine 150 mg orally on the night prior to, and the morning of, surgery; or metoclopramide 10 mg intramuscularly in combination with oral ranitidine 150 mg (the latter again given on the night prior, and the morning, of surgery). The effect of these medications on intragastric pH, volume and serum gastrin-17 was measured. No patient receiving ranitidine had a pH of less than 4. Magnesium trisilicate mixture resulted in the largest intragastric pH change although one woman in this group had a pH of 1.7. The largest intragastric volumes were seen in the patients who had received magnesium trisilicate mixture, whilst the patients who had received metoclopramide in combination with ranitidine had the smallest intragastric volumes. Magnesium trisilicate mixture and metoclopramide resulted in no change in serum gastrin levels. However, in the subjects who had received ranitidine on the night prior to surgery, the fasting serum gastrin was significantly higher (p less than 0.01) than the values in the remaining subjects, the mean (SEM) values being 60.3 (6.3) pg/ml in those not receiving ranitidine and 111.3 (19.5) pg/ml in those who had been given ranitidine.
八十名女性（40名接受择期剖宫产，40名接受择期妇科手术）被随机分配到五个治疗组之一，术前分别接受以下处理：不使用任何药物；服用30毫升三硅酸镁合剂（英国药典）；肌肉注射10毫克甲氧氯普胺；在手术前一晚及手术当天早晨口服150毫克雷尼替丁；或肌肉注射10毫克甲氧氯普胺并联合口服150毫克雷尼替丁（后者同样在手术前一晚及手术当天早晨给药）。测量了这些药物对胃内pH值、容量和血清胃泌素-17的影响。接受雷尼替丁治疗的患者胃内pH值均不低于4。三硅酸镁合剂导致胃内pH值变化最大，尽管该组中有一名女性的pH值为1.7。接受三硅酸镁合剂的患者胃内容量最大，而接受甲氧氯普胺联合雷尼替丁治疗的患者胃内容量最小。三硅酸镁合剂和甲氧氯普胺对血清胃泌素水平无影响。然而，在手术前一晚接受雷尼替丁治疗的受试者中，空腹血清胃泌素水平显著高于其余受试者（p<0.01），未接受雷尼替丁治疗者的平均（标准误）值为60.3（6.3）皮克/毫升，接受雷尼替丁治疗者为111.3（19.5）皮克/毫升。
